Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| incidence of avian leukosis virus infection in broiler stocks and its effect on early growth. | twenty-eight broiler breeder flocks were tested for avian leukosis virus (alv) group-specific (gs) antigen shedding into the albumen. the rate of shedding ranged from 0 to 17%, rates substantially lower than those observed previously in egg production stocks. the flock shedding at the highest rate was trap nested and dams positive and negative for gs antigen shedding in the albumen produced progeny for a growth trial. chicks produced by the positive and negative dams had 27 and 1% alv isolations ... | 1983 | 6322147 |
| proviral deletions and oncogene base-substitutions in insertionally mutagenized c-myc alleles may contribute to the progression of avian bursal tumors. | bursal lymphomas induced in chickens by avian leukosis viruses (alvs) harbor proviral insertions that augment expression of an adjacent cellular oncogene, c-myc. to analyze such insertionally mutagenized c-myc genes in greater detail, we isolated molecular clones from two independent tumors. precise proviral integration has occurred within the transcribed region of the c-myc gene in both mutant alleles. the proviruses bear different internal deletions that preclude the expression of the gag, pol ... | 1984 | 6322173 |
| specificity of avian leukosis virus-induced hyperlipidemia. | rous-associated virus 7 (rav-7) is a subgroup c avian leukosis virus which does not transform cells in vitro or carry an oncogene. when injected into 1-day-old hatched chicks, rav-7 causes a low incidence of lymphoid leukosis after a latent period of several months. in contrast, infection of 10-day-old chicken embryos with rav-7 leads to a disease syndrome characterized by stunting, obesity, atrophy of the bursa and the thymus, high triglyceride and cholesterol levels, reduced thyroxine levels, ... | 1984 | 6323732 |
| isolation of a feline leukaemia provirus containing the oncogene myc from a feline lymphosarcoma. | the molecular mechanism by which feline leukaemia virus (felv) induces lymphoid malignancy in domestic cats is largely unknown. using the insertional activation model of c-myc by avian leukosis virus in the induction of bursal lymphoma in chickens, we have now characterized the c-myc locus in feline tissues and investigated the possibility that felv may also insert within feline c-myc. we used the 1.5 kilobase (kb) psti fragment of mc29 v-myc in southern blot analysis to characterize the structu ... | 1984 | 6325921 |
| avian leukosis virus infection: analysis of viremia and dna integration in susceptible and resistant chicken lines. | avian leukosis viruses induce lymphoid leukosis, a lymphoma which develops within the bursa of fabricius several months after virus infection. chickens from the hyline sc and fp lines are, respectively, susceptible and resistant to avian leukosis virus-induced lymphoid leukosis. we examined plasma and cellular dna obtained from avian leukosis virus-infected chickens for the presence of viremia and integrated viral sequences to determine whether the extent of virus infection is comparable in indi ... | 1984 | 6328031 |
| differential response to avian leukosis virus infection exhibited by two chicken lines. | infection of susceptible chickens with avian leukosis virus (alv) results in the development of bursal lymphomas. these neoplasms develop within the bursa of fabricius following a latent period of several months. the response exhibited by two previously uncharacterized chicken lines to alv infection has been examined. the two lines, hyline sc and fp, responded differently to alv infection. during a 24-week period following intravenous alv infection, 27 of 50 sc chickens developed bursal lymphoma ... | 1984 | 6328748 |
| new findings on the congenital transmission of avian leukosis viruses. | rav-0, an endogenous avian leukosis virus, does not undergo congenital transmission in infected k28 chickens. in contrast, avian leukosis viruses of exogenous origin undergo highly efficient congenital transmission. the relative abilities of endogenous and exogenous viruses to undergo congenital transmission appear to be determined by the p27 capsid proteins of these viruses. | 1984 | 6330893 |
| transcriptional interference in avian retroviruses--implications for the promoter insertion model of leukaemogenesis. | the downstream (3') long terminal repeat (ltr) of an avian retroviral provirus is unable to act as an efficient promoter of transcription when a transcriptionally active upstream (5') ltr is present. this transcriptional interference may explain the observation that only deleted proviruses have been observed inserted adjacent to c-myc in avian leukosis virus induced lymphomas of chickens. | 1984 | 6363938 |
| using retroviruses as insertional mutagens to identify cellular oncogenes. | three criteria have been used to identify cellular genes that might play a role in oncogenesis: (i) homology with known viral transforming genes (v-onc's); (ii) activated expression in tumor cells; and (iii) transforming activity in cultured mouse cells. we have been exploring the hypothesis that retroviruses lacking oncogenes activate cellular oncogenes by insertional mutagenesis. our approach is to locate proviruses within the chromosomal dna of clonal populations of tumor cells, and to identi ... | 1983 | 6867028 |
| germline transmission of exogenous genes in chickens using helper-free ecotropic avian leukosis virus-based vectors. | we have used vectors derived from avian leukosis viruses to transduce exogenous genes into early somatic stem cells of chicken embryos. the ecotropic helper cell line, isolde, was used to generate stocks of nl-b vector carrying the neo(r) selectable marker and the escherichia coli lacz gene. microinjection of the nl-b vector directly beneath unincubated chicken embryo blastoderms resulted in infection of germline stem cells. one of the 16 male birds hatched (6.25%) from the injected embryos cont ... | 1995 | 7581517 |
| influence of the alv6 recombinant avian leukosis virus transgene on production traits and infection with avian tumor viruses in chickens. | the biological costs of the alv6 recombinant transgene that in chickens induces dominant resistance to the subgroup a avian leukosis virus (alv), in terms of effects on production traits, were studied. four generations of white leghorn chickens of line tr, segregating for alv6 but free of endogenous viral genes, as well as two generations of crosses between tr and ottawa line wg (wgtr) were tested under a specific-pathogen-free environment. in the birds studied, the transgene appeared unchanged ... | 1995 | 7603962 |
| functional analysis of avian class i (bfiv) glycoproteins by epitope tagging and mutagenesis in vitro. | similarities between the physical structures of avian and mammalian major histocompatibility complex (mhc) class i glycoproteins have been proposed based on comparative alignment of their amino acid sequences. to investigate the physical structure of the chicken class i glycoprotein, we cloned the cdna representing the bfiv locus of the b21 haplotype. a unique, chimeric class i glycoprotein was constructed by incorporating an epitope tag (flag) at the n terminus. monoclonal antibodies to the fla ... | 1995 | 7621880 |
| virofection: a one-step procedure for using replication-defective retrovirus vectors. | virofection is a simple new way to use replication-defective vectors. it consists of the cotransfection of two plasmids: one plasmid bearing the genome of the replication-defective retrovirus vector and a second "helper" plasmid expressing the gag, pol, and env retrovirus sequences. it provides stable integration into the chromosome and long-term expression of only vector-borne sequences. we present here several helper plasmids derived from avian leukosis viruses, which we have used for the viro ... | 1995 | 7645216 |
| in vitro analysis of a primary, major histocompatibility complex (mhc)-restricted, cytotoxic t-lymphocyte response to avian leukosis virus (alv), using target cells expressing mhc class i cdna inserted into a recombinant alv vector. | the interaction between the major histocompatibility complex (mhc) and cytotoxic t lymphocytes (ctls) is an important component of the host's resistance to viral infections and tumor formation. in this study, an avian leukosis virus (alv) vector system, rcasbp, expressing mhc chicken class i (b-f) cdna was used to develop target cells expressing the chicken class i glycoproteins complexed with alv antigens on the cell surface. peripheral blood from chickens inoculated with alv was shown to conta ... | 1995 | 7666545 |
| hprs-103 (exogenous avian leukosis virus, subgroup j) has an env gene related to those of endogenous elements eav-0 and e51 and an e element found previously only in sarcoma viruses. | the avian leukosis and sarcoma virus (alsv) group comprises eight subgroups based on envelope properties. hprs-103, an exogenous retrovirus recently isolated from meat-type chicken lines, is similar to the viruses of these subgroups in group antigen but differs from them in envelope properties and has been assigned to a new subgroup, j. hprs-103 has a wide host range in birds, and unlike other nontransforming alsvs which cause late-onset b-cell lymphomas, hprs-103 causes late-onset myelocytomas. ... | 1995 | 7815543 |
| diseases and management of backyard chicken flocks in chitungwiza, zimbabwe. | to gather information on backyard chicken flocks in chitungwiza, an urban center in zimbabwe, 85 flock owners were interviewed. the mean flock size was 53 birds (range 1-650), and most birds were kept for meat, for either domestic consumption or local sale. mean age at slaughter was 12.4 weeks (range 8-24). none of the owners vaccinated their birds, and reported mortality rates were high (mean 25%), most commonly being associated with diseases causing eye and respiratory problems. most owners co ... | 1994 | 7832719 |
| sequence of host-range determinants in the env gene of a full-length, infectious proviral clone of exogenous avian leukosis virus hprs-103 confirms that it represents a new subgroup (designated j). | a genomic dna library was constructed, in a bacteriophage lambda vector, from line 0 chick embryo fibroblasts (cefs) infected with hprs-103, an exogenous avian leukosis virus (alv; envelope subgroup j) recently isolated from meat-type chickens. the library was screened at high stringency using a full length rav-1 (subgroup a) proviral probe. from 10(6) plaques, two clones which hybridized strongly to the rav-1 probe were isolated; one contained a full-length copy of the proviral genome of hprs-1 ... | 1995 | 7844530 |
| reflections on the pathogenesis of diseases caused by the acute avian leukosis/sarcoma viruses with special reference to avian erythroblastosis. | the various diseases that follow experimental infection with the acute and non-acute avian oncoviruses are discussed with special reference to the pathogenesis of avian erythroblastosis. one view, based on in vitro studies, sees erythroblastosis as the product of a failure in the differentiation of virus-infected stem cells to mature erythrocytes, as a result of cell 'transformation'. the results of some in vivo studies, however, point to a resemblance of the disease to a haemolytic anaemia, whe ... | 1994 | 7863611 |
| structure and expression of endogenous retroviral sequences in the permanent lmh chicken cell line. | from dna mapping data, four endogenous proviral loci have been observed in the chicken permanent cell line lmh. the locus corresponding to endogenous virus (ev) ev1 is present in duplicate whereas the locus corresponding to ev3 is present in one copy. the other loci are probably ev6 and a solitary long terminal repeat. a rna northern blot analysis revealed both ev3 and ev6 transcripts but no ev1 transcript was detected. using avian leukosis virus (alv)-based vectors, transcomplementing assays we ... | 1995 | 7899200 |
| art-ch: a vl30 in chickens? | the complete sequence of art-ch, a recently found chicken retrotransposon (a. v. gudkov, e. a. komarova, m. a. nikiforov, and t. e. zaitsevskaya, j. virol. 66:1726-1736, 1992), was characterized. art-ch has the structure of a 3,300-bp-long provirus, including two 388-bp long terminal repeats (ltrs) (u3, 245 bp; r region, 17 bp; and u5, 126 bp), a trna(trp)-binding site, and a polypurine tract, similar to avian leukosis viruses. at least some of the approximately 50 genomic copies of art-ch are t ... | 1994 | 7904657 |
| a system for tissue-specific gene targeting: transgenic mice susceptible to subgroup a avian leukosis virus-based retroviral vectors. | avian leukosis viruses (alvs) have been used extensively as genetic vectors in avian systems, but their utility in mammals or mammalian cell lines is compromised by inefficient viral entry. we have overcome this limitation by generating transgenic mice that express the receptor for the subgroup a alv under the control of the chicken alpha sk-actin promoter. the skeletal muscles of these transgenic animals are susceptible to efficient infection by subgroup a alv. because infection is restricted t ... | 1994 | 7972042 |
| replication of an osteopetrosis-inducing avian leukosis virus in fibroblasts, osteoblasts, and osteopetrotic bone. | avian leukosis virus (alv)-induced osteopetrosis is caused by the abnormal growth and differentiation of osteoblasts. to evaluate the role of infection in osteopetrosis induction, the replication of an osteopetrosis-inducing virus (br21) has been compared in osteopetrotic bone, calvarial-derived osteoblasts, and chick embryo fibroblasts. much higher levels of infection occurred in diseased bone than in the cultures. severe cases of osteopetrosis contained 10 times more viral dna, 30 times more m ... | 1994 | 7975214 |
| integration of multiple chicken retroviruses into multiple chicken herpesviruses: herpesviral gd as a common target of integration. | integration of two different avian retroviruses, reticuloendotheliosis virus (rev) and avian leukosis virus (alv), into the genome of two different avian herpesviruses, the herpesvirus of turkeys (hvt) and marek's disease virus (mdv), was investigated. integration events occurred by the fourth and sixth in vitro passage of cells coinfected with rev/hvt and alv/mdv, respectively. in order to further characterize the integration events, integrated proviruses and surrounding herpesviral genetic mat ... | 1994 | 8030268 |
| the vbp and a1/ebp leucine zipper factors bind overlapping subsets of avian retroviral long terminal repeat ccaat/enhancer elements. | two long terminal repeat (ltr) enhancer-binding proteins which may regulate high rates of avian leukosis virus (alv) ltr-enhanced c-myc transcription during bursal lymphomagenesis have been identified (a. ruddell, m. linial, and m. groudine, mol. cell. biol. 9:5660-5668, 1989). the genes encoding the a1/ebp and a3/ebp binding factors were cloned by expression screening of a lambda gt11 cdna library from chicken bursal lymphoma cells. the a1/ebp cdna encodes a novel leucine zipper transcription f ... | 1994 | 8083963 |
| gene conversion in the chicken immunoglobulin locus: a paradigm of homologous recombination in higher eukaryotes. | gene conversion was first defined in yeast as a type of homologous recombination in which the donor sequence does not change. in chicken b cells, gene conversion builds the antigen receptor repertoire by introducing sequence diversity into the immunoglobulin genes. immunoglobulin gene conversion continues at high frequency in an avian leukosis virus induced chicken b cell line. this cell line can be modified by homologous integration of transfected dna constructs offering a model system for stud ... | 1994 | 8143801 |
| transcriptional regulation of alv bursal lymphomagenesis. | avian leukosis virus (alv) induces bursal lymphoma in chickens after rare integration of proviral long terminal repeat (ltr) sequences next to the c-myc proto-oncogene. labile ltr-binding proteins are essential for c-myc hyperexpression, since ltr-enhanced transcription, as well as the activity of the ltr-binding proteins, is specifically decreased following protein synthesis inhibition. this lability is restricted to hematopoetic cells of alv-susceptible chicken strains, suggesting that the lab ... | 1994 | 8152295 |
| consistent chromosomal aberration in cell lines transformed with marek's disease herpesvirus: evidence of genomic dna amplification. | a specific chromosomal aberration was observed in 14 of 15 avian lymphoblastoid cell lines transformed with marek's disease herpesvirus. this aberration, designated dup(1p)(p22-p23), appeared as an extra g-positive band and interband on the short arm of one chromosome i homolog. using fluorescent in situ hybridization, we identified amplified genomic dna sequences in this region. this amplification involves sequences linked to an endogenous retrovirus locus and genes in the histone multigene fam ... | 1993 | 8390410 |
| recovery of acutely transforming viruses from myeloid leukosis induced by the hprs-103 strain of avian leukosis virus. | viruses rapidly able to transform cultured chicken bone marrow cells have been isolated from cases of myelocytic myeloid leukosis (mml) induced experimentally by the hprs-103 strain of avian leukosis virus, and from field cases of mml. hprs-103 virus itself did not acutely transform cultured bone-marrow cells. these findings suggest that during myeloid leukemogenesis by hprs-103 virus, recombinant viruses are generated with transduced cellular oncogenes. the transformed cell appeared to be a mac ... | 1993 | 8395801 |
| research note: a rapid method for the detection of the rous-associated endogenous solitary long terminal repeat, ev15. | a rapid method has been developed for the detection of the solitary long terminal repeat ev15, a member of the avian leukosis virus (alv) family of endogenous viral elements (ev genes) in chickens. detection is accomplished by a polymerase chain reaction (pcr) assay that can be performed on purified genomic dna samples or crude preparations of partially purified whole blood lysates. the test discriminates unambiguously between birds that are homozygous ev15-, homozygous ev15+, or heterozygous ev ... | 1993 | 8397393 |
| identification of efiv, a stable factor present in many avian cell types that transactivates sequences in the 5' portion of the rous sarcoma virus long terminal repeat enhancer. | we define a protein complex present in avian nuclear extracts that interacts with the schmidt-ruppin strain of the rous sarcoma virus (rsv) long terminal repeat (ltr) between positions -197 and -168 relative to the transcriptional start site. we call this complex efiv and demonstrate that the efiv protein(s) is present in several avian cell types examined, including b cells (s13 and dt40), t cells (msb), and chicken embryo fibroblasts. we also report that the efiv binding site activates transcri ... | 1996 | 8523553 |
| production of avian leukosis virus particles in mammalian cells can be mediated by the interaction of the human immunodeficiency virus protein rev and the rev-responsive element. | in human immunodeficiency virus type 1-infected cells, the efficient expression of viral proteins from unspliced and singly spliced rnas is dependent on two factors: the presence in the cell of the viral protein rev and the presence in the viral rna of the rev-responsive element (rre). we show here that the hiv-1 rev/rre system can increase the expression of avian leukosis virus (alv) structural proteins in mammalian cells (d-17 canine osteosarcoma) and promote the release of mature alv virions ... | 1995 | 8524879 |
| a recombinant fowlpox virus expressing the envelope antigen of subgroup a avian leukosis/sarcoma virus. | a recombinant fowlpox virus (fpv) was constructed by inserting cloned sequences from schmidt-ruppin subgroup a avian sarcoma virus coding for the viral envelope (env) antigen into a nonessential region of fpv dna downstream from a synthetic promoter. sera from chickens hyperimmunized with the recombinant fpv neutralized the infectivity of the homologous subgroup a virus (rcasbp/ap) but only weakly neutralized the infectivity of rous sarcoma virus, another subgroup a avian leukosis virus. similar ... | 1995 | 8561735 |
| genomic analysis of collagen and endogenous virus loci in the ucd-200 and 206 lines of chickens, animal models for scleroderma. | university of california at davis (ucd) lines 200 and 206 chickens develop a hereditary systemic scleroderma-like connective tissue disease characterized by severe lymphocytic infiltration and excessive accumulation of collagen in skin and internal organs. the immune system seems to play an important role in the development and/or perpetuation of this condition. the main goal of our work with this strain is the investigation of interactions between endothelial cells, lymphocytes, macrophages and ... | 1995 | 8579730 |
| amino acid investigations of tumor-associated antigen of mc31 transformed cells. | there are numerous evidences (mainly indirect) for the presence of tumor-associated surface antigens (tasa) in cells transformed by avian oncornaviruses. hayami, et al. (1977) and ignjatovic et al. (1978) established that such antigens on avian leukosis virus (alv) cells have neither virus, nor oncofetal origin. on leukosis virus strain mc31-transformed turkey cells, filchev and ivanov (1986) and wesselinova (1989, 1991) also describe a tasa. but there are only a few studies on the nature and pr ... | 1995 | 8590434 |
| expression of transduced genes in mice generated by infecting blastocysts with avian leukosis virus-based retroviral vectors. | transgenic mouse lines have been developed that express the tv-a receptor under the control of the chicken beta-actin promoter. these mice express the tv-a receptor in most or all tissues and in the early embryo. an avian leukosis virus (alv)-based retroviral vector system was used for the efficient delivery of genes into preimplantation mouse embryos from these transgenic lines. experimental animals could be generated quickly and easily by infecting susceptible blastocysts with alv-based retrov ... | 1996 | 8643506 |
| effect of serotype 2 and 3 marek's disease vaccines on the development of avian leukosis virus-induced pre-neoplastic bursal follicles. | the effect of serotype 2 and 3 marek's disease virus (mdv) vaccines on the development of pre-neoplastic bursal lesions induced by two strains of subgroup a avian leukosis virus (alv) was studied. chickens of line 15i5 x 7(1) susceptible to alv-induced lymphoma were inoculated at hatch with rous-associated virus-1 (rav-1) or strain rpl-40 of subgroup a alv. all chickens, except for negative controls, were also inoculated at hatch with strain 301b/1 of serotype 2 mdv or strain fc126 of turkey her ... | 1995 | 8719208 |
| infectious agents and environmental factors in lymphoid malignancies. | a strong association was found to exist between patterns of lymphoid malignancies and socioeconomic status. b-cell lymphomas and t-acute lymphoblastic leukemia are much more prevalent in developing countries where the chances of acquiring infections especially at a younger age are high. b-cell precursor acute lymphatic leukemia, however, are much more prevalent in the western world. many infectious agents are associated with lymphatic malignancies. epstein-barr virus is involved in african burki ... | 1996 | 8813340 |
| intratesticular inoculation of avian leukosis virus (alv) in chickens--production of neutralizing antibodies and lack of virus shedding into semen. | in order to investigate the possibility of producing transgenic chickens by injection of avian leukosis virus-based vectors into testis, we have analyzed the infection rate of testicular cells following inoculation of rous-associated virus type 1 (rav-1) into the gonads of adult and 1-wk-old brown leghorn males. viroproduction, neutralizing antibody production, and vital dna presence in testis, blood, muscle, and semen were analyzed at various times after infection. inoculation of rav-1 into the ... | 1996 | 8980816 |
| bic, a novel gene activated by proviral insertions in avian leukosis virus-induced lymphomas, is likely to function through its noncoding rna. | the bic locus is a common retroviral integration site in avian leukosis virus (alv)-induced b-cell lymphomas originally identified by infection of chickens with alvs of two different subgroups (clurman and hayward, mol. cell. biol. 9:2657-2664, 1989). based on its frequent association with c-myc activation and its preferential activation in metastatic tumors, the bic locus is thought to harbor a gene that can collaborate with c-myc in lymphomagenesis and presumably plays a role in late stages of ... | 1997 | 9032277 |
| tissue tropism of the hprs-103 strain of j subgroup avian leukosis virus and of a derivative acutely transforming virus. | the tissue tropism was studied for the hprs-103 strain of avian leukosis virus, which belongs to a new envelope subgroup, designated j. studies were conducted in blood monocyte and bone marrow cell cultures and in chickens from six lines that had been shown previously to differ in susceptibility to induction by this virus of myeloid leukosis and other tumors. using an immunohistochemical technique to detect expression of viral group-specific antigen (gag) in various tissues, we detected no major ... | 1997 | 9066079 |
| avian retroviruses. | avian leukosis virus (alv) and reticuloendotheliosis virus (rev) are the most common naturally occurring avian retroviruses associated with neoplastic disease conditions in domesticated poultry. avian leukosis virus infects primarily chickens, whereas rev infects chickens, turkeys, and other avian species. in addition to causing tumors, both alv and rev can reduce productivity and induce immunosuppression and other production problems in affected flocks. | 1997 | 9071747 |
| role of contact and genetic transmission of endogenous virus-21 in the susceptibility of chickens to avian leukosis virus infection and tumors. | the role of contact and genetic transmission of endogenous virus-21 (ev21) on response of chickens to avian leukosis virus (alv) infection and tumors was studied. f1 progeny of a cross between rprl late-feathering (lf) line ev21+ males and rprl early feathering (ef) line 15b1 females harboring or lacking ev21 were used. the ef chicks lacking ev21 were inoculated with a field strain of subgroup a alv at hatch and contact exposed to lf, ev21+ hatchmates for various time intervals. in a second expe ... | 1997 | 9200232 |
| use of reverse transcriptase polymerase chain reaction for detection of vaccine contamination by avian leukosis virus. | a reverse transcriptase polymerase chain reaction (rt-pcr) for avian leukosis virus (alv) was developed for the detection of contamination of vaccines produced in embryonated eggs and cell cultures derived from chicken. alv is highly pathogenic and induces a wide spectrum of disease in infected animals. alv can be divided into five subgroups (a-e). the envelope glycoprotein (env gp85) is the main antigen determinant and responsible for subgroup classification. viral rna of all subgroups (a-e) wa ... | 1997 | 9220392 |
| vbp and rela regulate avian leukosis virus long terminal repeat-enhanced transcription in b cells. | the avian leukosis virus (alv) long terminal repeat (ltr) contains a compact transcription enhancer that is active in many cell types. a major feature of the enhancer is multiple ccaat/enhancer element motifs that could be important for the strong transcriptional activity of this unit. the contributions of the three ccaat/enhancer elements to ltr function were examined in b cells, as this cell type is targeted for alv tumor induction following integration of ltr sequences next to the c-myc proto ... | 1997 | 9223487 |
| homologous modification of human chromosomal genes in chicken b-cell x human microcell hybrids | chicken cell lines derived from avian leukosis virus-induced b-cell tumors are highly recombination-proficient. in these cells, homologous recombination between transfected dna sequences and the corresponding chromosomal alleles occurs at high frequency, and targeting efficiencies of 10-90% can be obtained. we previously described a chromosome shuttle approach in which these cells can be used to modify human chromosomal alleles at high efficiency. in this method, marked human chromosomes are tra ... | 1996 | 9245343 |
| minimal truncation of the c-myb gene product in rapid-onset b-cell lymphoma. | oncogenic activation of c-myb by insertional mutagenesis has been implicated in rapid-onset b-cell lymphomas induced by the nonacute avian leukosis virus eu-8. in these tumors, proviruses are integrated either upstream of the c-myb coding region or within the first intron of c-myb. tumors with either type of integration contained identical chimeric mrnas in which the viral 5' splice site was juxtaposed to the 3' splice site of c-myb exon 2 and myb exon 1 was eliminated. both classes of integrati ... | 1997 | 9261372 |
| genetic determinant of rapid-onset b-cell lymphoma by avian leukosis virus. | infection of 10 day-old chicken embryos with the recombinant avian leukosis virus (alv) eu-8 induces a high incidence of rapid-onset b-cell lymphoma by insertional activation of the c-myb gene. lr-9, a related alv with differences from eu-8 in the gag and pol genes, induces rapid-onset lymphoma at only a low incidence. to localize the viral determinant(s) responsible for this biologic difference, we constructed and tested a series of reciprocal chimeras between eu-8 and lr-9 alvs. the ability to ... | 1997 | 9261373 |
| viral diseases of the immune system and strategies to control infectious bursal disease by vaccination. | viral infections which are immunosuppressive can affect the economics of poultry production, often as a result of the chicken's increased susceptibility to secondary infections and sub-optimal response to vaccinations. the mechanism of this immunosuppression has been studied in detail for certain chicken viruses. the replicating virus can have both direct and indirect effects on the cells of the immune system. the special role of the bursa of fabricius, as a lympho-epithelial organ, will be ment ... | 1997 | 9276986 |
| avian tumor viruses: persistent and evolving pathogens. | most neoplasias of lymphoid and other hematopoietic cells in commercial poultry are caused by viruses which belong to one of four distinct groups. marek's disease virus (mdv) is an oncogenic herpesvirus. avian leukosis virus (alv), reticuloendotheliosis virus (rev) and lymphoproliferative disease virus (lpdv) are oncogenic retroviruses. each group is distinguished by nucleic acid type, molecular structure, antigenicity, epidemiology, host range and other characteristics. however, most of these v ... | 1997 | 9276987 |
| selection of an avian retrovirus mutant with extended receptor usage. | receptor recognition by avian retroviruses is thought to involve the interaction of two regions of the su protein, hr1 and hr2, with the host cell surface receptor. these regions exhibit considerable variation, concordant with differences in receptor usage among the many avian leukosis virus subgroups. we hypothesize that some retroviruses have altered receptor usage in response to selective pressures imposed by receptor polymorphisms in their hosts. to test this hypothesis, we passaged td-pr-rs ... | 1997 | 9311868 |
| identification of a cellular receptor for subgroup e avian leukosis virus. | genetic studies in chickens and receptor interference experiments have indicated that avian leukosis virus (alv)-e may utilize a cellular receptor related to the receptor for alv-b and alv-d. recently, we cloned car1, a tumor necrosis factor receptor (tnfr)-related protein, that serves as a cellular receptor for alv-b and alv-d. to determine whether the cellular receptor for alv-e is a car1-like protein, a cdna library was made from turkey embryo fibroblasts (tefs), which are susceptible to alv- ... | 1997 | 9326659 |
| some chickens which are viraemic with subgroup j avian leukosis virus have antibody-forming cells but no circulating antibody. | new immunoperoxidase-based assays for splenic igg -antibody-forming cells (afc) and serum igg-antibody were used to look for antibody to hprs-103 in meat-type birds. meat type birds are known to be less likely to produce neutralising antibody and to be less likely to clear virus from their serum than layer-type birds after infection at hatch. in this work all 12 of the brown leghorn layer-type birds and 5/12 of the line 21 meat-type birds had produced afc and serum antibody and had cleared serum ... | 1997 | 9368962 |
| a low incidence of histiocytic sarcomatosis associated with infection of chickens with the hprs-103 strain of subgroup j avian leukosis virus. | ten cases of histiocytic proliferative lesions in meat-type chickens associated in low incidence with infection by subgroup j avian leukosis virus (alv) are described. six were field cases in adult chickens from naturally infected flocks and four were from younger birds from transmission experiments with hprs-103 alv or the related acutely transforming alv strains 17 and 879. the lesions were observed mostly in the spleen and in some cases in other organs. microscopically, the lesions were compr ... | 1997 | 9454931 |
| isolation of serotype 2 marek's disease virus from a cell line of avian lymphoid leukosis. | to determine a serotype of marek's disease virus (mdv) persistently infected in a lymphoid leukosis (ll)-cell line, lscc-bk3, clone a (bk3a), and to examine the pathogenicity of the virus, an attempt was made to isolate mdv from culture fluid of the ll-cell line, using chick embryo fibroblast cultures resistant to infection with subgroup a avian leukosis virus (alv) to eliminate subgroup a alv. the mdv isolate, serologically identified as serotype 2 mdv and designated as the 2h strain, was free ... | 1998 | 9524935 |
| molecular characterization of endogenous viral genes of the avian leukosis virus family in an experimental population of brown-egg layers. | retroviral dna sequences similar to the exogenous avian leukosis virus can be found in the genome of many chicken breeds and have been identified as the alve family of endogenous viral (ev) genes. most of them have been described by a restriction fragment length polymorphism (rflp) procedure with two restriction enzymes and a full length viral probe. in order to facilitate the comparison of alve genes between strains, the nomenclature workshop held at the xxiv international society for animal ge ... | 1998 | 9565246 |
| antigenic variants of j subgroup avian leukosis virus: sequence analysis reveals multiple changes in the env gene. | hprs-103, the prototype of avian leukosis virus (alv) subgroup j, was isolated in 1989 from meat-type chickens from commercial flocks where it induces myelocytic myeloid leukosis (ml). the hprs-103 env gene differs considerably from other alv subgroups but shows high identity (75-97%) to env-like sequences of the different members of the eav family of endogenous avian retroviruses. recently, we have isolated several viruses related to hprs-103 from cases of ml. although these isolates showed pro ... | 1998 | 9568971 |
| differential selection of cells with proviral c-myc and c-erbb integrations after avian leukosis virus infection. | avian leukosis virus (alv) infection induces bursal lymphomas in chickens after proviral integration within the c-myc proto-oncogene and induces erythroblastosis after integration within the c-erbb proto-oncogene. a nested pcr assay was used to analyze the appearance of these integrations at an early stage of tumor induction after infection of embryos. five to eight distinct proviral c-myc integration events were amplified from bursas of infected 35-day-old birds, in good agreement with the numb ... | 1998 | 9621008 |
| detection of avian leukosis virus subgroup j using the polymerase chain reaction. | a polymerase chain reaction (pcr) assay was developed for the detection of avian leukosis virus strain j (alv-j) in chickens. primers were based in the e element and the 3' terminus of the long terminal repeat of proviral alv-j. pcr products were amplified from genomic dna extracted from chicken embryo fibroblasts (cef) infected with either strain hprs-103, the prototype of alv-j, or field isolates of alv-j obtained from broiler breeder flocks in the united states that exhibited myeloid leukosis ... | 1998 | 9645329 |
| development and application of polymerase chain reaction (pcr) tests for the detection of subgroup j avian leukosis virus. | subgroup j avian leukosis virus (alv) is a recently identified avian retrovirus associated with myeloid leukosis in meat-type chickens. the env gene of the hprs-103 strain of alv, the prototype of this subgroup, differs considerably from that of other subgroups, but shows close homology to the env-like sequences of members of the eav family of endogenous retroviruses. polymerase chain reaction (pcr) tests using two sets of primers were developed for the specific detection of the members of this ... | 1998 | 9660074 |
| examination of antisense rna and oligodeoxynucleotides as potential inhibitors of avian leukosis virus replication in rp30 cells. | avian leukosis virus (alv) is an economically important pathogen of chickens. both antisense rna and antisense oligodeoxynucleotides (odn) have been used to diminish the replication and spread of other retroviruses. the use of antisense rna and odn to inhibit alv replication has been examined in cultured rp30 cells. using an expression system that constitutively transcribes antisense alv rna, one transfected cell clone showed a significant reduction in virus growth. however, this effect was not ... | 1998 | 9733130 |
| response of chickens carrying germline insert alva11 to challenge with a field strain of subgroup a avian leukosis virus. | the alva11 germline insert in chickens is a defective subgroup a avian leukosis virus (alv) proviral insert that expresses a low-to-moderate level of subgroup a alv envelope glycoprotein. chicks carrying or lacking alva11 were evaluated for response to challenge by rpl-42, a pathogenic field strain of subgroup a alv, by either exposure to chicks shedding rpl-42 or direct injection with various doses of rpl-42. chicks carrying alva11 were significantly more resistant, as measured by infectious vi ... | 1998 | 9876848 |
| resistance to avian leukosis virus lymphomagenesis occurs subsequent to proviral c-myc integration. | most chicken strains are highly susceptible to avian leukosis virus (alv) induction of bursal lymphoma, involving proviral integration within the c-myc proto-oncogene, while certain strains are genetically resistant to lymphomagenesis. a nested pcr assay was developed to analyse the appearance of proviral c-myc integrations after alv infection of lymphoma-susceptible birds, and to determine whether these integrations arise in lymphoma-resistant birds. proviral c-myc integrations are detected in ... | 1999 | 9926935 |
| novel endogenous retroviral sequences in the chicken genome closely related to hprs-103 (subgroup j) avian leukosis virus. | hprs-103, the prototype of avian leukosis virus (alv) subgroup j, is a recently identified retrovirus associated with myeloid leukosis in meat-type chickens. although this virus shows high sequence identity to other alv subgroups within the gag and pol genes, its env gene is highly diverged (with only about 40% sequence identity) from other alv subgroups. on the other hand, the sequence of the env gene of hprs-103 was 75% identical to that of e51, a member of the eav family of endogenous avian r ... | 1999 | 9934710 |
| detection of avian leukosis virus in albumen of chicken eggs using reverse transcription polymerase chain reaction. | a reverse transcriptase polymerase chain (rt-pcr) assay was developed to detect avian leukosis retrovirus (alv) in egg albumen. eggs of single comb white leghorns were from a commercial breeder (stock f) and from a pathogen-free flock (stock n). rt-pcr was undertaken on isolated rna from 20 unfertilized egg samples using seven sets of primers that correspond to the alv gp85 envelope glycoprotein which determines the alv subgroup classification. an elisa assay for alv gs antigen of egg albumen wa ... | 1999 | 10204692 |
| genome structure and expression of the ev/j family of avian endogenous viruses. | we recently reported the identification of sequences in the chicken genome that show over 95% identity to the novel envelope gene of the subgroup j avian leukosis virus (s. j. benson, b. l. ruis, a. m. fadly, and k. f. conklin, j. virol. 72:10157-10164, 1998). based on the fact that the endogenous subgroup j-related env genes were associated with long terminal repeats (ltrs), we concluded that these ltr-env sequences defined a new family of avian endogenous viruses that we designated the ev/j fa ... | 1999 | 10364281 |
| evidence of avian leukosis virus subgroup e and endogenous avian virus in measles and mumps vaccines derived from chicken cells: investigation of transmission to vaccine recipients. | reverse transcriptase (rt) activity has been detected recently in all chicken cell-derived measles and mumps vaccines. a study of a vaccine manufactured in europe indicated that the rt is associated with particles containing endogenous avian retrovirus (eav-0) rna and originates from the chicken embryonic fibroblasts (cef) used as a substrate for propagation of the vaccine. we investigated the origin of rt in measles and mumps vaccines from a u.s. manufacturer and confirm the presence of rt and ... | 1999 | 10364336 |
| dynamics of protein 27 of avian leukosis virus and transforming growth factor beta2 in lymphoid leukosis susceptible and resistant broiler chicken breeding stock. | the dynamics of the serum concentration of protein 27 (p27) of avian leukosis virus and transforming growth factor beta2 (tgf-beta2) were compared during the period between 29 and 59 weeks of age in two flocks of broiler chicken breeding stock undergoing outbreaks of severe lymphoid leukosis (ll) associated with persistent high mortality (susceptible) and in another two flocks of breeding stock with the presence of avian leukosis virus in association with low mortality due to ll (resistant). the ... | 1999 | 10401723 |
| [avian leukosis: an old problem in a new coat: diagnostic possibilities and limitations]. | current problems in parent broiler chickens caused by the new avian leukosis virus subgroup j are described. the possibilities and limitations of diagnosing avian leukosis, and in particular that caused by the j subgroup virus, are reviewed and the eradication of the disease is discussed. | 1999 | 10488520 |
| isolation and some characteristics of a subgroup j-like avian leukosis virus associated with myeloid leukosis in meat-type chickens in the united states. | several subgroup j-like avian leukosis viruses (alv-js) were isolated from broiler breeder (bb) and commercial broiler flocks experiencing myeloid leukosis (ml) at 4 wk of age or older. in all cases, diagnosis of ml was based on the presence of typical gross and microscopic lesions in affected tissues. the isolates were classified as alv-j by 1) their ability to propagate in chicken embryo fibroblasts (cef) that are resistant to avian leukosis virus (alv) subgroups a and e (c/ae) and 2) positive ... | 1999 | 10494407 |
| avian leukosis virus subgroup j: a rapidly evolving group of oncogenic retroviruses. | a strain of avian leukosis virus (alv) belonging to a new envelope subgroup j was isolated in the uk in 1988 from meat-type chickens. the disease caused by the members of this subgroup has since spread very rapidly worldwide and has become one of the major problems facing the broiler meat industry. molecular characterisation of hprs -103, the prototype of subgroup j, has shown that it has a structure of a typical alv with gag, pol and env genes. however the env gene was distinct from that of oth ... | 1999 | 10502478 |
| soluble forms of the subgroup a avian leukosis virus [alv(a)] receptor tva significantly inhibit alv(a) infection in vitro and in vivo. | the interactions between the subgroup a avian leukosis virus [alv(a)] envelope glycoproteins and soluble forms of the alv(a) receptor tva were analyzed both in vitro and in vivo by quantitating the ability of the soluble tva proteins to inhibit alv(a) entry into susceptible cells. two soluble tva proteins were tested: the 83-amino-acid tva extracellular region fused to two epitope tags (stva) or fused to the constant region of the mouse immunoglobulin g heavy chain (stva-migg). replication-compe ... | 1999 | 10559319 |
| avian endogenous retrovirus eav-hp shares regions of identity with avian leukosis virus subgroup j and the avian retrotransposon art-ch. | the existence of novel endogenous retrovirus elements in the chicken genome, designated eav-hp, with close sequence identity to the env gene of avian leukosis virus (alv) subgroup j has been reported (l. m. smith, a. a. toye, k. howes, n. bumstead, l. n. payne, and k. venugopal, j. gen. virol. 80:261-268, 1999). to resolve the genome structure of these retroviral elements, we have determined the complete sequence of two proviral clones of eav-hp from a line n chicken genomic dna yeast artificial ... | 2000 | 10627540 |
| multiple infection of chickens and turkeys with avian oncogenic viruses: prevalence and molecular analysis. | the avian herpesvirus, marek's disease virus (mdv) and several retroviruses, reticuloendotheliosis virus (rev), avian leukosis virus (alv) (chickens) and lymphoproliferative disease virus (turkeys) are oncogenic and immunosuppressive agents. these viruses were detected either alone, or in various combinations in blood and tumor dnas of commercial birds using pcr. we present a 5-year retrospective study that included 207 chicken and 52 turkey flocks. of these, 32 chicken and 18 turkey flocks were ... | 1999 | 10696434 |
| identification and characterization of a shared tnfr-related receptor for subgroup b, d, and e avian leukosis viruses reveal cysteine residues required specifically for subgroup e viral entry. | genetic and receptor interference data have indicated the presence of one or more cellular receptors for subgroup b, d, and e avian leukosis viruses (alv) encoded by the s1 allele of the chicken tvb locus. despite the prediction that these viruses use the same receptor, they exhibit a nonreciprocal receptor interference pattern: alv-b and alv-d can interfere with infection by all three viral subgroups, but alv-e only interferes with infection by subgroup e viruses. we identified a tvb(s1) cdna c ... | 2000 | 10729132 |
| lesions of bone and bone marrow in myeloid leukosis occurring naturally in adult broiler breeders. | lesions of bone and bone marrow in myeloid leukosis (ml) occurring naturally in adult broiler breeders were investigated pathologically. during gross examination, nodules and protrusions were commonly observed on the surface of the sternum, ribs, vertebrae, and synsacrum. the bone marrow of all the bones of the body was pale in color. histologically, granulated myelocytes proliferated in the bone marrow of various bones and in the periosteum of the sternum, ribs, vertebrae, and synsacrum. the fi ... | 2000 | 10737666 |
| expression of nonspecific esterase (nse) by thyroid follicular epithelium as a marker for the target organ susceptibility to immune system attack. | spontaneous autoimmune thyroiditis in obese strain (os) chickens provides an excellent animal model for the study of hashimoto's autoimmune thyroiditis in humans. the data presented in this paper indicate that nonspecific esterases (nse) may play a role in or serve as a marker for the target organ susceptibility. experiments have shown that follicular epithelial cells and interfollicular macrophages in connective tissue stain positively for nse as early as the first day after hatching, a time at ... | 2000 | 10834316 |
| angiogenesis is an early event in the generation of myc-induced lymphomas. | angiogenesis was identified as an early consequence of myc gene overexpression in two models of retroviral lymphomagenesis. avian leukosis virus (alv) induces bursal lymphoma in chickens after proviral c-myc gene integration, while the hb-1 retrovirus carries a v-myc oncogene and also induces metastatic lymphoma. immunohistochemical studies of the effects of increased c-myc or v-myc overexpression revealed early angiogenesis within myc-transformed bursal follicles, which persisted in lymphomas a ... | 2000 | 10851079 |
| hypervariability in the envelope genes of subgroup j avian leukosis viruses obtained from different farms in the united states. | avian leukosis virus, subgroup j (alv-j), has a wide host range, preferentially infecting meat-type birds, and produces a high incidence of myelocytomatosis and nephromas. using the published sequences from hprs-103 (alv-j isolated in 1989 in great britain), we designed a set of pcr primers that amplified proviral dna from nine u.s. field samples. the primers were specific for alv-j, not amplifying dna from uninfected cells or cells infected with alv subgroups a-e. these primers expanded a 2.4-k ... | 2000 | 10873753 |
| selection of a subgroup a avian leukosis virus [alv(a)] envelope resistant to soluble alv(a) surface glycoprotein. | the host developing resistance to retroviral infection is believed to be a major force in the evolution of multiple receptor usage by retroviruses. the avian leukosis-sarcoma virus (alv) group of retroviruses provides a powerful system for studying the envelope-receptor interactions involved in retrovirus entry; different members of this group of closely related viruses use distinct cellular receptors. analysis of the alv envelope subgroups suggests that the different alvs evolved from a common ... | 2000 | 10915607 |
| a review of the development of chicken lines to resolve genes determining resistance to diseases. | the resolution of genes that determine resistance to disease is described using chicken lines maintained at the avian disease and oncology laboratory (adol). this description includes a summary 1) of existing selected and inbred lines differing for resistance to viral-induced tumors, i.e., marek's disease (md) and lymphoid leukosis (ll), and of the use of inbred and line crosses to define relevant disease-resistant genes, e.g., tv, alve, b, r, ly4, th1, bu1, and igg1; 2) of the development of tv ... | 2000 | 10947175 |
| tvb receptors for cytopathic and noncytopathic subgroups of avian leukosis viruses are functional death receptors. | the identification of tvb(s3), a cellular receptor for the cytopathic subgroups b and d of avian leukosis virus (alv-b and alv-d), as a tumor necrosis factor receptor-related death receptor with a cytoplasmic death domain, provides a compelling argument that viral env-receptor interactions are linked to cell death (4). however, other tvb proteins have been described that appear to have similar death domains but are cellular receptors for the noncytopathic subgroup e of alv (alv-e): tvb(t), a tur ... | 2000 | 11090145 |
| induction of host gene expression following infection of chicken embryo fibroblasts with oncogenic marek's disease virus. | microarrays containing 1,126 nonredundant cdnas selected from a chicken activated t-cell expressed sequence tag database (http://chickest.udel.edu) were used to examine changes in host cell gene expression that accompany infection of chicken embryo fibroblasts (cef) with marek's disease virus (mdv). host genes that were reproducibly induced by infection of cef with the oncogenic rb1b strain of mdv included macrophage inflammatory protein, interferon response factor 1, interferon-inducible protei ... | 2001 | 11119623 |
| identification of key residues in subgroup a avian leukosis virus envelope determining receptor binding affinity and infectivity of cells expressing chicken or quail tva receptor. | to better understand retroviral entry, we have characterized the interactions between subgroup a avian leukosis virus [alv(a)] envelope glycoproteins and tva, the receptor for alv(a), that result in receptor interference. we have recently shown that soluble forms of the chicken and quail tva receptor (stva), expressed from genes delivered by retroviral vectors, block alv(a) infection of cultured chicken cells ( approximately 200-fold antiviral effect) and chickens (>98% of the birds were not inf ... | 2001 | 11134286 |
| retroviruses in foreign species and the problem of provirus silencing. | retroviruses are known to integrate in the host cell genome as proviruses, and therefore they are prone to cell-mediated control at the transcriptional and posttranscriptional levels. this plays an important role especially after retrovirus heterotransmission to foreign species, but also to differentiated cells. in addition to host cell-mediated blocks in provirus expression, also so far undefined host specificities, deciding upon the pathogenic manifestation of retrovirus heterotransmission, ar ... | 2000 | 11164049 |
| avian leukosis virus subgroup j infection profiles in broiler breeder chickens: association with virus transmission to progeny. | profiles of infection with avian leukosis virus subgroup j (alv-j) and factors that predict virus transmission to progeny were studied. eggs from an infected broiler breeder flock were hatched at the laboratory. the flock was reared in a floor pen, transferred to laying cages at 22 wk, and inseminated to produce fertile eggs. a cohort of 139 chickens was tested at frequent intervals over a 62-wk period for virus, viral antigens, or antibodies in plasma, cloacal swabs, egg albumen, and embryos. v ... | 2000 | 11195648 |
| molecular characterization of the smyth chicken sublines and their parental controls by rflp and dna fingerprint analysis. | the smyth line (sl) chicken, a model for autoimmune human vitiligo, is characterized by a spontaneous posthatch epidermal pigment loss (vitiligo). even though the immunological and morphological changes accompanying the vitiligo process have been well studied, the genetics of this phenomenon remains elusive. the sl lines have been maintained by nonpedigreed matings since their inception, and therefore, the inbreeding status is unknown. the present study was designed to provide an estimate of the ... | 2001 | 11214327 |
| introduction of dt40 cells into chick embryos. | to examine the transfection of exogenous genes into chick embryos, applying the characteristics of avian leukosis virus (alv)-induced chicken b cell line dt40 to the production of chimeric birds. | 2001 | 11250794 |
| lack of evidence of endogenous avian leukosis virus and endogenous avian retrovirus transmission to measles, mumps, and rubella vaccine recipients. | the identification of endogenous avian leukosis virus (alv) and endogenous avian retrovirus (eav) in chick cell-derived measles and mumps vaccines in current use has raised concern about transmission of these retroviruses to vaccine recipients. we used serologic and molecular methods to analyze specimens from 206 recipients of measles, mumps, and rubella (mmr) vaccine for evidence of infection with alv and eav. a western blot assay for detecting antibodies to endogenous alv was developed and val ... | 2001 | 11266296 |
| acutely transforming avian leukosis virus subgroup j strain 966: defective genome encodes a 72-kilodalton gag-myc fusion protein. | avian leukosis virus subgroup j (alv-j), the most recent member of the avian retroviruses, is predominantly associated with myeloid leukosis in meat-type chickens. we have previously demonstrated that the acutely transforming virus strain 966, isolated from an alv-j-induced tumor, transformed peripheral blood monocyte and bone marrow cells in vitro and induced rapid-onset tumors, suggesting transduction of oncogenes (l. n. payne, a. m. gillespie, and k. howes, avian dis. 37:438-450, 1993). in or ... | 2001 | 11287571 |
| blocked b cell differentiation and emigration support the early growth of myc-induced lymphomas. | avian leukosis virus induces lymphoma in chickens after proviral integration within the c-myc gene, and subsequent expansion of myc-overexpressing lymphocytes within transformed bursal follicles. the clonal expansion of these follicles allowed us to examine how myc influences cell differentiation, growth, and apoptosis in lymphoid progenitors soon after the onset of myc overexpression. immunohistochemical analysis of developmental markers established that myc overexpression consistently blocks l ... | 2001 | 11423972 |
| resistance to marek's disease virus in white leghorn chickens: effects of avian leukosis virus infection genotype, reciprocal mating, and major histocompatibility complex. | genetic improvement for resistance to marek's disease (md) in chickens continues to be of interest to the poultry industry. the aims of this study were to identify effects of the mhc on the molecular level and of avian leukosis virus (alv) resistance status on md mortality in two noninbred white leghorn chicken lines that differ in b blood group type. previously, within each of the chicken lines, sublines had been selected for resistance or susceptibility to alv infection with subgroups a and b. ... | 2001 | 11495456 |
| heterophil function and resistance to staphylococcal challenge in broiler chickens naturally infected with avian leukosis virus subgroup j. | avian leukosis virus subgroup j has a high tropism for myeloid lineage cells and frequently induces neoplastic transformation of myelocytes. the impact of congenital avian leukosis virus subgroup j infection on the function of circulating heterophils and susceptibility to staphylococcal infection was investigated. six-week-old broiler chickens negative for exogenous avian leukosis viruses or congenitally infected with avian leukosis virus subgroup j were inoculated intravenously with 10(6) colon ... | 2001 | 11572559 |
| identification and characterization of human bic, a gene on chromosome 21 that encodes a noncoding rna. | bic was originally identified as a gene transcriptionally activated by promoter insertion at a common retroviral integration site in b cell lymphomas induced by avian leukosis virus (tam et al., mol. cell. biol. 17 (1997) 1490). the human homolog of this gene was cloned and characterized. it consists of three exons within a 13 kb region located in chromosome 21q21. similar to the avian homolog, the human bic lacks a long open reading frame (orf). highest levels of bic expression are detected in ... | 2001 | 11675008 |
| segregation of eav-hp ancient endogenous retroviruses within the chicken population. | avian leukosis virus subgroup j (alv-j), an exogenous avian retrovirus, is thought to have evolved by recombination with the highly identical env gene of the endogenous avian retrovirus eav-hp. embryonic expression of eav-hp env has been suggested to be associated with the induction of immunological tolerance, a feature observed in a significant proportion of meat-type chickens infected with alv-j. in support of this hypothesis, we demonstrate that eav-hp loci, some of which could be associated ... | 2001 | 11689680 |
| localization of avian leukosis virus subgroup j in naturally infected chickens by rna in situ hybridization. | the novel subgroup j of avian leukosis virus (alv-j) has emerged as a significant cause of myeloid neoplasia and weight suppression in broiler chickens. we investigated viral tropism using rna in situ hybridization (ish) in naturally infected chickens. formalin-fixed tissues were collected from 12-day-old embryos (seven infected, two control) and from 0-week-old (four infected, one control), 3-week-old (five infected, one control), 6-week-old (five infected, one control), and 9-week-old (10 infe ... | 2001 | 11732798 |
| development and characterization of monoclonal antibodies to subgroup j avian leukosis virus. | in an attempt to develop a specific diagnostic test for avian leukosis virus (alv) subgroup j (alv-j) strain hc1, four monoclonal antibodies (mabs), je9, g2, 145, and j47, were generated that are specific for alv-j envelope glycoprotein, gp85. polymerase chain reaction (pcr) was used to amplify genomic pro-viral dna of avian disease and oncology laboratory (adol)-hc1 and adol-4817 envelope genes. both open reading frames encoding glycoproteins gp85 and gp37 were cloned into baculoviruses. abunda ... | 2001 | 11785897 |
| immunohistochemical localization of avian leukosis virus subgroup j in tissues from naturally infected chickens. | the tissue tropism of avian leukosis virus (alv) subgroup j (alv-j) was investigated in congenitally infected broiler chickens by an immunohistochemistry technique detecting gp85 viral glycoprotein. all organs examined contained detectable antigen. the most intense staining was in the adrenal gland, heart, kidney, and proventriculus. intense staining for viral antigen in the heart may explain the ability of alvs to cause cardiomyopathy. although recent investigations failed to demonstrate specif ... | 2001 | 11785904 |
| consistent production of transgenic chickens using replication-deficient retroviral vectors and high-throughput screening procedures. | we have developed a novel method of dna extraction combined with a high-throughput method of gene detection allowing thousands of potentially transgenic chicks to be screened quickly and reliably. by using this method and a replication-deficient retroviral vector based on avian leukosis virus (alv), we have demonstrated germline transmission of three different transgenes. several generations of chickens carrying intact transgenes were produced, validating the use of the alv retroviral vectors fo ... | 2002 | 11873828 |
| expression of exogenous protein in the egg white of transgenic chickens. | using a replication-deficient retroviral vector based on the avian leukosis virus (alv), we inserted into the chicken genome a transgene encoding a secreted protein, beta-lactamase, under the control of the ubiquitous cytomegalovirus (cmv) promoter. biologically active beta-lactamase was secreted into the serum and egg white of four generations of transgenic chickens. the expression levels were similar in successive generations, and expression levels in the magnum of the oviduct were constant ov ... | 2002 | 11923848 |
| avian bic, a gene isolated from a common retroviral site in avian leukosis virus-induced lymphomas that encodes a noncoding rna, cooperates with c-myc in lymphomagenesis and erythroleukemogenesis. | bic is a novel gene identified at a common retroviral integration site in avian leukosis virus-induced lymphomas and has been implicated as a collaborator with c-myc in b lymphomagenesis. it lacks an extensive open reading frame and is believed to function as an untranslated rna (w. tam, gene 274:157-167, 2001; w. tam, d. ben-yehuda, and w. s. hayward, mol. cell. biol. 17:1490-1502, 1997). the oncogenic potential of bic, particularly its ability to cooperate with c-myc in oncogenesis, was tested ... | 2002 | 11932393 |