| the co2 sensitivity induced by two rhabdoviruses, piry and chandipura, in drosophila melanogaster. | piry and chandipura viruses induce co2 sensitivity after multiplication in d. melanogaster. flies infected with piry virus react to co2 like flies infected with sigma virus: after a post-infection delay the flies become sensitive; sister batches exposed later on remain persistently co2 sensitive. flies infected with chandipura virus react to co2 like flies infected with vsv: flies become sensitive, but sister batches exposed later on recover and fail to show any co2 sensitivity, although they re ... | 1975 | 813550 |
| [host range of drosophila melanogaster c virus among diptera and lepidoptera (author's transl)]. | the host range of the c picornavirus of drosophila melanogaster was studied, using numerous strains of drosophila together with four other genera of diptera and two species of lepidoptera. c virus was injected into the different hosts and serially passaged in them. the extracts from each passage were biologically assayed on virus free d. melanogaster. four different situations were found. 1) a high level of multiplication leading, in 45 strains of drosophilidae, to the early death of the hosts. ... | 1976 | 823856 |
| comparative evolution of p-m system and infection by the sigma virus in french and spanish populations of drosophila melanogaster. | in 1983, an extensive survey of populations of d. melanogaster was started in a southern french region (languedoc) in two non-mendelian systems: the p-m system of transposable elements and the hereditary rhabdovirus sigma. unexpectedly fast-evolving phenomena were observed and interesting correlations were noted, giving similar geographical pattern to the region in both systems. for these reasons, the analysis was continued and extended towards the north (rhône valley) and the south (spain). in ... | 1992 | 1334901 |
| the genome of bovine ephemeral fever rhabdovirus contains two related glycoprotein genes. | a 3789 nucleotide region of the bovine ephemeral fever virus (befv) genome, located 1.65 kb downstream of the n gene, has been cloned and sequenced. the region contains two long open reading frames (orfs) which are bounded by putative consensus (aacagg) and polyadenylation (catg[a]7) sequences and are separated by an intergenic region of 53 nucleotides. discrete mrnas corresponding to each orf have been identified. the first orf encodes a polypeptide comprising 623 residues which was identified ... | 1992 | 1413521 |
| [a genetic study of the interaction of piry virus with drosophila]. | piry virus mutants selected for altered growth properties in drosophila melanogaster have previously been designated agd mutants. this paper presents a classification scheme for grouping some of these mutants and also presents the characteristics of some members of each group. analysis, for each agd clone, of the mean incubation time at 20 degrees c relative to the mean incubation time at 28 degrees c (t20,t28), compared to the range of similar data for wild-type virus enabled us to define 4 cla ... | 1991 | 1796217 |
| evolution of natural populations in the drosophila melanogaster sigma virus system i. languedoc (southern france). | in natural populations of drosophila melanogaster, sigma virus is usually present in a minority of individuals. the virus is transmitted transovarially but is not contagious from fly to fly. two viral types (i and ii) are found in populations. one of them (type ii) is better adapted to an allele for resistance to the virus, present as a polymorphism in fly populations. previous observations have led to the hypothesis that a viral type ii originating in central france might be invading population ... | 1990 | 2116992 |
| evolution of natural populations in the drosophila melanogaster sigma system ii. northern and central france. | a survey of french natural populations of drosophila melanogaster has been systematically performed, concerning their status of infection by the sigma virus and the characteristics of viral clones. these investigations, which were not as extensive as those performed in the languedoc region (fleuriet et al., 1990) nevertheless give a good representation of the evolution of this system because of the long period involved (almost 20 years). some trends were observed in all french populations such a ... | 1990 | 2116993 |
| vertical transmission of the piry rhabdovirus by sigma virus-infected drosophila melanogaster females. | piry rhabdovirus is not transmitted from drosophila melanogaster females to their progeny. however, in mixed infections with sigma, another rhabdovirus, bearing the g+ genetic marker, piry may occasionally be transmitted to offspring. thus, an endemic drosophila virus can act as a helper virus enabling vertical transmission of a virus pathogenic to vertebrates. | 1989 | 2499659 |
| preparation of high-titred antisera for sigma virus strains from hawaii and france and their use in neutralization tests in vitro and in vivo. | antisera were prepared in rabbits against two strains of sigma virus, from france and hawaii respectively, using purified virus from cell cultures. all antisera had the same titre by immunofluorescence, 1/400 or 1/800, whether tested against the homologous or the heterologous virus. an antiserum prepared with the french strain neutralized the hawaiian virus at a dilution of 1/800 both in vitro and in vivo. the hawaiian virus was not neutralized to a significant extent by reference mouse ascitic ... | 1988 | 3144993 |
| transmission efficiency of the sigma virus in natural populations of its host, drosophila melanogaster. | a study of the viral samples collected in french natural populations of drosophila melanogaster since 1969, indicates that natural populations include, as expected, both stabilized and non stabilized infected individuals. in agreement with previous observations made on other characters of the virus, the viral samples collected appear to be homogeneous for the efficiency of the hereditary transmission. however, this efficiency is greater than the average value observed with virus perpetuated in i ... | 1982 | 6802102 |
| sequences of the n and m genes of the sigma virus of drosophila and evolutionary comparison. | the genome of the sigma rhabdovirus of drosophila melanogaster consists of six genes in the order 3' n-2-3-4-g-l 5'. the nucleotide sequences of the n and of the fourth genes were determined from cdna clones. each gene contained a single long open reading frame encoding polypeptides with predicted mw of 50 and 25 kda, respectively. evidence that these genes encode the nucleocapsid n and the matrix m proteins were obtained using antibodies raised against recombinant proteins derived from the clon ... | 1994 | 8128620 |
| female characteristics in the drosophila melanogaster-sigma virus system in natural populations from languedoc (southern france). | the drosophila melanogaster-sigma virus system has been extensively analysed for some years in languedoc. the sigma virus, endemically present in natural populations of the fly, is not contagious but vertically transmitted. the frequency of infected flies dramatically increased from 1983 to 1988 in languedoc and the increase was clearly correlated with some viral characteristics. from 1988 onwards, this frequency steadily decreased. three zones were identified in languedoc, from north to south, ... | 1994 | 8198448 |
| evolution of the drosophila melanogaster-sigma virus system in natural populations from languedoc (southern france). | an analysis of natural populations of drosophila melanogaster in a southern french region (languedoc) was started in 1983, concerning two non mendelian systems: the p-m system of transposable elements and the sigma virus. this virus is not contagious, but only transmitted through gametes; it is usually present in a minority of individuals in natural populations. the first data collected revealed unexpectedly clear and fast-evolving phenomena; they also gave evidence of some interesting correlati ... | 1993 | 8470948 |
| deduced structural model for animal rhabdovirus glycoproteins. | the g protein sequences of fourteen animal rhabdoviruses, representing all four recognized genera (vesiculovirus, lyssavirus, ephemerovirus and novirhabdovirus) and the ungrouped sigma virus, were aligned using clustal w and adjusted to account for obvious sequence similarities not detected by the algorithm. analysis of the alignment indicated remarkable preservation of g protein structural features including cysteine residues, antigenic sites and significant elements of secondary structure (alp ... | 1999 | 10355768 |
| drosophila melanogaster mounts a unique immune response to the rhabdovirus sigma virus. | rhabdoviruses are important pathogens of humans, livestock, and plants that are often vectored by insects. rhabdovirus particles have a characteristic bullet shape with a lipid envelope and surface-exposed transmembrane glycoproteins. sigma virus (sigmav) is a member of the rhabdoviridae and is a naturally occurring disease agent of drosophila melanogaster. the infection is maintained in drosophila populations through vertical transmission via germ cells. we report here the nature of the drosoph ... | 2008 | 18378641 |
| the dynamics of reciprocal selective sweeps of host resistance and a parasite counter-adaptation in drosophila. | host-parasite coevolution can result in consecutive selective sweeps of host resistance alleles and parasite counter-adaptations. to illustrate the dynamics of this important but little studied form of coevolution, we have modeled an ongoing arms race between drosophila melanogaster and the vertically transmitted sigma virus, using parameters we estimated in the field. we integrate these results with previous work showing that the spread of a resistance allele of the ref(2)p gene in the host was ... | 2012 | 23461326 |
| [drosophila genes which intervene in multiplication of sigma virus (author's transl)]. | | 1971 | 416336 |
| rhabdovirus sigma, the hereditary co2 sensitivity agent of drosophila: nucleotide sequence of a cdna clone encoding the glycoprotein. | sigma virus, the hereditary agent of a co2-induced paralysis of drosophila, is classified as a rhabdovirus on a molecular basis. we have purified its genome which after 32p-labelling was used as a probe to detect mrnas in infected cells. a cdna copy of the entire coding region of the glycoprotein mrna was cloned. nucleotide and deduced amino acid sequences were determined and compared to previously known sequences of other rhabdovirus glycoproteins to determine the relatedness of sigma virus to ... | 2010 | 2822842 |
| [germinal transmission of sigma virus in drosophila melanogaster. i. the effect of temperature on the vertical transmission by female flies originally infected by the paternal gamete exclusively]. | | 2014 | 4199631 |
| insect antiviral innate immunity: pathways, effectors, and connections. | insects are infected by a wide array of viruses some of which are insect restricted and pathogenic, and some of which are transmitted by biting insects to vertebrates. the medical and economic importance of these viruses heightens the need to understand the interaction between the infecting pathogen and the insect immune system in order to develop transmission interventions. the interaction of the virus with the insect host innate immune system plays a critical role in the outcome of infection. ... | 2013 | 24120681 |
| a polymorphism in the processing body component ge-1 controls resistance to a naturally occurring rhabdovirus in drosophila. | hosts encounter an ever-changing array of pathogens, so there is continual selection for novel ways to resist infection. a powerful way to understand how hosts evolve resistance is to identify the genes that cause variation in susceptibility to infection. using high-resolution genetic mapping we have identified a naturally occurring polymorphism in a gene called ge-1 that makes drosophila melanogaster highly resistant to its natural pathogen drosophila melanogaster sigma virus (dmelsv). by modif ... | 2016 | 26799957 |
| disease association mapping in drosophila can be replicated in the wild. | association and linkage mapping have become important tools in understanding the genetics of complex traits, including diseases in humans. as the success of association mapping is reduced by small effect sizes and limited power, linkage studies in laboratory-based model systems are still heavily used. but whether the results of these studies can be replicated in natural populations has been questioned. here, we show that a polymorphism in the gene ref(2)p, which had previously been linked to sig ... | 2010 | 20444760 |
| extrachromosomal inheritance of carbon dioxide sensitivity in the mosquito culex quinquefasciatus. | mosquitoes from a laboratory colony of culex quinquefasciatus from matsu island, china, develop irreversible paralytic symptoms after exposure to carbon dioxide at 1 degree. this co2 sensitivity is caused by an inherited infectious agent, probably a virus. crossing studies between co2-sensitive and -resistant mosquitoes showed that the sensitivity trait is inherited extrachromosomally in a fashion strictly analogous to the hereditary transmission of sigma virus in drosophila melanogaster. sensit ... | 0 | 6413297 |
| genetics of host-parasite interactions: towards a comprehensive dissection of drosophila resistance to viral infection. | one of the major challenges in evolutionary biology is to unravel the genetic basis of adaptation. this issue has been gaining momentum in recent years with the accelerated development of novel genetic and genomic techniques and resources. in this issue of molecular ecology, cogni et al. (2016) address the genetic basis of resistance to two viruses in drosophila melanogaster using a panel of recombinant inbred lines with unprecedented resolution allowing detection of rare alleles and/or alleles ... | 2016 | 27714976 |
| the genetic architecture of resistance to virus infection in drosophila. | variation in susceptibility to infection has a substantial genetic component in natural populations, and it has been argued that selection by pathogens may result in it having a simpler genetic architecture than many other quantitative traits. this is important as models of host-pathogen co-evolution typically assume resistance is controlled by a small number of genes. using the drosophila melanogaster multiparent advanced intercross, we investigated the genetic architecture of resistance to two ... | 2016 | 27460507 |
| study of the ref(2)p locus of drosophila melanogaster. ii. genetic studies of the 37df region. | the ref(2)p gene of drosophila melanogaster is implicated in sigma rhabdovirus multiplication. two common alleles of ref(2)p are known, ref(2)p0 which permits sigma virus multiplication and ref(2)pp which is restrictive for most sigma virus strains. this gene maps to the cytogenetic region 37e3-f3. using df(2l)e55 (= df(2l)37d2-e1;37f5-38a1), we have screened for lethal, semi-lethal and visible mutations following diepoxybutane (deb) or ethyl methanesulfonate (ems) mutagenesis. our data confirm ... | 1993 | 8316210 |
| mathematical analysis of a model for avl-hiv co-endemicity. | a model for the transmission dynamics of anthroponotic visceral leishmaniasis (avl) and human immunodeficiency virus (hiv) in a population is developed and used to assess the impact of the spread of each disease on the overall transmission dynamics. as for other vector-borne disease models, the avl component of the model undergoes backward bifurcation when the associated reproduction number of the avl-only sub-model (denoted by rl) is less than unity. uncertainty and sensitivity analyzes of the ... | 2016 | 26596715 |
| simultaneously estimating evolutionary history and repeated traits phylogenetic signal: applications to viral and host phenotypic evolution. | phylogenetic signal quantifies the degree to which resemblance in continuously-valued traits reflects phylogenetic relatedness. measures of phylogenetic signal are widely used in ecological and evolutionary research, and are recently gaining traction in viral evolutionary studies. standard estimators of phylogenetic signal frequently condition on data summary statistics of the repeated trait observations and fixed phylogenetics trees, resulting in information loss and potential bias. to incorpor ... | 2015 | 25780554 |
| the mechanism of arbovirus transovarial transmission in mosquitoes: san angelo virus in aedes albopictùs. | the mechanism of transovarial transmission of san angelo (sa) virus in aedes albopictus was investigated.a mosquito line with sa virus filial infection rates of almost 100% was developed by selection. results of crosses and back-crosses between this transovarial transmission-efficient line and noninfected mosquitoes indicated that sa virus was transmitted in ae. albopictus by maternal inheritance. the infection status of the male parent was of no consequence; the virus was passed from generation ... | 1980 | 7446826 |
| role of host-driven mutagenesis in determining genome evolution of sigma virus (dmelsv; rhabdoviridae) in drosophila melanogaster. | sigma virus (dmelsv) is ubiquitous in natural populations of drosophila melanogaster. host-mediated, selective rna editing of adenosines to inosines (adar) may contribute to control of viral infection by preventing transcripts from being transported into the cytoplasm or being translated accurately; or by increasing the viral genomic mutation rate. previous pcr-based studies showed that adar mutations occur in dmelsv at low frequency. here we use solid(tm) deep sequencing of flies from a single ... | 2016 | 27614234 |
| natural selection in a population of drosophila melanogaster explained by changes in gene expression caused by sequence variation in core promoter regions. | understanding the evolutionary forces that influence variation in gene regulatory regions in natural populations is an important challenge for evolutionary biology because natural selection for such variations could promote adaptive phenotypic evolution. recently, whole-genome sequence analyses have identified regulatory regions subject to natural selection. however, these studies could not identify the relationship between sequence variation in the detected regions and change in gene expression ... | 2016 | 26860869 |
| flies on the move: an inherited virus mirrors drosophila melanogaster's elusive ecology and demography. | vertically transmitted parasites rely on their host's reproduction for their transmission, leading to the evolutionary histories of both parties being intimately entwined. parasites can thus serve as a population genetic magnifying glass for their host's demographic history. here, we study the fruitfly drosophila melanogaster's vertically transmitted sigma virus dmelsv. the virus has a high mutation rate and low effective population size, allowing us to reconstruct at a fine scale how the combin ... | 2014 | 24597631 |
| sigma virus and male reproductive success in drosophila melanogaster. | the risk of disease transmission can affect female mating rate, and thus sexual conflict. furthermore, the interests of a sexually transmitted organism may align or diverge with those of either sex, potentially making the disease agent a third participant in the sexual arms race. in drosophila melanogaster, where sexual conflict over female mating rate is well established, we investigated how a common, non-lethal virus (sigma virus) might affect this conflict. we gave uninfected females the oppo ... | 2013 | 27616808 |
| virulence evolution in a host-parasite system in the absence of viral evolution. | how does virulence evolve in the drosophila melanogaster/sigma virus (dmelsv) system? | 2013 | 28217033 |
| detection of rhabdovirus viral rna in oropharyngeal swabs and ectoparasites of spanish bats. | rhabdoviruses infect a variety of hosts, including mammals, birds, reptiles, fish, insects and plants. as bats are the natural host for most members of the genus lyssavirus, the specificity of the amplification methods used for active surveillance is usually restricted to lyssaviruses. however, the presence of other rhabdoviruses in bats has also been reported. in order to broaden the scope of such methods, a new rt-pcr, able to detect a diverse range of rhabdoviruses, was designed. the method d ... | 2013 | 23100368 |
| phylogeny, integration and expression of sigma virus-like genes in drosophila. | the recent and surprising discovery of widespread nirvs (non-retroviral integrated rna viruses) has highlighted the importance of genomic interactions between non-retroviral rna viruses and their eukaryotic hosts. among the viruses with integrated representatives are the rhabdoviruses, a family of negative sense single-stranded rna viruses. we identify sigma virus-like nirvs of drosophila spp. that represent unique cases where nirvs are closely related to exogenous rna viruses in a model host or ... | 2012 | 22750113 |
| specific interactions between host and parasite genotypes do not act as a constraint on the evolution of antiviral resistance in drosophila. | genetic correlations between parasite resistance and other traits can act as an evolutionary constraint and prevent a population from evolving increased resistance. for example, previous studies have found negative genetic correlations between host resistance and life-history traits. in invertebrates, the level of resistance often depends on the combination of the host and parasite genotypes, and in this study, we have investigated whether such specific resistance also acts as an evolutionary co ... | 2012 | 22486692 |
| successive increases in the resistance of drosophila to viral infection through a transposon insertion followed by a duplication. | to understand the molecular basis of how hosts evolve resistance to their parasites, we have investigated the genes that cause variation in the susceptibility of drosophila melanogaster to viral infection. using a host-specific pathogen of d. melanogaster called the sigma virus (rhabdoviridae), we mapped a major-effect polymorphism to a region containing two paralogous genes called chkov1 and chkov2. in a panel of inbred fly lines, we found that a transposable element insertion in the protein co ... | 2011 | 22028673 |
| host-switching by a vertically transmitted rhabdovirus in drosophila. | a diverse range of endosymbionts are found within the cells of animals. as these endosymbionts are normally vertically transmitted, we might expect their evolutionary history to be dominated by host-fidelity and cospeciation with the host. however, studies of bacterial endosymbionts have shown that while this is true for some mutualists, parasites often move horizontally between host lineages over evolutionary timescales. for the first time, to our knowledge, we have investigated whether this is ... | 2011 | 21450721 |
| rhabdoviruses in two species of drosophila: vertical transmission and a recent sweep. | insects are host to a diverse range of vertically transmitted micro-organisms, but while their bacterial symbionts are well-studied, little is known about their vertically transmitted viruses. we have found that two sigma viruses (rhabdoviridae) recently discovered in drosophila affinis and drosophila obscura are both vertically transmitted. as is the case for the sigma virus of drosophila melanogaster, we find that both males and females can transmit these viruses to their offspring. males tran ... | 2011 | 21339477 |
| the prevalence and persistence of sigma virus, a biparentally transmitted parasite of drosophila melanogaster. | how do vertically transmitted parasites persist? | 2011 | 28217032 |
| host-parasite coevolution: genetic variation in a virus population and the interaction with a host gene. | host-parasite coevolution is considered to be an important factor in maintaining genetic variation in resistance to pathogens. drosophila melanogaster is naturally infected by the sigma virus, a vertically transmitted and host-specific pathogen. in fly populations, there is a large amount of genetic variation in the transmission rate from parent to offspring, much of which is caused by major-effect resistance polymorphisms. we have found that there are similarly high levels of genetic variation ... | 2010 | 20456575 |
| evidence for adar-induced hypermutation of the drosophila sigma virus (rhabdoviridae). | adars are rna editing enzymes that target double stranded rna and convert adenosine to inosine, which is read by translation machinery as if it were guanosine. aside from their role in generating protein diversity in the central nervous system, adars have been implicated in the hypermutation of some rna viruses, although why this hypermutation occurs is not well understood. | 2009 | 19941656 |
| sigma viruses from three species of drosophila form a major new clade in the rhabdovirus phylogeny. | the sigma virus (dmelsv), which is a natural pathogen of drosophila melanogaster, is the only drosophila-specific rhabdovirus that has been described. we have discovered two new rhabdoviruses, d. obscura and d. affinis, which we have named dobssv and daffsv, respectively. we sequenced the complete genomes of dobssv and dmelsv, and the l gene from daffsv. combining these data with sequences from a wide range of other rhabdoviruses, we found that the three sigma viruses form a distinct clade which ... | 2010 | 19812076 |
| the transcriptional response of drosophila melanogaster to infection with the sigma virus (rhabdoviridae). | bacterial and fungal infections induce a potent immune response in drosophila melanogaster, but it is unclear whether viral infections induce an antiviral immune response. using microarrays, we examined the changes in gene expression in drosophila that occur in response to infection with the sigma virus, a negative-stranded rna virus (rhabdoviridae) that occurs in wild populations of d. melanogaster. | 2009 | 19718442 |
| cellular and molecular aspects of rhabdovirus interactions with insect and plant hosts. | the rhabdoviruses form a large family (rhabdoviridae) whose host ranges include humans, other vertebrates, invertebrates, and plants. there are at least 90 plant-infecting rhabdoviruses, several of which are economically important pathogens of various crops. all definitive plant-infecting and many vertebrate-infecting rhabdoviruses are persistently transmitted by insect vectors, and a few putative plant rhabdoviruses are transmitted by mites. plant rhabdoviruses replicate in their plant and arth ... | 2009 | 18793103 |
| genetic variation affecting host-parasite interactions: major-effect quantitative trait loci affect the transmission of sigma virus in drosophila melanogaster. | in natural populations, genetic variation affects resistance to disease. whether that genetic variation comprises lots of small-effect polymorphisms or a small number of large-effect polymorphisms has implications for adaptation, selection and how genetic variation is maintained in populations. furthermore, how much genetic variation there is, and the genes that underlie this variation, affects models of co-evolution between parasites and their hosts. we are studying the genetic variation that a ... | 2008 | 18665899 |
| genetic variation affecting host-parasite interactions: different genes affect different aspects of sigma virus replication and transmission in drosophila melanogaster. | in natural populations, genetic variation affects resistance to disease. knowing how much variation exists, and understanding the genetic architecture of this variation, is important for medicine, for agriculture, and for understanding evolutionary processes. to investigate the extent and nature of genetic variation affecting resistance to pathogens, we are studying a tractable model system: drosophila melanogaster and its natural pathogen the vertically transmitted sigma virus. we show that con ... | 2008 | 18430944 |
| the recent spread of a vertically transmitted virus through populations of drosophila melanogaster. | the sigma virus is a vertically transmitted pathogen that commonly infects natural populations of drosophila melanogaster. this virus is the only known host-specific pathogen of d. melanogaster, and so offers a unique opportunity to study the genetics of drosophila-viral interactions in a natural system. to elucidate the population genetic processes that operate in sigma virus populations, we collected d. melanogaster from 10 populations across three continents. we found that the sigma virus had ... | 2007 | 17725574 |
| the age and evolution of an antiviral resistance mutation in drosophila melanogaster. | what selective processes underlie the evolution of parasites and their hosts? arms-race models propose that new host-resistance mutations or parasite counter-adaptations arise and sweep to fixation. frequency-dependent models propose that selection favours pathogens adapted to the most common host genotypes, conferring an advantage to rare host genotypes. distinguishing between these models is empirically difficult. the maintenance of disease-resistance polymorphisms has been studied in detail i ... | 2007 | 17550883 |
| control of sigma virus multiplication by the ref(2)p gene of drosophila melanogaster: an in vivo study of the pb1 domain of ref(2)p. | ref(2)p has been described as one of the drosophila proteins that interacts with the sigma virus cycle. we generated alleles to identify critical residues involved in the restrictive (inhibiting viral multiplication) or permissive (allowing viral multiplication) character of ref(2)p. we demonstrate that permissive alleles increase the ability of the sigma virus to infect drosophila when compared to null alleles and we confirm that restrictive alleles decrease this capacity. moreover, we have cre ... | 2007 | 17409092 |
| genetic and molecular features of su(p), a gene that interacts with ref(2)p in male fertility of drosophila melanogaster. | the ref(2)p gene is involved in the control of sigma rhabdovirus multiplication in drosophila melanogaster. ref(2)p activity is also necessary for male fertility. however, in one-third of laboratory strains tested, males that lacked ref(2)p activity were fertile. in all such strains studied, the male sterility phenotype was abolished due to the presence of a particular allele at the su(p) locus, at 73b1-2. these spontaneous suppressor alleles were dominant. we were able to induce dominant suppre ... | 2001 | 11361347 |
| molecular population genetics of ref(2)p, a locus which confers viral resistance in drosophila. | the ref(2)p locus (2-54.2) is polymorphic for two allelic forms in natural populations of drosophila melanogaster, ref(2)po and ref(2)pp. the latter allele confers resistance to the rhabdovirus sigma infecting wild populations. previous work, based on a small sample of prescreened restrictive (resistant) and permissive (susceptible) alleles, identified a large number of amino acid replacement changes (7) relative to synonymous changes (1). such protein variability could be the result of variatio ... | 1996 | 8583891 |
| gene 2 of the sigma rhabdovirus genome encodes the p protein, and gene 3 encodes a protein related to the reverse transcriptase of retroelements. | the nucleotide sequence of the genes 2 and 3 of the drosophila rhabdovirus sigma was determined from cdnas to viral genome and poly(a)+ mrnas. gene 2 comprises 1032 nucleotides and contains a long orf encoding a molecular weight 35,208 polypeptide present in infected cells and in virions which migrates in sds-page as a doublet of m(r) about 60 kda. the distribution of acidic charges as well as the electrophoretic properties of the protein are characteristic of the rhabdovirus p proteins. gene 3 ... | 1995 | 7491755 |
| localization of domains within the drosophila ref(2)p protein involved in the intracellular control of sigma rhabdovirus multiplication. | the ref(2)p gene of drosophila melanogaster interferes with sigma rhabdovirus multiplication. this gene is highly variable, and the different alleles are considered permissive or restrictive according to their effects on virus replication. in all cases, the mechanisms involve intracellular interactions between the sigma virus and ref(2)p proteins. we showed that the n-terminal domain of the ref(2)p protein was required for its activity in vivo. the protein was inactive in the null p(od)2 mutant ... | 1995 | 7769706 |
| immunological cross-reactions and interactions between the drosophila melanogaster ref(2)p protein and sigma rhabdovirus proteins. | the ref(2)p gene is one of the drosophila melanogaster genes involved in the inhibition of sigma rhabdovirus multiplication. the partial restriction of viral replication varies according to the ref(2)p alleles and virus strains and involves intracellular interactions between parasite and host products. we identified the protein encoded by the ref(2)p gene and produced polyclonal antibodies directed against the whole ref(2)p protein obtained from a recombinant baculovirus and against a part of th ... | 1993 | 7684462 |
| unusual variability of the drosophila melanogaster ref(2)p protein which controls the multiplication of sigma rhabdovirus. | the ref(2)p gene of drosophila melanogaster was identified by the discovery of two alleles, po and pp, respectively, permissive and restrictive for sigma rhabdovirus multiplication. a surprising variability of this gene was first noticed by the observation of size differences between the transcripts of permissive and restrictive alleles. in this paper, another restrictive allele, pn, clearly distinct from pp, is described: it exhibits a weaker antiviral effect than pp and differs from pp by its ... | 1993 | 8462852 |
| genome organization of the sigma rhabdovirus: six genes and a gene overlap. | the sequence of the sigma virus glycoprotein gene has been reported. we report here the cloning of the cdnas to four other genes, their physical map on the genome, the sequencing of the intergenic regions, and the determination of the gene junction signals. this analysis reveals unusual traits for a rhabdovirus: four genes map upstream of the glycoprotein gene and the glycoprotein gene overlaps the upstream gene by 33 nucleotides. northern analysis did not show bicistronic transcripts of the ove ... | 1993 | 8384742 |
| evolution of the drosophila melanogaster-sigma virus system in a natural population from tübingen. | in natural populations of d. melanogaster, usually, a minority of individuals are infected by a rhabdovirus called sigma. this virus is not contagious but is vertically transmitted through the gametes. in d. melanogaster, a polymorphism for two alleles (o, permissive and p, restrictive) of a gene responsible for resistance to the virus is regularly observed in the wild. on the virus side two types are found, which differ in their sensitivity to the p allele: type i is very sensitive, and type ii ... | 1992 | 24197303 |
| molecular analysis of ref(2)p, a drosophila gene implicated in sigma rhabdovirus multiplication and necessary for male fertility. | the ref(2)p gene of drosophila melanogaster is implicated in sigma rhabdovirus multiplication. a permissive allele was cloned and sequenced. the structural gene (3.1 kbp) is divided into three exons. the mrnas are heterogeneous in size. they differ only in the 5' end of the first exon. the sequence upstream of the short mrnas contains classical promoter elements. no tata and caat boxes are appropriately positioned upstream of the initiation sites of the long mrnas, but several repeats, palindrom ... | 1989 | 2510997 |
| [locus ref(2)p of drosophila melanogaster. i. cytogenetic localization of ref(2)p]. | the ref(2)p gene is a drosophila gene which acts on sigma virus multiplication. from recombination experiments the ref(2)p gene was located between hk and pr. this location was confirmed by the study of eight chromosomic aberrations, without ref(2)p gene activity, obtained following x irradiation. from the cytological study of three of these chromosomes and from the study of the ref(2)p gene activity of chromosomic aberrations obtained by other workers in the same region of the second chromosome ... | 1986 | 2943351 |
| the late functions of drosophila sigma virus. | several criteria can be used to characterize the temperature-sensitive mutants of sigma virus: the lability of infectious centers initiated by the efficient viral particles following the inoculation; the localization of the temperature-sensitive period; the hereditary transmission of infection in a maternal drosophila line at high temperature; the evolution of the co2 sensitivity symptom and of the viral titer per fly for hereditarily infected flies kept at a permissive temperature and shifted t ... | 1984 | 6437379 |
| role of the drosophila genome in sigma virus multiplication. ii. host spectrum variants among the hap mutants. | | 1982 | 7179741 |
| factors affecting the frequency of infection by the sigma virus in experimental populations of drosophila melanogaster. | the experiments reported in this paper deal with the maintenance of the non contagious, hereditary virus sigma in populations of its host, drosophila melanogaster. evidence was previously provided of the existence of two viral types i and ii, depending on their sensitivity to the ref(2)pp allele (the ref(2)p locus interferes with the multiplication of the virus in the fly). the viral type i which is the most sensitive to the ref(2)pp allele, is eliminated in the presence of this allele, even whe ... | 1982 | 6816192 |
| role of the drosophila genome in sigma virus multiplication. i. role of the ret(2)p gene; selection of host-adapted mutants at the nonpermissive allele pp. | the allele pp of gene ref(2)p of drosophila melanogaster is known to inhibit the multiplication of certain strains of sigma virus. from a viral strain for which the allele pp of ref(2)p is nonpermissive, host adapted (hap) mutants were selected after mutagenesis in vivo. mutagenized virus was extracted from infected flies fed with 5-fluorouracil. the mutagenized virus was used to inoculate restrictive flies to screen hap mutants. the surviving viruses were studied in permissive and restrictive h ... | 1981 | 18635100 |
| polymorphism of the hereditary sigma virus in natural populations of drosophila melanogaster. | previous studies have shown that, in natural french populations of drosophila melanogaster, 10 to 20% of the flies are infected by the noncontagious, hereditary rhabdovirus sigma responsible for co(2) sensitivity. these populations are also polymorphic for two alleles [ref(2)p(o) and ref(2)p(p)] of a gene for resistance to the sigma virus. evidence is given here that two viral genetic types, differing in their response to the ref(2)p(p) allele, are present in these populations of flies; the most ... | 1980 | 17249047 |
| [sigma virus and co2 sensitivity in fruit fly, drosophila (author's transl)]. | | 1979 | 121652 |
| reproduction in cage populations of a polymorphism regularly observed in the natural populations of drosophila melanogaster in france. | polymorphism for both alleles of a gene ref(2)p, which is a usual trait of french natural populations of drosophila melanogaster , can be reproduced in experimental conditions. ref(2)p is a gene for resistance to the hereditary, noncontagious rhabdovirus sigma, responsible for co(2) sensitivity in drosophila melanogaster . the equilibrium frequencies observed in cages are the same as in the wild, whether sigma virus is present or not. the rapid rate of return to these equilibrium frequencies ind ... | 1978 | 17248817 |
| a new strain of drosophila that inhibits the development of symptoms in imagoes infected with sigma virus. | a strain of drosophila melanogaster bearing the mutant gene ebony has been found to slow the development of symptoms (carbon dioxide sensitivity) in adult flies inoculated with sigma virus, a member of the rhabdovirus group. this inhibition is made evident by comparing mean incubation times of the virus in ebony and wild-type (oregon) flies. the increase in mean incubation time in ebony flies has ranged from about 3 to 8 days, depending on the virus strain, amount of virus injected, and the age ... | 1978 | 17248809 |
| [dosage effects of the non permissive allele of drosophila ref(2)p gene on sensitive strains of sigma virus (author's transl)]. | different characteristics of flies relating to sigma virus allow us to class the following drosophila genotypes according to their permissivity for the virus strains which are sensitive to the pp allele: (formula: see text). it is concluded 1) that the two alleles po and pp of ref(2)p gene are active and 2) that the viral protein which interact with the product of ref(2)p is effective, or effectively transformed, without interaction with the product of ref(2)p. the delayed appearance of co2 sens ... | 1978 | 416337 |
| [about the infection of drosophila female germ line cells by sigma virus (author's transl)]. | the results which have been presented by bregliano (1973) and bregliano et fleuriet (1975) in this "annales" are discussed. the author's conclusion is that there are two distinct mechanisms for contamination of the cysts of non-stabilized females (in stabilized females, all cells, including oogonial cells, are infected in carrier state by sigma). hypotheses are discussed. | 1977 | 869402 |
| [general transmission of sigma virus in "drosophila melanogaster". ii. - revelation of late vertical tansmission in females which have acquired the virus only by the father spermatozoon (author's transl)]. | this report concern work with drosophila melanogaster females, which have only acquired the sigma virus strictly vertically through the father spermatozoon. after than the 20th day of life, most of these show an increased frequency of infected progeny. these results obtained provide evidence that the phenomenon is similar to the classical "passing over to germen", described in sigma-drosophila relationships. they confirm that germ-line infection in non-stabilized females can only occur during oo ... | 1975 | 820234 |
| [concentration, purification, and isotopic labeling of sigma virus]. | sigma virus has been concentrated by means of polyethylene-glycol and diafiltration; the latter method is more efficient in preserving infectivity. when purified on sucrose gradient, sigma banded in a sharp peak without any polydispersion. we are now able to label sigma genome with 3h-uridine in drosophila cell cultures. | 1975 | 807415 |
| [isolation of drosophila melanogaster cell lines of different genotypes and study of multiplication of two variants of sigma rhabdovirus in those lines (author's transl)]. | strains of sigma virus which are called p- do not multiply in drosophila strains called paris, homozygous for the pp allele of gene ref(2)p. adsorption is normal and the virus is not destroyed. it seems that the viral function concerned is an early one. p+ variants isolated from a p- population do multiply in flies from the paris strain. three continuous cell lines homozygous for the pp allele and one homozygous for the po allele were isolated. several attempts to infect those cell lines with p- ... | 1975 | 804299 |
| [characterization of two temperature-sensitive mutants of sigma virus (authors transl)]. | | 1973 | 4201838 |
| [the multiplication of sigma virus in several primary cultures and in a continuous line of drosophila cells from embryos which perpetuate a defective sigma virus]. | | 1973 | 4198978 |
| [elimination of sigma virus, by temperature or by ethylmethane-sulfonate feeding, from the germ cells of female drosophila melanogaster flies stabilized for the virus]. | | 1973 | 4354027 |
| effect of actinomycin d and mitomycin c on sigma virus multiplication in drosophila melanogaster. | | 1973 | 4630827 |
| [sigma virus and the male germ cell of drosophila. relationships between efficiency of hereditary virus transmission, importance of virus maturation and infective content of testicular extract]. | | 1972 | 4627763 |
| [study of the localization of sigma virus during differentiation of germ cells of stabilized male drosophila]. | | 1972 | 4626266 |
| iv. sigma virus multiplication in drosophila cell lines of different genotypes. | | 1971 | 5142335 |
| [study of germinal issue infection in female drosophila infected by sigma virus. ii. demonstration of a correspondance between ovarian egg-chambers with high viral yield and stabilized descendants]. | | 1970 | 5533948 |
| [propagation of hereditary virus of drosophila (sigma virus) at the level of implanted disks: evolution of yield and of infectious power of implants]. | | 1970 | 5478270 |
| [study of infection of germ line in female drosophila injected with sigma virus. i. evolution during the time of diverse categories of descendants and infected cysts]. | | 1970 | 5429041 |
| [study of the symptom of co2 sensitivity induced by sigma virus in drosophila. ii. comparative course of yield of nervous centers and of some organs after inoculation in the abdomen and thorax]. | | 1970 | 5422867 |
| [study of co2 sensitivity symptom induced by sigma virus in drosophila. i. influence of inoculation place on delay of symptom appearance]. | | 1970 | 5430709 |
| [multiplication of the drosophila sigma virus in insects belonging to different orders]. | | 1969 | 4390589 |
| [relations between sigma virus and its host. contribution to the study of the character g-]. | | 1969 | 5366875 |
| [purification on cellulose columns of sigma virus from drosophila]. | | 1969 | 5406061 |
| sigma virus multiplication in whole-animal culture of drosophila. | | 1969 | 5784044 |
| [hereditary transmission of sigma virus by drosophila bearing "refractory" gene. ii. study of different mutants of sigma]. | | 1968 | 5711526 |
| [action of a strain of sigma virus on fertility of female drosophila]. | | 1968 | 5760444 |
| comparative resistance to sedimentation of three different strains of sigma virus of drosophila. | | 1968 | 5709353 |
| [hereditary transmission of sigma virus by drosophila bearing the "refractory" gene. i. study of a p- g- virus strain]. | | 1968 | 5650308 |
| the sigma virus infection of drosophila melanogaster. | | 1968 | 4883768 |
| effect of sigma virus on development delay in drosophila melanogaster caused by x-ray induced mutants in heterozygous condition. | | 2003 | 5591294 |
| [study of the propagation of the hereditary sigma virus in drosophila, at the level of transplanted imaginal disks]. | | 1966 | 4957240 |
| sigma virus content and hereditary transmission in drosophila melanogaster. | | 1966 | 5936630 |
| low titers in drosophila that regularly transmit the sigma virus infection. | | 1966 | 5900609 |
| [study of the quantity of infectious sigma virus contained in the ovarian cysts of stabilized and inoculated drosophila]. | | 1965 | 5851820 |