| a cloned drosophila dna fragment which codes for a 4 s rna species. | a collection of random drosophila melanogaster dna fragments cloned individually in escherichia coli was screened for the presence of sequences complementary to the 4 s, 5 s and 5.8 s rna species produced in the d. melanogaster kc tissue culture line. four d. melanogaster dna fragments were found which possessed sequences complementary to the 4 s rna species but not complementary to the 5 s or 5.8 s rna. one such cloned fragment (6.81 kilobase in length) was characterized further. it hybridizes ... | 1978 | 102349 |
| the role of the guanine insertion enzyme in o-biosynthesis in drosophila melanogaster. | drosophila trna can be guanylated by a crude enzyme from rabbit reticulocytes. guanylating activity is also present in crude extracts of adult drosophila. a major product of this reaction as well as several minor ones were resolved by rpc-5 chromatography. the main substrate of both the drosophila and rabbit reticulocyte enzymes was the non-q-containing aspartic acid trna, trna2gammaasp. the qu-lacking (gamma) forms of asparagine, histidine and tyrosine trnas were also substrates and gave rise t ... | 1978 | 106366 |
| the nucleotide sequence of lysine trna2 from drosophila. | the nucleotide sequence of drosophila melanogaster lysine trna2 was determined to be: pg-c-c-c-g-g-c-u-a-m2g-c-u-c-a-g-d-c-g-g-d-a-g-a-g-c-a-psi-g-a-g-a-c-u-c-u-u-t6a-a-psi-c-u-c-a-g-g-m7g-d-c-g-u-g-g-g-xm-u-c-g-m1a-g-c-c-c-c-a-c-g-u-u-g-g-g-c-g-c-c-a(oh). with minor differences in the state of modification of some nucleotides, the sequence is the same as that of lysine trna2b from rabbit liver. | 1979 | 106371 |
| properties of fructose 1,6-diphosphate aldolase from drosophila melanogaster. | | 1979 | 109045 |
| fructose 1,6-diphosphate aldolase of drosophila melanogaster: comparative sequence analyses of the cysteine-containing peptides. | | 1979 | 109046 |
| [heterochromatin and chromosomal polymorphism]. | the structure and sizes of different short deletions of drosophila melanogaster x-chromosome: left break in the region of locus y-ac-sc, right break in different parts of the heterochromatic region (hr) near the centromere, of the nuclei of salivary glands and metaphases of oogonia were compared. it is suggested, that the development of large blocks of deoxynucleoproteins by a small number of loci of the hr, observed in mitotic chromosomes, is due to their ability to undergo additional replicati ... | 1977 | 109749 |
| cell-free protein synthesis in lysates of drosophila melanogaster cells. | a procedure is described for preparing cell-free protein synthesizing lysates from drosophila melanogaster tissue culture cells and embryos. preparation of translationally active lysates from tissue culture cells is dependent on the presence of rat liver supernatant during cell lysis to inhibit ribonuclease activity. after micrococcal nuclease treatment of the lysate, protein synthesis is dependent on the addition of exogenous messenger rna. the fidelity of translation is very high. the conditio ... | 1979 | 106888 |
| mutagenicity studies with x-ray-contrast media, analgesics, antipyretics, antirheumatics and some other pharmaceutical drugs in bacterial, drosophila and mammalian test systems. | as part of our investigation into mutagenic effects of environmental compounds, we studied 21 pharmaceuticals most frequently sold in west germany: 6 x-ray-contrast media, 13 analgesics, antipyretics and antirheumatics, 1 central stimulant, and 1 antidepressant. they were studied in different bacterial, drosophila and mammalian test systems. 4 of these 21 compounds could be detected as mutagens in one of the test systems. namely: 1,2-dichloroethane induced an increase in the frequency of recessi ... | 1979 | 106272 |
| mutagenic effects of thioacetamide in drosophila melanogaster. | thioacetamide, which is carcinogenic in mice and rats, has been reported as negative in ames's test on salmonella his- with and without liver microsomal fraction (s 9 mix). tests on drosophila reported here showed a significant increase in sex-linked recessive lethals after treatment with thioacetamide, both after injection and after feeding of males. | 1978 | 106270 |
| isolation and characterization of x-linked mutants of drosophila melanogaster which are sensitive to mutagens. | thirteen x-linked mutants have been isolated in drosophila melanogaster which render male and homozygous female larvae sensitive to the mutagen methyl methanesulfonate. their characterization and preliminary assignment to functional groups is described. four of these mutants are alleles of mei-41 (baker and carpenter 1972). like previously isolated alleles of this locus, these mutants reduce fertility and increase loss and nondisjunction of the x-chromosome in homozygous females. the remaining m ... | 1976 | 187527 |
| absence of mutagenicity of praziquantel, a new, effective, anti-schistosomal drug, in bacteria, yeasts, insects and mammalian cells. | praziquantel (embay 8440, droncit) a new, effective anti-schistosomal drug, was tested in various short-term assays that have shown a predictive value for the detection of potential carcinogens. indicator organisms s. typhimurium strains, s. pombe, s. cerevisiae, cultured v79 chinese hamster cells or human heteroploid cells and drosophila melanogaster were treated with praziquantel. the induction of reverse and forward mutations, mitotic gene conversions, x-linked recessive lethals, sister-chrom ... | 1978 | 106268 |
| beta-galactosidase is induced by hormone in drosophila melanogaster cell cultures. | drosophila melanogaster cell lines kc and ca and clones fc and rf6, cultured in vitro, have no detectable beta-galactosidase (beta-galactoside galactohydrolase, ec 3.2.1.23) activity (as measured by hydrolysis of o-nitrophenyl-beta-d-galoctoside). ecdysterone, a hormonal steroid of critical importance in insect physiology, clearly induces beta-galactosidase activity in d. melanogaster cells cultured in vitro. induction occurs in cell lines or clones known to be sensitive to ecdysterone (k, ca, a ... | 1978 | 104299 |
| antisera against ecdysteroid-induced proteins in an established line and a clone of drosophila melanogaster cells. | | 1978 | 95973 |
| methods for studying the distribution of pigment in malpighian tubules of drosophila melanogaster. | the pigmented cells in malpighian tubules of drosophila melanogaster contain yellow globules which are blackened by osmium tetroxide. permanent preparations of the tubules showing pigmentation can thus be made. following prestaining acid hydrolysis, osmium-fixed tubules can be stained with orcein. for observations on pigment distribution and feulgen-dna content in the same preparation, tubules are fixed in mercuric chloride. color remains visible for several hours in unfixed tubules mounted in m ... | 1976 | 59419 |
| the characterization of multiple forms of kynurenine formidase in drosophila melanogaster. | two enzymic forms of kynurenine formamidase (ec 3.5.1.9) from drosophila melanogaster were separated and partially purified by ph fractionation, (nh4) 2so4 fractionation and sephadex g-75 gel filtration. the enzymes were also separated by deae-cellulose ion-exchange chromatography and distinguished by their different rates of thermal inactivation. the multiple forms are termed formamidase i and formamidase ii. the molecular weight of formamidase i as measured by sephadex g-75 chromatography is 6 ... | 1975 | 50862 |
| compositional relatedness of aldehyde reductases from several species. | the amino acid compositions of several monomeric nadph-dependent aldehyde reductases from a variety of species have been determined and analyzed by the difference index method of metzger et al. (1968). the difference indexes among mammals range from 4.15 - 6.10 indicating considerable homology. comparison of chicken aldehyde reductase with mammalian aldehyde reductases gave values in the range 6.8 - 9.9 suggesting a close relationship whereas the difference indexes for the enzymes from fruit fly ... | 1979 | 43905 |
| protein expression in e. coli minicells by recombinant plasmids. | the polypeptides synthesized in e. coli minicells from recombinant plasmids containing dna fragments from cauliflower mosaic virus, drosophila melanogaster, and mouse mitochondria were examined. molecularly cloned fragments of cauliflower mosaic virus dna directed the synthesis of high levels of three polypeptides, which were synthesized entirely from within the cloned virus dna fragments independent of their insertion into the plasmid vehicles. several fragments of d. melanogaster dna were capa ... | 1977 | 403011 |
| interbacterial transfer of escherichia coli--drosophila melanogaster recombinant plasmids. | recombinants were constructed between various escherichia coli plasmids and fragments of drosophila melanogaster dna. these recombinant plasmids are nonconjugative, but can be mobilized from one cell to another by conjugative sex factors. of 47 recombinants studied, 46 were mobilized at approximately the same or slightly lower frequencies than the parental plasmids, whereas one was mobilized 1000 times less efficiently. | 1977 | 403605 |
| the time and duration of meiosis. | ever since meiosis was recognized as a process there has been a continuing interest in its temporal aspects. two main types of meiotic timing experiments have been conducted: first, experiments to estimate the duration of meiosis (and sometimes its stages); second, experiments to locate the sensitive stage(s) when exposure of meiocytes to various treatments can affect meiotic chromosome behaviour (e.g. pairing or recombination). such experiments have played an important role in increasing our un ... | 1977 | 16285 |
| isolation and characterization of pteridines from heads of drosophila melanogaster by a modified thin-layer chromatography procedure. | an improved thin-layer chromatography technique is described for the separation of fluorescent compounds found in extracts of heads of drosophila melanogaster. eighteen to twenty fluorescent spots are resolved, two of which are xanthurenic acid and 3-hydroxykynurenine, and the remaining spots are presumably pteridines. of these, nine have been identified and quantitated directly on the chromatograms with a fluorometer. one of the spots present on the chromatogram apparently has not been describe ... | 1977 | 405968 |
| evaluation and re-evaluation of genetic radiation hazards in man. i. interspecific comparison of estimates of mutation rates. | a detailed presentation is made of the experimental data from the various systems used by abrahamson et al. [2] to conclude that the per locus per rad (low let) radiation-induced forward mutation rates in organisms, whose dna content varies by a factor of about 1000, is proportional to genome size. additional information pertinent in this context is also reviewed. it is emphasized that the mutation rates cited by abrahamson et al. [2], although considered as pertaining to mutations at specific l ... | 1976 | 132611 |
| the mutagenicity of azathioprine in mice, drosophila melanogaster and neurospora crassa. | the chemotherapeutic coumpound azathioprine was tested for possible mutagenicity in swiss albino mice, drosophila melanogaster and neurospora crassa. utilizing the dominant-lethal assay it was found that acute oral doses of azathioprine (2 times 25 mg/kg body weight), induced dominant-lethal mutations in mouse spermatocytes. chronic oral doses of azathioprine (2 times 25 mg/kg body weight/week for 10 weeks) resulted in a greater rate of dominant-lethality. this increase was not permanent, and by ... | 1975 | 124817 |
| drosophila melanogaster as an experimental host for study of multiplication and biology of the mycoplasma inducing the "lethargy of coleoptera". | the mulitplication of the mycoplasma responsible for the "lethargy of coleoptera" on a laboratory host, drosophila melanogaster, was obtained on the first passage. independant series of successive passages on d. melanogaster were performed without any apparent modifications of the properties of the microorganism. pathogenicity for its natural host melolontha melolontha was retained. the different forms of mycoplasma observed lead us to propose a probable cycle of development, composed of a succe ... | 1979 | 120120 |
| lengths of transcriptional units coding for the heat shock proteins in drosophila melanogaster. | | 1979 | 119864 |
| [effect of a dinitro-o-cresol-containing herbicide (hedolit) on human reproduction]. | after epicutaneous application of hedolit to guinea pigs the above mentioned substance was found less concentrated in the semen and in the testis than in the serum. hedolit concentrations, as they were found in the serum, lead already to motility limitations of human sperma and cause a small mutageneous effect in drosophila melanogaster. the chosen epicutaneous modus of application did not lead to such traceable concentrations of hedolit in the semen and in the testis. | 1979 | 118892 |
| sequence and secondary structure of drosophila melanogaster 5.8s and 2s rrnas and of the processing site between them. | drosophila melanogaster 5.8s and 2s rrnas were end-labeled with 32p at either the 5' or 3' end and were sequenced. 5.8s rrna is 123 nucleotides long and homologous to the 5' part of sequenced 5.8s molecules from other species. 2s rrna is 30 nucleotides long and homologous to the 3' part of other 5.8s molecules. the 3' end of the 5.8s molecule is able to base-pair with the 5' end of the 2s rrna to generate a helical region equivalent in position to the "gc-rich hairpin" found in all previously se ... | 1979 | 118436 |
| isolation and characterization of recombinant dna plasmids carrying drosophila trna genes. | recombinant plasmids carrying drosophila melanogaster trna genes were constructed by ligation of hindiii-cleaved drosophila dna to hindiii cut pbr322 dna. 90 clones were isolated that contained genes for one or more of eleven trnas. 43 of the plasmids were characterized by a number of methods: restriction nuclease digestion; agarose gel electrophoresis; hybridization with individual, purified, 125i-labelled drosophila trna molecules and in situ hybridization to drosophila chromosomes. the result ... | 1979 | 118082 |
| affinity labeling of a reactive sulfhydryl residue at the peptidyl transferase p site in drosophila ribosomes. | an affinity label has been prepared that is specific for the p site of a eucaryotic peptidyl transferase, that of drosophila melanogaster. it has the sequence c-a-c-c-a-(ac[3h]leu) with a mercury atom added at the c-5 position of all three cytosine residues (referred to as the mercurated fragment). this label is an analogue of the 3' terminus of n-acetylleucyl-trna. the mercurated fragment binds specifically to the p site of peptidyl transferase. it participates fully in peptide bond formation a ... | 1979 | 117829 |
| purine transport by malpighian tubules of pteridine-deficient eye color mutants of drosophila melanogaster. | uptakes of guanine into malpighian tubules of wild-type drosophila and the eye color mutants white (w), brown (bw), and pink-peach (pp) have been compared. tubules for each of these mutants are unable to concentrate guanine intracellularly. the transport of xanthine and riboflavin is also deficient in w tubules. the transport of guanosine, adenine, hypoxanthine, and guanosine monophosphate is similar in wild-type and white malpighian tubules. these data and other information about these mutants ... | 1979 | 117796 |
| synthesis of proteins coded by plasmid vectors of pcv series (apr, tcr) and their recombinant derivatives (pdm) in e. coli minicells. | polypeptide synthesis directed by vector plasmids of pcv series conferring ampicillin and tetracycline resistance (apr, tcr) and by recombinant plasmids (pdm) have been analyzed using the minicell system. it has been found that a polypeptide of 34 000 daltons is responsible for the tcr phenotype and regulated from the promoter near the hindiii site. cloning of dna fragments into hindiii site allowed to conclude that dna from drosophila melanogaster contains nucleotide sequences which may act as ... | 1979 | 116907 |
| xenobiotica-metabolizing enzymes in drosophila melanogaster: activities of epoxide hydratase and glutathione s-transferase compared with similar activities in rat liver. | activities of epoxide hydratase and glutathione (gsh) s-transferase were investigated in subcellular fractions of drosophila melanogaster, and these activities were compared with analogous enzymic activities in extracts from rat liver. microsomes of drosophila were active in the hydratation of styrene oxide catalyzed by epoxide hydratase. the post-microsomal supernatant of drosophila catalyzed the conjugation of gsh with 1-chloro-2,4-dinitrobenzene. however, gsh s-transferase activity with styre ... | 1979 | 116125 |
| in vitro transcription of heat-shock-specific rna from chromatin of drosophila melanogaster cells. | polyadenylylated rna synthesized after heat shock was isolated from polysomes of cultured cells of drosophila melanogaster and used as template to prepare cdna. an excess of poly(a)-rna from heat-shocked cells hybridized to 80% of the cdna, whereas cytoplasmic poly(a)-rna from cells grown at 25 degrees could drive only half of the cdna probe into hybrid. these sequences were removed from the cdna population by annealing to poly(a)-rna from cells grown at 25 degrees. the unreacted material repres ... | 1978 | 416440 |
| heterochromatin and satellite dna in man: properties and prospects. | in reviewing the properties of heterochromatin and satellite dna in man, it is clear that the human genome does not readily lend itself to experimental tests of the postulated functions for satellite dna. since the spectrum of known structural properties of vertebrate and invertebrate satellite dnas are broadly overlapping, an alternative avenue is to experimentally manipulate the heterochromatin of an organism, and then evaluate the generality of the results. when this is done in drosophila mel ... | 1979 | 111544 |
| environmental factors affecting the quantity of alcohol dehydrogenase in drosophila melanogaster. | | 1979 | 111149 |
| genetics of aneuoploidy in man reconsidered by banding studies. | the effects of aneuploidy are only partially known in man, but the information available suggests that they are remarkably similar to those in drosophila melanogaster. the fractions of the haploid genome that can be tolerated in three doses and in one dose approach 7 and 3%, respectively. hypoploidy is more deleterious than hyperploidy. the phenotypic effects of aneuploidy result in an 'aneuploid syndrome' of developmental, mental and growth retardation and multiple malformations. even if upon c ... | 1978 | 746292 |
| the temporal stability of the drosophila oocyte. | individual female drosophila melanogaster were maintained without yeast for up to 18 days. some of the females did not lay any eggs during this holding period. the females produce mature oocytes (stage 14) by day 3 and from day 5 onward the females each held about 60 mature oocytes. the nulliparous females were mated and its was shown that the first egg produced by females held up to 18 days before mating could be viable and develop into a normal, fertile adult. on day 2 each female contained ab ... | 1979 | 110902 |
| interspersion of repetitive and nonrepetitive dna sequences in the drosophila melanogaster genome. | cot analysis shows that the haploid drosophila genome contains 12 percent rapidly reassociating, highly reiterated dna, 12 percent middle repetitive dna with an average reiteration frequency of 70, and 70 percent single-copy dna. the distribution of the middle repetitive sequences in the genome has been studied by an examination in the electron microscope of the structures obtained when middle repetitive sequences present on large dna strands reassociate and by the hydroxyapatite binding methods ... | 1975 | 804998 |
| a method for studying tissue specificity of maternally affected drosophila melanogaster mutants: mosaic analysis of cinnamon. | | 1978 | 109330 |
| [the induction of chromosome loss and gain by colchicine (author's transl)]. | the fruit fly drosophila melanogaster is one of the standard systems used for mutagen screening. the colchicine-containing drugs colchicum-dispert and colchysat burger were fed at extremely low concentrations (1:300 000 and 1:50 000 respectively) to drosophila females. among their offspring a remarkably high frequency of aneuploid individuals (xo and xxy flies) were found. these aneuploids correspond karyotypically to the human ullrich-turner (xo) and klinefelter's (xxy) syndromes and result fro ... | 1976 | 135205 |
| comparison of the genetic activity of 5-nitroimidazole derivatives in escherichia coli, neurospora crassa, saccharomyces cerevisiae and drosophila melanogaster. | 5-nitroimidazoles, including metronidazole (compound 1) and 3 analogues (compounds 2, 3 and 4) of actual or potential chemotherapeutic use were assayed for genetic activity in test systems detecting forward and back mutations in escherichia coli k-12/343/113, forward mutations in neurospora crassa heterokaryon 12, mitotic gene conversion in the heteroallelic diploid yeast strain saccharomyces cerevisiae d4 and sex-linked recessive lethals in drosophila melanogaster. whereas metronidazole exhibit ... | 1979 | 154545 |
| inverted repeat sequences in the drosophila genome. | the properties of inverted repeat (foldback) sequences in drosophila melanogaster dna have been studied by hap chromatography and electron microscope methods. electron microscope observations show that there is a broad distribution of lengths of the duplex regions of the inverted repeats from very short to greater than 15 kb, with number and weight average values of 1.35 kb and 5.0 kb respectively. about 20% of the inverted repeats are separated by a single-strand spacer with lengths too short t ... | 1975 | 806348 |
| polypyrimidine segments in drosophila melanogaster dna: ii. chromosome location and nucleotide sequence. | long pyrimidine tracts, purified from drosophila melanogaster dna after treatment with formic acid-diphenylamine, were used as template for e. coli rna polymerase to produce a polynucleotide containing only purines. this polypurine rna hybridized specifically to d. melanogaster dna with high efficiency at low cot values. the resulting hybrid showed high thermal stability. when polypurine rna was subjected to complete hydrolysis with ribonuclease t1, over 90% of the nucleotide products were apgp ... | 1975 | 806350 |
| purified dnas are transcribed after microinjection into xenopus oocytes. | the possibility of using dna-injected xenopus laevis oocytes and eggs for studying the control of transcription in eukaryotes has been investigated. when purified dna of simian virus 40 (sv40) is injected into xenopus laevis oocytes, tritiated rna precursors are incorporated into dnase-i-resistant, rnase-a- and alkali-sensitive material that hybridizes specifically to sv40 dna. this viral transcription continues for at least 5 days and occurs only when the injected dna is directed to the nucleus ... | 1977 | 193103 |
| coupled transcription-translation of dna injected into xenopus oocytes. | a previous report from this laboratory showed that purified dnas are transcribed after injection into the nucleus of xenopus laevis oocytes (mertz and gurdon, 1977). here we demonstrate that at least some of the rna synthesized is translated within these injected cells to produce the correct protein products. injection of simian virus 40 dna into oocytes induces the synthesis of at least two proteins not normally synthesized in these cells. using two-dimensional polyacrylamide gel electrophoresi ... | 1977 | 198138 |
| biophysical and biochemical characterization of five animal viruses with bisegmented double-stranded rna genomes. | infectious pancreatic necrosis virus of fish, infectious bursal disease virus of chickens, tellina virus and oyster virus of bivalve molluscs, and drosophila x virus of drosophila melanogaster are naked icosahedral viruses with an electron microscopic diameter of 58 to 60 nm. the genome of each of these viruses consists of two segments of double-stranded rna (molecular weight range between 2.6 x 10(6) and 2.2 x 10(6), and the virion, capsid proteins fall into three size class categories (large, ... | 1979 | 228080 |
| magnification of genes coding for ribosomal rna in saccharomyces cerevisiae. | when a strain of saccharomyces cerevisiae monosomic for chromosome i and initially deficient for 25% of the genes coding for ribosomal rna is repeatedly subcultured, the number of these genes increases to and remains stable at the number in the wild type. this strain shows 2:2; viable: inviable first division segregation and hemizygosity for the ade1 gene (a chromosome i marker), evidence that the strain is still monosomic for chromosome i. the increase in the number of genes coding for ribosoma ... | 1977 | 322148 |
| the sequence arrangement of drosophila melanogaster 5s dna cloned in recombinant plasmids. | | 1977 | 407004 |
| cloning and characterization of a complex satellite dna from drosophila melanogaster. | | 1977 | 408008 |
| sequence arrangement of trna genes on a fragment of drosophila melanogaster dna cloned in e. coli. | a plasmid with the vector col e1 attached to an insert of drosophila melanogaster dna carrying four trna genes has been cloned in e. coli. some features of the sequence arrangement and the positions of the trna genes have been determined by electron microscopic methods and by restriction endonuclease mapping. trna genes were mapped at 1.4, 4.7, 5.9 and 8.6 kb from one of the drosophila/col e1 junctions in the drosophila insert of total length 9.34 kb. there are several secondary structure featur ... | 1977 | 408014 |
| genetic instability in drosophila melanogaster: putative multiple insertion mutants at the singed bristle locus. | a series of eleven independent mutants at the x chromosome singed bristle (sn) locus of drosophila melanogaster is described. all mutants descend from flies caught in the wild and bred in the laboratory. on the basis of their inordinately high spontaneous mutation frequency, ten of the mutants are classified as putative insertion mutants. reversions to wild type occur at frequencies of 10(-4)-10(-3). some reversions appear to be losses of the inserted element, others appear (by analogy with prok ... | 1977 | 408811 |
| the mitochondrial dna of drosophila melanogaster exists in two distinct and stable superhelical forms. | we have studied the structure and replication of mitochondrial dna from drosophila melanogaster embryos, larvae, adult flies and two established tissue culture lines. the most striking observation is that the organism maintains at least two stable, distinct closed circular forms of mitochondrial dna throughout development of the early embryo and in the adult fly. the major closed circular monomeric form comprises approximately 75% of the population and has a normal number of superhelical turns. ... | 1977 | 410503 |
| the mutational spectrum of procarbazine in drosophila melanogaster. | the antineoplastic agent procarbazine was tested for the induction of genetic damage in drosophila melanogaster. the compound was administered to adult males by oral application. the following types of genetic damage were measured: (1) sex-linked recessive lethals; (2) dominant lethals; (3) total and partial sex-chromosome loss; and (4) translocations. procarbazine is highly mutagenic in causing recessive lethal mutations in all stages of spermatogenesis. in sperm a clear-cut concentration-effec ... | 1977 | 411030 |
| translation of drosophila melanogaster sequences in escherichia coli. | thirty-seven independently cloned segments of drosophila melanogaster dna (dm segments) were individually tested for their ability to promote the synthesis of new polypeptides in escherichia coli k-12. the cloning vector was the psc101 plasmid and the test system consisted of e. coli k-12 minicells that contained the hybrid pdm plasmids. each of four pdm plasmids produced a new polypeptide, and one, pdm107, was selected for detailed mapping of the sequences required for the translation of its 38 ... | 1977 | 412196 |
| isolation and genetic characterization of alcohol dehydrogenase thermostability variants occurring in natural populations of drosophila melanogaster. | drosophila melanogaster collected from natural populations were examined fo thermostability variants within electrophoretic mobility classes of two enzymes. in alcohol dehydrogenases, two discrete forms of the "slow" allozyme and three discrete forms of the "fast" allozyme were revealed by postelectrophoretic treatments ranging from 15 sec at 40 c to 40 sec at 43 c. all variants have been mapped to within 0.7 unit of the adh locus. results of a geographic survey indicate that two alleles giving ... | 1977 | 412495 |
| mutagenicity of hair dye components relative to the carcinogen benzidine in drosophila melanogaster. | a comparative assay was undertaken in drosophila melanogaster for the assessment of the mutagenic efficiency of the hair dye components m-toluene-diamine (m-td) and 4-nitro-o-phenylenediamine (4-nopd) relative to the aromatic amine human carcinogen benzidine (bzd). the compounds were injected at equimolar dose ranges (5-20 mm) around the testes of adult males and their mutagenicities were measured separately on the various stages of spermatogenesis. genetic activity was simultaneously assayed w ... | 1977 | 413033 |
| variance component analysis of allozyme frequency data from eastern populations of drosophila melanogaster. | gene frequency variation at eight polymorphic allozyme loci in drosophila melanogaster populations in north carollina and the east coast of the united states were analyzed utilizing the variance component estimation procedures suggested by cockerham (1969, 1973). these variance components were used to estimate correlations of genes within small geographic regions. the average (over loci) correlation between genes in the same individual within subpopulations was estimated to be 0.033. that betwee ... | 1978 | 415939 |
| genomic organization in the flesh fly sarcophaga bullata. | the genome of the flesh fly sarcophaga bullata has been characterized both cytologically and biochemically. s. bullata has a haploid dna level of 0.61 picograms which is five times larger than the haploid genome size of drosophila melanogaster. reassociation kinetics of sarcophaga dna shows that its sequence organization is very similar to that of d. melanogaster in having a very large proportion of single copy dna (81%) and only small amounts of highly and moderately repetitive dna (9% and 6%, ... | 1979 | 533665 |
| determination of molecular weights by fluctuation spectroscopy: application to dna. | a method for determining molecular weights of macromolecules by measuring spontaneous concentration fluctuations is described. the method is absolute, rapid, and requires no shearing forces on the molecules. we have applied this technique to the determination of molecular weight of dna molecules. the molecular weight values obtained for t2 phage dna (1.14 x 10(8)) and replicating escherichia coli dna (3.9 x 10(9)) agree with previous results. by monitoring individual molecules, an estimate of th ... | 1976 | 822421 |
| a portion of all major classes of histone messenger rna in amphibian oocytes is polyadenylated. | ovaries of the amphibian triturus viridescens contain a considerable amount of 7 to 12 s rna which fractionates with poly(a)+ rna on oligo(dt)-cellulose column chromatography and directs the synthesis of all five classes of histones in a wheat germ cell-free system. the polyadenylate tracts associated with this 7 to 12 s poly (a)+ rna are heterogeneous in length, ranging from approximately 60 to 120 nucleotides. partially purified subfractions of histone mrna templates were isolated from this rn ... | 1978 | 564902 |
| investigations on radio-sensitive and radio-resistant populations of drosophila melanogaster. vii. high relative radio resistance to the induction of sex-linked recessive lethals in stage-7 oocytes of ro i4. | | 1976 | 781533 |
| [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 |
| effects of sr-spirochete infection on drosophila melanogaster carrying intersex genes. | three sex-transforming genes (ix, tra-d, and dsx) in d. melanogaster were examined with respect to possible interactions with the nsr strain sr-spirochetes. the sr-spirochetes exerted a lethal effect on xy but not on xx individuals, regardless of whether they were phenotypically males, intersexes, or females. these results, taken together with those reported by sakaguchi and poulson (1963)on tra and 2x3a intersexes, both of which are resistant to the androcidal action of sr-spirochetes, support ... | 1975 | 805080 |
| mutagenicity of organophosphorus compounds in bacteria and drosophila. | 140 organophosphorus compounds (op's) have been tested for mutagenic activity in bacteria, principally by using two specially constructed sets of tester strains of the bacteria salmonella typhimurium and escherichia coli. it was found that 20% gave positive mutagenic responses and that this group of chemicals produce base subsitutions rather than frame-shift mutations. in most cases the dna repair genes exra+ and reca+ were required for mutagenic activity. seven compounds were further tested in ... | 1975 | 806014 |
| characterization of six cloned dnas from drosophila melanogaster, including one that contains the genes for rrna. | pdm plasmids were constructed from d. melanogaster and psc101 dnas by a modification of the ecor1-ligase method which insured that each hybrid molecule contained a single segment of d. melanogaster chromosomal dna (dm segment). the sequences in the dm segments of six cloned pdm dnas were mapped within the d. melanogaster polytene chromosomes by in situ hybridization, and their repetition frequencies within the dm segment and within the genome were determined. four of these segments consist of se ... | 1975 | 806347 |
| acid treatment of drosophila deoxyribonucleic acid. | in cytologic preparations of chromosomes, acid-treated deoxyribonucleic acid (dna) is found largely in the native state. however, acid treatments widely used for chromosome preparations produce significant amounts of depurination in dna. dna is similarly sensitive to depurination in intact cells or as purified dna. if treated with alkali, these apurinic gaps can be converted to single strand breaks. acid treatment has widely different effects on specific fractions of dna. in drosophila melanogas ... | 1975 | 806634 |
| transcription and translation of cloned drosophila dna fragments in escherichia coli. | the expression of three unique dna fragments from drosophila melanogaster which have been inserted into escherichia coli (e. coli) via the plasmid, psc 101, was studied. the hybrid plasmid dna molecules containing drosophila dna were transformed into the minicell producing strain of e. coli, x1411. drosophila dna-directed rna synthesis was studied by hybridizing newly synthesized rna isolated from the minicells with various dna fragments which were immobilized on nitrocellulose filters. rna was ... | 1977 | 402934 |
| synthesis of hybrid bacterial plasmids containing highly repeated satellite dna. | hybrid plasmid molecules containing tandemly repeated drosophila satellite dna were constructed using a modification of the (da)-(dt) homopolymer procedure of lobban and kaiser (1973). recombinant plasmids recovered after transformation of reca bacteria contained 10% of the amount of satellite dna present in the transforming molecules. the cloned plasmids were not homogenous in size. recombinant plasmids isolated from a single colony contained populations of circular molecules which varied both ... | 1977 | 403010 |
| enzyme and chromosome polymorphisms in japanese natural populations of drosophila melanogaster. | collections of d. melanogaster from japanese populations were analyzed for enzyme and chromosomal polymorphisms. allelic frequencies at the adh and alphagpd loci were compared with polymorphic inversion (in(2l)b, in(2r)c) frequencies in the second chromosome. there was a significant positive correlation between the frequencies of adhs and in(2l)b, caused by linkage. on the other hand, inversion-free cage populations maintained in the laboratory for a long time showed considerably larger variatio ... | 1977 | 405274 |
| new results on the genetic characteristics of the far east race of drosophila melanogaster. | | 1976 | 829088 |
| enzymatic variation at seven loci in nine natural populations of drosophila melanogaster. | allozyme polymorphisms at seven loci have been studied in nine natural populations of drosophila melanogaster from the saône and rhône valleys sampled in 1973 and 1974. a great deal of polymorphism was observed; an individual was on the average heterozygous at 20.2% of its loci. the populations were genetically very homogeneous throughout the region sampled. the number of ovariolae per female varied from one group of populations to another depending on their geographical separation. yet the numb ... | 1977 | 406898 |
| the origin of folded dna rings from drosophila melanogaster. | | 1975 | 811808 |
| rna polymerase b from drosophila melanogaster larvae. purification and partial characterization. | a purification procedure is described by which we obtained dna-dependent rna polymerase b (or ii) from third-instar larvae of drosophila melanogaster in essentially pure form. the enzyme is similar to the analogous polymerases from other eukaryotes in its enzymic and structural properties. it preferentially transcribes dnas containing single-stranded regions, and it is inhibited by low amounts of the toxin alpha-amanitin; 50% inhibition occurs at an alpha-amanitin concentration of 0.03 mug/ml. d ... | 1975 | 812697 |
| 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 |
| serological relations between twelve small rna viruses of insects. | serological tests were done to examine the relationships between twelve picorna-like viruses of insects. the results of the tests indicated that the majority of the viruses are unrelated. however, cricket paralysis virus, isolated from australian wild field crickets, appeared to be identical to drosophila c virus, independently isolated in france. cricket paralysis virus was infective for adults of drosophila melanogaster and its infectivity towards galleria melonella was neutralised by drosophi ... | 1976 | 816992 |
| [an experimental study of the morphogenetic properties of several phenols inducing phenocopies of vitiligo]. | in an experiment with black guinea pigs a phenocopy of vitiligo was obtained by means of the exposure of the skin to the action of p-tert-butyl-phenol (ptbp) or to catechol (c). two other compounds: 2,2-dihydroxy-diphenylpropane (ddp) and 2, 4, 6-tri-tert-butyl-phenol (ttbp) exerted a hypopigmentary effect. ptbp and c depigmented the skin but caused no preceding inflammation. spots of depigmented (white) skin and hairs were surrounded by a zone of hyperpigmentation. leukoderma proved to be stabl ... | 1975 | 817974 |
| cleavage patterns of drosophila melanogaster satellite dna by restriction enzymes. | the five satellite dnas of drosophila melanogaster have been isolated by the combined use of different equilibrium density gradients and hydrolyzed by seven different restriction enzymes; hae iii, hind ii + hind iii, hinf, hpa ii, ecor i and ecor ii. the 1.705 satellite is not hydrolyzed by any of the enzymes tested. hae iii is the only restriction enzyme that cuts the 1.672 and 1.686 satellites. the cleavage products from either of these reactions has a heterogeneous size distribution. part of ... | 1976 | 818625 |
| molecular cloning of dna fragments produced by restriction endonucleases sa1i and bami. | the highly specific restriction endonucleases sa1i and bami produce dna fragments with complementary, cohesive termini that can be covalently joined by dna ligase. the escherichia coli kanamycin resistance factor pml21 has one sali site, at which dna can be inserted without interfering with the expression of drug resistance or replication of the plasmid. a more convenient cloning vehicle can be made with the tetracycline resistance factor psc101, since insertion of dna either at its single site ... | 1976 | 818638 |
| the circular dichroism of ribosomal ribonucleic acids. | 1. the c.d. (circular dichroism) of drosophila melanogaster rrna (42% g+c) and of g+c-rich fragments (78% g+c) obtained by partial hydrolysis of rabbit l-rrna (the largest rna species isolated from the large subribosomal particle) were measured and found to differ substantially. 2. to interpret these spectra a relation between c.d. of bihelical rna and % g+c was derived, namely delta epsilonfg = afg2+bfg+c, where deltaepsilonfg is the c.d. of rna characterized by a mole fraction, fg, of guanine ... | 1976 | 820335 |
| spectroscopic evidence for the uneven distribution of adenine and uracil residues in ribosomal ribonucleic acid of drosophila melanogaster and of plasmodium knowlesi and its possible evolutionary significance. | rna was isolated from subribosomal particles of the malaria parasite plasmodium knowlesi. the nucleotide composition (mole fraction) of the principal species was obtained (s-rrna, 0.295a, 0.36u, 0.25g, 0.105c: l-rrna, 0.326a, 0.31u, 0.228g, 0.144c). ribosomal rna was also isolated from drosophila melanogaster. optical properties of these a + u-rich species were measured. in all four cases analysis of the hypochromic effect revealed that adenine and uracil residues tended to form clusters along t ... | 1976 | 821475 |
| [experimental study of the morphogenetic properties of several phenols inducing a phenocopy of vitiligo]. | in an experiment with black guinea pigs a phenocopy of vitiligo was obtained by means of the exposure of the skin to the action of p-tert-butyl-phenol (ptbp) or to catechol (c). two other compounds: 2,2-dihydroxy-diphenylpropane (ddp) and 2, 4, 6-tri-tert-butyl-phenol (ttbp) exerted a slight hypopigmentary effect. ptbp and c depigmented the skin but caused no preceding inflammation. spots of depigmented (white) skin and hairs were surrounded by a zone of hyperpigmentation. leukoderma proved to b ... | 1975 | 821820 |
| preparation of specific antisera to drosophila acid phosphatase without rigorous protein purification. | extracts from an acid phosphatase crm- null mutant of drosophila melanogaster were used to eliminate contaminating antibodies in a nonspecific preparation of anti-acid phosphatase serum. this method of producing specific antisera makes unnecessary the rigorous purification of an antigen prior to immunization attempts in those cases where crm- null mutants of the antigen are available. antisera so prepared could be used for a wide variety of purposes. | 1976 | 822833 |
| structural analyses of mutant and wild-type alcohol dehydrogenases from drosophila melanogaster. | four genetic variants of alcohol dehydrogenase from drosophila melanogaster have been examined: wild-type f-enzyme (from the adhf strain), the d-type mutant form (from the adhd strain), which is catalytically active, and two proteins lacking enzymic activity (from the adhn11 and adhn5 strains). the proteins were compared by mapping of tryptic peptides. one pair of difference peptides was seen in the comparisons of the d and f-type enzymes. these peptides were purified and their sequences determi ... | 1976 | 823018 |
| fidelity of chromatin transcription in vitro. | chromatin and dna from schneider's drosophila melanogaster cell line 2 were transcribed in vitro with escherichia coli rna polymerase. using mercurated utp as precursor, the newly synthesized rna could be separated from dna and endogenous rna by affinity chromatography on sulfhydryl-sepharose 6b. characterization of the transcription products with complementary dna (cdna) made from polyadenylated nuclear rna and with fractionated cdna probe demonstrated a fair quantitative fidelity in the in vit ... | 1976 | 823961 |
| the effects of cinnamon on xanthine dehydrogenase, aldehyde oxidase, and pyridoxal oxidase activity during development in drosophila melanogaster. | | 1976 | 825401 |
| environmental determination of selective significance or neutrality of amylase variants in drosophila melanogaster. | strains homozygous at the amylase locus were derived from a polymorphic laboratory population of drosophila melanogaster. the amy4,6 strain has higher enzyme activity than amy1 strain.-maltose has the same nutritional value as starch.- the effect of starch in pure culture depends on the yeast level. at low yeast level increasing starch increases survival, at high yeast level increasing starch increases mean dry weight. the strains do not differ in survival or mean dry weight in pure culture.--in ... | 1976 | 825413 |
| base sequence complexity of the stable rna species of drosophila melanogaster. | the base sequence complexity of drosophila transfer rna (trna), 5s rna, and 18s + 28s ribosomal rna was determined by analyzing the kinetics of rna-dna hybridization on membrane filters. we find that drosophila trna is made up from about 59 basic nucleotide sequences distinguishable by hybridization, suggesting that many of the 99 trna species resolved by reverse phase chromatography (rpc-5) are homogenic. in contrast 5s rna was found to contain a single family of sequences. either 18s ribosomal ... | 1976 | 826268 |
| karyotype evolution in cell lines of drosophila melanogaster. | the chromosomal changes occurred in two independent cell lines (gm2 and gm3) of drosophila melanogaster maintained in medium supplemented with serum and in serum-free medium were compared. in both culture conditions and in both lines a chromosomal evolution was revealed. structural and numerical variations were analysed. the breaks giving rise to rearrangements were at heterochromatic level. moreover, a tetraploidisation followed by loss of chromosomes or of portions of chromosomes recalls an an ... | 1976 | 826374 |
| construction and characterization of a chimeric plasmid composed of dna pfrom escherichia coli and drosophila melanogaster. | a chimeric plasmid has been constructed in vitro from colicin e1 factor (col e1), nontransmissible r-factor rsf-1010, and drosophila melanogaster dnas by the sequential action of escherichia coli endonuclease ri(eco ri) and t4 phage dna ligase. the chimeric plasmid was assembled in two stages--first, a composite plasmid consisting of col e1 and rsf 1010 was constructed, followed by partial digestion of the composite with eco ri (in order to open one of the susceptible cleavage sites) and ligatio ... | 1975 | 807234 |
| the ribosomal proteins of drosophila melanogaster. iv. characterization by two-dimensional gel electrophoresis of the ribosomal proteins from nine postembryonic developmental stages. | the ribosomal proteins from nine postembryonic developmental stages of drosophila melanogaster were analyzed by two-dimensional gel electrophoresis. the ribosomal protein patterns thus obtained constitute reliable control patterns against which any potential mutant can be compared. furthermore, the results provide increased evidence for a qualitative and quantitative change in the protein composition of the total population of ribosomes which occurs mainly during the third larval instar. two aci ... | 1975 | 809664 |
| identical age-related patterns of enzyme activity changes in phormia regina and drosophila melanogaster. | | 1975 | 810357 |
| infectivity of fish rhabdoviruses for drosophila melanogaster. | two fish rhabdoviruses, spring viraemia of carp virus (svc) and pike fry rhabdovirus (pfr), have been shown to multiply in drosophila melanogaster. the other two fish rhabdoviruses, viral haemorrhagic septicaemia (vhs) and infectious hematopoietic necrosis (ihn), did not multiply under the conditions used. only those viruses which multiplied (i. e. svc, pfr) conferred a co2 sensitivity on the infected drosophila. no hereditary transmission of the fish viruses was detected. | 1975 | 811150 |
| a contribution to the study of linkage disequilibrium in drosophila melanogaster. | linkage disequilibrium was detected in 12 out of 30 cases involivng gene alleles and inversions in three cage populations and in a natural population of drosophila melanogaster from greece. the cage populations possessed practically the same gene pool at their origin and were maintained simultaneously under the effects of the ecological factors "food medium" and "humidity". it is dicussed that the correlation of the same direction found between the frequencies of nonallelic elements of adh locus ... | 1976 | 828514 |
| [adaptation of a sindbis virus population to "drosophila melanogaster" (author's transl)]. | the evolution of a sindbis virus population during serial passages in drosophila has been studied. the adaptation of sindbis virus to this unusual host was achieved within about twenty passages. of course, the viral population went on evolving: a thermosensitive mutant appeared which excluded the original virus; later, a new type, different in plaques morphology, was observed: it did not exclude the former type but remained balanced with it. the adaptation of sindbis virus to drosophila was reve ... | 1976 | 828837 |
| use of the electroretinogram to measure the quality of vision of the fruit fly. | the electroretinogram (erg) technique was used to measure the visual sensitivity of caribbean fruit flies anastrepha suspensa (loew), reared at 3 laboratories on 5 artificial diets. these ergs were compared with those of flies reared from field-infested fruit. flies reared on artificial diets differed greatly in visual sensitivity, and those reared on fruit were at least 10 times more sensitive than certain strains. since ergs can be obtained 3-4 days before the caribbean fruit fly is sexually ... | 1975 | 1204589 |
| analysis of the gene encoding a 16-kda proteolipid subunit of the vacuolar h(+)-atpase from manduca sexta midgut and tubules. | vacuolar atpases (v-atpases), originally characterised as components of endomembranes, have also been implicated in epithelial ion transport, both in vertebrates and in insects. the atpase is particularly noteworthy in lepidopteran larvae, where it generates large transepithelial potential differences and short-circuit currents across the midgut epithelium. a cdna library from manduca sexta larval midguts and malpighian tubules was screened with a drosophila melanogaster cdna encoding the 16-kda ... | 1992 | 1283142 |
| changes in superoxide dismutase and catalase in aging heat-shocked drosophila. | we have examined the age-dependent expression of cuzn superoxide dismutase (sod) and catalase (cat) in drosophila melanogaster following heat shock. quantitative northern blot analysis was performed after heat shock on 2-, 23- and 49-day-old flies, using a 0.48 kb sal1 ecor1 fragment of the drosophila sod cdna and a 1.4 kb fragment of the human catalase cdna. heat shock induction was monitored with a 5.4 kb dna fragment of the drosophila hsp70 gene. after exposure to 37 degrees c for 30 min and ... | 1992 | 1286836 |
| glycogen synthase kinase-3: functions in oncogenesis and development. | study of gsk-3 had an inauspicious beginning rooted in intermediary metabolism. however, owing to the fortuitous convergence of several disparate areas of biology, the enzyme now offers unique opportunities for study of the control of a variety cellular processes. while at first sight a role in transcriptional regulation appears unlikely for a protein first identified as acting on glycogen synthase, it is even more surprising that the same protein should be functionally interchangeable with a fr ... | 1992 | 1333807 |
| drosophila c virus cycle during the development of two drosophila melanogaster strains (charolles and champetières) after larval contamination by food. | drosophila c virus (dcv) cycle during drosophila melanogaster development was studied after feeding contamination at the first, most sensitive, instar (l1). two drosophila strains were examined and compared. presence of dcvc in apparently healthy animals (l3 larvae bred on a contaminated rearing medium and adults coming from larvae which were grown on medium containing dcvc) was demonstrated by biological tests. using the immunofluorescence technique, dcv was exhibited in the diseased charolles ... | 1992 | 1300196 |
| there are two mechanisms of achiasmate segregation in drosophila females, one of which requires heterochromatic homology. | there are numerous examples of the regular segregation of achiasmate chromosomes at meiosis i in drosophila melanogaster females. classically, the choice of achiasmate segregational partners has been thought to be independent of homology, but rather made on the basis of availability or similarities in size and shape. to the contrary, we show here that heterochromatic homology plays a primary role in ensuring the proper segregation of achiasmate homologs. we observe that the heterochromatin of ch ... | 1992 | 1304424 |
| variance component analysis of bristle characters in local populations of drosophila melanogaster. | the genetic variabilities of sternopleural and abdominal bristle numbers existing in local natural populations were assessed. using second chromosome lines of drosophila melanogaster extracted from three natural populations in japan (the ishigakijima, ogasawara and aomori populations), experiments were conducted to estimate the components of genetic variances, additive and dominance variances. the following results were obtained: for both sternopleural and abdominal bristle numbers, the additive ... | 1992 | 1304769 |