bluuebunny/crossref_metadata_2025_split huggingface dataset:
Search for ribosomal mutants inPodospora anserina: genetic analysis of cold-sensitive mutants
Authors: Picard-Bennoun Marguerite , Coze Denise Le 
Published: September 2009

SUMMARYTwenty-four cold-sensitive (prototrophic) mutants were isolated after UV mutagenesis of protoplasts of the fungusPodospora anserina. Genetic analysis of these mutants was performed in order to detect those among them which were most likely to be impaired in translational fidelity. The 24 mutations belonged to 24 different genes. One half of the mutants were pleiotropic and displayed an altered phenotype: growth rate at the permissive temperature, germination of the spores, fertility and/or sporulation. Nine mutants differed from wild-type in their resistance levels to cycloheximide, trichodermin and/or paromomycin. Several mutations were linked to known ribosomal loci. Two mutations behaved like informational antisuppressors: one is allelic to the previously describedAs3gene and the other one defines a new antisuppressor gene,AS6.
Genetics of lycopene cyclization and substrate transfer in β-carotene biosynthesis inPhycomyces
Authors: Torres-Martínez S. , Murillo F. J. , Cerdá-Olmedo E. 
Published: September 2009

SUMMARYThe mutations which block lycopene cyclization and those which stop substrate transfer along the carotene pathway are very closely linked inPhycomyces. Simultaneous blocking of both processes commonly results from single exposures to mutagens; and both blockings may be simultaneously removed after a second exposure. The frequencies of different kinds of mutants after treatments with the mutagensN-methyl-N′-nitro-N-nitrosoguanidine and ICR-170, their reversion patterns, and recombination analyses indicate that lycopene cyclization and substrate transfer are governed by separate segments of a single bifunctional gene.
Use of isozymes as chromosome markers in the isolation and characterization of wheat-barley chromosome addition lines
Authors: Hart Gary E. , Islam A. K. M. R. , Shepherd K. W. 
Published: September 2009

SUMMARYThe alcohol dehydrogenase (ADH), glutamic oxaloacetic transaminase (GOT), aminopeptidase (AMP), endopeptidase (EP), and esterase (EST) zymogram phenotypes of Chinese Spring wheat, Betzes barley, Chinese Spring-Betzes heptaploids, and a number of presumptive Betzes chromosome additions to Chinese Spring were determined. It was found that four disomic chromosome addition lines could be distinguished from one another and from the other three possible lines on the basis of the zymogram phenotypes of these isozymes.The structural geneAdh-H1was located in Betzes chromosome 4, the genesGot-H2andAmp-H1in chromosome 6, and the geneEp-H1in chromosome 1. These gene locations provide evidence of homoeology between Betzes chromosomes 4, 6, and 1 and the Chinese Spring chromosomes of homoeologous groups 4, 6, and 7, respectively.
Retarded development of females, a case of maternal inheritance in a moth, Ephestia kuehniella
Authors: Traut Walther 
Published: September 2009

SUMMARYRetarded development of females (Symbol: Rf) has arisen spontaneously as a new trait in a chromosome mutant strain, which has an autosome fused to the original W chromosome. Female imagines with this trait emerge 1–3 weeks later than the males, due to retarded larval development. The proportion of female imagines is low. Rf is maternally inherited, it is neither expressed in nor transmitted through males. The evidence suggests that it is a dominant or epistatic factor on the autosomal part of the W chromosome-autosome fusion.
Autosomal genetic maps of the Australian Sheep Blowfly,Lucilia cuprina dorsalisR.-D. (Diptera: Calliphoridae), and possible correlations with the linkage maps ofMusca domesticaL. andDrosophila melanogaster(Mg.)
Authors: Foster G. G. , Whitten M. J. , Konovalov C. , Arnold J. T. A. , Maffi G. 
Published: September 2009

SUMMARYLinkage data and revised maps for 52 autosomal loci inL. cuprinaare presented. Examination of the linkage relationships of biochemically and morphologically similar mutations inL. cuprina, Musca domesticaL. andDrosophila melanogaster(Mg) suggests that the major linkage groups have survived largely intact during the evolution of the higher Diptera.
Does ‘affinity’ hold the key to fertility in the female mule?
Authors: Chandley Ann C. 
Published: September 2009

SUMMARYMichie's hypothesis of ‘affinity’ is invoked to explain how fertility might theoretically be achieved in a female mule or hinny. Chromosomally balanced haploid gametes could be produced in these inter-specific hybrids by movement of centromeres of similar ancestry to opposite poles at anaphase I of meiosis. Male hybrids could probably never be fertile on account of the low numbers of spermatozoa produced; females, on the other hand, might occasionally achieve fertility by the ovulation of a chromosomally balanced egg.
Selfing mutants from heterothallic strains ofPhysarum polycephalum
Authors: Honey N. K. , Poulter R. T. M. , Winter P. J. 
Published: September 2009

SUMMARYPlasmodial formation in the myxomycetePhysarum polycephalumis controlled by a mating type (mt) locus, with heterothallic amoebae normally being unable to form plasmodia in pure clones. We report the isolation by mutagenesis of selfing mutants from heterothallic strains, and their analysis. Various amoebal strains of different mating types were mutagenized with a range of mutagens, and a number of selfing mutants (designated Het−) were isolated. A specific sensitivity ofmt2amoebae to mutagenesis by NMG was observed. This sensitivity segregated as a single locus closely linked or allelic to themt2locus. When the Het−clones were incubated at 30 °C, selfing was greatly inhibited. This property was used to determine themtspecificities of four Het−clones. The process of plasmodial induction in pure clones ofCLwas also studied using the 30 °C temperature effect.
A variation in mouse kidney pyruvate kinase activity determined by a mutant gene on chromosome 9
Authors: Johnson F. M. , Chasalow Fred , Anderson Gretchen , Macdougal Paul , Hendren R. Wayne , Lewis Susan E. 
Published: September 2009

SUMMARYPyruvate kinase activity was studied in kidney extracts of mice from various sources. One C57BL/6J female among several hundred examined expressed activity approximately one half of the normal level. This animal transmitted the trait, and a single gene responsible for the activity difference was identified and mapped to chromosome 9. Linkage withMod-1anddilutewas established. A spontaneous mutation in the C57BL/6J strain apparently was responsible for the variant pyruvate kinase.
Reversion analysis of [psi−] mutations inSaccharomyces cerevisiae
Authors: Lund P. M. , Cox B. S. 
Published: September 2009

SUMMARYMutants of [psi] a cytoplasmically inherited factor in the yeastSaccharomyces cerevisiaewere isolated after treatment with a variety of agents including conventional mutagens and a number of compounds which cause loss of [psi] at high frequencies, namely methanol, KCl, dimethyl sulphoxide and guanidine hydrochloride. In [psi−] mutants the suppressorSUQ5does not suppress ochre mutations such asade.2.1.Reversion analysis of the [psi−] mutants revealed three classes: (1) a class of agents producing [psi−] mutations which could readily revert to [psi+] (methanol, KCl and dimethyl sulphoxide belong to this class), (2) those which could not be shown to revert (GuHCl) and (3) the conventional mutagens which produced both revertible and apparently non-revertible [psi−] mutations. We conclude that GuHCl causes a deletion or loss of the [psi] factor. Methanol may cause an alteration of ‘state’ for example, of a promoter, and KCl may be selecting or inducing low copy number variants of [psi+] strains. It is possible that DMSO may be involved in regulation of [psi].
Relationship between the parental origin of theXchromosomes, embryonic cell lineage andXchromosome expression in mice
Authors: Papaioannou Virginia E. , West John D. 
Published: September 2009

SUMMARYThe electrophoretic variants of theX-chromosome-linked enzyme phosphoglycerate kinase (PGK-1) have been used to investigate the randomness ofXchromosome expression in the fetus and various extra-embryonic membranes of the mouse conceptus. The amnion shows essentially random expression of the maternally derivedXchromosome (Xm) and the paternally derivedXchromosome (Xp). The parietal endoderm, however, shows exclusive or preferential expression ofXm. The results support the idea that the randomness ofXchromosome expression is correlated with embryonic cell lineage such thatXmis preferentially (perhaps exclusively) expressed in derivatives of the primitive endoderm and trophectoderm but thatXmandXpare randomly expressed in the derivatives of the primitive ectoderm.Experiments involving ovary transplants, embryo transfers or crosses with heterozygous mothers confirm previous findings thatXmis preferentially expressed regardless of theXchromosome expressed in the reproductive tract. Additional experiments show that the preferentially expressedXchromosome in the parietal endoderm and visceral yolk sac endoderm of a normalXmXpconceptus is alwaysXmregardless of grand-parental origin ofXmand regardless of whether the mother is a normalXXfemale or anXOfemale.Xpis, however, expressed in these tissues hiXpOfemale conceptuses. It is argued that a form of chromosome imprinting occurs at each generation to markXmandXpas different and that this difference influences the choice of whichXchromosomes are expressed in each cell lineage.
Production of disomic wheat-barley chromosome addition lines usingHordeum bulbosumcrosses
Authors: Islam A. K. M. R. , Shepherd K. W. 
Published: September 2009

SUMMARYThe possibility of usingHordeum bulbosumCrosses to facilitate production of disomic wheat–barley addition lines from monosomic additions was investigated. Aneuhaploids with 22 chromosomes were obtained in the expected gametic frequencies after crossing monosomic, disomio and monotelo-disomic addition lines, involving four different barley chromosomes, as the female parent with tetraploidH. bulbosum. Thus the added barley chromosomes were not eliminated when preferential elimination of thebulbosumchromosomes took place in the hybrid embryos. Disomic addition lines were obtained after treating the aneuhaploids with colchicine. This method could have wider application in the production of other wheat–alien chromosome disomic addition lines, especially where the transmission frequency of the alien chromosome through the pollen is very low, but its use will depend on the wheat parent being crossarle withH. bulbosumand the alien chromosome being retained during the elimination ofbulbosumchromosomes.
Variation in activity and thermostability of alcohol dehydrogenase inDrosophila melanogaster
Authors: McKay J. 
Published: September 2009

SUMMARYThe activity and thermostability of alcohol dehydrogenase (ADH) from 247 strains ofDrosophila melanogasterwere studied by spectrophotometric assay. The strains, in which second chromosomes had been made homozygous in a standard genetic background, were derived from five natural populations from diverse geographical and ecological sites. Evidence is presented that the majority of variation in ADH activity is attributable to the presence, in all five populations, of two electromorphs of the enzyme. However, some variation does exist between strains carrying the same electromorph, to some extent associated with variation hi body weight. Two strains showed atypical ADH activities. Variation in ADH thermostability was almost wholly attributable to the presence of two electromorphs; only two strains had enzymes with thermostabilities atypical of their electromorph. In the four strains with abnormal ADH properties the locus (loci) responsible map in the region of theAdhlocus. Therelatively low level of heterogeneity within electrophoretic classes at this locus is discussed in view of recent findings at other enzyme loci inDrosophila.
The transposons Tn501(Hg) and Tn1721(Tc) are related
Authors: Altenbuchner J. , Choi C.-L. , Grinsted J. , Schmitt R. , Richmond M. H. 
Published: September 2009

SUMMARYInternal sequences of Tn501(Hg) and Tn721(Tc) have been compared by hybridization. In spite of the difference in the resistance they code for, there is extensive homology between the two elements. This homology resides in the transposon-coded genes that are necessary for transposition and indicates that the elements are closely related.
GPI expression in female germ cells of the mouse
Authors: McLaren Anne , Buehr Mia 
Published: September 2009

SUMMARYThe genetically determined oocyte-specific expression of glucose-phosphate isomerase activity in the mouse is first apparent at 6 to 7 days after birth, and occurs in XO as well as in XX oocytes. The regulator locus that controls oocyte-specific expression shows the same linkage relations as the structural gene, suggesting that both form part of a Gpi-1 gene complex.
Mobilization of the non-conjugative IncQ plasmid RSF1010
Authors: Willetts Neil , Crowther Carol 
Published: September 2009

SUMMARYThe broad host-range non-conjugative IncQ plasmid RSF1010 was mobilised with 100% efficiency in membrane filter matings, both inE. coliK12 andP. aeruginosaPAO, by broad host-range conjugative IncP plasmids. No homology between RSF1010 and an IncP plasmid could be detected. InE. coli, IncIα and IncX plasmids, but not IncF, IncN or IncW plasmids, were also relatively efficient at mobilising RSF1010, while inP. aeruginosa, R91–5 (IncP-10) was highly efficient, but pMG5 (IncP-2) and FP2 (IncP-8) were very inefficient. IncP plasmids also mobilised several plasmids derived from RSF1010 for use as in vectors inin vitrorecombination experiments very efficiently, and pSC101 quite efficiently: this reduces the level of biological containment possible with these plasmids.
X chromosome activity in female germ cells of mice heterozygous for Searle's translocation T(X;16)16H
Authors: Johnston P. G. 
Published: September 2009

SUMMARYThe expression of X-linked phosphoglycerate kinase (PGK-1) in germ cells from embryos heterozygous for both PGK-1 and Searle's translocation T(X; 16) 16H was examined to investigate X chromosome activity during oogenesis. ThePgk-lballele on the translocated X chromosome was the only allele active in somatic cells of all embryos and in germ cells from 12·5 d.p.c. embryos. However, an additional faint band representingPgk-laactivity was observed in germ cells from older embryos (13·5–18·5 d.p.c.) and neonates (1–2 d.p.p.). It is concluded that there is a period when only one X chromosome is active in early female germ cells and that reactivation of the inactive X chromosome takes place just prior to meiotic prophase.
The growth of mice selected for large and small size in relation to food intake and the efficiency of conversion
Authors: Roberts R. C. 
Published: September 2009

SUMMARYMice selected for large size show increases in both food intake and efficiency, and small mice show decreases in both. This is true whether the comparisons are made at the same age or at the same weight. Food intake and efficiency contributed more or less equally to the responses to selection for growth. Mice seem to regulate their food intake to a certain level of energy. On suspension of a period of food restriction, mice ate the same amount as others of the same strain that had not been restricted, and which were bigger. At the same time, they converted it more efficiently than the mice which had been full-fed throughout, because of a linear negative association between efficiency and body weight. Thus, following restriction, mice eat as much as bigger mice of the same age, and convert it as efficiently as younger mice of the same weight. The product of these two effects gives rise to rapid (compensatory) growth.
The control of body size in mouse chimaeras
Authors: Falconer D. S. , Gauld I. K. , Roberts R. C. , Williams D. A. 
Published: September 2009

SUMMARYAggregation chimaeras were made from embryos of strains of mice selected for large and small body size and of unselected controls. The strains were combined in pairs marked by albino coat colour and by allo-zyme variants at the Gpi-1 locus. The proportion of cells derived from each component was scored visually in the coat melanocytes and by electrophoresis in ten other organs or tissues (blood, liver, lung, spleen, spinal cord, brain, pituitary, kidney, adrenal and testis). The object was to find out how body weight is related to cell proportions in the body as a whole and in the separate organs. Individuals varied widely in their mean cell proportions but there were significant differences between organs within individuals. Body weight was linearly related to the mean cell proportions which accounted for most, or possibly all, of the chimaeric variance of body weight. No one of the organs studied could be identified as being solely responsible for growth control, or as having a predominant influence on growth. The weights of some organs were probably influenced to a small extent by their own cell proportions independently of the individual's mean, but the differences of body weight were too great to be accounted for by the summation of localized effects on organs. The mean cell proportion, averaged over individuals, was close to 50%, proving that there was no tendency for cells from the larger component to outgrow those from the smaller. It is concluded that growth control must be systemic, but it was not possible to decide whether the systemic effect comes from some particular organ not studied, or is in some undefined way the consequence of the cell proportions in the body as a whole. There was some evidence, though it was inconclusive, that chimaeras show ‘heterosis’ for body weight.
A gene (Neu-1) on chromosome 17 of the mouse affects acid α-glucosidase and codes for neuraminidase
Authors: Peters Josephine , Swallow Dallas M. , Andrews Sandra J. , Evans Lorraine 
Published: September 2009

SUMMARYAn electrophoretically detectable variant of acid α-glucosidase has been found in SM/J mice. This variant is attributable to excess sialylation of the enzyme and is determined by a gene, alpha-glucosidase processing,Aglp, on chromosome 17. In addition, as also reported by Potier, Lu Shun Yan & Womack (1979), SM/J mice are relatively deficient in neuraminidase and it appears that the low level of this enzyme in SM/J is determined by an autosomal codominant gene, neuraminidase-1,Neu-1. Preliminary data indicate thatNeu-1is also on chromosome 17. It seems probable that the several processing genesApl, AglpandMap-2which are all closely linked on chromosome 17 are one and the same, a geneNeu-1coding for neuraminidase.
Relationship between allozyme heterozygosity and rates of divergence
Authors: Skibinski D. O. F. , Ward R. D. 
Published: September 2009

SUMMARYThe relationship between locus variability and genetic identity is analysed in pooled data from a collection ofDrosophilaand vertebrate allozyme surveys. For vertebrates the analysis provides evidence that loci with high expected heterozygosity diverge at a faster rate than loci with low heterozygosity in comparisons involving pairs of populations and pairs of species. This relationship is not observed in comparisons ofDrosophilaspecies pairs.
The genetics of tasting in mice. I. Sucrose octaacetate
Authors: Lush Ian E. 
Published: September 2009

SUMMARYThirty-one inbred strains were tested for their reaction to drinking water which contained a low concentration (10−4 M) of sucrose octaacetate (SOA). One strain, SWR, showed a strong aversion to drinking the SOA solution. The other thirty strains, and two samples of wild-derived mice, tended to prefer the SOA solution to untreated drinking water. The pheno-typic difference between SWR and the other strains was shown to be determined by an autosomal gene. The allele present in SWR is dominant. The gene is not closely linked to jerker (je), pearl (pe) or waved-2 (wa-2).
Transcription inX-chromosomal segmental aneuploids ofDrosophila melanogasterand regulation of dosage compensation
Authors: Prasad Jayashree , Duttagupta Ashish K. , Mukherjee A. S. 
Published: September 2009

SUMMARYTranscription ofXchromosomal DNA has been examined autoradio-graphically in various 1X2Aand 2X2Anormal larvae and 1X2A(+Xfr) and 2X2A(+Xfr) segmental aneuploid larvae of speciesDrosophila melanogaster. The segmental aneuploids contained duplications for the segment 9A–11A and 15D–ISA of theXchromosome. Results show that in the aneuploid male containing 9A–11A duplicaton both the homologous segments involved in the aneuploidy are autonomously hyperactive; their combined activity, measured byX/Agrain ratio, is found to be nearly 70% more than the activity in normal male and about 100% more than that in diplo-Xfemale. In the aneuploid female, containing the aneuploid segment 15D–18A and having three doses of the segment of theXchromosome, the activity was over 100% more than the diplo-Xactivity. The per gene dose activity for the two segments in the aneuploid male and female, respectively, is also significantly higher than their male and female counterparts. The possible role of lack of contiguity of the genetic segments and an intra-nuclear variation has been ruled out by appropriate analysis. We, therefore, interpret these findings to be due to an autonomous expression of theXlinked compensatory genes, resulting from a primary modulation in the organization of the entireXchromosome. The autosomal signal then renders the individual genetic locus hyperactive.
A structural gene (Tcp-1) within the mouse t complex is separable from effects on tail length and lethality but may be associated with effects on spermatogenesis
Authors: Silver Lee M. 
Published: September 2009

SUMMARYThe Tcp-1 gene is located within the t complex and codes for a major testicular cell protein called p63/6.9. All wild-type chromosomes carry the Tcp-1b allele which codes for a basic form of this protein, while all complete t haplotypes carry the Tcp-1a allele which codes for an acidic form of this protein. It is not clear whether the Tcp-1 gene is associated with phenotypic effects of t haplotypes on embryogenesis and/or spermatogenesis, since the genetic basis for these effects is extremely complex. The elegant analysis of Lyon & Mason (1977) has allowed the identification and separation of a family of genetic factors which interact to produce the observed phenotypes associated with various combinations of t haplotypes. The data summarized in this report indicate that the Tcp-1a locus is separable from all of the identified t haplotype factors except for one; a complete correlation has been obtained between Tcp-1a and a proximal t haplotype factor which is involved in effects on transmission ratio distortion. Two other novel points emerge from this analysis. First, it appears that the tail interaction factor and the proximal sperm factors represent distinct genetic loci. Second, the accumulated data lead to the proposal that the TOrl chromosome carries a short segment of t haplotype chromatin containing Tcp-1a and proximal sperm factors involved in transmission ratio distortion and sterility.
Genetic studies of D-alanine-dehydrogenase-less mutants ofEscherichia coliK12
Authors: Franklin F. C. H. , Venables W. A. , Wijsman H. J. W. 
Published: September 2009

SUMMARYGenetic analysis of 12 mutants ofEscherichia coliK12 defective in D-alanine dehydrogenase showed thatalnAanddadare alternative names for the same locus.dadwas shown to be a single gene which codes for a protein of 55000–60000 mol. wt. Study of thermosensitive mutants ofdadindicated that its product is a structural component of D-alanine dehydrogenase. The regulatory genealnRwas shown to be involved in positive control ofdadexpression. This was concluded from (i) the absence of constitutive strains among Dad+revertants ofalnR–mutations, (ii) thetransdominance ofalnR+toalnR–, and (iii) the failure to isolate fully constitutive strains by any means. To obtain a uniform nomenclature it is proposed to re-namedadasdadBandalnRasdadQ.