bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dubious maternal inheritance of mitochondrial DNA inD. simulansand evolution ofD. mauritiana
Authors: Satta Yoko , Toyohara Nobue , Ohtaka Chiaki , Tatsuno Yumi , Watanabe Takao K. , Matsuura Etsuko T. , Chigusa Sadao I. , Takahata Naoyuki 
Published: September 2009

SummaryWithin-line heterogeneity has been found in the mitochondrial DNA (mtDNA) in two isofemale lines ofD. simulans. The co-existing types, S and M, were typical of the mtDNA inD. simulansand inD. mauritiana, respectively, their nucleotide divergence per site beingca.2·1%. Segregation analysis confirmed that some individuals in these lines were heteroplasmic and suggested incomplete maternal inheritance of mtDNA inDrosophila. Examination of other lines ofD. simulansrevealed that the M type ofD. mauritianaoccurs at 71% in Réunion, 38% in Madagascar and 0% in Kenya. This finding and interspecific sequence comparisons of both M types indicate thatD. mauritianadiverged fromD. simulansprobably less than 240000 years ago.
Identification of a variant growth hormone haplotype in mice selected for high body weight
Authors: Salmon R. Keith , Berg Roy T. , Yeh Francis C. , Hodgetts Ross B. 
Published: September 2009

SummaryRestriction site analysis revealed a variant growth hormone gene haplotype fixed within growth-selected mice (High line-3; HL-3) exhibiting growth rates 1·5 times greater than those of unselected Foundation population (FP-3) mice. Relative to the FP-3 haplotype, the HL-3 haplotype exhibited restriction fragment length polymorphisms for each of seven different restriction enzymes. Three of the polymorphic sites lie within 1·1 kb of the 5′ end of the structural gene; a fourth polymorphism exists within the structural gene. The HL-3 haplotype was also fixed within an additional three growth-selected lines (including a replicate of HL-3). This identification of an association, between the natural variant of a growth regulating gene and a growth-related phenotype, is the prototype of experiments that could lead to the isolation of variant genes which enhance livestock production characters.
Recessive mutation in a standard recombinant-inbred line of mice affects seminal vesicle shape
Authors: Shukri N. M. , Grew F. , Shire J. G. M. 
Published: September 2009

SummaryA recessive autosomal mutation has been found in the CXBI/ByEss recombinant-inbred line but in neither of the parental strains, C57BL/6ByEss and BALB/cByEss. Its presence in the CXBI/ByJax and CXBI/ByLac sublines suggests an origin early in inbreeding. The locus, seminal vesicle shape (svs), appears to be linked to the albino locus on chromosome 7. The homozygote has seminal vesicles with a smooth tubular external appearance. In segregating crosses homozygotes had slightly lighter seminal vesicles but the weights of other androgen target organs were not reduced. Exogenous testosterone increased the size of the seminal vesicles but did not alter their shape. The mutation did not affect the pattern of proteins on SDS–acrylamide gel electrophoresis, which did differ between the parental strains. The locus affecting a 27000 Da protein has provisionally been assigned the symbolsvp-4.
The Ontogeny of γ-crystallin mRNAs in CatFraser Mice
Authors: Kuliszewski Maciej , Rupert Jim , Gold R. 
Published: September 2009

SummaryMice which are either homozygous or heterozygous for the CatFraser mutation have ocular cataracts accompanied by selective reduction of the γ-crystallins, a homologous family of proteins present in the lens and encoded by a family of tightly linked genes. We measured the concentrations of four different mRNAs, each encoding a different γ-crystallin, in the lenses of homozygous CatFraser mice and in normal controls at various stages of development by preparing Northern blots from lens RNA, probing with RNAs complementary to each of the four messages and densitometry of the bands thus generated. The results show that, for each of these messages, the ontogenetic patterns observed in normal mice are retained in the mutant, but at much lower concentrations.
Drosophilagenescutandminiatureare associated with the susceptibility to infection bySerratia marcescens
Authors: Flyg Casper , Boman Hans G. 
Published: September 2009

SummaryA mutant strain ofDrosophila melanogasterwith five markers on theX-chromosome was found to be more sensitive than the wild type when infected with an insect-pathogenic strain ofSerratia marcescens. Two of the five mutations in this fly strain,cutandminiature, were found to be responsible for this sensitivity. A double-mutant, with bothcutandminiature, was as sensitive toSerratiainfection as was the original sensitiveDrosophilastrain with all five mutations. Recombinant flies with other alleles ofcutandminiaturewere also sensitive. A revertant ofcutwas found to be less sensitive than the parental flies. Our insect pathogenic strain ofSerratiaproduces several proteases and a chitinase. A bacterial mutant, lacking proteases and chitinase, was found to be less virulent than wild-type bacteria. When pupal shells from resistant andcut-miniatureflies were incubated with a mixture of protease and chitinase there was a release ofN-acetyl glucosamine, and 50% more material was liberated from pupal shells of sensitive flies. Sensitive flies reared on sucrose infected withSerratiashowed bacteria in their hemolymph earlier than wild-type flies. We conclude thatDrosophilagenes forcutandminiatureare associated with the sensitivity toSerratiainfection, presumably because the gut peritrophic membrane is more susceptible to bacterial proteases and chitinase.
The functions of the phage T4 immunity and spackle genes in genetic exclusion
Authors: Obringer John W. 
Published: September 2009

SummaryGenetic exclusion is the ability of a primary infecting phage to prevent a secondary infecting phage from contributing its genetic information to the progeny. The molecular mechanism of the phenomenon is not well understood. The two genes in phage T4 mainly responsible for genetic exclusion are the immunity (imm) gene and the spackle (sp) gene. Evidence is presented that the imm gp enables the host exonuclease V to degrade superinfecting phage DNA. This appears to be accomplished by the imm gp altering gp 2/64, the presumed pilot protein, which protects the 5′ end(s) of the phage DNA. Exonuclease III is also involved in genetic exclusion but its action does not appear to depend upon theimmorspgene products. Gp sp appears to interfere with the lysozyme activity of gp 5, a component of the central base plug, postulated to aid in tail tube penetration during the injection process. A molecular model of genetic exclusion is proposed. Genesimmandspare part of a cluster of genes which also includes42, beta-glucosyltransferase, anduvsX. The genes of this cluster encode proteins apparently adapted for competition and defence at the DNA level. These genes may encode fundamental adaptive strategies found throughout nature.
Influence of parental strains on the germination ofPhycomyces blakesleeanuszygospores
Authors: Sarabia María José F. , Eslava Arturo P. , Alvarez María Isabel 
Published: September 2009

SummaryPhycomyces blakesleeanuswild-type NRRL1555( − ), the standard strain, when crossed with UBC21( + ), another wild type, gives zygospores that germinate in 50–60 days. By backcrossing to UBC21 and selecting for shorter dormancy we have isolated a ( − ) strain, A803, and a ( + ) strain A804, which when crossed give zygospores that germinate in 32 days, the shortest dormancy period found inPhycomyces.The same result was obtained when A803 was crossed with UBC21. Zygospore dormancy decreased as the parental strains became more isogenic with UBC21, but the number of zygospores giving germsporangia with viable germspores also decreased to zero in the third backcross. The existence of germspore-killer alleles in the strain UBC21 is postulated. The strains of shortest dormancy can be used as helper strains (Orejaset al.1985) in sexual crosses. Tetrad analysis of the cross NRRL1554 × S102, a two-factor cross, showed 90% of reciprocal ditypes plus tetratypes in the progeny, indicating that the ( + ) wild-type strain NRRL1554, when crossed with the standard strain, gives regular meiosis and, contrary to current beliefs, may be used inPhycomycesgenetic analysis.
Organ-specific variability and inheritance of maize proteins revealed by two-dimensional electrophoresis
Authors: Leonardi A. , Damerval C. , de Vienne D. 
Published: September 2009

SummaryUsing two-dimensional polyacrylamide gel electrophoresis (2-D PAGE), the genetic variation of proteins was investigated in three organs (mesocotyl, sheath and blade of second leaf) from two maize lines and their hybrids. Nine hundred and eighty-six spots were numbered over the three organs. One hundred and fifty-five polypeptides were found to be genetically variable, due to allelic polymorphism of structural genes and/or to polymorphism of any genetic elements controlling protein amounts. Of these 155 variants 12% clearly showed complete dominance effects in the hybrid patterns, which could reveal dominance effects in the regulation of the protein biosynthesis. Comparison of the three organs showed that (i) the level of variability between lines depended upon the organ, since it varied from 7·5% for the blade to 12·6% for the mesocotyl and 13·2% for the sheath; (ii) 68 polypeptides displayed different kinds of variation in different organs and (iii) in all cases but one the dominant inheritance was organ-specific.
Sex reversal in a wild population of Talpa occidentalis (Insectivora, mammalia)
Authors: Jiménez R. , Burgos M. , Caballero L. , De La Guardia R. Díaz 
Published: September 2009

SummaryTwo sex-reversed males and eight intersexes have been found in a natural population of the mole species Talpa occidentalis. All individuals of karyotype 34,XY were normal males, while the 34,XX karyotype was found in normal females, intersexes and sex-reversed males. Small testes were present in XX males, and ovotestes in intersexes. Intersexes showed male antigen levels higher than for females and lower than for males (including XX males), as judged by cytotoxicity tests. The X chromosome of sex-reversed males and intersexes and the Y chromosome of males appeared morphologically normal.
Length of the chromosomal segment marked by galactose-1-phosphate uridyl transferase and soluble aconitase and conserved since divergence of lineages leading to mouse and man
Authors: Nadeau Joseph H. 
Published: September 2009

SummaryStandard linkage testing crosses and ovarian teratoma mapping were used to estimate the length of the chromosomal segment that is marked by galactose-1-phosphate uridyl transferase and soluble aconitase and that has been conserved since divergence of lineages leading to mouse and man. These experiments were also used to determine whether theRb(4·6)2BnrRobertsonian translocation suppresses recombination on the proximal portion of mouse Chromosome 4. The estimated length of the conserved segment marked by galactose-1-phosphate uridyl transferase and soluble aconitase in mouse and man was estimated to be 24 cM. It was also shown thatRb(4·6)2Bnrstrongly suppressed recombination on the centromeric portion of mouse Chromosome 4.
Evolutionary characterization of a Y chromosomal sequence conserved in the genusMus
Authors: Nishioka Yutaka 
Published: September 2009

SummaryThe extent of accumulation of mouseYchromosomal repetitive sequences generally correlates with the known phylogenetic relationships in the genusMus. However, we describe here aM. musculus Ychromosomal repetitive sequence, designated as ACClfl, whose accumulation patterns among eightMusspecies do not correspond to their phylogenetic relationships. Although male-specific hybridization bands were present in all the species examined, significant accumulation (> 200 copies) in theYchromosomes was found inM. minutoides(subgenusNannomys),M. pahari(subgenusCoelomys) andM. saxicola(subgenusPyromys) as well as in the three closely related speciesM. hortulanus, M. musculusandM. spretusthat belong to the subgenusMus. Unexpectedly, theYchromosomes ofM. caroliandM. cookii(both subgenusMus) had considerably reduced amounts of ACClfl-related sequences. Furthermore, in rats (Rattus norvegicus) the major accumulation sites appear to be autosomal. These observations suggest that caution must be taken in the interpretation of data obtained with repetitive sequences that have evolved quickly.
Codon usage as a reason for unsuccessful search for amber-suppressor mutants inStreptomyces lividans?
Authors: Schmieger Horst , Knerr Ralph , Köberlein Maria 
Published: September 2009

SummaryAn amber mutation was created in the CAT gene of plasmid vector pACYC184 and this modified plasmid was fused with theStreptomycesvector pIJ702 for use as an indicator for the identification ofStreptomycesstrains carrying nonsense suppressor tRNA mutations. The resulting hybrid plasmid pGM1109 was introduced into the chloramphenicol-sensitive mutant M252 ofStreptomyces lividans. Chloramphenicol-resistant colonies were isolated and characterized. None of them was a nonsense suppressor mutant. The failure to obtain such mutants is discussed on the basis of codon usage in streptomycetes.
The genes for two neuromuscular diseases of the mouse, ‘arrested development of righting response’, adr, and ‘myotonia’, mto, are allelic
Authors: Jockusch Harald , Bertram Kordula , Schenk Susanne 
Published: September 2009

SummaryTwo hitherto unmapped recessive autosomal mutations, ‘arrested development of righting response’ (adr) and ‘myotonia’ (mto, now adrmto), were found to be allelic, so that preliminary linkage data on adr and adrmto can now be combined. No linkage was found to the glucose phosphate isomerase (Gpi-1) locus on Chr 7 that marks a region of homology between mouse Chr 7 and human Chr 19, and in man is closely linked to the myotonic dystrophy (DM) gene. The adr gene was expressed on diverse genetic backgrounds including the athymic nude mouse.
The genetics of tasting in mice: V. Glycine and cycloheximide
Authors: Lush Ian E. , Holland Gail 
Published: September 2009

SummaryGlycine tastes both bitter and sweet to mice but there are differences between strains in their ability to detect each taste. With respect to the bitter taste, fifteen strains were classified as tasters and twelve strains as non-tasters. The difference is due to a single gene, Glb (glycine bitterness). Cycloheximide tastes bitter to all mice at a concentration of 8 μM, but strain differences in sensitivity to the taste of cycloheximide can be detected at lower concentrations. The BXD RI strains can be classified into two groups with respect to sensitivity to cycloheximide. This is probably due to the segregation of two alleles of a single gene, Cyx. A comparison of the distribution in RI strains of alleles of four bitterness-tasting genes shows that the loci are all closely linked and are probably in the order Cyx–Qui–Rua–Glb.
Can segregation distortion influence gametic disequilibrium?
Authors: Hedrick Philip W. 
Published: September 2009

SummaryThere are a number of reports of gametic disequilibrium between alleles causing segregation distortion (e.g.talleles inM. musculusandSDalleles inD. melanogaster) and linked loci. These observations have resulted in the conclusion by some researchers that segregation distortion may cause gametic disequilibrium. In this manuscript I have shown that (1) segregation distortion cannot generate gametic disequilibriumde novoand (2) because segregation distortion results in an excess of heterozygotes, the rate of decay of disequilibrium is faster than if segregation distortion were absent. Other factors, such as mutation or selection, appear to generate the observed disequilibrium, and extremely low recombination appears important in retarding its decay.
Effect of Y chromosome and H-2 complex derived from Japanese wild mouse on sperm morphology
Authors: Suh Dong-Sang , Styrna Jozefa , Moriwaki Kazuo 
Published: September 2009

SummarySegregation of sperm abnormality level and H-2 haplotypes was investigated in F2 hybrid males obtained from reciprocal crosses involving two B10.congenic strains carrying H-2 and the Y chromosome of Japanese wild mice: B10.MOL-OHM (H-2ωm4, 23·1% of sperm abnormalities) and B10.MOL-OKB (H-2ωm8, 11·1% of sperm abnormalities). In both types of crosses mean levels of abnormal spermatozoa were significantly higher for males typed as H-2ωm4/H-2ωm4 than for heterozygous H-2ωm4/H-2ωm8 or homozygous H-2ωm8/H-2ωm8. These results suggest that the gene for high sperm abnormality is linked to H-2 complex of the B10.MOL-OHM strain.
The transmission ratio distortion of theth2-haplotypein vivoandin vitro
Authors: Garside William , Hillman Nina 
Published: September 2009

SummaryTheth2-haplotype is transmitted at low frequencies (< 0·30)by+ /th2males in normal matings. In the studies described here, the transmission frequency of theth2-haplotype fromRb7 /th2males was determined for normal and delayed matings andin vitroinseminations. The data show the transmission frequency from the twoin vivoinseminations to be less than 0·30 and to be statistically equivalent. However, thein vitrotransmission frequency (0·80) is significantly greater than either of thein vivofrequencies. The results show that the environment in which fertilization occurs affects the transmission frequency of this specifict-haplotype significantly.
Variable evolutionary stability ofYchromosomal repeated sequences in the genusMus
Authors: Platt Timothy H. K. , Dewey Michael J. 
Published: September 2009

SummaryThe study reported here is an examination of the organization and evolution of threeYchromosomal repeated sequences, designated pBC10–0.6, pBC15–1.1, and pBA33–1.8, in five closely related species of the genusMus. The species distributions of major restriction fragment length polymorphisms produced with a panel of restriction enzymes is used to develop the phylogenetic relationships between the five species studied. However, the apparent degree of relatedness among these species varied a great deal with each of the three probes and was also highly dependent on the particular restriction enzyme used. The usefulness for phylogenetic studies of closely associated sequences varying in evolutionary stability is discussed.
The genetics of tasting in mice: VI. Saccharin, acesulfame, dulcin and sucrose
Authors: Lush Ian E. 
Published: September 2009

SummaryTwenty-six strains of mice were tested for their reaction to four different sweet substances; saccharin, acesulfame, dulcin and sucrose. There was considerable strain variation in the degree to which they found the sweet substances preferable to water. The variation in preference for any one sweet substance is very highly correlated with the variation in preference for the other sweet substances. This is interpreted to mean that there is only one sweetness receptor, although an alternative explanation in terms of variation in psychological motivation is not discounted. The difference between C57BL/6Ty and DBA/2Ty is largely due to a single gene,Sac.
Eight independentLdh-1 mutations of the mouse recovered in mutagenicity experiments: biochemical characteristics and chromosomal localization
Authors: Pretsch Walter 
Published: September 2009

SummaryEight mouse mutants with altered charge or activity of lactate dehydrogenase-1 have been detected in offspring derived from mutagen-treated spermatogonia. Using two chromosome-7 marker genes pooled recombination frequencies are estimated asc−14·4±0·8−p−6·9±0·6−Ldh-1.
The liver/erythrocyte pyruvate kinase gene complex [Pk-1] in the mouse: structural gene mutations
Authors: Fitton Lesley A. , Bulfield Grahame 
Published: September 2009

SummaryNine enzyme activity variants of liver/erythrocyte pyruvate kinase have been found amongst laboratory and wild mice. Four of these variants have been shown by biochemical and immunological criteria to be mutations of the structural gene,Pk-1s. These four structural gene mutations, and two regulatory gene mutations, define the gene complex, [Pk-1]. One allele of the structural gene,Pk-1sl, found in the inbred strain C57BL, has an unusual phenotype and affects the expression of pyruvate kinase in the liver but not erythrocyte. A possible mechanism for this tissue-specific structural gene mutation is suggested.
Inbreeding depression and the maintenance of deleterious genes by mutation: model of aDrosophilachromosome
Authors: Sved John A. , Wilton Alan N. 
Published: September 2009

SummaryInbreeding experiments inDrosophila, particularly those carried out using the ‘balancer equilibration’ technique, have revealed high levels of inbreeding depression. It has been estimated that non-lethal chromosomes have a fitness of 20% or less in homozygous condition compared to chromosome heterozygotes. Deleterious recessive genes are, in principle, capable of explaining such inbreeding depression. In this paper we have asked quantitatively whether the observed high levels are consistent with what is known about numbers of loci and mutation rates. We find that accepted mutation rates are easily high enough, provided that the deleterious genes are fully recessive. Partial dominance, even to the extent of 10% or less, reverses this conclusion. These calculations have been made assuming the multiplicative model. However the arguments are potentially sensitive to certain types of selective interactions, and a model which proposes quadratic gene interaction allows for higher levels of partial dominance. We also test the effect of taking into account a further constraint. Crow and Mukai have argued from estimates of the persistence of new deleterious mutations affecting viability that heterozygotes have a reduction in fitness of around 1–2% per locus, similar to the estimate for lethal genes. Application of this additional constraint would markedly reduce the range of permissible selection coefficients. However we argue that the selective disadvantages in heterozygotes of most mutations affecting fitness are unlikely to be as high as estimated for mutations affecting viability.