bluuebunny/crossref_metadata_2025_split huggingface dataset:
A chromosomal segment conserved since divergence of lineages leading to man and mouse: The gene order of aminoacylase-1, transferrin, and beta-galactosidase on mouse Chromosome 9
Authors: Nadeau Joseph H. 
Published: September 2009

SummaryLinkage crosses were used to determine the gene order of aminoacylase-1, beta-galactosidase, and transferrin on mouse Chromosome 9. The most likely gene order, which was more than 107times more likely than the next most likely order, was transferrin, aminoacylase-1, beta-galactosidase. These results demonstrate that aminoacylase-1 and beta-galactosidase mark a chromosomal segment that has been conserved since divergence of lineages leading to man and mouse. The length of this segment is about 11 cM and the estimate of the true length of the conserved segment marked by these two genes is 33 cM. A second aminoacylase allozyme, which requires MgCl2, is described.
Acyadeletion mutant ofEscherichia colidevelops thermotolerance but does not exhibit a heat-shock response
Authors: Delaney John M. 
Published: September 2009

SummaryAn adenyl cyclase deletion mutant (cya) ofE. colifailed to exhibit a heat-shock response even after 30 min at 42 °C. Under these conditions, heat-shock protein synthesis was induced by 10 min in the wild-type strain. These results suggest that synthesis of heat-shock proteins inE. colirequires thecyagene. This hypothesis is supported by the finding that a presumptive cyclic AMP receptor protein (CRP) binding site exists within the promotor region of theE. coli htp Rgene. In spite of the absence of heat-shock protein synthesis, when treated at 50 °C, thecyamutant is relatively more heat resistant than wild type. Furthermore, when heat shocked at 42 °C prior to exposure at 50 °C, thecyamutant developed thermotolerance. These results suggest that heat-shock protein synthesis is not essential for development of thermotolerance inE. coli.
The extended survival of tw5/tw5 mouse embryo cells in vitro
Authors: Garside William , Hillman Nina 
Published: September 2009

SummaryThe tw5 haplotype is a recessive mutation which is lethal when homozygous in mouse embryos following implantation. This series of studies was undertaken to determine the effect of the tw5/tw5 genotype on embryos developing in vitro. Blastocyst embryos from + / tw5inter se matings were compared with control blastocysts obtained from matings between T/ + and + / + females and + / tw5 males for their abilities to continue development in vitro in two culture media. The data show that there are no significant differences between the percentages of experimental and control blastocyst embryos which attach and outgrow or which contain inner cell masses on any day of culture up to equivalent gestation day 21 in either media. These findings show that the life span of cells from tw5 / tw5 embryos can be extended significantly by in vitro culture.
Meiotic drive in female mice heterozygous for the HSR inserts on chromosome 1
Authors: Agulnik Sergei I. , Agulnik Alexander I. , Ruvinsky Anatoly O. 
Published: September 2009

SummaryChromosome 1 with one or two long insertions has been previously found in natural mouse populations. The inheritance of chromosome 1 with two insertions from the Yakutsk population is analysed in this paper. It was demonstrated that heterozygous females transmit this chromosome to 80–85% of offspring. The observations made at M II, in conjunction with the recombination data, allowed us to conclude that preferential passage of the chromosome 1 with insertions to the oocyte and egg, rather than to the first and second polar bodies at meiosis, is the causative factor of the distorted segregation. A meiotic drive of such potency has not been previously reported for female mammals. The possible mechanism of the drive is discussed.
The distribution of allelic effects under mutation and selection
Authors: Frank Steven A. , Slatkin Montgomery 
Published: September 2009

SummaryThe Price (1970, 1972) equation is applied to the problem of describing the changes in the moments of allelic effects caused by selection, mutation and recombination at loci governing a quantitative genetic character. For comparable assumptions the resulting equations are the same as those obtained by different means by Barton & Turelli (1987; Turelli & Barton, 1989). The Price equation provides a natural framework within which to examine certain kinds of non-additive allelic effects, recombination and assortative mating. The use of the Price equation is illustrated by finding the equilibrium genetic variance under multiplicative dominance and epistasis and under assortative mating at an additive locus. The limitations of the use of recursion equations for the moments of allelic effects are also discussed.
Interactions among modifiers of retrotransposon-induced alleles of thewhitelocus ofDrosophila melanogaster
Authors: Rabinow Leonard , Birchler James 
Published: September 2009

SummaryMutations in five loci that modify the phenotype ofwhiteapricot(wa), caused by the retrotransposon,copia, were examined in two-way combinations to determine whether their effects were additive or epistatic. All two-way combinations of mutations in these five loci,mottler of white(mw),suppressor of forked(su(f)),suppressor of white apricot(su(wa)),Enhancer of whiteapricot, (E(wa)) andDarkener of apricot(Doa), are additive in their effects onwa, implying that each second-site modifier locus affects a different process. Three othercopia-induced mutations,HwUa, whd81b25andctnswere also examined for responsiveness to mutations in these modifier loci. None clearly responded. Mutations associated withB104insertions, includingGl, vgni, ctnandwricwere also examined for responsiveness tomwmutations, which have specificity for this element as well. Bothvgniandwricrespond to mutations inmw. The former interaction demonstrates thatmwis capable of interacting withB104 elements in loci other thanwhite. The significance of the results with respect to the nature of second-site modifier loci is discussed.
Induced recombination in the mitotic cell cycle of the yeastSaccharomyces cerevisiae
Authors: Johnston Leland H. , Johnson Anthony L. 
Published: September 2009

SUMMARYThe occurrence of induced recombination in the mitotic cell cycle in yeast has been analysed using conditional cell-cycle mutants held at the restrictive temperature. The strains used were heteroallelic atgalland assaying for functional galactokinase shortly after irradiation (Johnston, 1982) allowed an unambiguous determination of the cell cycle stages in which recombination could occur. Recombination was observed in most strains, including those with thecdc36mutation, defective in ‘start’; thecdc4, 7anddbf4mutations which arrest cells in G1; thedbf1, 2andcdc6mutations affecting S phase;cdc16andcdc17which block cells in G2 and alsocdc14and15which arrest cells in ‘late nuclear division’. Recombination can therefore occur within each of the major phases of the yeast cell cycle. This analysis has also revealed that thecdc8mutation results in a defect in induced mitotic recombination.
Genetic analysis of axonemal mutants inParamecium tetraureliadefective in their response to calcium
Authors: Hinrichsen Robert D. , Kung Ching 
Published: September 2009

SUMMARYSix axonemal mutants ofParamecium tetraureliahave been isolated that are unable to respond properly to calcium. The mutants, designated atalantas, cannot swim backward when stimulated by ions or heat. Genetic analyses reveal that all six mutants are recessive and fall into four complementation groups. Three of the mutants in one complementation group are phenotypically non-leaky, one is leaky and two are extremely leaky, only displaying their phenotypes at elevated temperatures. The complete mutants,ataA, are also abnormal in their forward swimming. This abnormality co-segregates with the inability to swim backward.ataA1is not allelic to several membrane mutants ofP. tetraurelia.
Knobbly, a new dominant mutation in the mouse that affects embryonic ectoderm organization
Authors: Jacobs-Cohen R. J. , Spiegelman M. , Cookingham J. C. , Bennett D. 
Published: September 2009

SUMMARYKnobbly,FuKb, a dominant mutation on chromosome 17 of the mouse, causes a kinked tail in heterozygotes and embryonic lethality at about nine days in homozygotes. Abnormal organization of the embryonic ectoderm is first apparent at about embryonic day 7, and the retarded and malformed embryos die by mid 9 days.Kink,FuKi, a dominant gene that maps in the same region, is also an embryonic lethal in homozygotes; heterozygotes have kinked tails and often a circling gait. We have shownFuKbandFuKiare allelic; theFuKb/FuKicompound dies at the same time asFuKb/FuKbembryos with the same morphological syndrome.TheFuKbphenotype is not seen in offspring in expected ratios. TheFuKbmales may have a low transmission ratio or penetrance may be incomplete.An incidental finding of our histological studies is a high incidence of complete twinning whenFuKbheterozygotes mateinter seor whenFuKb×FuKimatings are made.
Effects of selection on growth, body composition and food intake in mice I. Responses in selected traits
Authors: Sharp Gillian L. , Hill William G. , Robertson Alan 
Published: September 2009

SUMMARYMice were selected for one of three criteria: appetite (A), measured as 4- to 6-week food intake, adjusted by phenotypic regression to minimize change in 4-week body weight, fat percentage (F), using the ratio of gonadal fat pad weight to body weight in 10-week-old males, and total lean mass (protein, P), using the index, body weight in 10-week-old males − (8 × gonadal fat pad weight). For each selection criterion, there were 3 high, 3 low and 3 unselected control lines. At generation 11, the high and low A lines diverged by 17% of the control mean and the realized heritability from within family selection of adjusted food intake was 15%. Selection for this character produced changes in body weight, gross efficiency from 4 to 6 weeks, and percentage of fat, the high lines being heavier, more efficient and less fat than the lows. The high and low F lines diverged by 80% of the control mean and the realized heritability of the ratio of gonadal fat pad weight to body weight was 44%. Selection for this character produced changes in total fat per cent, but little change in percentage protein, body weight, food intake or gross efficiency. The high and low P lines diverged by 40% of the control mean and realized heritability of the lean mass index (10-week weight − [8 × gonadal fat pad weight]) was 51%. Selection for an increase in the index increased body weight at all ages, food intake and 4- to 6-week gross efficiency. There was no change in percentage fat. Responses in the selected traits were not highly correlated, and the different lines provide an opportunity for investigating responses in physiology, metabolism and gene products.
Sex determination in birds: progeny of nondisjunction canaries of Durham (1926)
Authors: Sittmann K. 
Published: September 2009

SUMMARYThe heterogametic sex in birds (ZW) is female for presence of theWor for lack of a secondZchromosome. These alternatives can be distinguished givenZOorZZWaneuploids and segregation of aZ-linked marker in their progeny. Having discovered theZ-linkedcinnamonlocus with two alleles (B, black eyes;b, red eyes), Durham observed 21 black-eyed daughters (BOorBbW) ofbbcocks andBhens. Using Durham's data on sex–colour phenotypes of 14 young of two of the 21 matroclinous females show that the sex chromosome constitution of the two exceptional hens were more likelyZOthanZZW. This case plus that of Crew's (1983) trisomic rooster (ZZW) shows that sex determination in birds follows the ‘genic balance’ scheme as inDrosophila, not the ‘dominant Y’ scheme as in mammals.
Studies of esterase 6 inDrosophila melanogaster: XIV. Variation of esterase 6 levels controlled by unlinked genes in natural populations
Authors: Tepper Craig S. , Terry Anne L. , Holmes James E. , Richmond Rollin C. 
Published: September 2009

SUMMARYThe esterase 6 (Est-6) locus inDrosophila melanogasteris located on the third chromosome and is the structural gene for a carboxylesterase (E.C.3.1.1.1) and is polymorphic for two major electromorphs (slow and fast). Isogenic lines containingXchromosomes extracted from natural populations and substituted into a common genetic background were used to detect unlinked factors that affect the activity of theEst-6locus. Twofold activity differences of esterase 6 (EST 6) were found among males from these derived lines, which differ only in theirXchromosome. These unlinked activity modifiers identify possible regulatory elements. Immunoelectrophoresis was used to estimate quantitatively the levels of specific cross-reacting material in the derived lines. The results show that the variation in activity is due to differences in the amount of EST 6 present. The data are consistent with the hypothesis that there is at least one locus on the X chromosome that regulates the synthesis of EST 6 and that this regulatory locus may be polymorphic in natural populations.
Aspects of temperature regulation in mice selected for large and small size
Authors: Lynch Carol Becker , Roberts R. C. 
Published: September 2009

SUMMARYWe measured traits involved in physiological and behavioural thermoregulation in the 6 replicates of a selection experiment for large and small size (6-week weight) in mice, including control lines (18 lines in all). The observed genetic correlations between body size and thermoregulatory traits are consistent with a thermoregulatory advantage of large size, including decreased weight-specific food consumption and increased nest-building, with no change in body temperature. The differences in food consumption were closely paralleled by differences in amount of brown adipose tissue, strongly suggesting that much of the decreased efficiency of the small lines is due to heat production by brown fat. These results are consistent with available observations on natural populations, that selection for temperature adaptation probably has had some influence on body size in this species.
Genetic variation in the dietary sucrose modulation of enzyme activities inDrosophila melanogaster
Authors: Geer Billy W. , Laurie-Ahlberg Cathy C. 
Published: September 2009

SUMMARYGenetic variation in the modulating effect of dietary sucrose was assessed inDrosophila melanogasterby examining 27 chromosome substitution lines coisogenic for theXand second chromosomes and possessing different third isogenic chromosomes derived from natural populations. An increase in the concentration of sucrose from 0·1% to 5% in modified Sang's medium C significantly altered the activities of 11 of 15 enzyme activities in third instar larvae, indicating that dietary sucrose modulates many, but not all, of the enzymes ofD. melanogaster. A high sucrose diet promoted high activities of enzymes associated with lipid and glycogen synthesis and low activities of enzymes of the glycolytic and Krebs cycle pathways, reflecting the physiological requirements of the animal. Analyses of variance revealed significant genetic variation in the degrees to which sucrose modulated several enzyme activities. Analysis of correlations revealed some relationships between enzymes in the genetic effects on the modulation process. These observations suggest that adaptive evolutionary change may depend in part on the selection of enzyme activity modifiers that are distributed throughout the genome.
Energy partitioning and growth in mice selected for high and low body weight
Authors: Stephenson S. K. , Malik R. C. 
Published: September 2009

SUMMARYThe partitioning of digestible energy intake on anad libitumdiet of standard mouse nuts was investigated in mice selected for high and low body weight at eight weeks and in an unselected control population. In selected mice aged from four to six weeks and housed at a temperature of 24·5 °C, almost all their energy intake could be attributed to basic maintenance and the deposition of extra protein and fat. Control mice, however, had an energy intake considerably in excess of their apparent maintenance and growth requirements. It was concluded that the unaccountable energy loss of the control line could be used to increase growth efficiency in the selected lines. The result is analogous to those obtained from studies on normal and obese mouse genotypes and indicates genetic changes in mechanisms controlling the conversion of food energy to heat.Provision of a nest to reduce thermoregulatory heat production caused a minor reduction in energy intake and a corresponding decrease in the energy discrepancy. There was no effect on growth.
Characterization of an antibiotic resistance plasmid pAV5 and its constituent replicons inAcinetobacter calcoaceticus
Authors: Divers Mark , Hinchliffe Edward , Vivian Alan 
Published: September 2009

SummaryA non-transmissible plasmid, pAV5, was isolated from a hospital strain ofAcinetobacter calcoaceticus, JC17. pAV5 confers resistance to the antibiotics tetracycline and neomycin in the genetically characterized strain of A.calcoaceticusEBF 65/65. Transfer of pAV5 can be mediated by the sex factors pAV1 and R751; transfer is occasionally associated with the segregation of the resistance determinants amongst the transconjugants. Phenotypic dissociation of pAV5 corresponds with the formation of two independent plasmids designated pAV51 and pAV52 mediating resistance to neomycin and tetracycline respectively.
Weight and age at puberty in female and male mice of strains selected for large and small body size
Authors: Falconer D. S. 
Published: September 2009

SummaryPuberty was studied in mice of the ninth selected generation of the Q-strain. There were 6 replicate lines selected for large body size (6-week weight), 6 replicates selected for small size and 6 replicate unselected controls. Female puberty was assessed by the opening of the vagina and male puberty by the first copulation plug. The sexes differed in the mean age at puberty, males being older by 13 days in the large, 4 days in the control and 8 days in the small lines. The sexes differed also in the way size affected puberty. In males the large and small lines reached puberty at the same age and both were older than the controls. In females the large lines on average were heavier and younger at puberty than the controls, and the small lines were lighter and older than the controls, though not significantly older. The replicates within each size-group, however, reached puberty at about the same weight, irrespective of their differences in growth rate. Thus, the differences of growth between the large, control and small groups affected both the weight and the age of females at puberty, but the differences of growth between the replicate lines within each size affected only the age at puberty. No explanation was found for this inconsistency between size-groups and replicates. Several lines of evidence led to the conclusion that in females puberty is partly or mainly weight-dependent, whereas in males it is almost wholly age-dependent.
An extension of path analysis revisited
Authors: Gimelfarb Alexander 
Published: September 2009

SummaryA method for analysing probabilistic models representing an extension of path analysis, and a model of mixed homogamy based on this method were introduced recently (Rao, Morton & Cloninger, 1979; Cloninger, 1980). However, constraints imposed by the method on linear models, or a rationale for and implications of the mixed homogamy model have not been clearly stated.A mathematical treatment of the extension of path analysis and of the mixed homogamy model is presented in this paper. Constraints on linear models imposed by the extension are obtained. It is demonstrated that the mixed homogamy model, when applied to analysing nuclear families in a population, implies the following mating system in the population: some individuals choose their mates strictly on the basis of group membership, others choose their mates strictly on the basis of phenotype, and no individual chooses a mate on the basis of both group membership and phenotype.
Characterization of dominant cataract mutations in mice: penetrance, fertility and homozygous viability of mutations recovered after 250 mg/kg ethylnitrosourea paternal treatment
Authors: Favor Jack 
Published: September 2009

SUMMARYSeventeen dominant cataract mutations of the mouse recovered in ethylnitrosourea mutagenesis experiments have been genetically characterized as to penetrance, fertility, and homozygous viability. Nine mutations were shown to be fully penetrant with no fertility effects, four mutations were classified as having reduced penetrance with no fertility effects, one mutation had reduced penetrance and reduced fertility, two mutations were shown to have a reduced frequency of mutant offspring due to penetrance and viability effects, and one mutation most likely has a reduced viability of carrier individuals. Of the eleven mutations for which definitive homozygous viability data were obtained, ten were shown to be homozygous viable and only one was shown to be homozygous lethal. In similar experiments in which dominant cataract, dominant skeletal or dominant visible mutations were recovered after radiation treatment, comparable frequencies of mutations with reduced penetrance were observed but there was a strikingly higher frequency of homozygous lethal mutations. These observations support the hypothesis of a qualitative difference in the mutations recovered after ethylnitrosourea as compared to radiation treatment. Finally, it is argued that a systematic comparison of the induced mutation rates to dominant and recessive alleles with subsequent genetic characterization of the recovered mutations provides a critical set of data necessary for an improvement in the indirect and direct procedures of genetic risk estimation.
Chromosomal anomalies that cause male sterility in the mouse also reduce ovary size
Authors: Mittwoch Ursula , Mahadevaiah Shantha , Setterfield Leslie A. 
Published: September 2009

SUMMARYTwo male-sterile chromosome anomalies, the insertion Is(7; 1)40H and the tertiary trisomy, Ts(512)31H, were found to be associated with reduced ovarian volumes in immature females. Together with the reciprocal translocation, T(11; 19)42H, in which this effect was described previously, reduced ovaries have been found in all three male-sterile chromosome anomalies investigated so far, suggesting that ovarian involvement is likely to be common in these conditions. Assuming that the smaller ovarian size reflects a reduction in the number of oocytes, it is suggested that male-sterile chromosome anomalies may exert basically similar deleterious effects on meiotic germ cells in males and females, the difference in outcome being due to cell-physiological differences between spermatocytes and oocytes and to the small number of surviving oocytes required for fertility in females.
Postmeiotic segregation as a source of mosaics in diploid organisms
Authors: Leslie John F. , Watt Ward B. 
Published: September 2009

SUMMARYPostmeiotic segregation (PMS) of genetic variants occurs when a DNA heteroduplex formed during meiotic recombination goes undetected by repair enzymes and is transmitted unresolved to the meiotic products. PMS provides an alternative explanation for the origin of mosaics now attributed to half-chromatid mutation. In multicellular diploid eukaryotes, PMS could result in mosaic individuals with unusual migration patterns for proteins studied by gel electrophoresis. If the gonade were mosaic, complex progenies containing as many as six phenotypic classes at a single locus could be produced.