abstract：:Fifty-two wee mutants that undergo mitosis and cell division at a reduced size compared with wild type have been genetically analyzed. The mutants define two genes, wee1 and cdc2, which control the timing of mitosis. Fifty-one of the mutants map at the wee1 locus, which is unlinked to any known cdc gene. One of the we...

journal_title：Genetics

authors： Nurse P,Thuriaux P

更新日期：1980-11-01 00:00:00

abstract：:The isolation of mutants of Saccharomyces cerevisiae that divide at approximately half the size of the wild type is described. Three mutants have been isolated in which the small size at bud initiation is due to a mutation in a single nuclear gene. ...

journal_title：Genetics

authors： Carter BL,Sudbery PE

更新日期：1980-11-01 00:00:00

abstract：:The HML and HMR loci carry unexpressed copies of MATa and MAT alpha information, and a replica of that information is transposed to MAT during mating-type interchange in Saccharomyces yeasts. A negative control mechanism keeps silent the information located at the HML and HMR loci. We mapped these loci by constructing...

journal_title：Genetics

authors： Klar AJ,McIndoo J,Hicks JB,Strathern JN

更新日期：1980-10-01 00:00:00

abstract：:A model is presented showing that natural selection operating at the individual level can adequately explain the evolution of multiple mating behavior by honey bee queens. Group selection need not be invoked. The fitness of a given female genotype is a function of the number of sex alleles in the population, the numbe...

journal_title：Genetics

authors： Page RE Jr

更新日期：1980-09-01 00:00:00

abstract：:The process of close recombinant formation in bacteriophage T5 crosses has been studied by examining the structure of internal heterozygotes (HETs), the immediate products of recombination events. The T5 system was chosen because it permits the study of internal heterozygotes exclusively, thus avoiding the ambiguities...

journal_title：Genetics

authors： Beck BN

更新日期：1980-09-01 00:00:00

abstract：:USING A NEWLY DEVELOPED PLATING SYSTEM, WE HAVE MEASURED CELL SURVIVAL AND THE FREQUENCIES OF VARIATION IN AN INHERITED TRAIT AFTER TREATMENT OF SOYBEAN CELL SUSPENSIONS WITH DIFFERENT MUTAGENS: ethyl methanesulfonate (EMS), methyl methanesulfonate (MMS), N-Methyl-N'-nitro-N-nitroso-guanidine (MNNG), hycanthone (1-{[2...

journal_title：Genetics

authors： Weber G,Lark KG

更新日期：1980-09-01 00:00:00

abstract：:In a previous study, a mitochondrial mutant expressing a specific enzymatic deficiency in co-enzyme QH2-cytochrome c reductase was described (TZAGO-LOFF, FOURY and AKAI 1976). Analysis of the mitochondrially translated proteins revealed the absence in the mutant of the mitochondrial product corresponding to cytochrome...

journal_title：Genetics

authors： Coruzzi G,Tzagoloff A

更新日期：1980-08-01 00:00:00

abstract：:Reversion from the suppressed to nonsuppressed phenotype in strains of geno;type SUQ5 [psi+] ade2-1 his5-2 lys1-1 can1-100 ura3-1 has been induced by treatment with ethyl methanesulphonate, nitrosoguanidine or UV (254 nm) light. Spontaneously occurring revertants have also been selected by two different methods. Rever...

journal_title：Genetics

authors： Cox BS,Tuite MF,Mundy CJ

更新日期：1980-07-01 00:00:00

abstract：:Using conditional probabilities and moment-generating matrices, I derived approximate algebraic equations that give expectations of gene frequency, population mean, gene frequency variance within lines, or heterozygosity, and gene frequency variance between lines, or drift, for repeated cycles of recurrent selection i...

journal_title：Genetics

authors： Silvela L

更新日期：1980-07-01 00:00:00

abstract：:The Drosophila melanogaster genome contains a single region (at 83DE on the polytene chromosome map) for which both heterozygous deficiency and heterozygous duplication are inviable. Seven EMS-induced mutations have been recovered that are viable in combination with a duplication of this region. Two classes of mutatio...

journal_title：Genetics

authors： Roehrdanz RL,Lucchesi JC

更新日期：1980-06-01 00:00:00

abstract：:Different electrophoretic alleles of amylase show associations with particular chromosome 3 inversions in D. pseudoobscura and D. persimilis. Relative adult amylase activities were compared in 37, 37 and 10 strains of D. pseudoobscura, D. persimilis and D. miranda, respectively. Strains carrying the same electrophoret...

journal_title：Genetics

authors： Norman RA,Prakash S

更新日期：1980-05-01 00:00:00

abstract：:The distribution within anthers of maize plants of microsporocytes of differing crossover class was studied by application of the serial-sectioning technique to plants heterozygous for a paracentric inversion. In such material, cells with four-strand double crossovers within the inversion are distinguishable from cell...

journal_title：Genetics

authors： Maguire MP

更新日期：1980-05-01 00:00:00

abstract：:Mutation of the two homothallic genes, HML alpha/HMLa and HMRa/HMR alpha, in homothallic strains of Saccharomyces cerevisiae was studied. Of 11 mutants of the HML alpha gene, eight were due to a phenotypic mutation from HML alpha to HMLa, i.e., a mutation causing a change in function of the original HML allele to that...

journal_title：Genetics

authors： Oshima T,Takano I

更新日期：1980-04-01 00:00:00

abstract：:We discuss the conceptual conflict between a slow series of gene substitutions as the mechanism of evolutionary change, and the apparent need for rapid and coordinated changes at many loci simultaneously in producing complex adaptations. To improve on the limitations of classical theory and accommodate the enormous am...

journal_title：Genetics

authors： Koehler DO,Whitten BL,Gregg TG

更新日期：1980-03-01 00:00:00

abstract：:Yeast cells subjected to a reversible thermal arrest of meiosis yielded progressively fewer spores per ascus as the arrest was extended. Dissection of two-spored asci by a newly developed method that prevents selection of false asci revealed that the spores were not a random sample of the haploid meiotic products. Mos...

journal_title：Genetics

authors： Davidow LS,Goetsch L,Byers B

更新日期：1980-03-01 00:00:00

abstract：:A series of clear mutants of the temperate phage 16-3 of Rhizobium meliloti were isolated that included various point and deletion mutants of the C cistron, coding for the phage repressor. It was observed that recombinant genotypes, such as c(+) and ti (temperature-sensitive allele), which form turbid plaques, can be ...

journal_title：Genetics

authors： Orosz L

更新日期：1980-02-01 00:00:00

abstract：:At least six nuclear loci are responsible for the genetic control of malate dehydrogenase (L-malate: NAD oxidoreductase; EC 1.1.1.37; MDH) in coleoptiles of maize. Three independently segregating loci (Mdh1, Mdh2, Mdh3) govern the production of MDH isozymes resistant to inactivation by ascorbic acid and found largely ...

journal_title：Genetics

authors： Goodman MM,Stuber CW,Lee CN,Johnson FM

更新日期：1980-01-01 00:00:00

abstract：:When a polygenic character is exposed to natural selection in which the curve giving fitness as a function of phenotype is a mixture of two Gaussian (normal) curves, the population may respond either by evolving to a specialized phenotype near one of the two optimum phenotypes, or by evolving to a generalized phenotyp...

journal_title：Genetics

authors： Felsenstein J

更新日期：1979-11-01 00:00:00

abstract：:Accumulation of RNA was measured in adult males of two genotypes: car bb/Ybb- and car bb/YbbSuVar-5. The two genotypes have similar amounts of rDNA, which is reduced in comparison to wild type (CLARK, STRAUSBAUGH and KIEFER 1977). Although genotypically bobbed, car bb/YbbSuVar-5 flies have a wild-type phenotype; car b...

journal_title：Genetics

authors： Strausbaugh LD,Clark SH,Grainger RM

更新日期：1979-11-01 00:00:00

abstract：:A large number of arginine-requiring mutants of Neurospora was isolated, using a strain already partially impaired in an enzyme of the pathway. Among the mutants, all previously described loci, except one, were represented, and several new loci were defined and mapped. Four groups of mutants were of particular interes...

journal_title：Genetics

authors： Davis RH

更新日期：1979-11-01 00:00:00

abstract：:Bacteriophage T4 cytosine-containing DNA is cleaved at a single site by the restriction endonuclease, Bam H1. The site lies within the late region of the T4 genome, close to, or within, gene 8, one of the structural genes of the phage particle baseplate. ...

journal_title：Genetics

authors： Wilson GG,Neve RL,Edlin GJ,Konigsberg WH

更新日期：1979-10-01 00:00:00

abstract：:Translocations between the two large autosomes were scored in the progeny of males that had been fed mitomycin-C. The frequencies were the same in spermatogonia sampled after 12 and 25 days and in spermatozoa stored for the same periods in untreated females. ...

journal_title：Genetics

authors： Shukla PT,Auerbach C

更新日期：1979-10-01 00:00:00

abstract：:New rudimentary (r) mutants have been isolated following mutagenesis with ethyl methanesulfonate (r(LE)), ICR-170 (r(LI)) and X rays (r(LX)). From wing phenotype measurements on homoallelic females, it has been shown that the r(LE) mutant series includes several leaky alleles, as well as alleles that produce moderate ...

journal_title：Genetics

authors： Rawls JM,Porter LA

更新日期：1979-09-01 00:00:00

abstract：:A total of 358 lys2 mutants of Saccharomyces cerevisiae have been characterized for suppressibility by the following suppressors: UAA and UAG suppressors that insert tyrosine, serine or leucine; a putative UGA suppressor; an omnipotent suppressor SUP46; and a frameshift suppressor SUF1-1. In addition, the lys2 mutants...

journal_title：Genetics

authors： Chattoo BB,Palmer E,Ono B,Sherman F

更新日期：1979-09-01 00:00:00

abstract：:Genetic analysis of 131 independent transpositions of the tetracycline-resistance element Tn10 from a single site in phage P22 into the histidine operon of Salmonella typhimurium reveals that Tn10 insertions are not randomly distributed along this chromosomal target. The insertions occur in 22 different "clusters"; in...

journal_title：Genetics

authors： Kleckner N,Steele DA,Reichardt K,Botstein D

更新日期：1979-08-01 00:00:00

abstract：:The present report is a study of 60 intragenic suppressors located in the A or E group of the b2 spore-color locus of Ascobolus immersus. The frameshift nature of the suppressors was shown by 19 combinations of plus and minus suppressor mutations. The location of the mutation sites on the genetic map of group A was de...

journal_title：Genetics

authors： Leblon G

更新日期：1979-08-01 00:00:00

abstract：:Sister-chromatid exchanges (SCE) were studied in allium cepa L. meristematic cells at the second and third divisions after BrdUrd-substitution during just the first or during the second and third cycles, respectively. The observed SCE nonreciprocal/reciprocal ratios detected at the third division in both experiments, ...

journal_title：Genetics

authors： Schvartzman JB,Cortés F,González-Fernández A,Gutiérrez C,López-Sáez JF

更新日期：1979-08-01 00:00:00

abstract：:Aimed at investigating the recovery of a specific mutant allele of the mating type locus (MAT) by switching a defective MAT allele, these experiments provide information bearing on several models proposed for MAT interconversion in bakers yeast, Saccharomyces cerevisiae. Hybrids between heterothallic (ho) cells carryi...

journal_title：Genetics

authors： Klar AJ,Fogel S,Radin DN

更新日期：1979-07-01 00:00:00

abstract：:Electron microscope serial section reconstruction analysis of all zygotene-pachytene nuclei of meiotic cells from three wild-type germaria (a subunit of the ovary containing the early meiotic stages arrayed in temporal developmental sequence) of Drosophila melanogaster females corroborates and extends earlier observat...

journal_title：Genetics

authors： Carpenter AT

更新日期：1979-06-01 00:00:00

abstract：:The forest tent caterpillar is polymorphic for two melanic genes affecting wing color of moths. These are the first genetically determined morphological traits reported for the genus. Dark (D) is a sex-limited, autosomal dominant with a phenotype of dark brown males. Frequencies in population samples varied from 8 to ...

journal_title：Genetics

authors： Lorimer N

更新日期：1979-06-01 00:00:00

abstract：:The infinite-sites model with no recombination is extended to include mutations that affect electrophoretic mobility. The model allows the effect of a single-site mutation to have a continuous effect on mobility. Formulae are obtained for the variance of electrophoretic mobility of alleles after an arbitrary lenght of...

journal_title：Genetics

authors： Cobbs G

更新日期：1979-06-01 00:00:00

abstract：:Equilibria are determined for the two-locus model in a partially selfing population when one locus is neutral and the other locus is heterotic. At an equilibrium point, the frequency of heterozygotes at the neutral locus is greater than that expected from one-locus theory, even if the heterotic locus is on a different...

journal_title：Genetics

authors： Strobeck C

更新日期：1979-05-01 00:00:00

abstract：:Several hypotheses and concepts have tended to oversimplify the problem of mutagenesis and can be misleading when used for genetic risk estimation. These include: (1) the hypothesis that radiation-induced mutation frequency depends primarily on the DNA content per haploid genome, (2) the extension of this concept to c...

journal_title：Genetics

authors： Russell WL

更新日期：1979-05-01 00:00:00

abstract：:Presynaptic association of homologous chromosomes is a prerequisite to the sequence of events that lead to chiasma formation. This association of homologous chromosomes, as entire units, occurs with probability a, and chiasma formation occurs independently in opposite chromosome arms with probability c. a and c have b...

journal_title：Genetics

authors： Driscoll CJ,Bielig LM,Darvey NL

更新日期：1979-04-01 00:00:00

abstract：:Mutants of Paramecium caudatum with abnormal swimming behavior or responses to cations were obtained by mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. Some of the mutants, like pawn in P. tetraurelia, cannot swim backward and are called CNR. Seven independently obtained CNR mutants belonged to three complement...

journal_title：Genetics

authors： Takahashi M

更新日期：1979-03-01 00:00:00

abstract：:Evolution of a multigene family is studied from the standpoint of population genetics. It is assumed that the multigene family is undergoing continuous interchromosomal unequal crossing over, mutation and random frequency drift. The equilibrium properties of the probability of gene identity (clonality) are investigate...

journal_title：Genetics

authors： Ohta T

更新日期：1979-03-01 00:00:00

abstract：:Two variations of the method of localized mutagenesis were used to introduce mutations into the 72 min region of the Escherichia coli chromosome. Twenty temperature-sensitive mutants, with linkage to markers in this region, have been examined. Each strain showed an inhibition of growth in liquid medium at 44 degrees, ...

journal_title：Genetics

authors： Champney WS

更新日期：1979-02-01 00:00:00

abstract：:Neural ganglia of wild type third-instar larvae of Drosophila melanogaster were incubated for 13 hours at various concentrations of BUdR (1, 3, 9, 27 micrograms/ml). Metaphases were collected with colchicine, stained with Hoechst 33258, and scored under a fluorescence microscope. Metaphases in which the sister chromat...

journal_title：Genetics

authors： Gatti M,Santini G,Pimpinelli S,Olivieri G

更新日期：1979-02-01 00:00:00

abstract：:The island model with stochastically variable migration rate and immigrant gene frequency is investigated. It is supposed that the migration rate and the immigrant gene frequency are independent of each other in each generation, and each of them is independently and identically distributed in every generation. The tre...

journal_title：Genetics

authors： Nagylaki T

更新日期：1979-01-01 00:00:00

abstract：:A reversion study of EMS- or ICR170-induced ascospore color mutants in Ascobolus immersus is reported. Twenty-three new intragenic suppressors were isolated within the b2 locus. These are localized within three distinct groups on a genetic fine-structure map containing 21 identifiable sites. The pattern of reversion i...

journal_title：Genetics

authors： Leblon G,Paquette N

更新日期：1978-11-01 00:00:00