bluuebunny/crossref_metadata_2025_split huggingface dataset:
ASSIGNMENT OF THREE GENE LOCI (PGK, HGPRT, G6PD) TO THE LONG ARM OF THE HUMAN X CHROMOSOME BY SOMATIC CELL GENETICS
Authors: Ricciuti Florence C , Ruddle Frank H 
Published: January 2021

ABSTRACT
The intrachromosomal localization of three X-linked gene loci (PGK, HGPRT and G6PD) has been determined using a somatic cell genetic approach. A human cell line possessing an X/14 translocation was used as one parent in the formation of human/mouse hybrids. The translocation separates the human X into two parts: Xp and t(Xq14q). The data indicate that all three X-linked loci segregate with the t(Xq14q) rearrangement product thus permitting their assignment to the X chromosome's long arm. Secondary rearrangements and data from other laboratories suggest that the order of the the three markers from the centromere to the distal end of the X long arm is PGK, HGPRT, G6PD. It was also observed that NP, an autosomal locus, segregated with the t(Xq14q) chromosome. This provides strong support for the assignment of NP to 14.
ANALYSES OF GENE FREQUENCIES
Authors: Cockerham C Clark 
Published: January 2021

ABSTRACT
Models of variance components and their intraclass correlational equivalences are developed for genes falling into various categories of subdivisions within a population. Estimable functions are elaborated demonstrating that intraclass correlations can be estimated only relative to that for the least related genes in the informational system. The effects of different types of subdivisions-and of ignoring them-on the parameters are demonstrated. Small sample estimators are formulated for all of the parameters by three different methods, including both a weighted and an unweighted method of analysis of the variation among subpopulations. How estimators change with assumptions about the parameters is illustrated. Various tests of hypotheses are outlined in X2 and F-test terminology. Discussed are factors which may affect the correlations and the manner in which their effects are manifest, hopefully in clarification of some of the misconceptions that have arisen in this connection.
A COMPETITIVE SELECTION MODEL
Authors: Milkman Roger 
Published: January 2021

ABSTRACT
The proportionate contribution of a genotype to the next generation is not independent of frequency and cannot always safely be equated with a constant. Survival potential (Haldane's viability) permits the use of a genetic selection model which deals more realistically with competition. A broader property than survival potential, called fitness potential, should be distinguished from fitness, which it determines in a competitive context.
GENETIC CONTROL OF QUANTITATIVE VARIATION IN SELF-INCOMPATIBILITY PROTEINS DETECTED BY IMMUNODIFFUSION
Authors: Nasrallah M E 
Published: January 2021

ABSTRACT
Single radial immunodiffusion was used to study the self-incompatibility (S) proteins present in stigmas of two inbred lines of Brassica oleracea: a self-incompatible line and a self-compatible mutant derived from it. The genetic basis of observed quantitative differences in S proteins between the two inbreds was shown to be determined by a single gene with dosage effects. Self-pollination of individual plants with high, intermediate and low levels of S protein in the stigmas, respectively, resulted in low, intermediate and high seed set.
REGULATION OF NEWLY EVOLVED ENZYMES. I. SELECTION OF A NOVEL LACTASE REGULATED BY LACTOSE IN ESCHERICHIA COLI
Authors: Hall Barry G , Hartl Daniel L 
Published: January 2021

ABSTRACT
Thirty-four lactose-utilizing strains of E. coli were selected from a lac Z deletion strain. In 31 of these, the synthesis of the newly evolved lactase is regulated by lactose. The lactase activity in all the strains is indistinguishable from the ebg + activity identified by Campbell, Lengyel and Langridge (1973).
SOME IMPROVED METHODS IN P22 TRANSDUCTION
Authors: Ely Bert , Weppelman Roger M , Massey Holman C , Hartman Philip E 
Published: January 2021

ABSTRACT
Recent refinements simplify methods for P22 transduction in Salmonella and allow improved recovery of phage-free transductional clones. The methods include use of: integration- and lysis-defective phage mutants, heat-killed bacteria to eliminate free phage, direct plating of phage and bacteria, replica-plating for detection of phage content of individual clones, improved broth for phage growth, and procurement of high titer phage from P22 lysogens.
GENETIC ANALYSIS OF THE ACTIVE SITES OF lac REPRESSOR
Authors: Pfahl Magnus , Stockter Christel , Gronenborn Bruno 
Published: January 2021

ABSTRACT
Selection methods for the isolation of i -d and i s mutants are described. Two hundred and forty-seven i -d and 98 i s mutations have been localized by deletion mapping. All i -d mutations map in the region of the i gene, which codes for the aminoterminal part of the lac repressor, whereas i s mutations map in the middle of the i gene and at the proximal end of the i -d cluster.
GENETICS OF CHEMICAL INDUCTION OF CONJUGATION IN PARAMECIUM AURELIA
Authors: Cronkite Donald L 
Published: January 2021

ABSTRACT
Certain stocks of P. aurelia, syngen 8, could not be induced to conjugate in a solution (KCl + acriflavine + calcium-poor conditions) which was effective in inducing conjugation in other species of Paramecium as well as in other stocks of syngen 8. Both stocks could conjugate by interaction with cells of complementary mating type. Breeding analysis shows that each of the two stocks is homozygous for a recessive gene that blocks induction of conjugation by the KCl-acriflavine solution. These two genes are neither allelic nor linked. Analyses of the phenotypes of the two uninducibles and the wild type were carried out by attempting to induce mating in cells of a single mating type by exposing them to detached mating-reactive cilia from cells of complementary mating type and to the KCl-acriflavine solution, either sequentially or simultaneously. The results confirm the conclusions of others that there is at least one unique step in chemical induction not shared with induction by interaction of complementary mating types. But the results also indicate that there is more than one unique step in chemical induction and that the effects of the two genes described here operate during different periods of the hour required for chemical induction.
TEMPERATURE-SENSITIVE PLEIOTROPIC REVERTANTS FROM A MUTANT IN THE AROM GENE CLUSTER OF NEUROSPORA CRASSA
Authors: Case Mary E , Giles Norman H 
Published: January 2021

ABSTRACT
Genetical and biochemical studies have been performed with revertants induced in a polyaromatic mutant (No. 58) in the arom gene cluster of Neurospora crassa. In addition to complete and partial revertants able to grow on minimal at both 25° and 35°, temperature-sensitive revertants capable of growth on minimal at 25° but not at 35° have been recovered. One of these revertants has been shown to lack biosynthetic dehydroquinase activity at both temperatures (utilizing the inducible catabolic isozyme for growth at 25°), to have dehydroshikimate reductase activity only at 25°, and to form an arom aggregate having a molecular weight approximately one-half that of wild type. These results are interpreted as indicating that pleiotropic mutants in the arom gene cluster can result from missense mutations, as well as from nonsense mutations as indicated in previous studies.
FINE STRUCTURE MAPPING IN YEAST WITH SUNLAMP RADIATION
Authors: Lawrence Christopher W , Christensen Roshan 
Published: January 2021

ABSTRACT
The X-ray mapping procedure of Manney and Mortimer (1964) is the most widely applicable and convenient method for fine structure analysis in yeast, but suffers the disadvantage that suitable X-ray machines or gamma ray sources are very expensive. Although many other recombinogens are known, none gives a linear dose-response like X-rays and few are as convenient or give as reproducible results. Experiments with Saccharomyces cerevisiae reported in this paper show, however, that the near-ultraviolet radiation emitted by fluorescent sunlamps gives linear dose-response relations, as reproducible results as ionizing radiations, and map distances which correlate highly with those obtained by using 60Co gamma rays. It is suggested that this convenient recombinogen may be a suitable low-cost substitute for ionizing radiations in fine structure mapping.
FEEDBACK-INSENSITIVE MUTANTS OF THE GENE FOR THE TYROSINE-INHIBITED DAHP SYNTHETASE IN YEAST
Authors: Meuris Pierre 
Published: January 2021

ABSTRACT
A yeast strain lacking the phenylalanine-sensitive DAHP synthetase exhibits a tyrosine-inhibited phenotype. Reversions from this phenotype were selected. They were the result of mutations affecting the tyrosine-sensitive DAHP synthetase which became insensitive to feedback inhibition, as shown by genetic and enzymatic studies. The feedback-insensitive mutations were located at five different sites scattered on the map of the aro4 gene.
SEX-LINKED AUXOTROPHIC AND PUTATIVE AUXOTROPHIC MUTANTS OF DROSOPHILA MELANOGASTER
Authors: Falk D R , Nash David 
Published: January 2021

ABSTRACT
Thirty-two mutants with improved growth response on a yeast-sucrose compared with a defined medium have been characterized with respect to ribonucleoside supplementability. Twenty mutants respond to either pyrimidine ribonucleoside. Four mutants respond to one or both purine ribonucleosides. Eight mutants ("putative" auxotrophs) do not respond to dietary RNA supplementation. Mapping and complementation studies suggest that eleven loci are represented: one, rudimentary, probably accounts for all pyrimidine requirers; there are three purine loci and seven at which the putative auxotrophs are found.
DEVELOPMENT IN GENETIC MOSAICS OF ARISTAPEDIA, A HOMOEOTIC MUTANT OF DROSOPHILA MELANOGASTER
Authors: Postlethwait J H , Girton J R 
Published: January 2021

ABSTRACT
Development of the homoeotic mutation, aristapedia (ss a), was investigated by means of genetic mosaics. The wild-type alleles of aristapedia and the bristle markers yellow, singed, and forked were removed from cells at different times in development by X-ray induced somatic crossing-over. The phenotype of the resulting clones was examined in order to ascertain whether it was leg or antenna. The y sn f; ssa clones showed a leg phenotype if induced before the mid-third instar, but showed an antennal phenotype if induced after this time. Late non-expression of ss a may be due either to an influence of surrounding ss + tissues on the small ss a clones, or to a persistence of the effect of ss + for one or two cell generations after it is removed from a cell line.
THE CYTOGENETIC ANALYSIS OF A FRACTURED GENE IN DROSOPHILA
Authors: Welshons W J 
Published: January 2021

ABSTRACT
The data presented in this study are derived from the analyses of Notch mutants known to be associated with visible cytological deficiencies. One mutant, Df(1)N62b1, described as a right-side deficiency, bears a deletion that apparently initiates within the Notch locus and extends to the right as far as the locus of dm. Recombination experiments using heterozygotes of Df(1)N62b1 with a series of intragenic point mutants within the Notch cistron suggest that this deficiency represents a deletion for the right-end portion of the gene. A consideration of the cytology of Df(1)N62b1 supports the cytogenetic inference that, if a Notch locus-3C7 relationship is valid, the missing portion of the gene as assayed by recombination experiments has an interband position between 3C7 and 8.—The data derived from two left-side deficiencies with a genetic lesion in Notch and a deletion extending to w are somewhat equivocal, but they do support the presumed Notch locus-3C7 band relationship and thereby enhance the likelihood that Df(1)N62b1 is correctly interpreted.—Cytogenetic information presently available suggests that, although a significant portion of the Notch cistron has a position on the salivary map identified as interband 3C7 to 8, the 3C7 band is part of the total picture of the Notch gene.
EXCHANGE WITHIN HETEROZYGOUS INVERSIONS IN DROSOPHILA MELANOGASTER
Authors: Robbins Leonard G 
Published: January 2021

ABSTRACT
The exchange behavior of non-attached, whole arm, X chromosome inversions was reexamined using nondisjunction in XXY females as an indirect measure of the frequency of nonexchange tetrads. Crossing over is quite normal in these inversion heterozygotes and is independent of the arrangement of the basal heterochromatin.
GENETIC ANALYSIS OF THE RECIPROCAL TRANSLOCATION T2(I;VIII) OF ASPERGILLUS USING THE TECHNIQUE OF MITOTIC MAPPING IN HOMOZYGOUS TRANSLOCATION DIPLOIDS
Authors: Ma Gloria C L , Käfer Etta 
Published: January 2021

ABSTRACT
A UV-induced sulphite-requiring mutant (sD50) consistently shows mitotic linkage to groups I and VIII in haploids from heterozygous mapping diploids. This linkage was found to be due to a reciprocal translocation T2(I;VIII) which could not be separated from the sulphite requirement in about 100 tested progeny from heterozygous crosses, and both may well have been induced by the same mutational event. T2(I;VIII) is the first case of a reciprocal translocation in Aspergillus which showed meiotic linkages between markers of different linkage groups, and, in addition, involved chromosome arms containing markers suitable for complete mapping by the technique of mitotic recombination in homozygous translocation diploids.—Using various selective markers, haploid segregants and diploid crossovers of all possible types were isolated from homozygous translocation diploids. (1) Haploid segregants showed new linkage relationships in T/T diploids: all available markers of VIII now segregated as a group with the majority of the markers of I, exceptfor the markers of the left tip of I. These formed a separate linkage group and are presumably translocated to VIII. (2) Diploid mitotic crossovers confirmed this information nd shhowed that the orientation of the translocated segments was unchanged. These findings conclusively demonstrate that T2(I; VIII) is a reciprocal translocation due to an exchange of the left tip of group I with the long right arm of group VIII.—Since the position of the break on VIIIR was found to be at sD50 this marker could be used to map the break on IL by meiotic recombination in heterozygous crosses. In addition, such crosses showed reduced recombination around the breaks, so that it was possiblc to sequence markers which normally are barely linked.
THE INTERACTION OF KNOBS AND B CHROMOSOMES OF MAIZE IN DETERMINING THE LEVEL OF RECOMBINATION
Authors: Chang C C , Kikudome Gary Y 
Published: January 2021

ABSTRACT
Enhancement of recombination by B chromosomes is influenced by the kind of heterochromatic knob present in or near the tested region of the A chramosomes. In homomorphic chromosome 9 bivalents of KS/KS constitution, double exchanges were increased at the expense of singles, but in the K*/Ks heteromorphs there was a gain in both single and double exchanges at the expense of no-exchange tetrads. Modification of the B chromosome enhancement in different knob compounds was observed only in the megasporocytes.—Different frequencies of recombination are found in plants with odd and even numbers of B Chromosomes; this effect is especially striking in the megasporocytes. The modification in recombination produced by an odd or even number of B chromosomes is a function of the interaction of a particular region and the knob constitution. Odd numbers of B chromosomes were more effective than even numbers in causing increased recombination.—It is concluded that heterochromatic knobs and the essentially heterochromatic supernumeraries may interact in the process of crossing over, with the level of recombination determined in part by knob constitution.
ALTERNATE-1 AND ALTERNATE-2 DISJUNCTIONS IN HETEROZYGOUS RECIPROCAL TRANSLOCATIONS
Authors: Endrizzi J E 
Published: January 2021

ABSTRACT
Alternate-1 and alternate-2 orientation of chromosomes, as well as the two types of adjacent orientation, were observed cytologically in the ring configurations of three reciprocal translocation heterozygotes of Gossypium hirsutum L. The observations indicate that the two types of alternate orientation should be characteristic of ring-forming translocations.
THE GENETICS OF CAENORHABDITIS ELEGANS
Authors: Brenner S 
Published: January 2021

ABSTRACT
Methods are described for the isolation, complementation and mapping of mutants of Caenorhabditis elegans, a small free-living nematode worm. About 300 EMS-induced mutants affecting behavior and morphology have been characterized and about one hundred genes have been defined. Mutations in 77 of these alter the movement of the animal. Estimates of the induced mutation frequency of both the visible mutants and X chromosome lethals suggests that, just as in Drosophila, the genetic units in C.elegans are large.
EVIDENCE FOR THE INVOLVEMENT OF SERINE TRANSHYDROXYMETHYLASE IN SERINE AND GLYCINE INTERCONVERSIONS IN SALMONELLA TYPHIMURIUM
Authors: Stauffer George V , Brenchley Jean E 
Published: January 2021

ABSTRACT
Salmonella typhimurium can normally use glycine as a serine source to support the growth of serine auxotrophs. This reaction was presumed to occur by the reversible activity of the cnzyme, serine transhydroxymethylase (E. C. 2. 1. 2. 1; L-serine: tetrahydrofolic-5, 10 transhydroxymethylase), which is responsible for glycine biosynthesis. However, this enzyme had not been demonstrated to be solely capable of synthesizing serine from glycine in vivo. The isolation and characterization of a mutant able to convert serine to glycine but unable to convert glycine to serine supports the conclusion that a single enzyme is involved in this reversible interconversion of serine and glycine. The mutation conferring this phenotype was mapped with other mutations affecting serine transhydroxymethylase (glyA) and assays demonstrated reduced activities of this enzyme in the mutant.
RECOMBINANTS BETWEEN CLOCK MUTANTS OF CHLAMYDOMONAS REINHARDI
Authors: Bruce Victor G 
Published: January 2021

ABSTRACT
Mutants affecting the period length of the biological clock in Chlamydomonas reinhardi have been isolated and a start has been made on analyzing the genetics of this system. In four mutants, the long period characteristic seems to be controlled by single genes at separate loci. Crosses between single mutants, as well as crosses involving three or four mutant genes, yielded progeny with periods characteristic of the parents as well as recombinant types, including normal period (wild type) and extra-long periods (double, triple and quadruple mutants). It was found that the period lengthening effect is additive; that is, the period of double mutants is lengthened by the sum of the period lengthening of the single mutants.
GENE CONVERSION OF DELETIONS IN THE HIS4 REGION OF YEAST
Authors: Fink G R , Styles C A 
Published: January 2021

ABSTRACT
A selection procedure has been devised which allows the recovery of deletions of the his4 region of Saccharomyces cerevisiae. Many deletions were obtained by this procedure and were characterized genetically and biochemically. These deletions permit the construction of a linear map of the his4A and his4B region. A deletion which was large on this genetic map reduced the size of the his4 gene product. Tetrad analyses revealed that deletions can affect the conversion frequency of other alleles at his4. Analysis of reciprocal recombination in conversion tetrads showed that the order of genes on chromosome III is: centromere-leuZ-his4A-his4C. This means that in his4 transcription and translation proceed away from the centromere.
ENZYME VARIABILITY IN NATURAL POPULATIONS OF DAPHNIA MAGNA III. GENOTYPIC FREQUENCIES IN INTERMITTENT POPULATIONS
Authors: Hebert Paul D N 
Published: January 2021

ABSTRACT
In temporary habitats populations of the cyclical parthenogen, Daphnia magna, are re-established each year from sexual eggs and reproduce partheno-genetically for two or at most three generations. The genetic effects of this breeding system have been investigated by analyzing allozyme frequencies in nineteen intermittent populations—Genotypic frequencies at polymorphic loci were ordinarily found to be in good agreement with Hardy-Weinberg proportions and disequilibria between loci were not observed. Although significant changes in gene frequencies were observed both during and between successive cycles, there was no evidence of the marked instability of genotype frequencies characteristic of permanent populations. The recombinational degradation of genotypes at the end of each annual cycle in temporaly habitats effectively prevents the genotypic structuring which develops when continued parthenogenesis is possible.
MICRODIFFERENTIATION IN A NATURAL POPULATION OF DROSOPHILA MELANOGASTER TO ALCOHOL IN THE ENVIRONMENT
Authors: McKenzie J A , Parsons P A 
Published: January 2021

ABSTRACT
Strains of D. melanogaster derived from a vineyard population were more resistant to alcohol in the environment than strains from a population derived from an area removed from the vineyard. Within the vineyard population those strains most closely associated with alcohol in the environment in the cellar were more resistant than those collected outside the cellar. There was evidence of gene flow between the inside and outside cellar components of this population, but microdifferentiation had occurred within the cellar in spite of this. The adaptation appears to be independent of the ADH system and involves both additive and dominance genetic effects. D. simulans, a species not found in the cellar and susceptible to the presence of alcohol, showed no differentiation between vineyard and removed populations.
THE DISTRIBUTION OF CROSSOVERS ALONG UNREPLICATED LAMBDA BACTERIOPHAGE CHROMOSOMES
Authors: Stahl Franklin W , McMilin Kenneth D , Stahl Mary M , Crasemann Jean M , Lam Stephen 
Published: January 2021

ABSTRACT
The distribution of crossovers along unreplicated chromosomes of bacteriophage lambda has been examined by determining the density distributions and genotypes of particles in the progenies of crosses of density-labeled by ordinary parents in the presence of genetic blocks to replication. The Red and Rec systems combined produce crossovers primarily near the ends (especially the right end) of the chromosome. Removal of the generalized lambda recombination functions by red and gam mutations results in loss of these terminal crossovers; coupled with this loss is a disappearance of the differential dependence of recombination frequencies in terminal and central intervals on DNA synthesis. Removal of the bacterial system by a recA mutation results in severe depression of crossing over among unreplicated phage, with the few recombinants produced by the lambda system occurring near the right end.