bluuebunny/crossref_metadata_2025_split huggingface dataset:
EVIDENCE FOR EVOLUTIONARY DUPLICATION OF GENES IN THE DOPA DECARBOXYLASE REGION OF DROSOPHILA
Authors: Eveleth David D , Marsh J Lawrence 
Published: January 2021

ABSTRACT
The region surrounding the dopa decarboxylase gene (Ddc) of Drosophila contains a cluster of genes, many of which appear to be functionally related by virtue of their effects on cuticle development and/or catecholamine metabolism. In this report we describe evidence that the Ddc gene and the closely linked alpha-methyldopa hypersensitive (amd) gene share extensive sequence homology and are the products of a gene duplication event. The two genes are transcribed convergently and are separated by 2.4 kb. A gene located between Ddc and amd expresses a 2.0-kb mRNA and appears to partially overlap the Ddc gene. The organization of these transcripts implies a complex series of events giving rise to the present pattern. The patterns of expression of these genes do not support a model of coordinate regulation, but are more consistent with a pattern of duplication and divergence to various related metabolic subspecialties. These data provide the first evidence for structural relationships among genes in the 37C cluster.
QUANTITATIVE GENETICS OF DROSOPHILA MELANOGASTER. I. SEXUAL DIMORPHISM IN GENETIC PARAMETERS FOR WING TRAITS
Authors: Cowley David E , Atchley William R , Rutledge J J 
Published: January 2021

ABSTRACT
Sexual dimorphism in genetic parameters is examined for wing dimensions of Drosophila melanogaster. Data are fit to a quantitative genetic model where phenotypic variance is a linear function of additive genetic autosomal variance (common to both sexes), additive genetic X-linked variances distinct for each sex, variance due to common rearing environment of families, residual environmental variance, random error variance due to replication, and variance due to measurement error and developmental asymmetry (left vs. right sides). Polygenic dosage compensation and its effect on genetic variances and covariances between sexes is discussed. Variance estimates for wing length and other wing dimensions highly correlated with length support the hypothesis that the Drosophila system of dosage compensation will cause male X-linked genetic variance to be substantially larger than female X-linked variance. Results for various wing dimensions differ, suggesting that the level of dosage compensation may differ for different traits. Genetic correlations between sexes for the same trait are presented. Total additive genetic correlations are near unity for most wing traits; this indicates that selection in the same direction in both sexes would have a minor effect on changing the magnitude of difference between sexes. Additive X-linked correlations suggest some genotype × sex interactions for X-linked effects.
SEQUENCE AND TRANSCRIPTS OF THE BACTERIOPHAGE T4 DNA REPAIR GENE uvsY
Authors: Gruidl Michael E , Mosig Gisela 
Published: January 2021

ABSTRACT
We have cloned, sequenced and analyzed transcription of the phage T4 uvsY gene. This gene is transcribed from a single gp MotA-dependent middle promoter to give a major transcript of approximately 930 nucleotides and a minor transcript of approximately 620 nucleotides. All in vivo and in vitro uvsY transcripts show anomalous migration in agarose gels. The uvsY transcript contains an open reading frame coding for an 137 amino acid [15.8 kilodaltons (kD)] UvsY protein and two unidentified open reading frames, ORF UvsY.-1 (9.0 kD) and ORF UvsY.-2 (6.0 kD). Our DNA sequence differs in only three places from that published by Takahashi et al.However, one of these changes alters the predicted carboxy terminus of the UvsY protein. Marker rescue experiments map gene 25 to the region upstream of uvsY. Gene 25 is likely, although not certain, to correspond to an ORF that is found upstream from uvsY and is translated in the same direction.
GENETIC LOCALIZATION AND ACTION OF REGULATORY GENES AND ELEMENTS FOR TISSUE-SPECIFIC EXPRESSION OF α-AMYLASE IN DROSOPHILA MELANOGASTER
Authors: Klarenberg A J , Visser A J S , Willemse M F M , Scharloo W 
Published: January 2021

ABSTRACT
Regulation of tissue-specific α-amylase (Amy) expression in Drosophila melanogaster was investigated with a newly developed method that detects the distribution of α-amylase allozymes in midguts of single adults or third-instar larvae. Trans regulation was found for α-amylase production in the posterior midgut (PMG) of adults, whereas cis regulation was demonstrated for the larval midgut. Independent regulation of components of the duplicated Amy locus was found in larvae. Recombination between the components of the Amy locus did not result in separation of the putative, very closely linked (less than 0.1 cM) cis-acting regulatory elements for α-amylase expression in the anterior midgut (AMG) of larvae. The expression of one of the components of the duplicated Amy locus in the AMG of larvae was influenced by a regulatory gene that was mapped at 2-79.1. α-Amylase expression in the adult PMG was controlled by a trans-acting regulatory gene localized at 2-79.0, in agreement with the data of Abraham and Doane.
Recessive Lethal Mutations and the Maintenance of Duplication-Bearing Strains of Dictyostelium discoideum
Authors: Welker Dennis L , Williams Keith L 
Published: January 2021

ABSTRACT
Recessive lethal mutations have been isolated and used to maintain n + 1 aneuploid strains of Dictyostelium discoideum carrying a duplication of part or all of linkage group VII. The recessive lethal mutations, relA351 and relB352, arose spontaneously in diploids; no mutagenic treatment was used in the isolation of these mutations. The probable gene order on linkage group VII is: centromere, relB, couA, bsgB, cobA, relA . Maintenance of aneuploids disomic for linkage group VII was made possible by complementation of a rel mutation on each linkage group VII homologue by the corresponding wild-type allele on the other linkage group VII homologue. The duplication-bearing disomic strains were slow-growing and produced faster-growing sectors on the colony edge. Haploid sectors probably arise by a combination of mitotic recombination and subsequent loss of one homologue, diploid sectors may be formed by chromosome doubling to 2n + 2, followed by chromosome loss to return to 2n, and aneuploid sectors may arise by deletion or new mutation.
Use of P-Element-Mediated Transformation to Identify the Molecular Basis of Naturally Occurring Variants Affecting Adh Expression in Drosophila melanogaster
Authors: Laurie-Ahlberg Cathy C , Stam Lynn F 
Published: January 2021

ABSTRACT
The purpose of the work reported here is to identify the molecular basis of the difference in level of expression between the polymorphic Slow and Fast alcohol dehydrogenase (Adh) alleles in Drosophila melanogaster . Previous studies have shown that Fast lines typically have a two- to threefold higher activity level than Slow lines and they also have a substantially higher level of ADH-protein (estimated immunologically). The results of a restriction fragment length polymorphism study in relation to ADH activity variation had previously suggested that the difference in Adh expression between allozymes might not be due entirely to the amino acid replacement substitution, but could be due in part to linkage disequilibrium with a regulatory site polymorphism. Here we describe an approach that makes use of P-element-mediated transformation in order to identify the nucleotide substitution(s) responsible for this difference in ADH level. This approach consists of generating recombinants in vitro between Adh region clones derived from a typical Slow/Fast pair of alleles and then testing for the effects of particular restriction fragments on expression in vivo by transformation. Using this approach, the effect on both ADH activity and ADH-protein level clearly maps to a 2.3-kb restriction fragment that includes all of the Adh coding sequence and some intron and 3' flanking sequence, but excludes all of the 5' flanking sequence of the distal (adult) transcriptional unit. Comparison of Kreitman's DNA sequences for this fragment from several Slow and Fast alleles showing the typical difference in activity level shows that only three nucleotide substitutions distinguish all Fast from all Slow alleles. Thus, it is likely that one or more of these substitutions causes the major difference in Adh expression between allozymic classes. One of these substitutions is, of course, the Slow/Fast amino acid replacement substitution (at 1490) while the other two are nearby third position silent substitutions (at 1443 and 1527). A quantiative analysis of variation among transformant stocks shows that the P-element transformation approach can be used to localize even relatively small effects on gene expression (on the order of 20%).
Ordered Linear Tetrads Are Produced by the Sporulation of Newly Formed Zygotes of Saccharomyces cerevisiae
Authors: Thomas James H , Botstein David 
Published: January 2021

ABSTRACT
Diploid Saccharomyces cerevisiae strains normally sporulate to produce tetrahedral unordered asci containing four spores (tetrads). We report that when newly formed zygotes are subjected to the same sporulation conditions, they form predominantly linear ordered tetrads. We show that the two spores from each end of such a linear tetrad invariably contain nonsister centromeres. Spore viability, recombination and independence of centromere segregation appear unaffected.
Hsp28stl: A P-Element Insertion Mutation That Alters the Expression of a Heat Shock Gene in Drosophila melanogaster
Authors: Eissenberg Joel C , Elgin Sarah C R 
Published: January 2021

ABSTRACT
We have identified and cloned a mutant allele of the small heat shock gene Hsp28 of Drosophila melanogaster. This allele, which we have called Hsp28stl, produces small amounts of a single aberrantly large, heat-inducible transcript in heat-shocked flies, while a normal-sized Hsp28 transcript is present only in fertile females. No Hsp28 transcript at all is detected in mutant prepupae, a stage when wild-type flies show high levels of Hsp28 RNA. We have cloned the Hsp28stl allele, and have found that a 1.3-kb defective P-element is present 5' to Hsp28 in the mutant line. The site of P-element insertion lies between the Hsp28 "TATA box" sequence and the Hsp28 RNA cap site; in contrast to previously described P-element insertions, the element at Hsp28stl is flanked by a two base pair duplication of the insertional target sequence. The results suggest that this insert may separate elements regulating heat-inducible and developmental expression of Hsp28, leading to the different patterns of transcription observed.
Cryptic Genes for Cellobiose Utilization in Natural Isolates of Escherichia coli
Authors: Hall Barry G , Betts Paul W 
Published: January 2021

ABSTRACT
The ECOR collection of natural Escherichia coli isolates was screened to determine the proportion of strains that carried functional, cryptic and nonfunctional genes for utilization of the three β-glucoside sugars, arbutin, salicin and cellobiose. None of the 71 natural isolates utilized any of the β-glucosides. Each strain was subjected to selection for utilization of each of the sugars. Only five of the isolates were incapable of yielding spontaneous β-glucoside-utilizing mutants. Forty-five strains yielded cellobiose+ mutants, 62 yielded arbutin+ mutants, and 58 strains yielded salicin+ mutants. A subset of the mutants was screen by mRNA hybridization to determine whether they were expressing either the cel or the bgl β-glucoside utilization operons of E. coli K12. Two cellobiose+ and two arbutin+-salicin+ strains failed to express either of these known operons. It is concluded that there are at least four gene clusters specifying β-glucoside utilization functions in E. coli populations, and that all of these are normally cryptic. It is estimated that in any random isolate the probability of any particular cluster having been irreversibly inactivated by the accumulation of random mutations is about 0.5.
Hypervariable Bkm DNA Loci in a Moth, Ephestia kuehniella : Does Transposition Cause Restriction Fragment Length Polymorphism?
Authors: Traut W 
Published: January 2021

ABSTRACT
Bkm sequences, originally isolated from snake satellite DNA, are a component of eukaryote genomes with a preferential location on sex chromosomes. In the Ephestia genome, owing to the presence of only a few Bkm-positive BamHI restriction fragments and to extensive restriction fragment length polymorphisms between and within inbred strains, a genetic crossbreeding analysis was feasible. No sex linkage of Bkm was detected. Instead-depending on the strain-two or three autosomal Bkm DNA loci were identified. All three loci were located on different chromosomes. Fragment length and transmission of fragments was stable in some crosses. In others, changes in fragment length or loss of the Bkm component were observed, probably depending on the source strain of the fragment. The anomalous genetic behaviour is best accounted for by the assumption that Bkm sequences are included in mobile genetic elements.
The Genes for Mouse Salivary Androgen-Binding Protein (ABP) Subunits Alpha and Gamma Are Located on Chromosome 7
Authors: Dlouhy Stephen R , Taylor Benjamin A , Karn Robert C 
Published: January 2021

ABSTRACT
We demonstrate that the previously described gene Androgen binding protein (Abp; Dlouhy and Karn, 1984) codes for the Alpha subunit of ABP and rename the locus Androgen binding protein alpha (Abpa). A study of recombinant inbred strains demonstrates that Abpa is located on chromosome 7 near Glucose phosphate isomerase-1 (Gpi-1). Biochemical and genetic evidence indicates the existence of another ABP subunit, Gamma, and its locus, Androgen binding protein gamma (Abpg), that is closely linked to Abpa. Although no polymorphism has yet been found for the previously described Beta subunit of ABP (Dlouhy and Karn, 1983; 1984), we suggest that it represents a third locus, Androgen binding protein beta (Abpb). ABP subunits appear to dimerize randomly and a model is presented demonstrating the origin of six ABP dimers in the salivas of AbpaaAbpga/AbpabAbpgb heterozygous mice. The results of cell-free translation studies in which the pre-ABP subunits are identified specifically by immunoprecipitation with anti-ABP antibody supports the idea that independent mRNAs code for the Alpha, Beta and Gamma subunits.
Components of Genetic Variation Associated with Second and Third Chromosome Gene Arrangements in Drosophila melanogaster
Authors: Ferrari James A 
Published: January 2021

ABSTRACT
The effects of naturally occuring combinations of second and third chromosome gene arrangements of Drosophila melanogaster on two quantitative traits were partitioned into parameters of additive, dominance and interaction components of genetic variation. Development time and preadult survival of the gene arrangement genotypes were measured under four experimental conditions. Gene arrangement effects, when significant, were predominantly additive under all conditions. Experimental conditions, however, did influence gene arrangement effects. A second chromosome effect on development time was detected when amount of food or temperature was reduced, but not under optimal conditions. A third chromosome additive effect on development was observed under all experimental conditions. A consistent interaction effect between second and third chromosome gene arrangements was detected only at low temperature. Gene arrangement effects on survival were not as consistent as for development time, but also depended on experimental conditions.
Distribution of the Sex combs reduced Gene Products in Drosophila melanogaster
Authors: Mahaffey James W , Kaufman Thomas C 
Published: January 2021

ABSTRACT
The spatial and temporal distribution of RNA and protein encoded by the homeotic Sex combs reduced (Scr) gene were examined during Drosophila development. The gene products are present in the epidermis of both the labial and first thoracic segments as would be predicted from prior genetic studies. However, the pattern in the central nervous system (CNS) and mesoderm is further restricted; the major expression located in the labial neuromere of the CNS and the mesoderm of the first thoracic segment. The spatial restriction within the CNS is correlated with and may be due to a differential timing of expression in the labial and first thoracic ectoderm. The labial ectoderm accumulates the Scr RNA prior to segregation of the neuroblasts while expression in the first thoracic ectoderm occurs after neuroblast segregation. The protein is also observed in the subesophageal ganglia of both larvae and adults, as well as in the labial and first thoracic imaginal discs. Surprisingly, the protein is also present to a lesser extent in second and third thoracic leg discs.
Nucleotide Sequence of the Adh Gene Region of Drosophila pseudoobscura: Evolutionary Change and Evidence for an Ancient Gene Duplication
Authors: Schaeffer Stephen W , Aquadro Charles F 
Published: January 2021

ABSTRACT
The alcohol dehydrogenase (Adh) locus (ADH; alcohol: NAD+ oxidoreductase, EC 1.1.1.1) of Drosophila pseudoobscura was cloned and sequenced. Forty-five percent of the "effectively silent sites" have changed between Adh in D. pseudoobscura of the obscura species group and the homologous DNA sequence in D. mauritiana, the latter representing the melanogaster species group. The untranslated leader sequence of the adult transcript of D. pseudoobscura has two deletions relative to the D. mauritiana message. The ADH protein sequences of D. pseudoobscura is missing the third and fourth amino acids at the N-terminus relative to the D. mauritiana enzyme. Of the remaining 254 amino acid positions, 27 (10.64%) differ between the two species. Amino acid replacements are randomly distributed into hydrophilic and hydrophobic domains of ADH. However, replacement substitutions are distributed nonrandomly across the three exons among D. pseudoobscura and members of the melanogaster subgroup, suggesting that functional constraints across the exons are different. Surprisingly, silent substitutions are also nonrandomly distributed with the third exon being the most divergent. This pattern suggests possible selective constraints on supposedly neutral silent substitutions and/or variation in underlying mutation rates across the gene. The presence of transcriptional and translational signals at the beginning and end of conserved sequences 3′ to Adh implies the existence of a previously undescribed gene. Codon usage and patterns of nucleotide divergence are consistent with a protein coding function for this gene. In addition, conservation of nucleotide and amino acid sequence and similarity in hydropathy plots suggests that the gene 3′ to Adh represents an ancient duplication of the Adh gene.
Physiological Significance of the Alcohol Dehydrogenase Polymorphism in Larvae of Drosophila
Authors: Heinstra Pieter W H , Scharloo Willem , Thörig George E W 
Published: January 2021

ABSTRACT
This study deals with biochemical and metabolic-physiological aspects of the relationship between variation in in vivo alcohol dehydrogenase activity and fitness in larvae homozygous for the alleles Adh71k, AdhF, AdhS, of Drosophila melanogaster, and for the common Adh allele of Drosophila simulans. The Adh genotypes differ in the maximum oxidation rates of propan-2-ol into acetone in vivo. There are smaller differences between the Adh genotypes in rates of ethanol elimination. Rates of accumulation of ethanol in vivo are negatively associated with larval-to-adult survival of the Adh genotypes. The rank order of the maximum rates of the ADHs in elimination of propan-2-ol, as well as ethanol, is ADH-71k &gt; ADH-F &gt; ADH-S- &gt; simulans-ADH. The ratio of this maximum rate to ADH quantity reveals the rank order of ADH-S &gt; ADH-F &gt; ADH-71k &gt; simulans-ADH, suggesting a compensation for allozymic efficiency by the ADH quantity in D. melanogaster.—Our findings show that natural selection may act on the Adh polymorphism in larvae via differences in rates of alcohol metabolism.
Allelic Variation Within the Emv-15 Locus Defines Genomic Sequences Closely Linked to the agouti Locus on Mouse Chromosome 2
Authors: Siracusa Linda D , Russell Liane B , Jenkins Nancy A , Copeland Neal G 
Published: January 2021

ABSTRACT
Gene(s) at the agouti locus act within the microenvironment of the hair follicle to switch pigment synthesis in the melanocyte between eumelanin (black or brown pigment) and phaeomelanin (yellow pigment). Many phenotypic variants of this locus have been described. The mechanism(s) of gene action causing such variation in coat-color phenotype is not known. The close linkage of an endogenous ecotropic murine leukemia provirus, Emv-15, to the lethal yellow mutation of the agouti locus provides a means to molecularly access genes at or near the agouti locus. We have identified and used a unique mouse sequence flanking the Emv-15 provirus to define three alleles of the Emv-15 locus. We found a correlation between the presence of specific Emv-15 alleles and the origins of specific agouti locus mutations, confirming close linkage. However, we found some exceptions which suggest that the Emv-15 locus is closely linked to, but genetically separable from, the agouti locus.
Extended Region of Nodulation Genes in Rhizobium meliloti 1021. I. Phenotypes of Tn5 Insertion Mutants
Authors: Swanson Jean A , Tu Janice K , Ogawa Joy , Sanga Raghu , Fisher Robert F , Long Sharon R 
Published: January 2021

ABSTRACT
Rhizobium meliloti Nod- mutant WL131, a derivative of wild-type strain 102F51, was complemented by a clone bank of wild-type R. meliloti 1021 DNA, and clone pRmJT5 was recovered. Transfer of pRmJT5 conferred alfalfa nodulation on other Rhizobium species, indicating a role in host range determination for pRmJT5. Mutagenesis of pRmJT5 revealed several segments in which transposon insertion causes delay in nodulation, and/or marked reduction of the number of nodules formed on host alfalfa plants. The set of mutants indicated five regions in which nod genes are located; one mutant, nod-216, is located in a region not previously reported to encode a nodulation gene. Other mutant phenotypes correlated with the positions of open reading frames for nodH, nodF and nodE, and with a 2.2-kb Eco RI fragment. A mutant in nodG had no altered phenotype in this strain. One nodulation mutant was shown to be a large deletion of the common nod gene region. We present a discussion comparing the various studies made on this extended nod gene region.
Molecular and Recombinational Mapping of Mutations in the Ace Locus of Drosophila melanogaster
Authors: Nagoshi Rodney N , Gelbart William M 
Published: January 2021

ABSTRACT
The Ace locus in Drosophila melanogaster is known to be the structural gene for acetylcholinesterase. Ace is located in a region of chromosome arm 3R which has been subjected to intensive genetic and molecular analysis. Previous deletion mapping studies have identified a 40-kb region within which the Ace gene resides. This report focuses on the further localization of Ace within this 40-kb interval. Within this region, selective fine structure recombinational analysis was employed to localize three recessive Ace lethals relative to unselected restriction site variations. These three mutations fall into a segment of 7 kb within the Ace interval. Fine structure recombinational analysis was also used to confirm that the Ace - phenotype of one deletion, Df(3R)AceHD1, co-segregated with the molecular deletion. This deletion does not fully remove Ace activity, but it behaves as a recessive Ace lethal. Df(3R)AceHD1is the most distal Ace lesion identified and indicates that the Ace locus must extend at least 16 kb. Several poly(A)transcripts are detectable in the region defined by the Ace lesions. The position and extent of the Ace locus, as well as the types of transcripts found, is consistent with the recent findings which identified Torpedo-AChE homologous cDNA sequences in this region.