Isozyme variability in species of the genus Drosophila. VII. Genotype-environment relationships in populations of D. melanogaster from the eastern United States

Collections of D. melanogaster were analyzed for genetic variation at nine enzyme loci. Allelic frequencies were determined, and comparisons between observed phenotypic proportions and those expected under equilibrium conditions were made. A significant tendency toward homozygote excess was noted. Relationships between patterns of genetic variability and between patterns of genetic and environmental variability were examined by the method of principal components and correlation analysis. Several of the loci showed a clinal pattern in gene frequencies, and overall there was an appreciable amount of genetic-genetic and genetic-environmental association.This work was supported by PHS Research Grant No. GM 11546 and AEC Contract No. AT-(40-1)-3980. Paper No. 4026 of the Journal Series of the North Carolina Agricultural Experiment Station, Raleigh, North Carolina.     

Electrophoretic variability in island populations of Drosophila simulans and Drosophila immigrans

Genetic structure and variability were investigated in several Hawaiian populations of D. simulans and D. immigrans. Genetic variability is lower in Hawaiian populations of D. simulans than in Texas populations, and allelic differences exist as well. For D. immigrans, Hawaiian and Korean populations are similar in variability, allelic content, and gene frequencies. Several hypothesis are advanced to account for the patterns in gene variation observed between island and continental populations of these two colonizing species.This research was supported by Grant GB-23230 to the Hawaii Subprogram of the International Biology Program, by Grant GB-27586 to Dr. H. L. Carson, and by the Research Board of the School of Life Sciences, University of Illinois, Urbana, Illinois.Technical Report No. 57 of the U.S. IBP, Hawaii Integrated Research Program.     

Order of the ilv genes of Salmonella montevideo

Summary Ilv mutants of aSalmonella typhimurium-Salmonella montevideo hybrid were used in cotransduction studies to obtain evidence for the order of theilv genes ofS. montevideo. The following order, which is the same as that previously reported forS. typhimurium, is derived:ilvE-ilvD-ilvA-ilvC.From the Departments of Genetics and Biochemistry, School of Agriculture and Life Sciences, and School of Physical and Mathematical Sciences, North Carolina State University, Raleigh, North Carolina 27607. Paper No. 3300 of the Journal Series of the North Carolina State University Agricultural Experiment Station, Raleigh, North Carolina. Supported by Research Grant GM 14184-04 from the Public Health Service.     

Cytogenetic study of a large black kindred: Inversions,heteromorphisms, and segregation analysis

Summary Q-and C-band heteromorphisms were determined by sequentially staining cells from 81 members of an American Black kindred. The incidence of heteromorphs is reported for 14-people who married into the family.Small pericentric inversions of chromosome 3 were found in 23 kindred members, three of whom were homozygous. Six complete chromosome 9 inversions and a single partial inv9 were detected. There was no apparent phenotypic effect associated with the inversions, nor were duplication-deficiency chromosomes observed.Evidence for preferential segregation of Q-heteromorphs is reported, and comparison with data from other authors points to chromosome 13 as showing the most distortion.This paper is based on a thesis submitted by the senior author in partial fulfillment of the Ph. D. degree at North Carolina State University, Raleigh.Research supported by the National Heart and Lung Institute Grant HLO-3341, National Institute of Medical Health Grant MH 2671, and National Institute of General Medical Sciences Grant GM 16697; paper number 6280 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, North Carolina.     

Isozyme variability in species of the genus Drosophila. VIII. The alcohol dehydrogenase polymorphism in north carolina populations of D. melanogaster

Adult Drosophila melanogaster flies collected from populations broadly dispersed over ecological and geographic strata of North Carolina, and over a period of 4 years, were analyzed for alcohol dehydrogenase phenotypes by gel electrophoresis. Gene frequencies in spring-summer-fall field collections were remarkably stable over all strata. Two winter collections exhibited contrasting gene frequency changes. In one case the results are interpreted in terms of long-distance migration from Florida, while the other is explicable by assignment of a causal role to environmental factors which accompany the winter season.This investigation was supported in part by NIH Research Grant No. GM11546 from the National Institute of General Medical Sciences and by Contract No. AT-(40-1)-3980 from the United States Atomic Energy Commission.Paper No. 4719 of the Journal Series of the North Carolina Agricultural Experiment Station, Raleigh, North Carolina 27609.     

Linkage relationships of biochemical markers to Q- and C-band variants in a large black kindred

Summary Lod scores are reported for 86 biochemical to cytogenetic marker comparisons in a Black kindred. Analysis with unconfirmed locus assignments resulted in 12 exclusions of close linkage.This paper is based on a thesis submitted by the senior author in partial fulfillment of the Ph.D. degree at North Carolina State University, Raleigh.Research supported by the National Heart and Lung Institute Grant HLO-3341, National Institute of Mental Health Grant MH 26621, and National Institute of General Medical Sciences Grant GN 16697; paper number 6281 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, North Carolina.     

Major histocompatibility complex variation in red wolves: evidence for common ancestry with coyotes and balancing selection

We examined variation at a class II major histocompatibility complex (MHC) gene (DRB1) in the captive red wolf population and samples of coyotes from Texas and North Carolina. We found 4 alleles in the 48 red wolves, 8 alleles in the 10 coyotes from Texas and 15 alleles in the 29 coyotes from North Carolina. Two of the four alleles found in red wolves, Caru-2 and Caru-4, were found in both the Texas and North Carolina coyote samples. Allele Caru-1, previously found in gray wolves, was also found in the North Carolina sample. The most frequent red wolf allele, Caru-3, was not found in any of the coyote samples. However, an allele found in both the Texas and North Carolina coyote samples is only one nucleotide (one amino acid) different from this red wolf allele. Overall, it appears from examination of this MHC gene that red wolves are more closely related to coyotes than to gray wolves. There were a number of different types of evidence supporting the action of balancing selection in red wolves. Namely, there was: (i) an excess of heterozygotes compared with expectations; (ii) a higher rate of nonsynonymous than synonymous substitution for the functionally important antigen-binding site positions; (iii) an eight times higher average heterozygosity of individual amino acids at the positions identified as part of the antigen-binding site than those not associated with it; (iv) the amino acid divergence of four red wolf alleles was greater than that expected from a simulation of genetic drift; and (v) the distribution of alleles, and the distributions of amino acids at many positions were more even than expected from neutrality. Examination of the level and pattern of linkage disequilibria between pairs of sites suggest that the heterozygosity, substitution and frequencies at individual amino acids are not highly dependent upon each other.     

Biochemical genetics of Fundulus heteroclitus (L.). IV. Spatial variation in gene frequencies of Idh-A,Idh-B, 6-Pgdh-A,and Est-S

The spatial variation in gene frequencies of four unlinked polymorphic loci was studied in the teleost Fundulus heteroclitus. Three loci (Idh-A, Idh-B, and Est-S) exhibit significant north-south clinal variation in allelic frequencies along the Atlantic Coast of North America, while a fourth locus (6-Pgdh-A) shows a modest clinal variation. These data, together with our previous data for Ldh-B, Mdh-A, Gpi-B, and Pgm-A, reveal a pattern of low gene diversity in the colder northern extremes of the species range and high gene diversity in warmer southern latitudes.This work was supported by Grants DEB76-19877 and DEB79-12216 from the National Science Foundation and by Grant P60-80-04 from the State of Maryland. REC and RVB were supported by NIH Training Grant GM07231 to the Department of Biology.Contribution No. 1104 from the Department of Biology, The Johns Hopkins University.     

Hemoglobin polymorphism in the encinal mouse,Peromyscus pectoralis

Horizontal starch gel electrophoresis revealed five hemoglobin phenotypes in natural populations of the encinal mouse, Peromyscus pectoralis, from northeastern Mexico. Populations of the encinal mouse from Texas, Oklahoma, and northwestern and north central Mexico were monomorphic for multiple-band phenotypes. Analysis of the hemoglobin polymorphism indicates that two loci control this variation.This research was supported by Faculty Research Grant 35053 from North Texas State University.     

Inheritance,intracellular localization,and genetic variation of phosphoglucomutase isozymes in maize (Zea mays L.)

Phosphoglucomutase (PGM; EC 2.7.5.1) isozyme variants were studied in a large number of inbred lines, crosses, and races of maize (Zea mays L.). Patterns of Mendelian inheritance demonstrated for PGM isozyme variants indicated that they are encoded by nuclear genes. Two unlinked loci, Pgm1 and Pgm2, located on the long arm of chromosome 1 and the short arm of chromosome 5, respectively, specify the observed electrophoretic variation on starch gels. No intra- or interlocus hybrid bands were found, suggesting that each isozyme band consists of a single polypeptide. PGM isozymes were present in all plant parts studied and the activity specified by both loci appears to reside in the cytoplasm. In studies of 520 racial collections of maize from Latin America, a single allele at each locus predominated in most collections. Likewise, the same alleles predominated in a set of 406 inbred lines of maize from the United States and Canada.This work was supported in part by NIH Research Grant GM 11546.Paper No. 8496 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, North Carolina.     

Variation in coding exons of two electrophoretic alleles at the pigtail macaque carbonic anhydrase I locus as determined by direct,double-stranded sequencing of polymerase chain reaction (PCR) products

Two, electrophoretically distinct, forms of carbonic anhydrase I (CA Ia and CA Ib) are found at high polymorphic frequencies in red cells of natural populations of pigtail macaques,Macaca nemestrina, from southeast Asia. By use of the polymerase chain reaction, exons of the CA I gene were amplified from homozygous (a/a, b/b) and heterozygous (a/b) animals. Direct sequencing of the amplified DNA from four animals revealed differences between the a and the b electrophoretic alleles ranging from three to six nucleotides, and from one to three differences within each allele. These results indicate a greater genetic variability at the CA I locus in this macaque species than previously realized. We thank the personnel of the University of Washington, Regional Primate Research Center, Seattle, for sending us blood and tissue samples from pigtail macaques (supported by NIH Grant RR 00166). Our work was supported by NIH Grant GM 24681.     

Genetic,ontogenetic, and tissue-specific variation of dipeptidases in Drosophila melanogaster

Three dipeptidases in Drosophila melanogaster are under independent genetic control and their structural genes have been localized, Dip-A to 2R and Dip-B and Dip-C to 3R (Voelker and Langley, 1978; Ohnishi and Voelker, 1981). These enzymes were characterized with respect to their substrate specificities, genetic variability (electrophoretic mobility and quantitative activity level), ontogeny (activity and isozyme pattern), and tissue localization. The dipeptide substrate specificities of DIP-A and DIP-B overlap each other considerably, but do not overlap with DIP-C. In natural populations, DIP-B and DIP-C are essentially monomorphic electrophoretically whereas DIP-A is polymorphic for three allozymes. Both DIP-A and DIP-B show quantitative genetic variation of activity level within an allozyme class. All three enzymes are expressed at all stages in the life cycle, but DIP-A and DIP-B activities vary considerably according to developmental stage and sex of adult. The tissue localizations of DIP-A and DIP-B activities show similar patterns and a nearly ubiquitous occurrence of both enzymes, but with particularly high values in larval and adult midguts and in the adult female reproductive system. These results suggest a general metabolic role for the enzymes, such as regulation of the concentrated pools of amino acids and oligopeptides found in Drosophila tissues.This work was supported by Public Health Service Grant GM 11546.Paper No. 7066 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh.     

Isozyme variability in species of the genus Drosophila. I. A multiple allelic isozyme system in Drosophila busckii: Inheritance and general considerations

Starch gel electrophoretic analysis of a triallelic leucine aminopeptidase polymorphism in a laboratory population of Drosophila busckii is described. The three alleles involved are expressed without dominance. A series of single-pair matings revealed an excess of heterozygous types in most segregating families, suggesting selection against the homozygous genotypes. A few cases of heterogeneity among progeny extracted from a single family were the result of matings that produced Mendelian ratios. These few cases had no clear genetic explanation, but there is a suggestion of two isoalleles for the electrophoretically intermediate enzyme.The research reported here was begun at the University of Hawaii and completed at the University of Texas and was supported (in part) by Public Health Service Research Grant No. GM 11609 to W. S. Stone and M. R. Wheeler and by Training Grant No. 2 T1-GM-337-06 and GM 00337-07 to R. P. Wagner et al., from the National Institutes of Health.     

Comparison of growth curves of mice selected and unselected for postweaning gain

Summary Mice were sampled from a line selected for increased postweaning weight gain from three to six weeks and from a randombred control line originating from the same base population. Body weights were recorded at each of 14 ages from day 5 to day 98. The Richards and logistic growth functions were fitted to the growth trajectories of each individual mouse by a generalized non-linear least squares procedure. Estimated growth parameters (asymptotic weight, rate, shape of curve, age and weight at inflection, mean absolute growth rate and mean relative growth rate) were computed for each individual. The effects of line, litter within line, sex and line × sex interactions on these estimated parameters were then studied.Both the Richards and logistic functions fitted the data equally well and the plotted trajectories coincided over most of the growth curve. There was excellent agreement between the estimates of asymptotic weight and both age and weight at inflection based on the different functions. However, both functions apparently underestimated the asymptotic weight.Analyses of the line differences showed that selection for postweaning gain increased the mean absolute growth rate over the entire curve but had no effect on the relative growth rate or the shape of the growth curve. Full-sib analyses suggested the presence of considerable genetic variation and some high genetic correlations among the estimated growth parameters.Paper number 2942 of the Journal Series of the North Carolina State University Agricultural Experiment Station, Raleigh, North Carolina. This research was supported in part by Public Health Service Research Grant GM 11546. Computing services were supported by NIH Grant FR-00011.     

Fine structure of the ventral organ of the house fly larva,Musca domestica L.

Summary The ventral organs of the cephalic lobes of the house fly larvae, Musca domestica L., were studied by scanning and transmission electron microscopy. Four sensilla were found. Three of them are each innervated by a single dendrite whose ending possesses a tubular body and communicates to the exterior through an opening. These sensilla are assumed to be mechanoreceptors. The 4th sensillum is supplied by 2 bipolar neurons with the unbranched dendritic tips (without tubular bodies) exposed to the exterior through a single opening and is probably a contact chemoreceptor.This research was supported in part by the Office of Naval Research and NIH Training Grant ES-00069. Paper no. 3724 of the North Carolina State University Agricultural Experiment Station journal series.     

Histochemical activation of rat-liver lysosomes by dimethyl sulfoxide

Summary The Gomori reaction for acid phosphatase was enhanced by inclusion of dimethyl sulfoxide (DMSO) in reaction media for incubation of cryostat sections of unfixed rat-liver tissue. The reaction was also detectably increased by DMSO in formol-calcium fixed tissue. Enhancment of the Gomori reaction for acid phosphatase by DMSO was reversible.Supported by Grant GB-3817 from the National Science Foundation and by the University Research Coucil and the Cancer Institutional Grant Committee of the University of North Carolina     

Esterase alterations in the liver and kidneys of ducky,a neurological mutation in mice

We have investigated qualitative and quantitative changes which occur with development and disease progression in nonspecific esterases of livers and kidneys of ducky mice. Total activity in both organs is reduced compared with normal mice, and permanent and temporary deletions of isozyme bands occur. The isozyme profile depends upon the stage of the disease.Supported in part by NIH Research Grant NB 06448 from the National Institutes of Neurological Diseases and Stroke, and grants from the National Foundation for Neuromuscular Diseases, Inc., the Southwaite Foundation, and the United Health Services of North Carolina.Visiting Scientist, The Jackson Laboratory, Bar Harbor, Maine. On leave of absence from the Department of Physiology, Wakayama Medical College, Wakayama, Japan.     

Age-related variation in genetic control of height growth in Douglas-fir

Summary The development of genetic variances in height growth of Douglas-fir over a 53-year period is analyzed and found to fall into three periods. In the juvenile period, variances in environmental error increase logarithmically, genetic variance within populations exists at moderate levels, and variance among populations is low but increasing. In the early reproductive period, the response to environmental sources of error variance is restricted, genetic variance within populations disappears, and populational differences strongly emerge but do not increase as expected. In the later period, environmental error again increases rapidly, but genetic variance within populations does not reappear and population differences are maintained at about the same level as established in the early reproductive period. The change between the juvenile and early reproductive periods is perhaps associated with the onset of ecological dominance and significant allocations of energy to reproduction.This paper is published with the approval of the Director of Research, North Carolina Agricultural Experiment Station, as No. 3361 of the Journal Series. The computing services in this project were supported by NIH Grant GM-11 546, held by the Institute of Statistics, North Carolina State University at Raleigh.     

Genetic control and racial variation of β-glucosidase isozymes in maize (Zea mays L.)

-Glucosidase (-D-glucoside glucohydrolase, E.C. 3.2.1.21, -Glu) isozyme variants were studied in a large number of inbred lines, crosses, and races of maize (Zea mays L.). The pattern of Mendelian inheritance demonstrated for -GLU variants indicated that they are under nuclear gene control. Twenty-two allelic forms at a single locus were identified in the materials studied by starch gel electrophoresis. Genetic data indicate that -GLU in maize is functionally a dimer. Variation of -GLU isozymes in 51 racial collections of maize from Mexico showed little correlation with morphological or geographical data. In 39 collections from Central America, variation patterns appeared to have some association with altitude.This work was supported in part by NIH Research Grant GM 11546.Paper No. 5040 of the Journal Series of the North Carolina Agricultural Experiment Station, Raleigh, North Carolina.     

Suppressor Systems of Segregation Distorter (SD) Chromosomes in Natural Populations of DROSOPHILA MELANOGASTER

Several natural populations of D. melanogaster were investigated for the presence (or absence) of the Segregation Distorter ( SD) chromosomes and their suppressor systems. The SD chromosomes were found, at frequencies of a few percent, in two independent samples taken in different years from a Raleigh, North Carolina, population, whereas no SD chromosomes were found in samples collected from several populations in Texas. The populations in these localities were found to contain suppressor X chromosomes in high frequencies (75% or higher). They also contained relatively low frequencies of partial suppressor or insensitive second chromosomes of varying degrees, but completely insensitive second chromosomes were practically absent in all populations examined. The frequencies of suppressor X chromosomes, as well as those of the partially insensitive or suppressor second chromosomes, were the same among the populations investigated. This suggests the possibility that the development of a suppressor system of SD in a population could be independent of the presence of an SD chromosome. Segregation distortion appeared to be occurring in natural genetic backgrounds, but the degree of distortion varied among males of different genotypes. There were many instances in which the SD chromosomes showed transmission frequencies from their heterozygous male parents that were smaller than 0.6 and, in several cases, even smaller than 0.5. The presence of a recessive suppressor, or suppressors, of SD in natural populations was suggested.