Genetic Variation in Steelhead (Salmo gairdneri) from the North Coast of Washington

1989 ◽  
Vol 46 (1) ◽  
pp. 66-73 ◽  
Author(s):  
R. R. Reisenbichler ◽  
S. R. Phelps
Keyword(s):  
Genetic Variation ◽  
Wild Fish ◽  
Salmo Gairdneri ◽  
North Coast ◽  
Starch Gel Electrophoresis ◽  
Protein Coding ◽  
Hatchery Fish ◽  
The North ◽  
Starch Gel ◽  
S Allele

Steelhead (Salmo gairdneri) collected from various sites in nine drainages in northwestern Washington were genetically characterized at 65 protein-coding loci by starch-gel electrophoresis. Genetic differentiation within and among drainages was not significant, and genetic variation among drainages was much less than that reported in British Columbia; these results may be the consequence of gene flow from hatchery stocks that have been released in Washington since the 1940's. Allele frequencies varied significantly among year-classes (hence, genetic characterization studies must include data from several year-classes), and also between hatchery fish (including a stock developed with local wild fish) and wild fish, indicating that few wild fish have been successfully and routinely included in hatchery brood stocks. Conservation of genetic diversity along the north coast of Washington should be facilitated by reducing the numbers of hatchery fish that spawn in streams and by including wild fish in hatchery brood stocks.

scholarly journals PROTEIN POLYMORPHISMS, SEGREGATION IN GENETIC CROSSES AND GENETIC DISTANCES AMONG FISHES OF THE GENUS XIPHOPHORUS (POECILIIDAE)

Genetics ◽  
1982 ◽  
Vol 102 (3) ◽  
pp. 539-556
Author(s):  
Don C Morizot ◽  
Michael J Siciliano
Keyword(s):  
Goodness Of Fit ◽  
Inbred Strains ◽  
Interspecific Backcross ◽  
Genetic Distances ◽  
Rapid Expansion ◽  
Starch Gel Electrophoresis ◽  
Lower Vertebrate ◽  
Protein Coding ◽  
Group I ◽  
Starch Gel

ABSTRACT The products of 49 protein-coding loci were examined by starch gel electrophoresis for populational variation in six species of Xiphophorus fishes and/or segregation in intra- and interspecific backcross and intercross hybrids. Electrophoretic variation was observed for 29 of the 35 locus products in a survey of 42 population samples. The highest frequency of polymorphic loci observed in noninbred populations was 0.143. After ten or more generations of inbreeding, all loci studied were monomorphic. Inbred strains generally exhibited the commonest electrophoretic alleles of the population from which they were derived. An assessment of genetic distances among Xiphophorus populations reflected classical systematic relationships and suggested incipient subspeciation between X. maculatus from different drainages as well as several species groups. Thirty-three loci were analyzed with respect to segregation in hybrids. The goodness of fit of segregations to Mendelian expectations at all loci analyzed (except loci in linkage group I) is interpreted as evidence for high genetic compatibility of the genomes of Xiphophorus species. It is anticipated that these data will result in a rapid expansion of the assignment of protein-coding loci to linkage groups in these lower vertebrate species.

Survey of the Genetic Variation Among Eastern Lake Superior Lake Trout (Salvelinus namaycush)

1981 ◽  
Vol 38 (12) ◽  
pp. 1738-1746 ◽  
Author(s):  
Terrence R. Dehring ◽  
Anne F. Brown ◽  
Charles H. Daugherty ◽  
Stevan R. Phelps
Keyword(s):  
Genetic Variation ◽  
Gel Electrophoresis ◽  
Lake Trout ◽  
Lake Superior ◽  
Salvelinus Namaycush ◽  
Starch Gel Electrophoresis ◽  
Average Heterozygosity ◽  
Management Implications ◽  
Salmonid Species ◽  
Starch Gel

Patterns of genetic variation among lake trout (Salvelinus namaycush) of eastern Lake Superior were examined using starch gel electrophoresis. We used 484 individuals sampled from three areas, representing three morphological types (leans, humpers, and siscowets). Of 50 loci examined, 44 were monomorphic in all groups sampled. Genetic variation occurs at six loci AAT-1,2, MDH-3,4, ME-1, and SOD-1. The average heterozygosity found (H = 0.015) is low relative to other salmonid species. A significant amount of heterogeneity exists among the 10 lake trout samples. These differences are due to variation within as well as between morphological types. The significance and management implications of these data are discussed.Key words: genetic variation, lake trout, Salvelinus namaycush, Lake Superior

Genetic variation in pika populations

1977 ◽  
Vol 55 (11) ◽  
pp. 1841-1845 ◽  
Author(s):  
D. G. Glover ◽  
M. H. Smith ◽  
L. Ames ◽  
J. Joule ◽  
J. M. Dubach
Keyword(s):  
Genetic Variation ◽  
Gel Electrophoresis ◽  
Starch Gel Electrophoresis ◽  
Genetic Loci ◽  
Starch Gel

Analysis of 26 genetic loci by horizontal starch gel electrophoresis was performed on 197 pikas from one Montana and four Colorado populations. Only four loci were polymorphic within populations and individual heterozygosity was low for a mammal [Formula: see text]. The Montana and Colorado populations were fixed for alternate allelles at three loci. Because of the insular nature of pika habitat, drift is probably important in determining low heterozygosities and genetic similarities measured between widely separated pika populations.

scholarly journals Enzyme variability in the Drosophila willistoni Group. V. Genic variation in natural populations of Drosophila equinoxialis

1972 ◽  
Vol 20 (1) ◽  
pp. 19-42 ◽  
Author(s):  
Francisco J. Ayala ◽  
Jeffrey R. Powell ◽  
Martin L. Tracey
Keyword(s):  
Genetic Variation ◽  
Allelic Variation ◽  
Natural Populations ◽  
Starch Gel Electrophoresis ◽  
Gene Frequencies ◽  
Group V ◽  
Neutral Genetic Variation ◽  
Starch Gel ◽  
Genic Variation ◽  
Standard Techniques

SUMMARYWe have studied genetic variation at 27 loci in 42 samples from natural populations of a neotropical species, Drosophila equinoxialis, using standard techniques of starch-gel electrophoresis to detect allelic variation in genes coding for enzymes. There is considerarle genetic variability in D. equinoxialis. We have found allelic variation in each of the 27 loci, although not in every population. On the average, 71% of the loci are polymorphic – that is, the most common allele has a frequency no greater than 0·95 – in a given population. An individual is heterozygous on the average at 21·8% of its loci.The amount of genetic variation fluctuates widely from locus to locus. At the Mdh-2 locus arout 1% of the individuals are heterozygotes; at the other extreme more than 56% of the individuals are heterozygous at the Est-3. At any given locus the configuration of allelic frequencies is strikingly similar from locality to locality. At each and every locus the same allele is generally the most common throughout the distribution of the species. Yet differences in gene frequencies occur between localities. The pattern of genetic variation is incompatible with the hypothesis that the variation is adaptively neutral. Genetic variation in D. equinoxialis is maintained by balancing natural selection.The amount and pattern of genetic variation is similar in D. equinoxialis and its sibling species, D. willistoni. Yet the two species are genetically very different. Different sets of alleles occur at nearly 40% of the loci.

Isozyme variation in eastern hemlock

1992 ◽  
Vol 22 (12) ◽  
pp. 1838-1842 ◽  
Author(s):  
Catherine Zabinski
Keyword(s):  
Genetic Variation ◽  
Polymorphic Locus ◽  
Continuous Distribution ◽  
Eastern Hemlock ◽  
Unexpected Result ◽  
Starch Gel Electrophoresis ◽  
Coniferous Species ◽  
Disjunct Populations ◽  
Starch Gel ◽  
Two Populations

Tsugacanadensis (L.) Carr., commonly known as eastern hemlock, is a coniferous tree native to eastern North America. The western and southern edges of its geographic distribution are characterized by disjunct populations 50–100 km or more from the continuous distribution. Genetic variation was measured using starch gel electrophoresis of needle tissue enzymes from 17 populations throughout the species' distribution. Six enzyme systems including 10 putative loci were assayed, with only 1 of the 10 loci being polymorphic. The polymorphic locus, cytochrome oxidase, consisted of two alleles present in all but two populations. Allele frequencies averaged 0.69 and 0.31. The low level of genetic variation in eastern hemlock was an unexpected result, given that most coniferous species are highly variable.

Population genetics of two tropical sharks, Carcharhinus tilstoni and C. sorrah, in Northern Australia

1989 ◽  
Vol 40 (5) ◽  
pp. 541 ◽  
Author(s):  
S Lavery ◽  
JB Shaklee
Keyword(s):  
Eastern Coast ◽  
Population Subdivision ◽  
Starch Gel Electrophoresis ◽  
Northern Australia ◽  
Tissue Samples ◽  
North West ◽  
The North ◽  
North Eastern ◽  
Starch Gel ◽  
Sufficient Variation

The genetic structure of the Australian populations of Carcharhinus tilstoni and C. sorrah was investigated by starch gel electrophoresis. Tissue samples were taken from 1580 sharks from throughout the fishery, which extends from the North-West Shelf (off Western Australia) to the north-eastern coast of Queensland. From a total of 47 enzyme loci screened in each species, 13 proved to be polymorphic (P0.99) for at least one species, with only 5 loci for each species showing sufficient variation (P0.95) to be of use in the analysis of population structure. Mean heterozygosity values were relatively low: 0.037 for C. tilstoni and 0.035 for C. sorrah. A low level of population subdivision was found within each species, with FST values of 0.0094 for C. tilstoni and 0.0076 for C. sorrah. There was insufficient evidence to suggest that there is more than one population of either species of shark in Australian waters.

Little genetic variation in the oil sardine, Sardinella longiceps Val., from the western coast of India

1994 ◽  
Vol 45 (2) ◽  
pp. 257 ◽  
Author(s):  
MR Menezes
Keyword(s):  
Genetic Variation ◽  
Gel Electrophoresis ◽  
Western Coast ◽  
Starch Gel Electrophoresis ◽  
Marine Fish Species ◽  
Average Heterozygosity ◽  
Enzyme Gene ◽  
Starch Gel ◽  
Sardinella Longiceps ◽  
Gene Variability

Enzyme gene variability in the oil sardine, Sardinella longiceps, from three localities along the western coast of India was studied by starch-gel electrophoresis. Out of 19 loci scored, no locus was polymorphic by the 95% criterion. Seven loci were polymorphic at the P=0.99 level. The average heterozygosity ranged from 0.6% to 0.9%. These values are very low compared with those of other marine fish species.

Genetic variation in populations of the endemic Achillea millefolium ssp. megacephala from the Athabasca sand dunes and the widespread ssp. lanulosa in western North America

1996 ◽  
Vol 74 (7) ◽  
pp. 1138-1146 ◽  
Author(s):  
Brett G. Purdy ◽  
Randall J. Bayer
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Diversity ◽  
Sand Dunes ◽  
Achillea Millefolium ◽  
Starch Gel Electrophoresis ◽  
Widespread Species ◽  
Polymorphic Loci ◽  
Endemic Taxon ◽  
Starch Gel

As part of an analysis of genetic diversity in endemic taxa of the Athabasca sand dunes in northern Saskatchewan, Canada, genetic variation was examined by starch gel electrophoresis in six populations of the endemic Achillea millefolium ssp. megacephala, and 13 populations of the closely related widespread taxon, A. millefolium ssp. lanulosa. Endemic populations had more alleles per locus, a higher percentage of polymorphic loci, and greater genetic diversity than did populations of the widespread taxon. At polymorphic loci, total gene diversity was comparable in both taxa, although within-population gene diversity was higher in the endemic taxon. Population differentiation (GST) was considerably lower in ssp. megacephala than in ssp. lanulosa, although GST values were reduced when the parameter was calculated separately for geographic subdivisions of the widespread taxon. Our results differ from previous studies in which the endemic is typically depauperate of genetic variation relative to related widespread species. We suggest that obligate sexual reproduction and the absence of long-term asexual reproduction may be one of a number of factors that help populations of ssp. megacephala maintain higher levels of genetic variation on the Athabasca sand dunes. Keywords: genetic variation, endemic, rare species, Athabasca sand dunes, Achillea millefolium.

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