Ecological Genetics of the Wild Rabbit in Australia. II. Protein Variation in British, French and Australian Rabbits and the Geographical Distribution of the Variation in Australia

1980 ◽  
Vol 33 (3) ◽  
pp. 371 ◽  
Author(s):  
BJ Richardson ◽  
PM Rogers ◽  
GM Hewitt
Keyword(s):  
Genetic Distances ◽  
Ecological Genetics ◽  
Wild Rabbit ◽  
Effective Population ◽  
Average Heterozygosity ◽  
Control Programs ◽  
Phosphogluconate Dehydrogenase ◽  
Protein Variation ◽  
Population Sizes ◽  
Mediterranean France

A survey for genetic variation was carried out using 21 proteins controlled by 26 loci in rabbits from Britain, Mediterranean France and Australia. Five enzymes, adenosine deaminase, phosphogluconate dehydrogenase, carboxylesterase, carbonate dehydratase and dihydrolipoamide reductase (NAD+) were found to be polymorphic. The average heterozygosity in wild rabbits was 6%. The genetic distances separating the various populations indicated that three different stocks were present in these populations. The rabbits from Britain and mainland Australia belonged to one group, those from France to a second group and the rabbits from southern Tasmania were a distinctive third group. Highly significant differences in gene frequency were found between the various local populations studied from mainland Australia. This variation showed no clear pattern and was attributed to genetic drift due to small effective population sizes. Bottlenecks in population size occur regularly in local rabbit populations in Australia through, for example, drought, myxomatosis outbreaks or rabbit control programs.

scholarly journals Ecological Genetics of the Wild Rabbit in Australia. III. Comparison of the Microgeographical Distribution of Alleles in Two Different Environments

1980 ◽  
Vol 33 (3) ◽  
pp. 385 ◽  
Author(s):  
BJ Richardson
Keyword(s):  
Adenosine Deaminase ◽  
Survival Rates ◽  
Ecological Genetics ◽  
High Survival ◽  
Wild Rabbit ◽  
Gene Frequencies ◽  
High Productivity ◽  
Phosphogluconate Dehydrogenase ◽  
Carboxylesterase 1 ◽  
Pattern Of Variation

The differences in distribution of gene frequencies at three polymorphic loci (adenosine deaminase, carboxylesterase-1 and phosphogluconate dehydrogenase) were determined for rabbit populations living in two markedly different environments. One, a highland population from Snowy Plains N.S.W., has low productivity and high survival rates, and the second, a dry plains population from Urana, N.S.W., has high productivity and low survival rates. The amount of sub population differentiation at each locus was distinctive, and was different in the two environments with significant differentiation occurring for phosphogluconate dehydrogenase at both areas, for carboxylesterase-1 at Snowy Plains and for adenosine deaminase at Urana. The general significance of these results was demonstrated by determining the distribution of the variation in a third population. This population was subject to the same historical climatic events as the Urana population and showed a similar pattern of variation. Various explanations of the data are considered and a combination of chance and selection, rather than either alone, seems to offer the most satisfactory explanation. The demographic differences between the populations seemed to play no part in explaining the patterns observed.

scholarly journals Microsatellite variation in honey bee (Apis mellifera L.) populations: hierarchical genetic structure and test of the infinite allele and stepwise mutation models.

Genetics ◽  
1995 ◽  
Vol 140 (2) ◽  
pp. 679-695 ◽  
Author(s):  
A Estoup ◽  
L Garnery ◽  
M Solignac ◽  
J M Cornuet
Keyword(s):  
Apis Mellifera ◽  
Phylogenetic Trees ◽  
Microsatellite Data ◽  
Effective Population ◽  
Average Heterozygosity ◽  
Microsatellite Variation ◽  
Infinite Allele Model ◽  
Population Sizes ◽  
Stepwise Mutation ◽  
Allele Model

Abstract Samples from nine populations belonging to three African (intermissa, scutellata and capensis) and four European (mellifera, ligustica, carnica and cecropia) Apis mellifera subspecies were scored for seven microsatellite loci. A large amount of genetic variation (between seven and 30 alleles per locus) was detected. Average heterozygosity and average number of alleles were significantly higher in African than in European subspecies, in agreement with larger effective population sizes in Africa. Microsatellite analyses confirmed that A. mellifera evolved in three distinct and deeply differentiated lineages previously detected by morphological and mitochondrial DNA studies. Dendrogram analysis of workers from a given population indicated that super-sisters cluster together when using a sufficient number of microsatellite data whereas half-sisters do not. An index of classification was derived to summarize the clustering of different taxonomic levels in large phylogenetic trees based on individual genotypes. Finally, individual population x loci data were used to test the adequacy of the two alternative mutation models, the infinite allele model (IAM) and the stepwise mutation models. The better fit overall of the IAM probably results from the majority of the microsatellites used including repeats of two or three different length motifs (compound microsatellites).

scholarly journals HIV-2 Diversity Displays Two Clades within group A with Distinct Geographical Distribution and Evolution

2021 ◽  
Author(s):  
Benoit Visseaux ◽  
Mélanie Bertine ◽  
Quentin Le Hingrat ◽  
Valentine Ferré ◽  
Charlotte Charpentier ◽  
...  
Keyword(s):  
Ivory Coast ◽  
Genetic Distances ◽  
Human Populations ◽  
Effective Population ◽  
African Countries ◽  
Guinea Bissau ◽  
Western Africa ◽  
Early Diversification ◽  
Population Sizes ◽  
Group A

Abstract Genetic diversity of HIV-2 groups A and B has not yet been fully described, especially in a few Western Africa countries such as Ivory-Coast or Mali. We collected 444 pol, 152 vif, 129 env, and 74 LTR sequences from patients of the French ANRS CO5 HIV-2 cohort completed by 221 pol, 18 vif, 377 env, and 63 LTR unique sequences from public databases. We performed phylogenetic reconstructions and revealed two distinct lineages within HIV-2 group A, herein called A1 and A2, presenting non-negligible genetic distances and distinct geographic distributions as A1 is related to coastal Western African countries and A2 to inland Western countries. Estimated early diversification times for groups A and B in human populations were 1940 [95% HPD: 1935-53] and 1961 [1952-70]. A1 experienced an early diversification in 1942 [1937-58] with two distinct early epidemics in Guinea-Bissau or Senegal, raising the possibility of group A emergence in those countries from an initial introduction from Ivory-Coast to Senegal, two former French colonies. Changes in effective population sizes over time revealed that A1 exponentially grew concomitantly to Guinea-Bissau independence war, but both A2 and B lineages experienced a latter growth, starting during the 80’s economic crisis. They all decreased after the 2000’s but at a slow rate for A2 and B lineages. This large HIV-2 genetic analysis provides suggest the existence of two distinct subtypes within group A and new data about HIV-2 early spreading patterns and recent epidemiologic evolution for which data are scarce outside Guinea-Bissau.

Genetic variation in the greenback flounder Rhombosolea tapirina GÜnther (Teleostei, Pleuronectidae) and the implications for aquaculture

2000 ◽  
Vol 51 (1) ◽  
pp. 23 ◽  
Author(s):  
Tony van den Enden ◽  
Robert W. G. White ◽  
Nicholas G. Elliott
Keyword(s):  
Genetic Variation ◽  
New Zealand ◽  
Genetic Distance ◽  
West Coast ◽  
Gel Electrophoresis ◽  
Effective Population ◽  
Average Heterozygosity ◽  
The West ◽  
Order Of Magnitude ◽  
Population Sizes

Samples of the greenback flounder, Rhombosolea tapirina, were collected from five Tasmanian sites and from one site each off Victoria and New Zealand. Thirty enzyme-coding loci were analysed by gel electrophoresis. Seventeen loci were variable, nine of which were polymorphic in at least four samples. Average heterozygosity across all 30 loci was relatively high at 0.086 ± 0.032. There were significant genetic differences between the Australian and New Zealand samples, with a genetic distance of 0.041, which was an order of magnitude larger than that observed between any Australian samples. Samples from the west coast of Tasmania and from Victoria were genetically isolated from each other and from the remaining four Tasmanian samples; the latter showed little variation among themselves. Reductions in genetic variation (heterozygosity and alleles) were observed in two cultured cohorts when compared with the wild-caught samples, with corresponding low estimates of effective population sizes compared with putative breeding numbers. No genetic variation was detected between normal and malpigmented individuals from the same culture cohort.

scholarly journals Ecological Genetics of the Wild Rabbit in Australia I. Geographical Distribution and Biochemical Characterization of Phosphogluconate Dehydrogenase Variants

1974 ◽  
Vol 27 (6) ◽  
pp. 671 ◽  
Author(s):  
Marjorie Coggan ◽  
J Baldwin ◽  
BJ Richardson
Keyword(s):  
Biochemical Characterization ◽  
Natural Populations ◽  
Release Site ◽  
Rare Allele ◽  
Ecological Genetics ◽  
Wild Rabbit ◽  
Thermal Stabilities ◽  
Phosphogluconate Dehydrogenase ◽  
Eastern Australia ◽  
Initial Release

Three electrophoretically distinguishable phQsphogluconate dehydrogenase (EC 1.1.1.44) isoenzyme patterns, probably resulting from the expression of two alleles at one locus, were found in natural populations of rabbits in Eastern Australia. The homopolymers and heteropolymer were isolated and characterized kinetically. The three proteins were found to be indistinguishable with respect to Km for 6-phospho-D-gluconate and NADP+ (both in the presence and absence of magnesium), energies of activation, specific activities in liver, pH profiles and thermal stabilities. The rare allele was not found near the major initial release site of the rabbit in Australia and may have arisen in Australia.

scholarly journals Isoenzymatic variability in tropical maize populations under reciprocal recurrent selection

2003 ◽  
Vol 60 (2) ◽  
pp. 291-297 ◽  
Author(s):  
Luciana Rossini Pinto ◽  
Maria Lúcia Carneiro Vieira ◽  
Cláudio Lopes de Souza Jr. ◽  
Rainério Meireles da Silva
Keyword(s):  
Genetic Variability ◽  
Recurrent Selection ◽  
Zea Mays L ◽  
Genetic Distances ◽  
Reciprocal Recurrent Selection ◽  
Tropical Maize ◽  
Effective Population ◽  
Selection Procedures ◽  
Maize Populations ◽  
Population Sizes

Maize (Zea mays L.) is one of the crops in which the genetic variability has been extensively studied at isoenzymatic loci. The genetic variability of the maize populations BR-105 and BR-106, and the synthetics IG-3 and IG-4, obtained after one cycle of a high-intensity reciprocal recurrent selection (RRS), was investigated at seven isoenzymatic loci. A total of twenty alleles were identified, and most of the private alleles were found in the BR-106 population. One cycle of reciprocal recurrent selection (RRS) caused reductions of 12% in the number of alleles in both populations. Changes in allele frequencies were also observed between populations and synthetics, mainly for the Est 2 locus. Populations presented similar values for the number of alleles per locus, percentage of polymorphic loci, and observed and expected heterozygosities. A decrease of the genetic variation values was observed for the synthetics as a consequence of genetic drift effects and reduction of the effective population sizes. The distribution of the genetic diversity within and between populations revealed that most of the diversity was maintained within them, i.e. BR-105 x BR-106 (G ST = 3.5%) and IG-3 x IG-4 (G ST = 4.0%). The genetic distances between populations and synthetics increased approximately 21%. An increase in the genetic divergence between the populations occurred without limiting new selection procedures.

scholarly journals EFFECTS OF POPULATION SIZE AND SELECTION INTENSITY ON SHORT-TERM RESPONSE TO SELECTION FOR POSTWEANING GAIN IN MICE

Genetics ◽  
1973 ◽  
Vol 73 (3) ◽  
pp. 513-530
Author(s):  
J P Hanrahan ◽  
E J Eisen ◽  
J E Legates
Keyword(s):  
Population Size ◽  
Selection Response ◽  
Selection Intensity ◽  
Realized Heritability ◽  
Family Selection ◽  
Effective Population ◽  
Population Sizes ◽  
Selection For ◽  
Selection Intensities ◽  
Term Response

ABSTRACT The effects of population size and selection intensity on the mean response was examined after 14 generations of within full-sib family selection for postweaning gain in mice. Population sizes of 1, 2, 4, 8 and 16 pair matings were each evaluated at selection intensities of 100% (control), 50% and 25% in a replicated experiment. Selection response per generation increased as selection intensity increased. Selection response and realized heritability tended to increase with increasing population size. Replicate variability in realized heritability was large at population sizes of 1, 2 and 4 pairs. Genetic drift was implicated as the primary factor causing the reduced response and lowered repeatability at the smaller population sizes. Lines with intended effective population sizes of 62 yielded larger selection responses per unit selection differential than lines with effective population sizes of 30 or less.

scholarly journals The effect of life-history and mode of inheritance on neutral genetic variability

2001 ◽  
Vol 77 (2) ◽  
pp. 153-166 ◽  
Author(s):  
BRIAN CHARLESWORTH
Keyword(s):  
Sequence Variation ◽  
Adult Mortality ◽  
Structured Populations ◽  
Human Populations ◽  
Effective Population ◽  
Transmission Modes ◽  
Population Sizes ◽  
Age Structured ◽  
Infinite Sites Model ◽  
Site Diversity

Formulae for the effective population sizes of autosomal, X-linked, Y-linked and maternally transmitted loci in age-structured populations are developed. The approximations used here predict both asymptotic rates of increase in probabilities of identity, and equilibrium levels of neutral nucleotide site diversity under the infinite-sites model. The applications of the results to the interpretation of data on DNA sequence variation in Drosophila, plant, and human populations are discussed. It is concluded that sex differences in demographic parameters such as adult mortality rates generally have small effects on the relative effective population sizes of loci with different modes of inheritance, whereas differences between the sexes in variance in reproductive success can have major effects, either increasing or reducing the effective population size for X-linked loci relative to autosomal or Y-linked loci. These effects need to be accounted for when trying to understand data on patterns of sequence variation for genes with different transmission modes.

Contemporary and historical effective population sizes of Atlantic sturgeon Acipenser oxyrinchus oxyrinchus

2018 ◽  
Vol 20 (2) ◽  
pp. 167-184 ◽  
Author(s):  
John Waldman ◽  
S. Elizabeth Alter ◽  
Douglas Peterson ◽  
Lorraine Maceda ◽  
Nirmal Roy ◽  
...  
Keyword(s):  
Atlantic Sturgeon ◽  
Effective Population ◽  
Population Sizes ◽  
Acipenser Oxyrinchus
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