scholarly journals H-2 polymorphisms are more uniformly distributed than allozyme polymorphisms in natural populations of house mice.

Genetics ◽  
1988 ◽  
Vol 118 (1) ◽  
pp. 131-140
Author(s):  
J H Nadeau ◽  
J Britton-Davidian ◽  
F Bonhomme ◽  
L Thaler
Keyword(s):  
Gene Diversity ◽  
Natural Populations ◽  
House Mice ◽  
Allozyme Polymorphism ◽  
Mus Musculus Domesticus ◽  
Wild Mice ◽  
Analysis Of Similarity ◽  
Allozyme Polymorphisms ◽  
Similarity Networks ◽  
Encoding Genes

Abstract Patterns of H-2 and allozyme polymorphism in natural populations of house mice from Europe, North Africa and South America were analyzed. The purpose of the analysis was to determine whether H-2 and allozyme polymorphisms were similarly distributed both geographically and temporally in wild mice. Two subspecies of house mice, Mus musculus domesticus and M. m. musculus were sampled and the polymorphisms of two H-2 class I genes, H-2K and H-2D, and 34 allozyme-encoding genes were surveyed. The three kinds of analyses that were conducted included a hierarchical gene diversity analysis, an analysis of the effects of barriers to gene flow, and an analysis of similarity networks. Each of the comparisons demonstrated that H-2 polymorphisms were more uniformly distributed than allozyme polymorphisms and provided additional evidence that H-2 and allozyme polymorphisms are subject to different evolutionary pressures. The analysis of similarity networks also demonstrated that H-2 genes provide little information about the phylogeny of wild mice.

scholarly journals Microsatellites and the Genetics of Highly Selfing Populations in the Freshwater Snail Bulinus truncatus

Genetics ◽  
1996 ◽  
Vol 142 (4) ◽  
pp. 1237-1247 ◽  
Author(s):  
Frédérique Viard ◽  
Philippe Bremond ◽  
Rabiou Labbo ◽  
Fabienne Justy ◽  
Bernard Delay ◽  
...  
Keyword(s):  
Microsatellite Markers ◽  
Gene Diversity ◽  
Natural Populations ◽  
Freshwater Snail ◽  
Allozyme Polymorphism ◽  
Good Opportunity ◽  
Bulinus Truncatus ◽  
Linkage Disequilibria ◽  
Limited Gene Flow ◽  
Different Populations

Abstract Hermaphrodite tropical freshwater snails provide a good opportunity to study the effects of mating system and genetic drift on population genetic structure because they are self-fertile and they occupy transient patchily distributed habitats (ponds). Up to now the lack of detectable allozyme polymorphism prevented any intrapopulation studies. In this paper, we examine the consequences of selfing and bottlenecks on genetic polymorphism using microsatellite markers in 14 natural populations (under a hierarchical sampling design) of the hermaphrodite freshwater snail Bulinus truncatus. These population genetics data allowed us to discuss the currently available mutation models for microsatellite sequences. Microsatellite markers revealed an unexpectedly high levels of genetic variation with ≤41 alleles for one locus and gene diversity of 0.20–0.75 among populations. The values of any estimator of F  is, indicate high selfing rates in all populations. Linkage disequilibria observed at all loci for some populations may also indicate high levels of inbreeding. The large extent of genetic differentiation measured by F  st, R  st or by a test for homogeneity between genic distributions is explained by both selfing and bottlenecks. Despite a limited gene flow, migration events could be detected when comparing different populations within ponds.

scholarly journals The contribution of genetic and environmental effects to Bergmann’s rule and Allen’s rule in house mice

2021 ◽  
Author(s):  
Mallory A Ballinger ◽  
Michael W Nachman
Keyword(s):  
Natural Populations ◽  
Tail Length ◽  
Rapid Expansion ◽  
Bergmann’S Rule ◽  
House Mice ◽  
Clinal Variation ◽  
Bergmann's Rule ◽  
Mus Musculus Domesticus ◽  
Genetic Changes ◽  
Allen’S Rule

Distinguishing between genetic, environmental, and genotype-by-environment effects is central to understanding geographic variation in phenotypic clines. Two of the best-documented phenotypic clines are Bergmann’s rule and Allen’s rule, which describe larger body sizes and shortened extremities in colder climates, respectively. Although numerous studies have found inter- and intraspecific evidence for both ecogeographic patterns, we still have little understanding about whether these patterns are driven by genetics, environment, or both. Here, we measured the genetic and environmental contributions to Bergmann’s rule and Allen’s rule across introduced populations of house mice (Mus musculus domesticus) in the Americas. First, we documented clines for body mass, tail length, and ear length in natural populations, and found that these conform to both Bergmann’s rule and Allen’s rule. We then raised descendants of wild-caught mice in the lab and showed that these differences persisted in a common environment, indicating that they have a genetic basis. Finally, using a full-sib design, we reared mice under warm and cold conditions. We found very little plasticity associated with body size, suggesting that Bergmann’s rule has been shaped by strong directional selection in house mice. However, extremities showed considerable plasticity, as both tails and ears grew shorter in cold environments. These results indicate that adaptive phenotypic plasticity as well as genetic changes underlie major patterns of clinal variation in house mice and likely facilitated their rapid expansion into new environments across the Americas.

scholarly journals Variance analysis of immunoglobulin alleles in natural populations of rabbit (Oryctolagus cuniculus): the extensive interallelic divergence at the b locus could be the outcome of overdominance-type selection.

Genetics ◽  
1993 ◽  
Vol 135 (1) ◽  
pp. 171-187 ◽  
Author(s):  
W van der Loo
Keyword(s):  
Heavy Chain ◽  
Light Chain ◽  
Gene Diversity ◽  
Natural Populations ◽  
Constant Region ◽  
Immunoglobulin Light Chain ◽  
Evolutionary Patterns ◽  
B Locus ◽  
Type Selection ◽  
Predominant Allele

Abstract Population genetic data are presented which should contribute to evaluation of the hypothesis that the extraordinary evolutionary patterns observed at the b locus of the rabbit immunoglobulin light chain constant region can be the outcome of overdominance-type selection. The analysis of allele correlations in natural populations revealed an excess of heterozygotes of about 10% at the b locus while heterozygote excess was not observed at loci determining the immunoglobulin heavy chain. Data from the published literature, where homozygote advantage was suggested, were reevaluated and found in agreement with data here presented. Gene diversity was evenly distributed among populations and showed similarities with patterns reported for histocompatibility loci. Analysis of genotypic disequilibria revealed strong digenic associations between the leading alleles of heavy and light chain constant region loci in conjunction with trigenic disequilibria corresponding to a preferential association of b locus heterozygosity with the predominant allele of the heavy chain e locus. It is argued that this may indicate compensatory or nonadditive aspects of a putative heterozygosity enhancing mechanism, implying that effects at the light chain might be more pronounced in populations fixed for the heavy chain polymorphism.

scholarly journals Insights into mammalian biology from the wild house mouse Mus musculus

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Megan Phifer-Rixey ◽  
Michael W Nachman
Keyword(s):  
House Mouse ◽  
Mus Musculus ◽  
Genetic Model ◽  
Inbred Strains ◽  
Mendelian Inheritance ◽  
Model Organisms ◽  
House Mice ◽  
Small Subset ◽  
Wild Mice ◽  
Wide Range

The house mouse, Mus musculus, was established in the early 1900s as one of the first genetic model organisms owing to its short generation time, comparatively large litters, ease of husbandry, and visible phenotypic variants. For these reasons and because they are mammals, house mice are well suited to serve as models for human phenotypes and disease. House mice in the wild consist of at least three distinct subspecies and harbor extensive genetic and phenotypic variation both within and between these subspecies. Wild mice have been used to study a wide range of biological processes, including immunity, cancer, male sterility, adaptive evolution, and non-Mendelian inheritance. Despite the extensive variation that exists among wild mice, classical laboratory strains are derived from a limited set of founders and thus contain only a small subset of this variation. Continued efforts to study wild house mice and to create new inbred strains from wild populations have the potential to strengthen house mice as a model system.

scholarly journals Intragenomic and intraspecific heterogeneity in rrs may surpass interspecific variability in a natural population of Veillonella

Microbiology ◽  
2010 ◽  
Vol 156 (7) ◽  
pp. 2080-2091 ◽  
Author(s):  
Anne-Laure Michon ◽  
Fabien Aujoulat ◽  
Laurent Roudière ◽  
Olivier Soulier ◽  
Isabelle Zorgniotti ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Diversity ◽  
Natural Populations ◽  
Variable Region ◽  
Housekeeping Gene ◽  
Single Copy ◽  
Population Based ◽  
Rrna Gene ◽  
Gene Copies

As well as intraspecific heterogeneity, intragenomic heterogeneity between 16S rRNA gene copies has been described for a range of bacteria. Due to the wide use of 16S rRNA gene sequence analysis for taxonomy, identification and metagenomics, evaluating the extent of these heterogeneities in natural populations is an essential prerequisite. We investigated inter- and intragenomic 16S rRNA gene heterogeneity of the variable region V3 in a population of 149 clinical isolates of Veillonella spp. of human origin and in 13 type or reference Veillonella strains using PCR-temporal temperature gel electrophoresis (TTGE). 16S rRNA gene diversity was high in the studied population, as 45 different banding patterns were observed. Intragenomic heterogeneity was demonstrated for 110 (74 %) isolates and 8 (61.5 %) type or reference strains displaying two or three different gene copies. Polymorphic nucleotide positions accounted for 0.5–2.5 % of the sequence and were scattered in helices H16 and H17 of the rRNA molecule. Some of them changed the secondary structure of H17. Phylotaxonomic structure of the population based on the single-copy housekeeping gene rpoB was compared with TTGE patterns. The intragenomic V3 heterogeneity, as well as recombination events between strains or isolates of different rpoB clades, impaired the 16S rRNA-based identification for some Veillonella species. Such approaches should be conducted in other bacterial populations to optimize the interpretation of 16S rRNA gene sequences in taxonomy and/or diversity studies.

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