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Microsatellite variation and evolution in the Peromyscus maniculatus species group
Scott E Chirhart1, Rodney L Honeycutt, Ira F Greenbaum
1Department of Biology, Texas A&M University, College Station, TX 77843-3258, USA. schirhar@centenary.edu
Molecular Phylogenetics and Evolution
|December 28, 2004
Summary
Microsatellite analysis of Peromyscus species reveals genetic diversity patterns. Insular populations show reduced variation, suggesting founder effects and limited gene flow, impacting species classification.
Area of Science:
- Population genetics
- Molecular evolution
- Mammalian genomics
Background:
- Microsatellites are valuable genetic markers for studying population structure and evolutionary relationships.
- The Peromyscus maniculatus species group presents a model for investigating speciation and genetic variation in mammals.
Purpose of the Study:
- To assess genetic variation across species within the Peromyscus maniculatus group and Peromyscus leucopus using microsatellite markers.
- To evaluate the evolutionary relationships and population genetic structure of these Peromyscus species.
Main Methods:
- Analysis of variation at 12 dinucleotide microsatellite loci across multiple Peromyscus species.
- Comparison of polymorphism levels and allele size distributions between mainland and insular populations.
- Phylogenetic analyses using genetic distances based on shared allele frequencies and allele size differences.
Main Results:
- Most microsatellite loci provided reliable estimates of genetic variation across the studied Peromyscus species.
- Mainland populations exhibited similar levels of genetic variation, while insular P. sejugis populations showed significantly lower variation, indicative of founder effects.
- Phylogenetic trees based on shared allele frequencies strongly supported the established relationships within the P. maniculatus group, unlike analyses based on allele size differences.
Conclusions:
- Microsatellite data support a sister-group relationship between P. sejugis and P. keeni, refuting their conspecific status with P. maniculatus.
- Founder effects and lack of recent gene flow likely shaped the genetic diversity of insular P. sejugis populations.
- Shared allele frequencies are a more robust measure for inferring phylogenetic relationships in this Peromyscus complex compared to allele size differences.