Sampling for microsatellite-based population genetic studies: 25 to 30 individuals per population is enough to accurately estimate allele frenquencies
Date
2012
Authors
Hale, Marie L.
Burg, Theresa M.
Steeves, Tammy E.
Journal Title
Journal ISSN
Volume Title
Publisher
Public Library of Science
Abstract
One of the most common questions asked before starting a new population genetic study using microsatellite allele
frequencies is ‘‘how many individuals do I need to sample from each population?’’ This question has previously been
answered by addressing how many individuals are needed to detect all of the alleles present in a population (i.e. rarefaction
based analyses). However, we argue that obtaining accurate allele frequencies and accurate estimates of diversity are much
more important than detecting all of the alleles, given that very rare alleles (i.e. new mutations) are not very informative for
assessing genetic diversity within a population or genetic structure among populations. Here we present a comparison of
allele frequencies, expected heterozygosities and genetic distances between real and simulated populations by randomly
subsampling 5–100 individuals from four empirical microsatellite genotype datasets (Formica lugubris, Sciurus vulgaris,
Thalassarche melanophris, and Himantopus novaezelandia) to create 100 replicate datasets at each sample size. Despite
differences in taxon (two birds, one mammal, one insect), population size, number of loci and polymorphism across loci, the
degree of differences between simulated and empirical dataset allele frequencies, expected heterozygosities and pairwise
FST values were almost identical among the four datasets at each sample size. Variability in allele frequency and expected
heterozygosity among replicates decreased with increasing sample size, but these decreases were minimal above sample
sizes of 25 to 30. Therefore, there appears to be little benefit in sampling more than 25 to 30 individuals per population for
population genetic studies based on microsatellite allele frequencies.
Description
Sherpa romeo green journal
Keywords
Population genetics , Microsatellite , Allele frequencies , Diversity , Sample size
Citation
Hale, M. L., Burg, T. M., & Steeves, T. E. (2012). Sampling for microsatellite-based population genetic studies: 25 to 30 individuals per population is enough to accurately estimate allele frequencies. PLoS ONE, 7(9), e45170. doi:10.1371/journal.pone.0045170