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Genetic variability in Irish populations of the invasive zebra mussel, Dreissena polymorpha : discordant estimates of population differentiation from allozymes and microsatellites
Author(s) -
GOSLING ELIZABETH,
ASTANEI IULIAN,
WAS ANNA
Publication year - 2008
Publication title -
freshwater biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 156
eISSN - 1365-2427
pISSN - 0046-5070
DOI - 10.1111/j.1365-2427.2008.01965.x
Subject(s) - biology , microsatellite , population genetics , locus (genetics) , population , dreissena , genetic diversity , zebra mussel , genetics , evolutionary biology , allele , zoology , ecology , mussel , bivalvia , mollusca , gene , demography , sociology
Summary 1. The recent arrival and explosive spread of the zebra mussel, Dreissena polymorpha (Pallas), in Ireland provided a rare opportunity to study the population genetics of an invasive species. 2. Eight polymorphic allozyme loci ( ACO‐1, ACO‐2 , EST‐D, GPI, IDH‐2, MDH, OPDH and PGM ) were used to investigate genetic diversity and population structure in five Irish populations, and the results were compared with those from a previous microsatellite study on the same samples. 3. The mean number of alleles per locus (2.7 ± 0.1) was similar to the mean for the same loci in European populations, suggesting that Irish founder populations were large and/or multiple colonization events took place after foundation. A deficiency of heterozygotes was observed in all populations, but was uneven across loci. 4. Pairwise comparisons, using Fisher’s exact tests and F ST values, revealed significant genetic differentiation among populations. The overall multilocus F ST estimate was 0.118 ± 0.045, which contrasted with an estimate of 0.015 ± 0.007 from five microsatellite loci on the same samples in a previous study. 5. Assuming that microsatellites can be used as a neutral baseline, the discordant results from allozymes and microsatellites suggest that selection may be acting on some allozyme loci, specifically ACO‐1, ACO‐2 , IDH‐2 and MDH, which contributed most to the significant differentiation between samples.