Differential patterns of male and female mtDNA exchange across the Atlantic Ocean in the blue mussel, Mytilus edulis.
Comparisons among loci with differing modes of inheritance can reveal unexpected aspects of population history. We employ a multilocus approach to ask whether two types of independently assorting mitochondrial DNAs (maternally and paternally inherited: F- and M-mtDNA) and a nuclear locus (ITS) yield concordant estimates of gene flow and population divergence. The blue mussel, Mytilus edulis, is distributed on both North American and European coastlines and these populations are separated by the waters of the Atlantic Ocean. Gene flow across the Atlantic Ocean differs among loci, with F-mtDNA and ITS showing an imprint of some genetic interchange and M-mtDNA showing no evidence for gene flow. Gene flow of F-mtDNA and ITS causes trans-Atlantic population divergence times to be greatly underestimated for these loci, although a single trans-Atlantic population divergence time (1.2 MYA) can be accommodated by considering all three loci in combination in a coalescent framework. The apparent lack of gene flow for M-mtDNA is not readily explained by different dispersal capacities of male and female mussels. A genetic barrier to M-mtDNA exchange between North American and European mussel populations is likely to explain the observed pattern, perhaps associated with the double uniparental system of mitochondrial DNA inheritance.
Riginos
Cynthia
C
Department of Biology, Box 90338, Duke University, Durham, North Carolina 27708, USA. riginos@duke.edu
Hickerson
Michael J
MJ
Henzler
Christine M
CM
Cunningham
Clifford W
CW
D000818:Animals; D001267:Atlantic Ocean; D001483:Base Sequence; D049872:Bivalvia / Q000235:genetics*; D016000:Cluster Analysis; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics; D003710:Demography; D019143:Evolution, Molecular; D005260:Female; D005828:Genetics, Population; D008297:Male; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA; D012737:Sex Factors
D017931:DNA Primers; D004272:DNA, Mitochondrial