title: Mitochondrial DNA panmixia in the little brown seastar Echinaster spinulosus suggests a recent population expansion.
abstract: In North America, the Atlantic-Gulf discontinuity depicts genetic breaks between populations distributed along the Florida peninsula. This study examines 83 specimens of E. spinulosus obtained from seven locations along the Florida coast to examine phylogeographic patterns, population structure and examine historical demographic patterns. Analyses of 511 bp from the cytochrome oxidase 1 (COI) mitochondrial gene inferred no significant genetic structure for E. spinulosus along either side of the Florida coast nor was there a genetic discontinuity associated with a "Gulf-Atlantic" split. Population-based statistical analyses revealed no significant degree of genetic differentiation (Fst, p < 0.05) among populations, thus indicating substantial gene flow. Similarly, summary statistics (Fu's Fs, mismatch distributions) were significant indicating that there has been a population increase in the recent past. Recent range expansion, possibly due to a leading edge effect, combined with some level of contemporary larval mixing seems to be the main source of panmixia in this species.
authors.affiliation: a Department of Biology , University of West Georgia , Carrollton , GA , USA.
authors.forename: Frank M
authors.initials: FM
authors.lastname: Fontanella
mesh_terms: D000818:Animals; D001267:Atlantic Ocean; D003576:Electron Transport Complex IV / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014644:Genetic Variation; D005828:Genetics, Population; D054629:Genome, Mitochondrial; D060851:Gulf of America; D006239:Haplotypes; D010802:Phylogeny; D058974:Phylogeography; D013215:Starfish / Q000145:classification / Q000235:genetics*
chemical_list: D003576:Electron Transport Complex IV
keywords: Echinaster spinulosus; mitochondrial DNA; panmixia; population expansion