Population Genetic Structure and Demographic History of Atrina pectinata Based on Mitochondrial DNA and Microsatellite Markers

Abstract

The pen shell, Atrina pectinata, is one of the commercial bivalves in East Asia and thought to be recently affected by anthropogenic pressure (habitat destruction and/or fishing pressure). Information on its population genetic structure is crucial for the conservation of A. pectinata. Considering its long pelagic larval duration and iteroparity with high fecundity, the genetic structure for A. pectinata could be expected to be weak at a fine scale. However, the unusual oceanography in the coasts of China and Korea suggests potential for restricted dispersal of pelagic larvae and geographical differentiation. In addition, environmental changes associated with Pleistocene sea level fluctuations on the East China Sea continental shelf may also have strongly influenced historical population demography and genetic diversity of marine organisms. Here, partial sequences of the mitochondrial Cytochrome c oxidase subunit I (COI) gene and seven microsatellite loci were used to estimate population genetic structure and demographic history of seven samples from Northern China coast and one sample from North Korea coast. Despite high levels of genetic diversity within samples, there was no genetic differentiation among samples from Northern China coast and low but significant genetic differentiation between some of the Chinese samples and the North Korean sample. A late Pleistocene population expansion, probably after the Last Glacial Maximum, was also demonstrated for A. pectinata samples. No recent genetic bottleneck was detected in any of the eight samples. We concluded that both historical recolonization (through population range expansion and demographic expansion in the late Pleistocene) and current gene flow (through larval dispersal) were responsible for the weak level of genetic structure detected in A. pectinata.

Genetic variation and population structure of the Pacific oyster Crassostrea gigas in the northwestern Pacific inferred from mitochondrial COI sequences

“…The level of genetic diversity of C. gigas was characterized by moderate haplotype diversity (4 of 12 populations had low values, including LZ, PL, ZS and SU) and low nucleotide diversity, which was partly consistent with the previous conclusions reported by Sekino et al [52]. In addition, the level of genetic variation for C. gigas was relatively lower than that of some co-distributed bivalves (Table 5), such as C. sinensis [13], Tegillarca granosa [14], Crassostrea ariakensis [53] and Atrina pectinate [21]. A different population history of these species was assumed to be responsible for the differences in genetic variations.…”

“…Weak genetic differentiation of C. gigas was also detected by Sekino et al [52] in a fine scale. Moreover, similar population structures have been revealed in some other marine species distributed in these coastal areas, such as Chelon haematocheilus [8], Eriocheir sensu strict [11], A. pectinate [21], Chinese shrimp Feneropenaeus chinensis [55] and Rapana venosa [56,57]. The possibility of anthropogenic habitat expansion that leads to gene flow can be ruled out by the observation that the C. gigas population samples shared very few mtDNA haplotypes [52].…”

“…Obviously, weak genetic structure, as revealed by mtCOI data in this study, is consistent with the view that marine organisms with larval stages often show low genetic differentiation among populations as a result of high dispersal capabilities and large-scale oceanic mixture [62,63]. However, low, but significant, genetic differentiation (only 4 of 66 pairwise Φ ST values) observed between some of the Chinese samples and Japanese samples might be the result of demographic fluctuation, which could be caused by any of several other factors, including genetic drift before recruitment and natural selection during early life stages [21,64,65]. populations is highly likely to be the ancestral haplotype.…”

“…Within interglacial periods, the sea level rose and quickly submerged the land bridges, leading to the reconnection of these marginal seas and the population-level expansion of species [21]. Such recurrent fluctuations in sea levels and water temperature caused by glacial/ interglacial cycles inevitably affected the spatial distribution and genetic patterns of marine organisms [9,11].…”

Biogeography and temporal progression during the evolution of striped dolphin population structure in European waters

“…Wares & Cunningham, ) contributed to altering genetic structure among populations throughout the Quaternary period. During Pleistocene glaciations, sea level was reduced and environmental conditions were re‐distributed sometimes creating isolated refugia, imposing at first geographical barriers to gene flow followed by post‐glacial dispersal and expansion (Xue, Wang, Zhang, & Liu, ). This has been reported for various fish species (e.g.…”