Microsatellite variation of mussels (Mytilus galloprovincialis) in central and eastern Mediterranean: genetic panmixia in the Aegean and the Ionian Seas

Abstract

Genetic variation of mussels Mytilus galloprovincialis in central -eastern Mediterranean Sea is investigated in this study. A total of 550 individuals sampled from two cultured and 11 wild populations from Italy, Croatia, Greece and Turkey were genotyped at 10 microsatellite loci. Significant deviations from Hardy-Weinberg expectations were observed in more than 75% of the tests performed. All populations showed extensive heterozygote deficits, which remained at significant levels even after correction for null alleles, providing evidence that null alleles were only partly responsible for deviations from Hardy-Weinberg equilibrium in these molluscs. Moreover, null alleles seem to have limited influence on the population genetic differentiation. Similar levels of multi-locus heterozygosity and allelic richness were observed in all populations, cultured and wild, implying the sustainability of the exploited populations. Lack of isolation by distance and markedly low genetic differentiation between the nine Greek sampling sites (shoreline .1000 km) was revealed by Mantel tests, F ST values, exact tests and analyses of molecular variance, indicating that mussels from these regions are either at or close to panmixia. Similarly, patterns of genetic homogeneity were also found between the two Italian samples, whereas the observed genetic differentiation of the populations from Turkey and Croatia probably reflects the specific topographic and oceanographic conditions of these regions.

Development of a Medium Density Combined-Species SNP Array for Pacific and European Oysters (Crassostrea gigasandOstrea edulis)

“…A lack of population structure according to geographical original was observed in the other O. edulis population samples tested, for example the majority of samples from the coast of the UK and Ireland ( Figure S9 ). This is consistent with existing evidence that suggests that marine organisms with larval stages (such as bivalves) often show low genetic differentiation ( Li et al 2015 ; Shabtay et al 2014 ; Rohfritsch et al 2013 ; Giantsis et al 2014 ), with temporal factors rather than geographical factors often playing the major role in population structure. It is also possible that historical stock translocations might have also played an important role in the lack of genetic structure and admixture of the O. edulis populations ( Bromley et al 2016 ).…”

Phylogeographic past and invasive presence of Arion pest slugs in Europe

“…; Giantsis et al . ), as well as in other terrestrial invertebrates with low dispersal rates (e.g. Choi et al .…”

Octopus vulgaris (Cuvier, 1797) in the Mediterranean Sea: Genetic Diversity and Population Structure

“…Among invertebrates, molluscs include sessile, slow walking or fast swimming species characterised by internal or external fertilization and direct or indirect development, living in a wide variety of habitats such as open sea, rocky or sandy bottoms. Several patterns of genetic structure have been identified, from genetic homogeneity [ 7 , 8 ] to isolation by distance [ 9 , 10 ], and island models of isolation [ 11 ]. Due to their short life-cycles, variable temperature- [ 12 – 14 ] and food availability-dependent growth rate, cephalopod stocks are highly unstable, being susceptible to overfishing and sensitive to environmental changes [ 15 ].…”