Mitochondrial control region variability in Mytilus galloprovincialis populations from the central-Eastern Mediterranean Sea

Abstract

The variable domain 1 (VD1) domain of the control region and a small segment of the rrnaL gene of the F mtDNA type were sequenced and analyzed in 174 specimens of Mytilus galloprovincialis. Samples were collected from eight locations in four Central-Eastern (CE) Mediterranean countries (Italy, Croatia, Greece and Turkey). A new primer, specific for the F mtDNA type, was designed for the sequencing procedure. In total 40 different haplotypes were recorded, 24 of which were unique. Aside from the two populations situated in Thermaikos gulf (Northern Aegean, Greece), relatively high levels of haplotype and nucleotide diversity were estimated for both Central and Eastern Mediterranean populations. Eight out of the 40 haplotypes were shared by at least three populations while two of them were found in all populations. ΦST and cluster analysis revealed lack of structuring among CE Mediterranean populations with the exception of those located at the Sea of Marmara and Croatian coast which were highly differentiated. Apart from the species' inherit dispersal ability, anthropogenic activities, such as the repeated translocations of mussel spat, seem to have played an important role in shaping the current genetic population structure of CE M. galloprovincialis mussels.

Figure 1

Bayesian admixture analysis of individuals. Each color represents one distinct haplogroup (cluster) while each bar represents a different individual.

Figure 2

Maximum likelihood dendrogram of the haplotypes found. Group A and B consist mainly from Turkish and Croatian populations, respectively. Population codes as listed in Table 2. Bootstrap values greater than 60% are demonstrated on the branches.

Figure 3

Geographical locations of the analyzed populations. Population codes as listed in Table 2.