Genetic Analysis Based on Mitochondrial <i>nad2</i> Gene Reveals a Recent Population Expansion of the Invasive Mussel, <i>Mytella strigata</i>, in China

Abstract

Mytella strigata is a highly adaptable invasive alien species that has been established in coastal China since 2014. Mitochondrial DNA (mtDNA) is an important tool for studying the evolution and population genetics of invasive species. In this study, the mitochondrial genome of M. strigata from China was sequenced by Illumina high-throughput sequencing and characterized with 13 protein-coding genes (PCGs). By assessing the selective pressure of 13 PCGs, the nad2 gene had the fastest evolutionary rate and was finally selected for population genetic analysis. A total of 285 nad2 sequences from seven M. strigata populations in China were analyzed and showed obviously T-rich and C-rich characteristics. According to population genetic diversity analysis, all the seven populations had haplotype (gene) diversity (Hd) ≥ 0.5 and nucleotide diversity (Pi) M. strigata in China may have passed the bottleneck period and is currently in a state of population expansion.

Keywords

• alien species
• <i>Mytella strigata</i>
• biological invasion
• <i>nad2</i>
• population genetics