Positive Selection of Mitochondrial <i>cytochrome b</i> Gene in the Marine Bivalve <i>Keenocardium buelowi</i> (Bivalvia, Cardiidae)

Abstract

The mitochondrial genome provides valuable data for phylogenetic analysis and evolutionary research. In this study, we sequenced, assembled, and annotated the mitochondrial genome of Keenocardium buelowi using the Illumina platform. The genome spanned 16,967 bp and included 13 protein-coding genes (PCGs), two ribosomal RNAs, and 22 transfer RNAs. All PCGs utilized standard ATN start codons and TAN stop codons. The phylogenetic tree based on maximum likelihood and Bayesian inference analyses revealed Clinocardiinae as the sister group to Trachycardiinae, with the estimated divergence time being 44.5 million years ago (MYA) between K. buelowi and Vasticardium flavum. Notably, the cytochrome b gene (cob) exhibited a positive selection signal. Our findings provide valuable insights into the evolutionary history and molecular phylogeny of K. buelowi.

Keywords

• Cardiidae
• <i>Keenocardium buelowi</i>
• complete mitochondrial genome
• selection pressure
• phylogenetic relationship