Mitogenome comparative analysis of 3 Myotis species endemic to Mexico and detecting selection in OXPHOS genes

Concerning metabolic demands, powered flight stands out as a mode of locomotion characterized by exceptionally high energy requirements. Bats exhibit distinct anatomical and physiological features associated with flight, prompting the anticipation of adaptive evolution in protein-coding genes within their mitochondrial genomes crucial for the oxidative phosphorylation pathway. In this study, the complete mitogenomes of 3 Myotis species endemic to Mexico were obtained and evaluated to obtain signatures of adaptive evolution in genes encoding mitochondrial proteins. The mitochondrial genomes span 17,147; 17,148; and 17,171 bp in size of M. findleyi, M. vivesi, and M. planiceps, respectively. A phylogenetic analysis focusing on the 13 protein-coding genes supports the delimitation of several clades included in the genus Myotis. Notably, Branch Models propose that Cox1, Cytb, and Nad4 may be subject to more robust purifying selection compared to other mitochondrial genes, while the Nad5 gene likely experiences positive selection pressure. The statistical analysis supports that Branch-Site Models contribute insights into 5 genes featuring amino acid sites potentially under selection pressure. Further analysis revealed episodic diversifying selection in Cox3 and signatures of diversifying/positive selection in 5 genes. This research significantly advances our understanding of the adaptive evolution of mitochondrial protein-coding genes in chiropterans, shedding light on their potential role in sustaining active flight.