Phylogeny and evolution ofLasiopodomysin subfamily Arvivolinae based on mitochondrial genomics

Abstract

The species ofLasiopodomysLataste 1887 with their related genera remains undetermined owing to inconsistent morphological characteristics and molecular phylogeny. To investigate the phylogenetic relationship and speciation among species of the genusLasiopodomys, we sequenced and annotated the whole mitochondrial genomes of three individual species, namelyLasiopodomys brandtiiRadde 1861,L. mandarinusMilne-Edwards 1871, andNeodon(Lasiopodomys)fuscusBüchner 1889. The nucleotide sequences of the circular mitogenomes were identical for each individual species ofL. brandtii,L. mandarinus, andN. fuscus. Each species contained 13 protein-coding genes (PCGs), 22 transfer RNAs, and 2 ribosomal RNAs, with mitochondrial genome lengths of 16,557 bp, 16,562 bp, and 16,324 bp, respectively. The mitogenomes and PCGs showed positive AT skew and negative GC skew. Mitogenomic phylogenetic analyses suggested thatL. brandtii,L. mandarinus, andL. gregalisPallas 1779 belong to the genusLasiopodomys, whereasN. fuscusbelongs to the genusNeodongrouped withN. irene.Lasiopodomysshowed the closest relationship withMicrotus fortisBüchner 1889 andM. kikuchiiKuroda 1920, which are considered as the paraphyletic species of genera Microtus.TMRCAand niche model analysis revealed thatLasiopodomysmay have first appeared during the early Pleistocene epoch. Further,L. gregalisseparated from others over 1.53 million years ago (Ma) and then diverged intoL. brandtiiandL. mandarinus0.76 Ma. The relative contribution of climatic fluctuations to speciation and selection in this group requires further research.