When paleontology meets genomics: complete mitochondrial genomes of two saber-toothed cats' species (Felidae: Machairodontinae)

Abstract

Within the Machairodontinae subfamily, commonly referred as saber-toothed cats, it is worth noting that only two species, namely Homotherium latidens, recognized as the scimitar-toothed cat, and Smilodon populator, renowned as the saber-toothed tiger, possess partial mitochondrial genomes accessible in the NCBI database. These sequences, however, do not include the mitogenome control region (D-loop) and have several gaps in their genes, including protein-coding genes (PCGs) that are widely used in phylogenetic analysis. In this study, we aimed to obtain a complete assembly of the mitogenomes of these two species from next-generation sequencing data available at NCBIs SRA. The de novo assemblies showed complete mitogenomes with 17,323bp (H. latidens) and 16,769 bp (S. populator), both with 13 PCGs, 22tRNAs, two rRNAs and the D-loop (Control region), with all genes following the standard order and position of most vertebrate mitogenomes. Our phylogeny and molecular dating, despite being generally very similar to previous studies, reveals an earliest divergence between North American and North Sea H. latidens specimens which may be related to an Early Pleistocene migration across Beringia.