Molecular Systematics of the Genus Lasiurus (Chiroptera: Vespertilionidae) Based on Restriction-Site Maps of the Mitochondrial Ribosomal Genes

Abstract

Phylogenetic relationships among some members of the chiropteran genus Lasiurus were investigated using a restriction-enzyme analysis of the ribosomal genes of the mitochondrial DNA (mtDNA). A restriction-site mapping strategy was used that provides high-resolution maps by partial endonuclease digestion of the target sequence. One hundred thirty-five sites were mapped onto a 1.56-kilobases fragment that includes most of the 12S and 16S ribosomal RNA (rRNA) genes. The results of this study agree with previous work based on protein electrophoresis and, in some cases, do not support traditional taxonomic allocations based on morphology. The relationships among the three species groups (red, hoary, and yellow bats) constitute an unresolved trichotomy. Among hoary bats, the endemic Hawaiian hoary bat is more similar to the North American subspecies than to the South American subspecies. Separation of the North American red bats into two species, L. borealis and L. blossevillii, is supported. The Cuban L. pfeifferi, considered by some to be a subspecies of L. borealis, is closer to L. seminolus and possibly is a subspecies of the latter. The yellow bats L. xanthinus and L. insularis are shown to be distinct species separated from L. ega and L. intermedius, respectively. These last two species are closely related taxa, as previously suggested by karyotypic evidence. Based on the estimated time of origin of the genus Lasiurus, the ribosomal genes have evolved at a rate of ca. 0.87% divergence/106 years, which is comparable to estimates in other mammalian groups based on nucleotide-sequence data.