Meeting Abstract

P1.205  Saturday, Jan. 4 15:30  Phylogentic relationships in the rodent genus Thomasomys DAUGHTRY, T. K.*; KHONG, G. M.; LEE, T. E.; BROKAW, J. M.; Abilene Christian University; Abilene Christian University; Abilene Christian University; Abilene Christian University jmb97t@acu.edu

Phylogenetic relationships in the genus Thomasomys were analyzed based on sequences for the mitochondrial cytochrome b gene and the nuclear RAG1 gene. The primary objective of this study was to test previous taxon descriptions for species of Thomasomys to facilitate creation of an updated key for the mammals of Ecuador. New sequences were collected primarily from animals in Sangay National Park of Ecuador and combined with sequences from GenBank. New sequences were generated using the primers P484 and P485 for cytochrome b and newly designed primers for RAG1 and standard extraction, amplification and sequencing protocols. Sequences were edited and aligned manually. Maximum likelihood (ML) searches were performed with gaps treated as missing data and each codon position treated as a separate partition. In the ML reconstruction using cytochrome b alone, nodes at the species level were well resolved, and most species of Thomasomys were shown to be monophyletic, with the exception of T. baeops. A subclade of T. baeops was grouped together with T. ischyurus (95% bootstrap), but all of the T. baeops specimens were otherwise grouped together (85% bootstrap). In contrast, most deep nodes joining multiple species into clades had bootstrap values lower than 70%. One exception was the grouping of T. silvestris and T. caudivarious (73% bootstrap). These species were collected from the eastern slope and western slope of the Andes respectively, suggesting allopatric speciation. Mitochondrial DNA has been found to contain more homoplasy than nuclear DNA. To address this deficiency, we are exploring the RAG1 gene to potentially obtain better resolution of the deeper nodes in order to test hypotheses of speciation.