Meeting Abstract

P2.203  Saturday, Jan. 5  Evaluation of cross-species Microsatellite Loci to investigate population genetics underlying a case of Island Dwarfism in Fowlers Toad KLINGER, J.M.*; BARRILE, G.M.; BOWER, C.D.; DOWNS, L.K.; HRANITZ, J.M.; Bloomsburg University, Bloomsburg jmk62794@huskies.bloomu.edu

Microsatellites are an extremely versatile and powerful tool for studying population genetics. Microsatellite primers for ecological studies can be created at low prices and can yield great genetic insight (e.g., bottleneck effects, founder events, population size, migration). For this reason, 12 microsatellite loci primers originating from the cane toad Rhinella (formerly Bufo) marinus were tested for cross-species amplification in Anaxyrus fowleri. Tissues of Anaxyrus fowleri were collected from six populations on the Eastern Shore of Virginia. Screening of the microsatellites for cross-specie amplification was carried out by PCR reactions followed by gel electrophoresis. We compared the GC composition of the primers to investigate effects on primers effectiveness. We also downloaded sequences for three mtDNA loci sequenced for several species of toad and calculated genetic distances were also calculated because primers originating from a more closely related species will have better chances for cross-species amplification. Only two of 12 primers amplified cross-species PCR products. Primers composed of 50 percent GC or more appear to be species specific and result in low levels of cross-species amplification. Genetic distances for 16S ribosomal RNA, and cytochrome oxidase subunit I (COI), and the control region confirmed that cane toad primers would not be expected to amplify microsatellite loci in A. fowleri. Genetic distance, moreover than GC content, explained the low levels of cross-species amplification witnessed in this experiment, and predicts that primers originating from the more closely related species Anaxyrus americanus should be explored for cross-species amplification.