The use of molecular scatology to study river otter ( Lontra canadensis) genetics.

摘要

North American river otters (Lontra canadensis) were extirpated throughout all of Western New York due to habitat loss, pollution, and trapping. Between 1995 and 2000, 279 river otters were released throughout Western New York, 31 of which were released in the Genesee river watershed. Since their release there have been no follow-up studies on the river otters until the RIT River Otter Lab was formed in 2004. Researchers surveyed three local creeks to record data on toilet site locations and collect otter feces in order to perform dietary and genetic analyses. Through the use of molecular scatology I extracted DNA from feces in order to determine the amount of genetic diversity of the reintroduced river otter population. I also utilized otter scat samples from British Columbia and the Thousand Islands. Using a QIAGEN QIAamp Stool Mini Kit I attempted to extract mitochondrial cytochrome b DNA from 177 samples, roughly 16% of which were successfully amplified and sequenced. From the sequenced scat samples I identified two otter, 14 raccoon, one beaver, one coyote, and three fish: common carp, golden redhorse, and shorthead redhorse from the Genesee watershed. I have also sequenced one sample as otter and one sample as pink salmon from British Columbia and five samples as bullhead catfish from the Thousand Islands. It is believed that the samples that were sequenced as fish were likely from otters. I then utilized microsatellites, and I included a raccoon sample as well. To my surprise the raccoon sample worked with the river otter microsatellite primer, despite a 25% divergence between the two species' cytochrome b sequences. I determined that out of ten river otter microsatellite primers: three river otter primers do not work with raccoons, five primers produced identical or nearly identical sequence, and two primers need more research to determine if they work with raccoons. These results stress the importance of confirming species identification from fecal samples using mitochondrial DNA prior to the use of microsatellites to avoid misleading results.