Rochelle Molitor

Conservation genetics investigation of the margined sculpin (Cottus marginatus)

Biology, Dr. CarlinRochelle Molitor
About My Research:

I, along with my advising professor, Dr. Joel Carlin, will be continuing a population genetics research project investigating the status of the Margined Sculpin (Cottus marginatus), a fish that is found cloistered in river drainages in the southeastern corner of the state of Washington. Although this fish has the smallest range of any other fish in the state, the population size is presumed large so it has not merited the status of an endangered species. Other species found in small areas (like island or zoo populations) can exhibit health problems due to inbreeding, but the health status of these fish is totally unknown. To this end, I have isolated DNA from these fish for use as a template in a Polymerase Chain Reaction (PCR), so that I may sequence mitochondrial DNA and identify some fast-evolving nuclear DNA (microsatellites). The degree of similarity among the DNA sequences reveals how closely related the fish are to each other and gives the likelihood of inbreeding in the species. A high incidence of genetic similarity means greater concern for monitoring the health of this unique species.

This research was supported by the 2007 Greater Gustavus Summer Research Fund.

In the student's own words:

"The best part of doing research at Gustavus is that you can connect what you have learned in lecture to real-life applications. Instead of just words on a page of a textbook, the concept takes on a whole new meaning when it is experienced from the "hands-on" approach that research offers. I have learned more in the few months I have been in the lab than I could learn if the same material was taught to me in a classroom."

Professional Abstract:

The margined sculpin (Cottus marginatus) is an isolated streamfish species found in southeastern Washington and northeastern Oregon. Although it has one of the smallest ranges of any other fish in these states, the population size is presumed large so it has not been granted the status of an endangered or threatened species. However, recent analyses reveal that the habitat in which it lives is rapidly degrading. In this study, DNA from a set of 55 fish was used to assess the species’ resulting genetic condition. The entire cytochrome b gene from mitochondrial DNA was amplified in 21 samples and sequenced. In addition, 3 nuclear microsatellite loci were amplified in 25 samples. The genetic diversity (heterozygosity and percent sequence divergence) at these loci were analyzed and will be used to provide insight into short term evolution as well as guide future conservation efforts.


More student thoughts:

"I enjoy doing research at Gustavus because I have the opportunity to get to know my current and future professors on a more personal basis. During the school year, it seems that many interactions with professors are strictly related to academics. Although this is a necessary aspect of a teacher-student relationship, it is also beneficial (and interesting) to get to know your professors as people as well."