Genomic Variation Laboratory Broadens Aquaculture Program

Walk into Dr. Bernie May's lab at any time of day or night and you are likely to find someone working. With 11 graduate students, one postdoctoral researcher, six undergraduate students and two full-time employees, it is a dynamic research facility filled with interesting people, ideas and projects. Researchers in the laboratory employ the latest molecular genetic techniques and analyses to address a wide variety of questions for both the conservation of wildlife and the improvement of aquaculture species. This wide-ranging program is in keeping with the broad vision of its director, Dr. May, who began the Genomic Variation Laboratory in 1995 with two main goals: to apply molecular genetic data to ecological and management questions and to educate and provide hands-on experience to as many students as possible in molecular ecology and aquaculture genetics.

Two ongoing research studies in the laboratory involve assessing the genetic integrity of the California golden trout (Oncorhynchus mykiss aguabonita), the state fish. Over the years, many of California's rivers and tributaries have been stocked with non-native rainbow trout (Oncorhynchus mykiss mykiss). These introductions have threatened the existence of the California golden trout by interbreeding with it to create a hybrid of the two subspecies. Jan Cordes, a postdoctoral researcher in the laboratory, has taken the lead on this project over the past year. He recently completed a study that assessed the genetic status of California golden trout in Golden Trout Creek and the surrounding headwater lakes using various nuclear DNA markers. A second study will evaluate the degree of rainbow trout hybridization within another subspecies of rainbow trout endemic to the Kern River Basin, the Little Kern golden trout (O. mykiss whitei).

The California golden trout, Onchrorhynchus mykiss aguabonita, is threatened by hybridization with introduced non-native trout secies.

Another organism currently undergoing investigation in the Genomic Variation Laboratory is the blue whale, the largest animal ever to have lived and a species in danger of extinction due to overexploitation by the whaling industry. Carole Conway, a doctoral student in Ecology, has been focusing on a fundamental question directly related to its conservation: What are the geographic boundaries of the breeding populations? Her results so far include the finding that the blue whales off the California coast are part of an eastern Pacific Ocean group that is genetically unique compared with the three subspecies of blue whales in the Atlantic, Indian and Southern Oceans.

The Genomic Variation Laboratory has also contributed to the Animal Science-initiated aquaculture of white sturgeon. As part of his doctoral dissertation research in Genetics, Jeff Rodzen, in collaboration with commercial white sturgeon growers, formulated a breeding plan for the white sturgeon that merged molecular genetic technology with traditional animal breeding practices. His plan entails the selection of broodstock using animals with the greatest body length and weight, traits that he showed in his analysis to be heritable and positively correlated with caviar weight and yield.

Many other interesting projects are being conducted by doctoral students in the Genomic Variation Laboratory. Zeb Hogan, Graduate Group in Ecology, is investigating the population structure of migratory catfish currently threatened by hydropower in southeast Asia. Fernanda Rodriguez of the Genetics Graduate Group is using various molecular genetic markers to assist aquaculture managers in the development of strains of disease-resistant rainbow trout. Kevin Williamson, Ecology, is generating a baseline of the genetic variation present in chinook salmon in the Central Valley, while Chris Floyd, Ecology, is using microsatellite markers to measure dispersal among marmot populations in Colorado and Nevada. Josh Israel, Ecology, is determining whether migrating green sturgeon in California are panmictic or form reproductively isolated populations. Amy Welsh, Ecology, is investigating the population structure of the endangered lake sturgeon in the Great Lakes region, while Yongjiu Chen, Ecology, studies introgression in endangered tui chubs. Molly Stephens, Ecology, is conducting a phylogenetic analysis to elucidate the evolutionary relationships between the western and Yosemite toads. Jennifer Beyer, Genetics, is working on a computer program to determine family units in natural populations, and Rick Topinka, Ecology, is examining the distribution of genetic diversity within Kearney's blue star, an endangered desert plant in Arizona.

To learn more about the Genomic Variation Laboratory and its current members and projects, visit us on the web at http://genome-lab.ucdavis.edu, or contact us at:

Genomic Variation Laboratory
Animal Science Deptartment, 2403 Meyer Hall
University of California, Davis
One Shields Avenue
Davis, CA 95616
(530) 754-8123
bpmay@ucdavis.edu