Plant & Animal Genome V Conference
Town & Country Hotel, San Diego, CA, January 12-16, 1997.
PAG-V: W9 - DEVELOPMENT OF EXPRESSED SEQUENCE TAGS (ESTs) AND MICROSATELLITE MARKERS FOR MAPPING THE SHRIMP GENOME
W9
DEVELOPMENT OF EXPRESSED SEQUENCE TAGS (ESTs) AND MICROSATELLITE MARKERS FOR MAPPING THE SHRIMP GENOME
ALCIVAR-WARREN, ACACIA
Department of Comparative Medicine, Tufts University School of Veterinary Medicine, 200 Westboro Road, North Grafton, MA 01536
Emerging viral diseases plague the marine shrimp aquaculture industry worldwide and threaten its sustainability. The U.S. Marine Shrimp Farming Program, funded by USDA, has established a selective breeding program to supply high health seed stocks to farmers. In addition to other quantitative measures, this program relies on molecular genetic approaches to identify genetic markers associated with economically important traits. Highly polymorphic markers are being developed for mapping loci controlling growth performance and resistance to Taura Syndrome Virus in cultured Penaeus vannamei shrimp. These markers include expressed sequenced tags (ESTs) and microsatellites. ESTs are isolated from cDNA libraries and by mRNA differential display. Preliminary ESTs data indicate that some partially sequenced cDNA clones are 52-65% homologous with genes of C. elegans, C. perfingens, S. cerevisiae, mouse and human but others have no homology to known genes. Microsatellites are obtained by screening size-fractionated genomic libraries with simple sequence repeats. So far, 25 of 134 positive clones have been characterized and are being tested in wild stocks and reference families. Preliminary data with a few microsatellite primers has shown highly polymorphic markers in wild shrimp with heterozygosity levels reaching 100%. Future work is aimed at identifying the chromosomes of penaeid shrimp, cloning chromosome-specific libraries and generating additional markers from YAC and BAC libraries. Efforts are underway to implement a genome mapping project aimed at developing a linkage map for shrimp.