Plant & Animal Genome VI Conference

P14

DEVELOPMENT OF CROSS-SPECIES EXPRESSED SEQUENCE TAGS FOR GENOME MAPPING OF PENAEID SHRIMP

1. Department of Biology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
2. CSIRO Tropical Agriculture, Animal Molecular Genetics Centre, University of, Queensland, St. Lucia, QLD 4072, Australia

Shrimp farming has been the fastest growing sector of aquaculture over the last decade but has experienced recent setbacks due to severe disease outbreaks. Domestication of shrimp stocks and selection for traits such as disease resistance would be of great benefit to the industry. A genome project aimed at developing a linkage map applicable to genetic improvement of cultured stocks has now been initiated. As there are a number of Penaeus species under culture, it is of great interest to identify polymorphic molecular markers for cross-species comparison, thus promoting rapid development of comparative mapping. We have isolated two clones from a cDNA library of Penaeus japonicus and designed primers based on the nucleotide sequences of the clones for amplifying expressed sequence tags (ESTs) of 419 and 512 bp by PCR. We have demonstrated that PCR products with the same molecular weight could be obtained from genomic DNA of other cultured species, including P. monodon, P. vannamei, and P. chinensis. The homology of the products was confirmed by nucleotide sequencing. Determination of polymorphic alleles with PCR-single stranded conformational polymorphism is in progress. This strategy of isolating cross-species ESTs should facilitate the construction of a synteny map for Penaeus species.