Mining ESTs to determine the usefulness of SNPs across shrimp species

Expressed sequence tag (EST) libraries from members of the Penaeidae family and brine shrimp (Artemia franciscana) are currently the primary source of sequence data for shrimp species. Penaeid shrimp are the most commonly farmed worldwide, but selection methods for improving shrimp are limited. A better understanding of shrimp genomics is needed for farmers to use genetic markers to select the best breeding animals. The ESTs from Litopenaeus vannamei have been previously mined for single nucleotide polymorphisms (SNPs). This present study took publicly available ESTs from nine shrimp species, excluding L. vannamei, clustered them with CAP3, predicted SNPs within them using SNPidentifier, and then analyzed whether the SNPs were intra- or interspecies. Major goals of the project were to predict SNPs that may distinguish shrimp species, locate SNPs that may segregate in multiple species, and determine the genetic similarities between L. vannamei and the other shrimp species based on their EST sequences. Overall, 4,597 SNPs were predicted from 4,600 contigs with 703 of them being interspecies SNPs, 735 of them possibly predicting species' differences, and 18 of them appearing to segregate in multiple species. While sequences appear relatively well conserved, SNPs do not appear to be well conserved across shrimp species.