Random amplified polymorphic DNA (RAPD) markers for determination of genetic variation in wild populations of the black tiger prawn (Penaeus monodon) in Thailand.

Random amplified polymorphic DNA (RAPD) analysis was used to amplify the genome of black tiger prawns (Penaeus monodon) to detect DNA markers and assess the utility of the RAPD method for investigating genetic variation in wild P. monodon in Thailand. A total of 200 ten-base primers were screened, and 84 primers yielded amplification products. Six positive primers that gave highly reproducible RAPD patterns were selected for the analysis of three geographically different samples of Thai P. monodon. A total of 70 reproducible RAPD fragments ranging in size from 200 to 2000 bp were scored, and 40 fragments (57%) were polymorphic. The RAPD analysis of broodstocks from three different locales, Satun-Trang, Trat, and Angsila, revealed different levels of genetic variability among the samples. The percentages of polymorphic bands were 48% and 45% in Satun-Trang and Trat, respectively, suggesting a high genetic variability of the two samples to be used in selective breeding programs. Only 25% polymorphic bands were found in the Angsila sample, indicating the lowest polymorphic level among the three samples examined. Primer 428 detected a RAPD marker that was found only in P. monodon originating from Satun-Trang, suggesting the potential use of this marker as a population-specific marker in this species.