Genetic diversity and gene flow of giant tiger shrimp Penaeus monodon Fabricius in Thailand using PCR-RFLP of mitochondrial DNA

Abstract

Genetic diversity of five geographic samples of Penaeus monodon in Thailand (Satun, Trang and Phangnga located in the Andaman Sea and Chumphon and Trat located in the Gulf of Thailand) was examined using PCR-RFLP of two mitochondrial genes composing of the 16S ribosomal (r) DNA digested with Mbo I and an intergenic region of cytochrome oxidase subunits I and II (COI-COII) digested with Alu I, Mbo I, Taq I, Hint I and Dde I. Thirty-seven mtDNA composite haplotypes were identified and could be allocated into one or the other of two mtDNA lineages, A and B joined in a UPGMA dendrogram with the sequence divergence of 2.558%. The mtDNA haplotypes generated from digestion of an intergenic COI-COII with Alu I and Taq I represented these mtDNA lineages accurately offering simpler mtDNA typing in p. monodon. The average haplotype diversity of p. monodon mtDNA was 0.8548 ± 0.0001. The average nucleotide diversity within and between samples was 3.3283% and 3.3648%, respectively. The nucleotide divergence of five p. monodon samples was 0.0365% implying degrees of population subdivisions in Thai p. monodon. Significant geographic heterogeneity was observed between the Andaman Sea and the Gulf of Thailand samples (P< 0.0001). As a result, five p. monodon samples were differentiated to two different populations; A (Sato, Trang and Phangnga) and B (Chumphon and Trat). Results from this study indicated that potential female-mediated dispersal (biased female gene flow) may exist between p. monodon from Trat and Chumphon.