Genetic variation inferred from RAPD fingerprinting in three species of tilapia

This study used random amplified polymorphic DNA (RAPD) fingerprinting for estimating genetic variation and species differentiation in three species of tilapia. A 16-mer random primer generated RAPD markers ranging from 250 to 2400 base pairs (bp). Genetic similarity estimates obtained by pairwise comparisons based on the method of Nei and Li (1979) indicated high genetic similarity (mean genetic similarity ( plus or minus SD), 0.73 ( plus or minus 0.15) for Nile tilapia; 0.78 ( plus or minus 0.12) for Mozambique tilapia; and 0.87 ( plus or minus 0.07) for Aureus tilapia) within each of the tilapia species. The average interspecies genetic similarities obtained among the three species were 0.59 ( plus or minus 0.07) for Mozambique/Nile tilapia, 0.46 ( plus or minus 0.09) for Aureus/Nile tilapia and 0.38 ( plus or minus 0.07) for Aureus/Mozambique tilapia pair. DNA profiles generated in each species of tilapia were unique. A total of 13 RAPD markers differentiating the three species of tilapia were detected. Our study presented RAPD markers as a new class of useful genetic markers for assessment of genetic diversity and species differentiation in tilapia.