Microsatellite Analysis of Six Populations of Chrysichthys nigrodigitatus from Nigeria

Aim: To investigate the patterns and levels of genetic polymorphism and population structures of wild C. nigrodigitatus using the microsatellite DNA in Nigeria.
Place and Duration of Study: in Nigeria between 2008 and 2009, and Laboratory of Mariculture, Ocean University of China, 2009-2010.
Methodology: A total of 93 individuals of Chryscichthys nigrodigitatus obtained from 6 sites in Nigeria were used for the study. DNA extracted from alcohol preserved muscle tissue was amplified by PCR. Amplified products were detected using the silver staining technique to visualize bands.
Results: The four microsatellite loci indicate high genetic variation in all 6 populations of the species with the number of alleles and HO varying from 2-10 and 0.800-1.00 per locus, respectively. The NJ tree revealed a marginal genetic differentiation between two clades, which were not well supported. Significant genetic differences were detected between most samples. Freshwater or brackishwater habitat, limited long-distance dispersal of the adult and juveniles may account for breakdown of gene flow.
Conclusion: C. nigrodigitatus maintains sufficient intra population genetic variability and moderate inter population differentiation in the studied area.