MHC-DAB II gene polymorphism in silver carp (Hypophthalmicthys molitrix) propagated by semi-natural method

Silver carp (Hypophthalmichthys molitrix) as the major species in total production of freshwater fish, has a special place in the aquaculture industry of Iran. The common method for breeding of this species in our country is semi-natural which provides the brooders opportunities for mate selection that is one of the most striking features in this method. Given the importance of MHC gene complex to sexual behaviors and its historical role in the process of evolution of living organisms especially in terms of safety issues, various patterns of mentioned loci between two generations of Silver carp were studied. 33 males and female silver carp were reproduced in two independent groups by semi-natural method after that larvae in each group were sampled. Using data in NCBI and designing the appropriate primer, MHC-DAB loci of the parents and their F1 were studied by SSCP method. Analysis of six different genotypes between the samples indicated an increased level of observed heterozygosity (1) compare to the expected value (0.660 -0.709). Deviation from Hardy-Weinberg equilibrium was observed in most groups and the main share of genetic diversity assigned to individual differences. The pattern of genetic diversity distributed in larvae and high variation of MHC-DAB loci meanwhile retaining number of the alleles, represents a positive selection.