UNDERSTANDING HYBRID INCOMPATIBILITY AND REPRODUCTIVE ISOLATION OF CHANNEL CATFISH AND BLUE CATFISH

The hybrid catfish produced by mating female channel catfish and male blue catfish is the predominant genotypes used by the US catfish industry. However, artificial fertilization is required of making the F1 hybrids because of reproductive isolation of channel catfish and blue catfish. Therefore, understanding the sex determination mechanisms and molecular basis of the reproductive isolation and hybrid incompatibility is critical to release the bottleneck. The objectives of this project are 1) to determine and compare the sex determination mechanisms of channel catfish and blue catfish by analysis of their epigenetic regulation using whole genome bisulfate sequencing and RNA-Seq; 2) Compare whole genome methylation profiles of blue catfish strains with high and low compatibility for the production of the interspecific hybrids; and 3) Compare epigenomic and expression profiles of reciprocal interspecific F1 hybrids (channel catfish female x blue catfish male and blue catfish female x channel catfish male) to determine allelic methylation and expression of genes involved in sex determination during early embryonic development and sex differentiation.