4 - Genome Analysis Approach Detects Meiotic Failure in Hybrid Male Catfish Between Bighead and North African Species

Hybrid sterility, a hallmark of postzygotic isolation, stems from incompatibilities between parental genomes that disrupt the meiotic process. While chromosomal incompatibility is often suggested as a cause, the precise mechanisms remain unclear. This study explored meiotic behavior and genome-wide differences in bighead catfish (Clarias macrocephalus), North African catfish (Clarias gariepinus), and their sterile male hybrids, which are significant in aquaculture. Through bioinformatic and cytogenetic analyses of repetitive DNA, we uncovered substantial divergence in satellite DNA (satDNA) families between the two parental species. Interestingly, one hybrid exhibited successful meiosis and sperm production, indicating potential variability in sterility outcomes. Our findings suggest that genome-wide satDNA divergence, rather than variations in chromosome number, may play a key role in meiotic failure and male sterility in these catfish hybrids.

Co-Author 1
Artem Lisachov
Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand

Co-Author 2
Kornsorn Srikulnath
Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand