Validation of a male-specific DNA marker confirms XX/XY-type sex determination in African catfish (Clarias gariepinus)

Abstract

African catfish (Clarias gariepinus) is a promising food fish species with significant potential and growing mass of production in freshwater aquaculture. Male African catfish possess improved production characteristics over females, therefore the use of monosex populations could be advantageous for aquaculture production. However, our knowledge about the sex determination mechanism of this species is still limited and controversial. A previously isolated male-specific DNA marker (CgaY1) was validated using offspring groups from targeted crosses (n=630) and it was found to predict the sex of 608 individuals correctly (96.43% accuracy). Using the proportion of recombinants, we estimated the average genetic distance between the potential sex determination locus and the sex-specific marker to be 2.69 cM. As an earlier study suggested that both XX/XY and ZZ/ZW systems coexist in this species, we tested the applicability of their putative moderately sex-linked loci and found that no sex-specific amplification could be detected for any of them. In addition, temperature-induced masculinization suggested by others was also tested, but no such effect was detected in our stocks when the published parameters were used for heat treatment. Altogether, our results support an exclusive XX/XY sex determination system in our African catfish stock and indicate a good potential for the future use of this male-specific DNA marker in research and commercial production.

Haplotype-resolved assembly of the African catfish (Clarias gariepinus) provides insights for semi-terrestrial adaptation of airbreathing catfishes

“…To identify the putative paternal haplotype in our assemblies, the full-length nucleotide sequences of two previously identified and validated male-specific DNA markers (Accession numbers: CgaY1: AF332597; CgaY2: AF332598) were obtained from GenBank 29,55 . Both sequences, 2.6 kb (CgaY1) and 458 bp (CgaY2) in length, were BLASTed against Hap1, Hap2, and Prim assemblies, requiring stringent mapping criteria (identity >98%; queryCoverage >98%).…”

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“…It inhibits the role of neurotransmitter acetylcholinesterase (AchE) in the central nervous system of an organism (Insect) by its primary metabolite and carbon sulfide resulting to death. Clarias gariepinus is a hardy fish of high commercial importance, distributed in the tropical regions example Nigeria and mostly utilized aquaculture candidate for the purpose of eco-toxicological investigations (Nwani et al, 2013;Odo et al, 2017;Balogh et al, 2023) [56,59,7] . Sub-lethal concentrations of pollutants in the aquatic habitats alter behavioral, structural and functional changes in fish and other aquatic organisms which occurs than mortality (Srivastava and Singh, 2013c, Ullah et al, 2014) [80,83] .…”