An investigation of ZZ/ZW and XX/XY sex-determination systems in bighead catfish (Clarias macrocephalus, Günther, 1864​), North African catfish (Clarias gariepinus, Burchell, 1822), and hybrid catfish (Clarias macrocephalus x Clarias gariepinus)

Name: Dung, Nguyen Ho My

LCSH: Kasetsart University -- Dissertations. Ph.D. (Genetics) 2021

Classification :.LCCS: QL638.C6

LCSH: Kasetsart University. -- Department of Genetics -- Dissertations

LCSH: Catfishes -- Genetics

LCSH: Clarias gariepinus

LCSH: Sex determination

Abstract: Aquaculture plays an important role in the food and nutrition of many countries and is particularly significant in rural development. Clariid catfish (Clarias spp.) are regarded as one of the most promising aquaculture species and contribute significantly to the economy of Thailand. The hybrid freshwater catfish from native parental species (C. gariepinus x C. macrocephalus) has faster growth and disease resistance as a favored breed in aquaculture but the sterility of F1 male hybrids has presented a major obstacle to commercial production. The complex sexdetermination system (SDS) between the two parental species might affect sterility. This study explored the SDSs of these two species using diversity arrays technology sequencing (DArTseq) to generate single nucleotide polymorphism (SNP) loci and restriction site specific presence-absence (PA) markers. DArTseq is a successful method for identifying sex-linked markers in non-model species. Male and femalelinked loci reached the criteria of moderately sex-linked loci at 70:30, 80:20, 90:10 and 100:0. Results suggest that the male heterogametic XX/XY SDS should coexist with the ZZ/ZW system in African catfish. The SDS of African catfish might be influenced by a polygenic sex-determination (PSD) system, consisting of many independently segregating sex “switch” loci to determine sex within a species, while bighead catfish may also exhibit a male heterogametic XX/XY sexdetermination system. One male-linked locus showed homology with the GTSF1L gene, which exhibits a testis-enriched expression pattern. Male-linked loci on the putative Y sex chromosome were identified as an extremely small proportion of the genome. A PCR-based DNA marker was developed to validate the male-linked loci in bighead catfish. Research results disclosed that ZZ/ZW SDS can co-exist with XX/XY SDS as PSD in the same individuals of hybrid catfish. Most of these loci were not sex-linked in the parental species, suggesting that the hybrid exhibits a combination of different alleles. One female-linked locus was homologous with the B4GALNT1 gene, which is involved in the spermatogenesis pathway and hatchability. These SDS findings can be applied to improve commercial breeding of this species in Thailand. This approach, using moderately sex-linked loci, provides a baseline to identify potential sex determination regions in catfish, thereby enabling genetic enhancement in breeding programs.

Kasetsart University. Office of the University Library

Address: Bangkok

Email: tdckulib@ku.ac.th

Name: Kornsorn Srikulnath

Role: Thesis Advisor

Name: Surin Peyachoknagul

Role: Thesis CO-Advisor

Name: Narongrit Muangmai

Role: Thesis CO-Advisor

Created: 2021

Modified: 2025-07-26

Issued: 2025-07-26

วิทยานิพนธ์/Thesis

application/pdf

URL: https://www.lib.ku.ac.th/KUthesis/2564/nguyen-dun-all.pdf

CallNumber: QL638.C6 .D86

eng

DegreeName: Doctor of Philosophy

Level: Doctoral Degraee

Descipline: Genetics

Grantor: Kasetsart University

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