World Aquaculture Singapore 2022

November 29 - December 2, 2022

Singapore

PHYLOGENETIC ANALYSIS OF GONADOTROPIN-RELEASING HORMONE (GnRH) GENES OF TROPICAL CATFISHES Pangasius nasutus AND Hemibagrus nemurus

Zarirah Zulperi*, Amirah Syafiqah Zamri, Fatin Nabilah Mohamad Sahadan, Yuzine Esa

 

Department of Aquaculture

Faculty of Agriculture

Universiti Putra Malaysia

43400 UPM Serdang

Selangor, Malaysia

zarirah@upm.edu.my

 

 



Pangasius nasutus (patin buah) and Hemibagrus nemurus (river catfish) are among the most popular tropical catfish species due to its flesh quality and nutritional values.  Department of Fisheries Malaysia reported the production of H. nemurus and P. nasutus in 2021 were approximately 1,337.68 and 16.49 tonnes, which only covered 1.26% and 0.29% of the whole freshwater fish production in Malaysia. The production of H. nemurus could not fulfill the market demand since hatcheries encountered problems in induced spawning, especially the failure of female brood stock to undergo final oocyte maturation, preventing its ability to spawn. Meanwhile, the availability of P. nasutus is still depending on wild-captured, which led to its low population in their natural habitat. Study of gonadotropin-releasing hormone (GnRH), an essential hormone for reproduction, is important to understand its molecular properties in regulating gametogenesis in catfishes. This study involved cloning and characterization of a complete open reading frame (ORF) of GnRH genes, GnRH-1 and GnRH-2. Full-length cDNA encoding GnRH-1 and GnRH-2 genes were detected at 312 bp and 376 bp, respectively. Multiple sequence alignment showed GnRH-1 and GnRH-2 of P. nasutus and H. nemurus shared highest similarities (>95% values) to other catfish species; channel catfish (Ictalurus punctatus) and African catfish (Clarias garienpinus). Phylogenetic tree showed both species grouped in a similar cluster to Siluriformes followed by Cypriniformes. This is the first study of GnRH genes in P. nasutus and H. nemurus, thus the study should contribute as an initial step for a development of a better reproductive strategy in catfish species to increase their production in the industry.