Suitability of Microsatellite DNA Marker UNH995 in Sex Linkage Study of Nile tilapia <i>Oreochromis niloticus</i> L

Abstract

The Nile tilapia ( Oreochromis niloticus ) is one of the most commonly farmed species all over the world including Bangladesh. Monosex (male) tilapias are preferred to prevent uncontrolled reproduction by females and for the faster growth of males in case of intensive and semi-intensive aquaculture. In most of the tilapia hatchery of Bangladesh hormonal sex reversal are practiced indiscriminately by feeding androgen hormone to fry starting from their first feeding stage up to 30 days. To avoid public health concern due to direct administration of hormone in food chain, recent YY technology has become an acceptable model to produce genetically all male tilapia (GMT). However due to the plastic nature of sex determination system, the monosex production approach in Nile tilapia is yet to be practical in commercial venture. The present study was performed to analyze the suitability of sex-linked microsatellite DNA marker UNH995 for the identification of polymorphocity and informatory on allelic discrimination with polyacrylamide gel electrophoresis (PAGE) in three different families (HRT23, HRT26 and HTZF824) of Nile tilapia. Locus duplication was observed in the progeny of HRT23 and HRT26 families. In family HRT23 two alleles were equally distributed in male as well as in female offspring. Offspring of Family HRT26 contained more 231bp in female offspring, less in male offspring and totally absent in putative YY males. This information could be investigated thoroughly in future broodstock and their offspring for undertaking a monosex production approach in Nile tilapia.