Location: Warmwater Aquaculture Research Unit
Title: Molecular Identification of XY Sex-Reversed Female and YY Male Channel Catfish Authors
Submitted to: International Conference on Animal Genetics
Publication Type: Abstract Only
Publication Acceptance Date: May 27, 2010
Publication Date: July 26, 2010
Citation: Waldbieser, G.C., Davis Jr, K.B. 2010. Molecular Identification of XY Sex-Reversed Female and YY Male Channel Catfish. 32nd Conference of the International Animal Genetics, Edinburgh, Scotland, July 26-30, 2010. pg.114. Technical Abstract: Production of channel catfish leads U.S. aquaculture, and monosex culture may provide higher production efficiencies. Determination of phenotypic sex is labor intensive and not practical for large scale culture. Catfish have an X-Y sex determination system with monomorphic sex chromosomes. Hormonal sex reversal can produce viable XY females which produce XY and YY male offspring when mated with normal XY males. The YY males are phenotypically identical to XY males and must be identified by progeny testing which requires 2.5 years or longer. Therefore a molecular method of sex determination would improve the efficiency of YY male production. Four microsatellite loci that were linked to the sex determining locus were used to genotype normal females and males and sex-reversed females from a pool of three full-sibling families from the 2005 year class (YC2005). Putative XY females were spawned with normal XY males to produce YC2007 offspring, and microsatellite analysis identified putative XX, XY, and YY genotypes. The YC2007 XY and YY males were mated naturally or manually in 2009 with normal XX females, and sex ratios of YC2009 offspring were determined by examination of reproductive tissues. The data showed that all offspring from four putative YY sires were male while 34-66% of offspring from six putative XY sires were male. These experiments demonstrated microsatellite allele genotypes could be used to predict sex phenotype in these families to improve the efficiency of production of all male populations.