무지개송어 양식어업인 소득증대를 위한 전 암컷 대량생산

Abstract

This study was conducted to increase the efficiency of farming practice in rainbow trout, Oncorhynchus mykiss, by sex reversal and chromosome-set manipulation techniques. 1. Physiological sex-reversal by steroid hormone To obtain phenotypic male, hormonal sex reversal was carried out using exogenous hormone treatment method. 5 ㎎ of 17α-methyltestosterone per kg diet was supplied for 82 days after first feeding at 10℃ and 13℃. More than 93% of male population was produced by this method and growth of hormone-treated-fish at 13℃ was faster than that of untreated bi-sexual groups. 2. Induction of gynogenetic diploid rainbow trout Induced diploid gynogenesis was carried out using artificial insemination of UV-irradiated sperm into haploid eggs. Based on the appearance of the rate of haploid syndrome and survival of embryo, the dose of UV ray of at least 3,600 erg/㎠ was required to inactivate rainbow trout sperm genetically. Haploid embryos were restored to diploid by blocking the extrusion of the second polar body using heat shock treatment at 28℃ for 20 min, 10 min post insemination. Gynogenetic diploid was confirmed sex ratios after maturation of the fish erythrocyte measurements and chromosome counts. 3. Induction of sex-reversed gynogenetic diploid rainbow trout male and mass production of all-female rainbow trout by genetic sex reversal Phenotypic males in gynogenetic diploid group were induced successfully by dietary administration of 5 mg of 17α-methyltestosterone per kg diet for 82 days. All female population was produced by crossing between normal female and sex-reversed gynogenetic diploid male rainbow trout.