Successful sex reversal of brook trout with 17α-methyldihydrotestosterone treatments
Successful sex reversal of brook trout with 17α-methyldihydrotestosterone treatments
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DOI：
10.1577/c02-039
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发表时间：
2003-07-01
影响因子：
1
通讯作者：
Sherrill, LW
中科院分区：
文献类型：
--
作者：
Galbreath, PF;Adams, ND;Sherrill, LW
Monosex female stocks are widely used in the commercial production of rainbow trout Oncorhynchus mykiss. The potential for commercial production of brook trout Salvelinus fontinalis, however, is constrained by the lack of published protocols for producing the sex-reversed males required to create monosex female stocks. Immersion and immersion plus feeding treatments with 17alpha-methyltestosterone (MT) and 17alpha-methyldihydrotestosterone (MDHT) were applied to genotypically female gynogenetic brook trout to induce phenotypic sex reversal. The fry were exposed to a 6-h immersion in a solution of NIT or MDHT on day 10 following completion of hatch and/or to a steroid-treated diet for 60 d beginning at first feeding, Immersion dosages were 0.5 or 1.0 mg/L, and feeding dosages were 1.0 or 2.0 mg/kg of feed for MT and 0.5 or 1.0 mg/kg for MDHT. Phenotypic sex of the fish was determined 19 or 22 months after first feeding. Control gynogenetic fish were 100% phenotypic females. Treatments with MT had minimal effect: most fish remained female, with only a low incidence of phenotypic males (1-3% in four of the treatments), intersex fish, or sterile fish. In contrast, a substantial number of phenotypic males were observed in several of the MDHT treatments, with the hi-hest proportion (45%) occurring in the 0.5 mg/L immersion plus 0.5 mg/kg feeding treatment. Sperm was obtained from 29 males from five MDHT treatment groups and one MT treatment group examined at maturity (22 months) and was used in progeny tests of these males. The progeny were 100% female, confirming the male parents to be genotypically female. These protocols may be used to create sex-reversed brook trout males for the production of monosex female progeny, although additional trials are ongoing to test similar MDHT immersion dosages applied once or multiple times, with or without feeding treatments, to identify protocols with increased efficacy.
