Effects of 17α-Methyltestosterone and Aromatase Inhibitor Letrozole on Sex Reversal, Gonadal Structure, and Growth in Yellow Catfish Pelteobagrus fulvidraco.
Monosex populations are in demand in many fish species with sexual dimorphism, e.g., better growth performance, higher gonad value, superior ornamental value. From the point of view of research, a monosex population is one of the best materials for investigating sex-determining mechanisms, sex differentiation, and sex-linked markers. Sex reversal of females (phenotypic reversal from XX female to XX male) is the first step in all-female production in species with an XX/XY system for sex determination. In the present study, masculinization of yellow catfish, a species with XX/XY sex determination, was investigated by oral administration of various doses of 17α-methyltestosterone (MT) or an aromatase inhibitor (AI) letrozole (LZ); effects on survival, growth performance, sex ratio, and changes in gonadal structure were evaluated. Three doses (20, 50, and 100 mg kg(-1) diet) of oral MT or LZ were administered to fry from 10 days post-hatching (DPH) to 59 DPH. Oral administration of MT at all doses did not significantly change the ratio of males (45.8%, 33.3%, and 50.0% respectively) compared to the control group (37.5%), while yielding intersex fish at all doses (4.2% to 8.3%). Oral administration of LZ produced a significantly higher proportion of males in all doses (75.5%, 83.3%, and 75.0%, respectively). Additionally, the lowest dose of LZ improved the growth of treated fish compared to the control, and all doses of LZ enhanced spermatogenesis in treated males.
College of Fishery, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China; and.
Zhi-Gang
ZG
Shen
College of Fishery, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China; and kugeshen1@163.com.
Qi-Xue
QX
Fan
College of Fishery, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China; and.
Wei
W
Yang
College of Fishery, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China; and.
Yun-Long
YL
Zhang
Aquaculture Genetics and Breeding Laboratory, The Ohio State University South Centers, 1864 Shyville Road, Piketon, Ohio 45661, USA.
Han-Ping
HP
Wang
D045930:Anabolic Agents / Q000494:pharmacology; D000818:Animals; D047072:Aromatase Inhibitors / Q000494:pharmacology; D002397:Catfishes / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology*; D012734:Disorders of Sex Development / Q000139:chemically induced; D005260:Female; D006066:Gonads / Q000187:drug effects*; D006128:Growth / Q000187:drug effects*; D000077289:Letrozole; D008297:Male; D008777:Methyltestosterone / Q000494:pharmacology*; D009570:Nitriles / Q000494:pharmacology*; D012744:Sex Ratio; D013091:Spermatogenesis / Q000187:drug effects; D014230:Triazoles / Q000494:pharmacology*
D045930:Anabolic Agents; D047072:Aromatase Inhibitors; D009570:Nitriles; D014230:Triazoles; D000077289:Letrozole; D008777:Methyltestosterone