Artificial sex reversal of white grouper ( Epinephelus aeneus ) utilizing aromatase inhibitor (Fadrozole)

The white grouper is a desirable aquaculture species that adapts to captivity, grows well and commands a high market price. However, little is known about reproductive biology or control of sex reversal of this protogynous hermaphrodite. In this study, female white groupers were implanted with one dose of 17α‐methyltestosterone (10 mg/kg body weight [BW], MT) and two doses of aromatase inhibitor, fadrozole (1 and 3 mg/kg BW, FD1 and FD3) once a month for 4 months (April–July). At the start of the study, the fish had gonads full of oocytes compared to the end of the experiment when the control group mature oocytes compared to the experimental groups MT, FD1 and FD3 that exhibited different stages of testicular tissue. Plasma levels of testosterone were significantly highest in the FD3 group and the highest 11‐Ketotestosterone levels were observed in the MT group. Plasma levels of oestradiol (E₂) were significantly lower in the FD implanted groups, compared to initial individuals and control groups. The use of aromatase inhibitor, FD for sex reversal both gives further insight into the mechanisms controlling sex differentiation and provides an alternative to steroid treatment.

[1]  O. Eroldoğan,et al.  Observations on the Artificial Sex Inversion of Dusky Grouper (Epinephelus marginatus) from the North-East Mediterranean Sea, Turkey , 2016 .

[2]  Guan-Chung Wu,et al.  Sexual Fate Reprogramming in the Steroid-Induced Bi-Directional Sex Change in the Protogynous Orange-Spotted Grouper, Epinephelus coioides , 2015, PloS one.

[3]  H. Yılmaz,et al.  Induction of sex-reversed males using 17 α-methlytestosterone in the gold blotch grouper (Epinephelus costae) , 2015 .

[4]  R. Ranjan,et al.  Efficacy of 17 α-methyl testosterone and letrozole on sex reversal of protogynous grouper, Epinephelus tauvina (Forskal, 1775) and spawning performance of sex-reversed males , 2015 .

[5]  Sedat Gündoğdu.  The Usage of Common Multiple Comparison Tests (Post-Hoc) in Fisheries Sciences , 2014 .

[6]  L. Floeter-Winter,et al.  Involvement of pituitary gonadotropins, gonadal steroids and breeding season in sex change of protogynous dusky grouper, Epinephelus marginatus (Teleostei: Serranidae), induced by a non-steroidal aromatase inhibitor. , 2013, General and comparative endocrinology.

[7]  F. Piferrer,et al.  Gonadal sex differentiation in the Senegalese sole (Solea senegalensis) and first data on the experimental manipulation of its sex ratios , 2013 .

[8]  Sung-Pyo Hur,et al.  Masculinization in juvenile longtooth grouper, Epinephelus bruneus, with aromatase inhibitor: changes in GtH subunit mRNA expression and steroids hormone levels , 2012 .

[9]  Tohru Kobayashi,et al.  Differentiation of steroid-producing cells during ovarian differentiation in the protogynous Malabar grouper, Epinephelus malabaricus. , 2011, The International journal of developmental biology.

[10]  Tsai Ya-ju,et al.  Development of Gonadal Tissue and Aromatase Function in the Protogynous Orange-Spotted Grouper Epinephelus coioides , 2011 .

[11]  A. Bart,et al.  Cryopreservation of sperm from natural and sex‐reversed orange‐spotted grouper (Epinephelus coioides) , 2010 .

[12]  O. Kah,et al.  Aromatase in the brain of teleost fish: Expression, regulation and putative functions , 2010, Frontiers in Neuroendocrinology.

[13]  Masaru Nakamura,et al.  Precocious sex change and spermatogenesis in the underyearling Malabar grouper Epinephelus malabaricus by androgen treatment , 2010 .

[14]  D. E. Roberts,et al.  INDUCED SEX INVERSION, MATURATION, SPAWNING AND EMBRYOGENY OF THE PROTOGYNOUS GROUPER, Mycteroperca microlepis , 2009 .

[15]  J. Gui,et al.  Molecular mechanisms underlying sex change in hermaphroditic groupers , 2010, Fish Physiology and Biochemistry.

[16]  Masaru Nakamura,et al.  Efferent duct differentiation during female-to-male sex change in honeycomb grouper Epinephelus merra , 2007 .

[17]  Hao-ran Lin,et al.  Seasonal changes of serum sex steroids concentration and aromatase activity of gonad and brain in red-spotted grouper (Epinephelus akaara). , 2007, Animal reproduction science.

[18]  M. Papadaki,et al.  Permanent sex inversion in 1-year-old juveniles of the protogynous dusky grouper (Epinephelus marginatus) using controlled-release 17α-methyltestosterone implants , 2006 .

[19]  Yong Zhang,et al.  Gonadal development, aromatase activity and P450 aromatase gene expression during sex inversion of protogynous red‐spotted grouper Epinephelus akaara (Temminck and Schlegel) after implantation of the aromatase inhibitor, fadrozole , 2006 .

[20]  P. Munday,et al.  Diversity and flexibility of sex-change strategies in animals. , 2006, Trends in ecology & evolution.

[21]  Masaru Nakamura,et al.  Sex change in coral reef fish , 2005, Fish Physiology and Biochemistry.

[22]  Masaru Nakamura,et al.  Induction of Female-to–male Sex Change in the Honeycomb Grouper (Epinephelus merra) by 11-ketotestosterone Treatments , 2006, Zoological science.

[23]  Hao-ran Lin,et al.  Effects of aromatizable and nonaromatizable androgens on the sex inversion of red-spotted grouper (Epinephelus akaara) , 2006, Fish Physiology and Biochemistry.

[24]  Masaru Nakamura,et al.  Aromatase inhibitor induces complete sex change in the protogynous honeycomb grouper (Epinephelus merra) , 2004, Molecular reproduction and development.

[25]  Masaru Nakamura,et al.  Sex Inversion of Sexually Immature Honeycomb Grouper (Epinephelus merra) by Aromatase Inhibitor , 2004, Zoological science.

[26]  C. Miura,et al.  Molecular control mechanisms of fish spermatogenesis , 2003, Fish Physiology and Biochemistry.

[27]  Y. Zohar,et al.  Use of GnRHa-delivery systems for the control of reproduction in fish , 2000, Reviews in Fish Biology and Fisheries.

[28]  Masaru Nakamura,et al.  Gonadal Restructuring and Correlative Steroid Hormone Profiles during Natural Sex Change in Protogynous Honeycomb Grouper (Epinephelus merra) , 2003, Zoological science.

[29]  C. Kuo,et al.  Androgens stimulate sex change in protogynous grouper, Epinephelus coioides: spawning performance in sex-changed males. , 2003, Comparative biochemistry and physiology. Toxicology & pharmacology : CBP.

[30]  S. Moslemi,et al.  Aromatase inhibitors: past, present and future , 2001, Molecular and Cellular Endocrinology.

[31]  E. Azzurro,et al.  Reproduction in the dusky grouper from the southern Mediterranean , 2001 .

[32]  B. Glamuzina,et al.  Induced sex reversal of dusky grouper, Epinephelus marginatus (Lowe) , 1998 .

[33]  Y. Siau,et al.  Observations on the female reproductive cycle and fecundity of three species of groupers (Epinephelus) from the southeast Tunisian seashores , 1983 .