• Title/Summary/Keyword: sex reversal

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Effects of Dietary $17\alpha-Methyltestosterone$ on Body Composition and Gonosomatic Indices in Blue Tilapia, Oreochromis aureus(Steindachner) (청틸라피아의 체조성과 생식소 중량 지수에 미치는 $17\alpha-Methyltestosterone$ 호르몬의 영향)

  • Jo Jae-Yoon;Smitherman R. Oneal;Tave Douglas
    • Journal of Aquaculture
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    • v.8 no.3
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    • pp.183-193
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    • 1995
  • Blue tilapia, Oreochromis aureus swim-up fry were fed,0, 1, 10, or 60 ppm $17\alpha-methyltestosterone$(MT) for 30 days (sex reversal period). Fish that had been fed 0 ppm MT during the sex reversal period were subsequently fed 0 ppm MT (0-0), 10 ppm MT (0-10) or 60 ppm MT (0-60) for the next 57 days (post sex reversal period) ; fish that had been fed 60 ppm MT during the sex reversal period were subsequently fed 0 ppm MT (60-0), 10 ppm MT (60-10), or 60 ppm MT (60-60) during the post sex reversal period. One group was fed 1 ppm MT (1-1), while another group was fed 10 ppm MT (10-10) during the entire 87-day experiment. There was a significant inverse relationship between concentration of MT and percentage body protein and percentage body fat at the end of the sex reversal period, while there was a significant positive relationship between concentration of MT and percentage body moisture. MT treatment during the post sex reversal period had greater effects on body composition of males at the end of the post sex reversal period than did MT treatment during the sex reversal period. There was a significant inverse relationship between MT concentrations, during both the sex reversal and post sex reversal periods, and gonosomatic indices (GSI) in males. In females, there was a significant inverse relationship between MT concentrations during the post sex reversal period and GSI.

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Sex Ratio and Sex Reversal in Two-year-old Class of Oyster, Crassostrea gigas (Bivalvia: Ostreidae)

  • Park, Jung Jun;Kim, Hyejin;Kang, Seung Wan;An, Cheul Min;Lee, Sung-Ho;Gye, Myung Chan;Lee, Jung Sick
    • Development and Reproduction
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    • v.16 no.4
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    • pp.385-388
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    • 2012
  • The sex ratio (F:M) in the same population of oyster, Crassostrea gigas at the commencement of the study (2007) was 1:1.0, but changed to 1:2.8 by the end of the study (2008). The sex reversal rate in two-year-old oysters was 40.2%. Specifically, female to male sex reversal rate was 66.1%, which is higher than the male to female sex reversal rate of 21.1%. The sex reversal pattern of C. gigas appears to go from male ${\Rightarrow}$ female ${\Rightarrow}$ male, and as such is determined to be rhythmical hermaphroditism.

Indirect Evidence on Sex Reversal of Sinonovacula constricta (Bivalvia: Euheterodonta) and Gomphina veneriformis (Bivalvia: Veneridae)

  • Shin, Yun Kyung;Park, Jung Jun;Choi, Ji Sung;Lee, Jung Sick
    • Development and Reproduction
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    • v.18 no.2
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    • pp.73-78
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    • 2014
  • This study attempts to propose the possibility of the sex reversal in Sinonovacula constricta and Gomphina veneriformis by confirming the changes in the sex ratio with the shell length in the same population level. For analysis of sex ratio, 100 individuals of S. constricta (SL 26.5-95.0 mm) and 2385 individuals of G. veneriformis (SL 15.1-60.1 mm) were used. Sex was analyzed histologically. Both species displayed the tendency of increase in the female proportion with increase in shell length. In this study, changes in the sex ratio in accordance with the growth of S. constricta and G. veneriformis are determined to be indirect evidence that signifies their sex reversal.

Indirect Evidence on Sex Reversal with Sex Ratio of Tegillarca granosa (Bivalvia: Arcidae) and Ruditapes philippinarum (Bivalvia: Veneridae)

  • Lee, Jung-Sick;Ku, Ka-Yeon;Kim, Hye-Jin;Park, Ji-Seon;Park, Jung-Jun;Shin, Yun-Kyung;Jeon, Mi-Ae
    • Development and Reproduction
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    • v.16 no.3
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    • pp.177-183
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    • 2012
  • This study attempts to propose the possibility of the sex reversal in Tegillarca granosa and Ruditapes philippinarum by confirming the changes in the sex ratio with the shell length (SL) in the same population level. For analysis of sex ratio with SL, 1500 individuals of T. granosa (SL 10.1-45.0 mm) and 712 individuals of R. philippinarum (SL 15.1-70.0 mm) were used. Sex was analyzed histologically. The average sex ratios (F:M) of T. granosa and R. philippinarum were 1:1.22 and 1:0.96, respectively. However, sex ratio was found to differ when the clams were divided into groups according to SL in 5.0 mm intervals. Both species displayed the tendency of increase in the proportion of female with increase in SL. In this study, changes in the sex ratio in accordance with the growth of T. granosa and R. philippinarum are determined to be indirect evidence that signifies their sex reversal.

Sex and Sex Reversal of Bivalves (이매패류의 성과 성전환)

  • Lee, Jung Sick
    • The Korean Journal of Malacology
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    • v.31 no.4
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    • pp.315-322
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    • 2015
  • The sex of bivalves is classified into gonochorism and hermaphroditism, and hermaphroditism is further divided into simultaneous (synchronous or functional), and sequential (asynchronous). The sequential hermaphroditism signifies sex reversal in accordance with seasons. In general, in the case of gonochoristic bivalves, manifestation of sex as female and male, after having identified the morphological sex, is limited to a period of the life cycle in any given individual. In order to accurately identify sex, continuous monitoring of changes in the sex during life cycle is necessary by tagging the sex. In the bivalves, sex reversal and sequential hermaphroditism has been reported in the Ostreidae, Pectinidae, Veneridae and Arcidae etc.. Most of these studies have reached this conclusion based on evidence derived from sex ratio change in accordance with the age within same populations. Sex change in the sequential hermaphroditic bivalves normally occurs when the gonad is undifferentiated between spawning seasons. Two factors are involved in sex determination and sex change in bivalves, namely genetic and environmental. However, more detailed research is needed on the effect of the genetic and environmental factors involved in sex determination and sex change of bivalves.

Hormonal Induction of Sex Reversal in Serranid Fish, Epinephelus septemfasciatus (호르몬처리에 의한 능성어(Epinephelus septemfasciatus)의 성전환)

  • Lee Young-Don;Kim Hyung-Bae;Song Choon-Bok;Rho Sum;Lee Jung-Jae
    • Journal of Aquaculture
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    • v.9 no.1
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    • pp.19-23
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    • 1996
  • Hormonal induction of sex reversal was examined by using sex steroid hormones in serranid fish, Epinephelus septemfasciatus. Young fish were collected from the coastal area of Cheju Island, and reared for 2 years before fish were used for the experiments. Without any hormonal treatment, gonads of fish ($1,000\~2,800$ g in body weight) were occupied by oocytes of the perinucleolus stage and bundles of protogonial cells in the area of germinal epithelium. When the induction of sex reversal was attempted by daily oral administration of $17\alpha$-methyltestosterone (0.5 mg/kg fish) for 90 days, active spermatogenesis was induced, and spermatogonia and spermatocytes and spermatids were appeared in all gonads we examined. However, after daily, oral treatment of $17\beta$-estradiol (0.5 mg/kg fish) to. 50 days with the following injection of human chorionic gonadotrophin ($1,000\~1,500$ IU/kg fish) mature oocytes were not induced in fish gonad.

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Sex Reversal Pattern of Wrasse in Jeju Coastal Waters

  • Lee, Young-Don;Kim, Se-Jae
    • Proceedings of the Korean Society of Developmental Biology Conference
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    • 2003.10a
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    • pp.76-76
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    • 2003
  • Eleven wrasse species inhabit the coastal waters of Jeju Island, Korea. They are the target of leisure fishing and are considered good eating. We investigated the distribution of standard length (SL) by sex of wrasse in Jeju coastal waters for Halichores poecilopterus, H. tenuispinis, Pseudolabrus japonicus, and Pteragogus flagellifera. A cross-section of the ovary showed the ovarian cavity and ovarian lamellae containing oocytes. A cross-section of the testis showed many lobules containing spermatogonia and spermatocytes. A cross-section of a gonad undergoing sex reversal showed the regression or reduction of oocytes and some spermatocytes located in the ovarian lamellae. A cross-section of a sex-reversed testis showed the primary structure of the ovary, with spermatocytes distributed in the epithelium of the lamellae, and reformed seminiferous ducts in the basement lamellae. (중략)

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Sex Reversal and Masculinization according to Growth in Longtooth Grouper Epinephelus bruneus

  • Oh, Seong-Rip;Kang, Hyeong-Cheol;Lee, Chi-Hoon;Hur, Sang-Woo;Lee, Young-Don
    • Development and Reproduction
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    • v.17 no.2
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    • pp.79-85
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    • 2013
  • To understand the sex reversal characteristics in the longtooth grouper (Epinephelus bruneus), this study examined the sex reversal and artificial masculinization of wild caught E. bruneus reared in indoor rearing tank after a 17${\alpha}$-methyltestosterone injection. To domesticate a broodstock, 64 wild caught E. bruneus, between 47.0 to 110.0 cm in total length and from 1.5 to 21.4 kg in body weight, were reared in indoor rearing tank (4.0 to 5.0 m wide, and 2.5 to 3.0 m depth) for four years. Seven specimens showed sex reversal from female to male during indoor rearing condition, whose total length and body weights were from 63.0 to 99.0 cm and from 4.4 to 13.2 kg, respectively. After inducing artificial masculinization in 14 female E. bruneus with a 17${\alpha}$-methyltestosterone (2.0 mg/kg BW) implants for 3 years, spermiation occurred in 9 specimens (total length: 54.0 to 68.0 cm, body weight: 2.3 to 4.3 kg). Among the female to male sex reversals, two specimens returned back to being female, whose body weights were 2.8 kg (initially 2.6 kg) and 2.7 kg (initially 2.3 kg). Therefore, this study suggested that E. bruneus (> 3.0 kg) was more effective in masculinizing by 17${\alpha}$-methyltestosterone implants.

Analysis of SRY-negative XX True Hermaphroditism in an English Cocker Spaniel

  • Jang, Goo;Byeon, Ye-Eun;Kim, Min-Kyu;Koo, Ok-Jae;Lee, Byeong-Chun
    • Journal of Veterinary Clinics
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    • v.25 no.3
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    • pp.221-223
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    • 2008
  • SRY gene is normally responsible for testis induction, yet testis development can occur in the absence of SRY. In here, we analyzed the SRY-negative sex reversal in cocker spaniel, at 1.5 year-old. The attacked dog was suffered from enlarged clitoris, and resulted in disorder of urination. By surgically approach, enlarged clitoris and one testis, which are apparently seen, are removed. Additionally, thorough the abdomen surgery, uterus and ovary-like mass were removed. The dog had XX, chromosome, showed negative for SRY-gene, and the mass had the ovary-testis structure. In other words, based on the macroscopic, cytogenic, and histological study, we can diagnose the cocker spaniel as SRY-negative sex reversal.