Sex Reversal and Analyses of Possible Involvement of Sex Steroids in Scallop Gonadal Development in Newly Established Organ-Culture Systems

2017 ◽  
Vol 34 (2) ◽  
pp. 86 ◽  
Author(s):  
Ayano Otani ◽  
Tadaaki Nakajima ◽  
Tomomi Okumura ◽  
Shiro Fujii ◽  
Yasuhiro Tomooka
Reproduction ◽  
2012 ◽  
Vol 144 (2) ◽  
pp. 257-267 ◽  
Author(s):  
Rafał P Piprek ◽  
Anna Pecio ◽  
Jacek Z Kubiak ◽  
Jacek M Szymura

Sex hormones are essential for sexual differentiation and play a key role in the development of gonads in amphibians. The goal of this study was to evaluate the influence of exogenous sex steroids, testosterone, and 17β-estradiol (E2) on development of gonads in five anuran species differing in their evolutionary positions, sex determination, and mode of gonadogenesis. We found that in two closely related species of fire-bellied toad, Bombina bombina and Bombina variegata, testosterone and E2 exposure results in sex reversal as well as intersex and undifferentiated gonads. Similarly, sex reversal was observed in Hyla arborea after exposure to male or female sex steroids. Xenopus laevis was sensitive to E2 but only moderately to testosterone. In Bufo viridis, treatment with either sex hormone provoked a developmental delay in gonads and Bidder's organs. Therefore, susceptibility to hormonal sex reversal appeared species dependent but unrelated to genetic sex determination and the type of gonadogenesis. We also found that the onset of sex steroid exposure influences gonad differentiation and the meiotic status of the germ cells depends on their location within the gonad. Our findings reveal differential sensitivity of amphibians to testosterone and E2, establishing a hierarchy of sensitivity to these hormones among different anuran species.


2008 ◽  
Vol 159 (suppl_1) ◽  
pp. S9-S15 ◽  
Author(s):  
Eveline M Delemarre ◽  
Bram Felius ◽  
Henriette A Delemarre-van de Waal

Puberty is the result of increasing pulsatile secretion of the hypothalamic gonadotropin releasing hormone (GnRH), which stimulates the release of gonadotropins and in turn gonadal activity.In general in females, development of secondary sex characteristics due to the activity of the gonadal axis, i.e., the growth of breasts, is the result of exposure to estrogens, while in boys testicular growth is dependent on gonadotropins and virilization on androgens.Hypogonadotropic hypogonadism is a rare disease. More common is the clinical picture of delayed puberty, often associated with a delay of growth and more often familial occurring. Especially, boys are referred because of the delay of growth and puberty. A short course (3–6 months) of androgens may help these boys to overcome the psychosocial repercussions, and during this period an increase in the velocity of height growth and some virilization will occur.Hypogonadotropic hypogonadism may present in a congenital form caused by developmental disorders, some of which are related to a genetic disorder, or secondary to hypothalamic–pituitary dysfunction due to, among others, a cerebral tumor.In hypogonadotropic hypogonadism puberty can be initiated by the use of pulsatile GnRH, gonadotropins, and sex steroids. Sex steroids will induce development of the secondary sex characteristics alone, while combined administration of gonadotropins and GnRH may induce gonadal development including fertility.


1976 ◽  
Vol 35 (1) ◽  
pp. 27-45 ◽  
Author(s):  
Alexander M. Spence ◽  
Lucien J. Rubinstein ◽  
Frances K. Conley ◽  
Mary M. Herman

1990 ◽  
Vol 36 (5) ◽  
pp. 1145-1152
Author(s):  
Yoshiaki YURA ◽  
Hiroki IGA ◽  
Yasuo KONDO ◽  
Ryoji KAJI ◽  
Shinichi NAGAMINE ◽  
...  

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