Action of sex steroid hormones on temperature-induced sex determination in the snapping turtle (Chelydra serpentina)

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Abstract

Administration of exogenous estradiol benzoate (EB) or an estrogen agonist, R2858, into eggs of snapping turtles caused all embryos incubated at male-producing temperatures to develop as females, whereas testosterone propionate (TP) caused 42% of the embryos to develop as females. Some of the embryos treated with EB, R2858, or TP also had hypertrophied oviducts. Neither dihydrotestosterone (DHT) nor cholesterol had any apparent effect on the sex determination of embryos incubated at male-producing temperatures. Injections of TP, DHT, the androgen agonist R1881, or cholesterol had no apparent effect on sex determination of embryos incubated at female-producing temperatures. Administration of estradiol antiserum or testosterone antiserum resulted in some individuals having undifferentiated or ambiguous gonads. Although both exogenous estrogens and androgens can induce embryonic gonads to develop as ovaries, the findings of this study indicate that estrogen is the female-inducing hormone and that androgens may feminize gonads via aromatization to estrogen. Furthermore, the results of the antisera injections suggest that endogenous steroid hormones may have a natural role in gonadal differentiation of reptiles with environmental sex determination.

References (44)

  • Y. Tanabe et al.

    Ontogentic steroidogenesis by testes, ovary, and adrenals of embryonic and postembryonic chickens (Gallus domesticus)

    Gen. Comp. Endocrinol

    (1986)
  • E. Witschi et al.

    Steroid hormones at early developmental stages of vertebrates

    Gen. Comp. Endocrinol. (Suppl.)

    (1962)
  • C.L. Brown et al.

    Thyroid hormones in early development, with special reference to teleost fishes

  • C.L. Brown et al.

    Maternal triiodothyronine injections caused increases in swimbladder inflation and survival rates in larval striped bass, Morone saxatilis

    J. Exp. Zool

    (1988)
  • J.J. Bull

    Sex determination in reptiles

    Q. Rev. Biol

    (1980)
  • J.J. Bull

    Temperature-sensitive periods of sex determination in a lizard: Comparisons with turtles and crocodilians

    J. Exp. Zool

    (1987)
  • J.H. Clark et al.
  • O. Doi et al.

    Pretreatment of chick embryos with estrogen in ova prevents mullerian duct regression in organ culture

    Endocrinology

    (1988)
  • P.K. Donahoe et al.

    Mullerian inhibiting substance; an update

    Recent Prog. Horm. Res

    (1982)
  • M. Dorizzi et al.

    Effets de la température, de l'oestradiol et du tamoxifène sur la différenciation sexuelle des gonades chez les tortues

    Arch Anat. Microsc

    (1987)
  • H.H. Feder

    Peripheral plasma levels of gonadal steroids in adult male and adult, nonpregnant female mammals

  • J.-M. Gasc

    Estrogen target cells in gonads of the chicken embryo during sexual differentiation

    J. Embryol. Exp. Morphol

    (1980)
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