Shimada K, Yoshida K, Saito N
Laboratory of Animal Physiology, School of Agricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan.
Gen Comp Endocrinol. 1996 May;102(2):241-6. doi: 10.1006/gcen.1996.0065.
On Day 5 of incubation fertilized eggs of single-comb White Leghorn hens were injected with an aromatase inhibitor (AI) and the sex reversal effect and levels of mRNA of P450(17alpha-hydroxylase) (P450(17alpha)) and 450(aromatase) (P450(arom)) were evaluated by observation of gonadal phenotype and by Northern and slot blot analysis. Individual genetic sex was evaluated by Southern blot analysis of red blood cells using a female sex chromosomal W-specific DNA probe. Saline injection had no sex reversal effect, whereas AI injection resulted in 50% sex reversal from genetic female but no effect on male. Levels of P450(17-alpha) mRNA were high in both ovary and testis in the control group but these levels were lowered significantly in ovary, testis, and sex-reversed gonad (testis) in the AI-treated group. On the other hand, levels of P450(arom) mRNA in the ovary were higher than those in the testis of the control group. AI treatment significantly suppressed ovarian levels of P450(arom) mRNA. Although estradiol alone failed to prevent the phenotypic male to female change, coadministration of estrogen suppressed the sex-reversal effect of AI and restored mRNA levels of P450(arom) in the ovary to control levels. These results suggest that expression of P450(arom) mRNA and estrogen plays an important role in sex differentiation of the female gonad of the chicken.
在孵化的第5天，给单冠白来航鸡的受精卵注射一种芳香化酶抑制剂（AI），通过观察性腺表型以及进行Northern印迹和狭缝印迹分析，评估其性别逆转效应以及P450（17α-羟化酶）（P450（17α））和P450（芳香化酶）（P450（arom））的mRNA水平。使用雌性性染色体W特异性DNA探针，通过对红细胞进行Southern印迹分析来评估个体的遗传性别。注射生理盐水没有性别逆转效应，而注射AI导致50%的遗传雌性发生性别逆转，但对雄性没有影响。对照组中卵巢和睾丸的P450（17-α）mRNA水平都很高，但在AI处理组的卵巢、睾丸和性别逆转的性腺（睾丸）中，这些水平显著降低。另一方面，对照组卵巢中P450（arom）mRNA的水平高于睾丸。AI处理显著抑制了卵巢中P450（arom）mRNA的水平。虽然单独使用雌二醇未能阻止表型由雄性向雌性的转变，但雌激素的联合给药抑制了AI的性别逆转效应，并使卵巢中P450（arom）的mRNA水平恢复到对照水平。这些结果表明，P450（arom）mRNA的表达和雌激素在鸡雌性性腺的性别分化中起重要作用。
