The regulation of androgen and estrogen formation in fetal gonads
نویسنده
چکیده
Several aspects of the functional development of the testis and ovary have been characterized in the fetal rabbit. First, the capacity of the fetal ovary to form 17p-estradiol develops at the same time in embryogenesis as the onset of testosterone formation in the fetal testis. Second, both fetal ovaries and testes have the capacity to form these steroid hormones from cholesterol de novo. Third, the enzymatic differentiation of the fetal testis occurs at the expected time in organ culture suggesting that this aspect of development is not hormone-induced. Fourth, gonadotropin receptors appear in testes concomitant with the initial rise in testosterone content but are virtually absent in ovaries throughout gestation. However, the onset of testosterone synthesis and the initial rise in testosterone content in the fetal testis do not appear to be coupled to gonadotropin stimulation since hCG does not stimulate testosterone formation until late in embryogenesis.
منابع مشابه
Characterization of Gonadal Transcriptomes from Nile Tilapia (Oreochromis niloticus) Reveals Differentially Expressed Genes
Four pairs of XX and XY gonads from Nile tilapia were sequenced at four developmental stages, 5, 30, 90, and 180 days after hatching (dah) using Illumina Hiseq(TM) technology. This produced 28 Gb sequences, which were mapped to 21,334 genes. Of these, 259 genes were found to be specifically expressed in XY gonads, and 69 were found to be specific to XX gonads. Totally, 187 XX- and 1,358 XY-enha...
متن کاملAndrogen Receptor Analysis in Relation to Estrogen and Progesterone Receptors as well as Histological Grade for Ductal Carcinoma In Situ of the Breast
Background and Objective: Since the advent of mammography screening, ductal carcinoma in situ (DCIS) of the breast has been diagnosed increasingly. In contrast to the situation in invasive breast carcinoma, there are only a few reports on androgen receptor (AR) status in DCIS and few reports on estrogen ...
متن کاملContributions of androgen and estrogen to fetal programming of ovarian dysfunction
In female mammals, including humans, deviations from normal androgenic or estrogenic exposure during fetal development are detrimental to subsequent adult ovarian function. Androgen deficiency, without accompanying estrogen deficit, has little apparent impact on ovarian development. Fetal estrogen deficiency, on the other hand, results in impaired oocyte and follicle development, immature and a...
متن کاملA Novel Null Mutation in P450 Aromatase Gene (CYP19A1) Associated with Development of Hypoplastic Ovaries in Humans
OBJECTIVE The CYP19A1 gene product aromatase is responsible for estrogen synthesis and androgen/estrogen equilibrium in many tissues, particularly in the placenta and gonads. Aromatase deficiency can cause various clinical phenotypes resulting from excessive androgen accumulation and insufficient estrogen synthesis during the pre- and postnatal periods. In this study, our aim was to determine t...
متن کاملDifferentiation of steroid-producing cells during ovarian differentiation in the protogynous Malabar grouper, Epinephelus malabaricus.
To understand the mechanism of sex differentiation in the protogynous Malabar grouper Epinephelus malabaricus, we performed an immunohistochemical investigation of the expression of three steroidogenic enzymes, cholesterol-side-chain-cleavage enzyme (CYP11a), aromatase (CYP19a1a), and cytochrome P45011beta-hydroxylase (CYP11b), in the gonads during ovarian differentiation. Strong positive immun...
متن کامل