In vitro effects of gonadotrophic and steroid hormones on the interstitial cells of the chick embryo ovaries.
The embryonic gonads produce and secrete the steroid hormones that induce secondary sex differentiation in different species. The production of estrogens, testosterone and progesterone by interstitial cells of the chick embryo ovary has been demonstrated in experiments in ovo and in vitro. Estrogens would be responsible at the 7th day of in ovo incubation, of the evolution of the functional left ovary. According to Gasc, only the cells of the germinative epithelium of the left ovary possess receptors for estrogens, thus originating the formation of a cortex in this functional gonad and not in the right one. On the other hand, extragonadal factors, such as gonadotrophins, would participate in gonadal differentiation. Involvement of the hypophysis in the morphological and functional differentiation of the ovary in the chick embryo, has been considered in several studies. Woods and Week established the functional hypophysealgonadal axis at 13 days of in ovo incubation. However, the effects of individual gonadotrophins on the interstitial cells of the chick embryo remain unclear. Avila et al. and Grassi Milano observed that when the female gonads were cultured without steroid or gonadotrophic hormones at the start of differentiation an hermaphrodite left ovary and a male right one were formed. Kyparissi and Vakolopoulu observed that the inoculation in ovo of FSH at the end of embryonic development led to an increment in the number and size of follicles in the left ovary. Pittini and Grassi Milano added FSH and LH to cultures of 15 days-old chick embryos testicles and ovaries and found that only male gonads developed similar to normal embryos.(ABSTRACT TRUNCATED AT 250 WORDS)
Avila
R E
RE
II Cátedra de Histología, Universidad Nacional de Córdoba, República, Argentina.
Samar
M E
ME
de Fabro
S P
SP
D000818:Animals; D002642:Chick Embryo; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D007986:Luteinizing Hormone / Q000494:pharmacology*; D010053:Ovary / Q000196:embryology* / Q000648:ultrastructure; D012733:Sex Differentiation / Q000187:drug effects; D013256:Steroids / Q000494:pharmacology; D013799:Theca Cells / Q000187:drug effects* / Q000648:ultrastructure
D006063:Chorionic Gonadotropin; D013256:Steroids; D007986:Luteinizing Hormone