Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Gonad development”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25Linked to original sources
PubMed1991

[Brain development and gonadal hormones].

Gonadal steroids play an important role in exerting functional sexual differentiation of the brain. Recently there has been accumulating evidence that gonadal steroids regulate neuron number, axonal and dendritic growth and synapse formation in the neuronal system containing sex steroid receptors. These provide morphological bases for sexually dimorphic function of the brain. Other than in the developmental process, gonadal steroids are found to take care of neuronal plasticity in certain brain areas.

Androgens↗
PubMedDate not supplied

Human reproduction and a D.D.D. (determination, differentiation, development) pathogenetical classification of genital anomalies in phenotypic females.

Analysing 90 cases of different genital anomalies in phenotypic females a new pathogenetical classification is presented. The different anomalies are classified in 5 groups of disorders in the steps of genital development: gonadal determination, differentiation and development, genital ducts differentiation and development. Symptoms in reproductive age, diagnostic approach and therapeutic possibilities with particular attention to assisted reproduction are presented.

Female↗
PubMed1993

Sensitive stages for the effects of temperature on gonadal aromatase activity in embryos of the marine turtle Dermochelys coriacea.

Many data suggest an involvement of estrogens in gonadal differentiation in reptiles with temperature-dependent sex determination (TSD). However, the site of estrogen synthesis in two species of freshwater turtles is unclear. In Emys orbicularis, estrogens were shown to be produced by the gonads, whereas in Trachemys scripta, gonadal steroids were not detected. The marine turtle Dermochelys coriacea exhibits TSD but in gonadal development, ovarian differentiation is delayed. Gonadal aromatase activity and estrogen content in this species were measured in embryos incubated at 27 degrees and in embryos incubated at 30.5 degrees, respectively, masculinizing and feminizing temperatures within the range of temperatures found in natural nests. At all stages studied, aromatase activity was present and found to be higher at 30.5 degrees than at 27 degrees. Estrogens were only found at 30.5 degrees. The effects of temperature shifts on gonadal aromatase activity were then examined. Eggs were shifted from 27 to 35 degrees (feminizing temperature) at different embryonic stages and exposed to 35 degrees for 6 days. An increase in gonadal aromatase activity, although with significant individual variations, was seen only when eggs were shifted between stages 23 and 27. These stages are in the range of the thermosensitive stages for sexual differentiation of the gonads determined in other turtles. These results are similar to those previously obtained in E. orbicularis and agree with a key role for endogenous estrogens in gonadal differentiation of reptiles with TSD.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

[Gonadal ontogenesis and sex differentiation in the sea bass, Dicentrarchus labrax, under fish-farming conditions].

The histology of the different stages of gonadal development (appearance of PGC, edification of gonad primordium, organization of an undifferentiated gonad, testicular or ovarian development) has been studied in fingerlings and juveniles of sea-bass in fish-culture conditions. Sex differentiation with a caudo-cranial gradient was direct and more in accordance with length than with age. Ovarian and testicular differentiation occurred in fish 11 to 23 months old and from 90 to 187 mm SL. Testis ova were frequently observed.

Aging↗
PubMed1994

A substance secreted by rat Sertoli cells induces feminization of embryonic chick testes in vitro.

Male and female gonads from 7- to 9-day-old chick embryos were cultured for 6 days in Sertoli cell-conditioned medium or in serum-free medium to investigate the possible effect of substances secreted by rat Sertoli cells on chick gonad development. Histological analysis showed that whereas all female gonads proceed through normal ovarian development in both culture media, most of male gonads showed clear feminization only when cultured in Sertoli cell-conditioned medium; male gonads cultured in serum-free medium developed as normal testes. Because the only substance detected in our conditioned medium with the potential to cause these effects was sex-specific antigen (Sxs), our results provide further evidence that Sxs antigen may play a role in sexual differentiation in birds, and probably in mammals.

Androgen-Insensitivity Syndrome↗
PubMed1996

The roles of steroidogenic factor-1 in reproductive function.

The cytochrome P450 steroid hydroxylases are expressed in a tissue-specific and developmentally regulated manner, and the orphan nuclear receptor steroidogenic factor 1 (SF-1) participates in both aspects of regulated expression. SF-1 is expressed in mouse embryos from the inception of adrenal and gonadal development, suggesting that SF-1 plays important roles in their differentiation. SF-1 is also expressed in the embryonic pituitary gland and ventral diencephalon, suggesting additional roles within the hypothalamic-pituitary-steroidogenic organ axis. To examine the roles of SF-1 in vivo, we used targeted gene disruption to "knock out" the mouse gene encoding SF-1. Analyses of these knockout mice established roles of SF-1 at levels of endocrine development that include adrenal and gonadal differentiation, pituitary gonadotrope function, and formation of the ventromedial hypothalamic nucleus. These results indicate that SF-1 plays multiple roles in endocrine development that are essential for reproduction.

Adrenal Glands↗
PubMed1998

Patterns of gonadal dysfunction following bone marrow transplantation.

We reviewed gonadal function in 270 patients who underwent bone marrow transplantation (BMT) between 1974 and 1988. Age at transplant ranged from 6 to 54 years (mean 25.6 years). Diagnoses included acute myelogenous leukemia, chronic myelogenous leukemia, aplastic anemia, acute lymphoblastic leukemia, non-Hodgkin lymphoma, Hodgkin's disease and other diagnoses. Effects of patient characteristics on risk of gonadal dysfunction were analyzed by comparing the cumulative probability of developing gonadal dysfunction over time from BMT. Ninety-two percent of the males and 99% of the females developed evidence of gonadal dysfunction. Females were not only more likely to develop elevated gonadotrophin levels than males, but did so earlier after BMT. Odds ratios were calculated to determine potentially important prognostic factors for the development of an elevated gonadotrophin level. Older age at BMT was correlated with an increased risk in the development of elevated gonadotrophin levels. Individuals who received radiation were more likely to develop an elevated FSH level over time than those who had received no preparative radiation treatment. Males were more likely to experience gonadal recovery than females. In those cases that did recover, males tended to recover more quickly after BMT than females.

Adult↗
PubMed2002

Cloning and expression of zebra finch (Taeniopygia guttata) steroidogenic factor 1: overlap with hypothalamic but not with telencephalic aromatase.

The zebra finch (Taeniopygia guttata) brain is highly sexually dimorphic. The organization and production of sex-specific song is considerably influenced by estrogens and androgens. Because the brain itself expresses several steroidogenic enzymes, the local production of sex steroids may contribute to sex differences in neural development. Sex steroid production in gonads is directed by a master regulatory factor, steroidogenic factor 1 (SF1). We have identified a cDNA encoding the homologue of SF1 in the zebra finch and utilized reverse transcription-polymerase chain reaction and in situ hybridization to examine early and late developmental expression of SF1 in brain and in early gonadal development. We found that SF1 is expressed early in embryonic development in the Rathke pouch, beginning at stage 15 and extending to at least stage 27 in both males and females. The earliest expression of SF1 in gonads was found at stage 17 for both males and females and extended to at least stage 27. In brain, we assessed SF1 mRNA expression in posthatch and adult telencephalon, and we compared SF1 and aromatase mRNA expression in adult hypothalamus. In the telencephalon and hippocampus, aromatase was expressed independently of SF1, whereas in the hypothalamus, aromatase and SF1 expression were more closely associated. Expression of SF1 and of aromatase overlapped in restricted regions of the hypothalamus, suggesting that SF1 may regulate aromatase expression in these regions. These findings suggest that steroidogenesis in the zebra finch brain may be regulated by both SF1-dependent and SF1-independent mechanisms. No sex differences were detected in SF1 expression in brain.

Adrenal Glands↗