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Query: UNIPROT:Q9UIJ5 (
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58,342
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Multiple connexins have been identified in testicular cells. Several lines of evidences indicate that, among them, connexin 43 (Cx43) may be unique for control of gonad development and spermatogenesis. To date, however, it is not known whether Cx43 is expressed in the fetal testis and what possible types of cellular interactions mediated by this connexin are critical to male fertility. In the present work, expression of Cx43 was investigated at various developmental ages in cryosections from mouse testis by using specific antibodies against Cx43. In serial or double-labeled sections, Cx43 localization was compared with immunocytochemical distribution of steroidogenic enzyme,
3beta-hydroxysteroid dehydrogenase
(
3betaHSD
), Mullerian inhibitory hormone (MIH), and germinal nuclear cell antigen (GCNA1), which are specific markers, respectively, of interstitial Leydig, Sertoli, and germinal cells. Sections were analyzed by fluorescence microscopy. We found that Cx43 immunofluorescence (IF) was uniformly distributed in the undifferentiated gonad at 11.5 days post coitus (dpc) and in cells of the mesonephric tubules. In the undifferentiated gonad, Cx43 was localized between primordial germ cells and somatic cells. At 12.5 dpc, when the gonad has undergone sexual differentiation, in the interstitium Cx43 was localized in Leydig cells and in the seminiferous cord it was localized between adjacent Sertoli cells. In Leydig and Sertoli cells, Cx43 labeling increased at 14.5, 16.5, and 18.5 dpc. From day 12.5 up to 18.5 dpc, Cx43 was also localized in cell borders between germinal and Sertoli cells. In conclusion, this study demonstrates that from the earliest stages of gonadal development, Cx43 is expressed in the principal cell types that participate in the control of male fertility. It also shows that Cx43 expression in Leydig and Sertoli cells increase during fetal life. Finally, it provides evidence that, throughout embryonic life, Cx43 forms gap junctions between Sertoli and germinal cells.
Anat
Rec
2001 11 01
PMID:Developmental regulation of connexin 43 expression in fetal mouse testicular cells. 1159 6
Freemartins are XX/XY chimaeras that develop as a result of the fusion of the placental circulation of at least one male and one female fetus. Of 19 freemartin ewes, 13 had testis-like structures, seven of them in an abdominal position and six in an inguinal position. Histologically, their gonads had structures resembling seminiferous tubules and interstitial cells, and grossly, most had structures derived from the mesonephric ducts (vasa deferentia, epididymides and vesicular glands). The other six freemartin ewes had small, undifferentiated gonads that lacked either follicles or seminiferous tubule-like structures. They also lacked any structures derived from the mesonephric ducts. No derivatives of the paramesonephric ducts were detectable in any of the freemartin ewes. The gonads of the male-type freemartins stained immunocytochemically for
3beta-hydroxysteroid dehydrogenase
(3beta-HSD) and histochemically for alkaline phosphatase (AP) in a similar way to, but more extensively and intensely than, the gonads of normal rams, and the staining was confined to interstitial cell-like structures. The staining in the undifferentiated-type freemartins was weak, but both 3beta-HSD and AP were present in unidentified cell types.
Vet
Rec
2003 Feb 08
PMID:Morphological, histological and histochemical studies of the gonads of ovine freemartins. 1262 86
Developmental studies have shown that connexin43 (Cx43) is expressed in the ovary from the first day of life and throughout the rest of postnatal development. In both mouse embryonic ovaries and testes, target-directed deletion of Cx43 gene induces a significant decrease in germinal cells, but the exact mechanism determining this reduction remains unknown. Moreover, recently we found that Cx43 is abundantly expressed in mouse testes from the earliest stages of its fetal development. In the present work we investigate whether Cx43 transcript and protein are expressed in mouse embryonic ovaries. Total RNA was analyzed with specific Cx43 oligonucleotides in RT-PCR studies. A Cx43 PCR product was detected in ovaries at 16.5 and 18.5 days postcoitum (dpc). Bands of 43-45 kDa, characteristic of Cx43, were detected in immunoblots of total homogenates of ovaries at 14.5 and 18.5 dpc. Cell type-specific expression of Cx43 was investigated using double-labeled sections incubated with specific antibodies against Cx43 and the enzyme
3beta-hydroxysteroid dehydrogenase
(
3betaHSD
) or a germ cell nuclear antigen (GCNA1), which are cell markers of steroidogenic and germinal cells, respectively. At 18.5 dpc, Cx43 was found in conglomerates of
3betaHSD
-positive cells. Cx43 was also localized at homocellular junctions between parenchyma pregranulosa cells, and at heterocellular junctions between pregranulosa and germinal cells. At these two latter localizations, Cx43 was traced back to 12.5 dpc. In conclusion, this study demonstrates for the first time that from the earliest stages of embryonic ovary development, Cx43 is expressed in principal cell types involved in control of female fertility. These data suggest that the gap junctions formed with Cx43 between somatic and germinal cells may be necessary for prenatal expansion of germinal cells at initial stages of fetal gonadal development.
Anat
Rec
A Discov Mol Cell Evol Biol 2003 Apr
PMID:Connexin43 is expressed in mouse fetal ovary. 1262 78
The effects of trilostane, a
3beta-hydroxysteroid dehydrogenase
inhibitor on basal cortisol concentrations and the results of ACTH stimulation tests in dogs with pituitary-dependent hyperadrenocorticism were investigated. In eight of nine dogs trilostane suppressed the concentration of cortisol below the lower limit of the reference range (<50 nmol/l) for a mean (sd) of 3.5 (2.3) hours during the day, but for no longer than 13 hours. In another 10 dogs, there was a clear difference between the post ACTH cortisol concentrations observed four and 24 hours after the administration of trilostane. Furthermore, in the six dogs whose clinical signs were poorly controlled the post-ACTH concentrations observed four and 24 hours after the administration of trilostane were always higher than the equivalent cortisol concentrations in the four dogs whose clinical signs were controlled. A short duration of drug action may be responsible for the failure of some dogs to respond adequately to once daily trilostane administration.
Vet
Rec
2006 Aug 26
PMID:Study of the effects of once daily doses of trilostane on cortisol concentrations and responsiveness to adrenocorticotrophic hormone in hyperadrenocorticoid dogs. 1694 10