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PubMedDate not supplied

[Leydig cell development].

This review is about the study of the testis Leydig cells formation and development in prenatal and postnatal periods. Leydig cells of testis are the main place of synthesis and secretion of androgens including testosterone--the main male sexual hormone. Testosterone plays an important role in male reproduction regulation. There are two types (two populations) of Leydig cells during ontogenesis. The first type is fetal Leydig cells, which appear and function in the prenatal masculinization period of the male urogenital system. Another type is adult Leydig cells, which originate during sexual maturation postnatally. Fetal and adult Leydig cells pass the same stages both in the prenatal and postnatal periods. They are Leydig cell progenitors, immature Leydig cells and adult Leydig cells.

Animals↗
PubMed2000

Multiple effects of retinoids on the development of Sertoli, germ, and Leydig cells of fetal and neonatal rat testis in culture.

We investigated the effect of retinoids on the development of Sertoli, germ, and Leydig cells using 3-day culture of testes from fetuses 14.5 and 18.5 days post-conception (dpc) and from neonates 3 days postpartum (dpp). Addition of 10(-6) M and 3.10(-8) M retinoic acid (RA) caused a dose-dependent disruption of the seminiferous cords in 14.5-day-old fetal testes, without any change in the 5-bromo-2'-deoxyuridine (BrdU) labeling index of the Sertoli cells. RA caused no disorganization of older testes, but it did cause hyperplasia of the Sertoli cells in 3-dpp testes. Fragmentation of the Sertoli cell DNA was not detected in control or RA-treated testes at any age studied. The cAMP produced in response to FSH was significantly decreased in RA-treated testes for all studied ages. Both 10(-6) M and 3.10(-8) M RA dramatically reduced the number of gonocytes per 14.5-dpc testis. This resulted from a high increase in apoptosis, which greatly exceeded the slight increase of mitosis. RA caused no change in the number of gonocytes in testes explanted on 18.5 dpc (the quiescent period), whereas it increased this number in testes explanted on 3 dpp (i.e., when gonocyte mitosis and apoptosis resume). Lastly, RA and retinol (RE) reduced both basal and acute LH-stimulated testosterone secretion by 14.5-dpc testis explants, without change in the number of 3beta-hydroxysteroid dehydrogenase-positive cells per testis. Retinoids had no effect on basal or LH-stimulated testosterone production by older testes. In conclusion, RE and RA are potential regulators of the development of the testis and act mainly negatively during fetal life and positively during the neonatal period on the parameters we have studied.

Animals↗
PubMed1999

Expression of protein gene product 9.5, a neuronal ubiquitin C-terminal hydrolase, and its developing change in sertoli cells of mouse testis.

Protein gene product 9.5 (PGP9.5), originally isolated as a neuron-specific protein, belongs to a family of ubiquitin carboxyl-terminal hydrolases that play important roles in the nonlysosomal proteolytic pathway. Antibodies against PGP9.5 have been used for immunohistochemical detection of neural elements, although some non-neuronal cells are also immunoreactive for PGP9.5. In the present study, developing testes of the mouse were immunostained after autoclave pretreatment of sections. In the testes of days 8 and 16, PGP9.5 was only localized on the spermatogonia, whereas on day 30 and in adults it appeared not only on spermatogonia, but also on Sertoli cells. In the testis of the male sterile W/W(v) mutant, very little, but strong, immunoreactivity was detected at some Sertoli cells, which were phagocytizing Sertoli cell aggregations that had fallen from the basal membrane. Additionally, it was confirmed that the nucleotide sequence of PGP9.5 in mice was highly conserved, like that in other mammals. These results suggest that PGP9.5 is a useful marker for activated Sertoli cells, playing an important role in degradation of abnormal proteins.

Animals↗
PubMed1997

Maternal oestrogen/xenoestrogen exposure alters expression of steroidogenic factor-1 (SF-1/Ad4BP) in the fetal rat testis.

Expression of steroidogenic factor 1 (SF-1/Ad4BP) is essential for gonadal differentiation. We have assessed whether expression of SF-1 in the gonads of rat fetuses was altered following maternal treatment with diethylstilbestrol (DES, a synthetic oestrogen) or 4-octylphenol (OP, a xenoestrogen). Pregnant rats were injected subcutaneously with DES (500 microg/kg), OP (600 mg/kg) or vehicle (oil, control) on days 11.5 and 15.5 post coitum (p.c.) and fetal rat testes were recovered on day 17.5 p.c. The level of expression of SF-1 was determined by RNase protection assay and immunocytochemistry. In both DES- and OP-exposed fetuses immunoexpression of SF-1 was reduced in Sertoli and interstitial cells when compared with controls. In parallel, a significant decrease occurred in the total amount of SF-1 mRNA (P < 0.05) in fetal testes but not in fetal ovaries. These results suggest that: (a) Sertoli cell-derived oestradiol may be important in the physiological regulation of SF-1 in the fetal testis; and (b) one mechanism by which inappropriate exposure to oestrogens might alter the genetic cascade that ensures normal development of the testis is via altered expression of SF-1.

Animals↗
PubMed1991

Laminin ultrastructural immunolocalization in rat testis during ontogenesis.

The synthesis of one of the main glycoproteins of the basement membrane, the laminin, was demonstrated by ultrastructural immunolocalization during rat foetal (16th day to 20th day of gestation) and postnatal development of the testis. The lamina densa, part of seminiferous tubular basement membrane, is labeled uniformly at all studied stages. The lamina lucida is not well defined before the postnatal stages, at which times discrete immunostaining extends from the lamina densa to the adjacent seminiferous epithelial cells (spermatogonia and Sertoli cells). The extracellular matrix around the peritubular cells is not labeled before birth. Intracellular immunostaining was detected as early as the 16th day of gestation in both Sertoli cells and cells around the seminiferous tubules which will transform later into peritubular cells. It was located in rough endoplasmic reticulum (RER) cisternae and secretory vesicles. After 18-20 days of postnatal life, the immunostaining faints progressively. Some positive material is seen in the RER of the gonocytes at all studied stages. Sertoli cells and peritubular cells are the main producing cells of laminin after the 16th of gestation. The laminin secreted by gonocytes may play an important role in adhesion of gonocytes to the lamina densa and adjacent Sertoli cells before their transition from basal compartment to adluminal compartment.

Animals↗
PubMed2005

Temporal and spatial expression of liver receptor homologue-1 (LRH-1) during embryogenesis suggests a potential role in gonadal development.

Liver receptor homologue-1 (LRH-1), an orphan member of the nuclear receptor family highly expressed in adult mouse ovary, is closely related to steroidogenic factor 1 (SF-1), known to be important in gonadal formation. To analyze the potential role of LRH-1 in gonadal differentiation, we compared LRH-1 and SF-1 expression during mouse embryonic and postnatal development. LRH-1 expression was first detected in the urogenital ridge before sexual determination, in primordial germ cells and surrounding somatic cells; expression persisted after differentiation into testes and ovaries. Of interest, LRH-1 expression declined in the developing ovary and testis at embryonic day 15.5 but increased again just after birth in the ovary in granulosa cells and transiently in oocytes of developing follicles. By comparing and contrasting LRH and SF-1 expression with the two tissue-specific steroidogenic markers, cytochromes P450 aromatase and P450 17alpha-hydroxylase/17,20 lyase, we provide evidence for a potential role for LRH-1 in gonadal development, the initiation of folliculogenesis and regulation of estrogen biosynthesis within the ovary.

Animals↗
PubMed1979

Immunological unresponsiveness during induction of experimental autoimmune orchitis in guinea-pigs: studies in vivo and in vitro.

Groups of male and female guinea-pigs were immunized with homologous sperm derived from testis (TS) or epididyimis (ES) in Freund's complete adjuvant (FCA). In vivo investigations included skin tests at 2 weeks and development of aspermatogenesis (testis weight) at 4 weeks; in vitro assays were inhibition of migration of peritoneal exudate cells (PEC) and culture of blood leucocytes (lymphocyte transformation) at weekly intervals after immunization. Antigens used were heat-treated extracts of sperm used for immunization (BTS, BES); cells were also cultured simultaneously with PPD. Skin tests revealed anergy in males as compared with females: a larger quantity of antigen which caused partial unresponsiveness in females, caused profound unresponsiveness in males although the aspermatogenesis was less severe. In vitro tests also showed anergy during the active stages of the orchitis. This was non-specific for PEC (specific unresponsiveness was not excluded), but blood leucocytes showed only specific unresponsiveness (to BES). These and previous studies suggest that the unresponsiveness results from a desensitisation by sperm antigens released during the development of aspermatogenesis.

Animals↗
PubMed1980

H-Y antigen in 46,XY gonadal dysgenesis.

Presence of H-Y antigen has been correlated with testicular differentiation, and absence of H-Y with failure of testicular differentiation, in a variety of mammalian species. To determine more precisely the relationship between expression of H-Y antigen and development of the testis, we studied the cells of phenotypic females with the 46,XY male karyotype. Blood leukocytes were typed H-Y+ in five XY females with gonadal dysgenesis, although in other studies blood leukocytes from XY females with gonadal dysgenesis were typed H-Y-. Thus mere presence of H-Y antigen is not sufficient to guarantee normal differentiation of the testis. In the present paper we review evidence for an additional factor in gonadal organogenesis, the H-Y antigen receptor. We infer that testicular development requires engagement of H-Y and its receptor. It follows that XY gonadal dysgenesis is the consequence of functional absence of the H-Y testis inducer as in the following conditions: failure of synthesis of H-Y or failure of specific binding of H-Y.

Adolescent↗
PubMed1997

Calmodulin content, Ca2+-dependent calmodulin binding proteins, and testis growth: identification of Ca2+-dependent calmodulin binding proteins in primary spermatocytes.

In contrast with the transient pre-replicative increase in calmodulin (CaM) level observed in proliferative activated cells, postnatal development of rat testis was paralleled by 3 specific rises in CaM. The first one occurred between 5 and 10 days, coincident with the appearance and proliferation start of spermatogonia and Sertoli cells. Meiosis accomplishment and spermatid differentiation were paralleled by 2 additional rises, at 24 and 32 days, respectively. The plateau phase of testis growth was coincident with the appearance of maturating spermatids and spermatozoa in the germinal epithelium, and with a decrease in CaM content. Testicular DNA:g wet tissue ratio reached the highest level in 15-day-old rats and gradually decreased up to 35 days, when a constant level was reached. A similar level of Ca2+-CaMBPs was observed in 5- and 20-day-old rat testis. Although all subcellular fractions showed the ability to bind CaM in a Ca2+-dependent manner, CaM was mainly recovered in the nuclear and soluble fractions of adult and immature rat testis. Several Ca2+-CaMBPs with an apparent M(r) of 82, 75, 64, 19, and 14 kD were purified by affinity chromatography from pachytene primary spermatocyte nuclear matrix. Ca2+-CaMBPs showing an M(r) of 120, 78, 72, and 66 kD were also purified from the supernatant obtained after DNA and RNA hydrolysis of meiotic nuclei. Major cytosolic Ca2+-CaMBPs of primary spermatocytes showed an M(r) of 120, 84, 44, and 39 kD. The functions that these Ca2+-CaMBPs might have during the first meiotic prophase is discussed.

Animals↗
PubMed1995

Pubertal development of intersertoli cell junctions in the testis of corriedale ram lambs.

The ultrastructure of the tight junctional complex of pubertal ram lamb Sertoli cells was studied in immersion-fixed samples and related to clinical data and a light microscopical classification of the degree of spermatogenesis attained in the corresponding seminiferous tubule. Although the process followed the general mammalian developmental trend for tight junction complex formation, 2 unusual ultrastructural features were detected: the presence of an active Golgi complex during the early stage of tight junction formation and the transitory presence of ribosomes on both faces of the ectoplasmic cisternae bordering the developing junctions. The significance of these findings is discussed.

Animals↗
PubMed2005

Testicular development of Zebu bulls after chronic treatment with a gonadotropin-releasing hormone agonist.

The objective was to compare testis characteristics of Zebu bulls treated with the GnRH agonist, deslorelin, at different times and for different durations during their development. An additional objective was to determine the usefulness of a stain for the transcription factor GATA-binding protein 4 (GATA-4) as a specific marker for Sertoli cell nuclei in cattle. Bulls (54) were allocated to nine groups (n = 6) and received s.c. deslorelin implants as follows: G1 = from birth to 3 mo of age; G2 = from 3 to 6 mo; G3 = from 6 to 9 mo; G4 = from 9 to 12 mo; G5 = from birth to 15 mo; G6 = from 3 to 15 mo; G7 = from 6 to 15 mo; G8 = from 12 to 15 mo; and G9 (control) = no implant. Bulls were castrated at 19 mo of age. Paraffin sections (10 microm) were subjected to quantitative morphometry and GATA-4 immunohistochemistry. At castration, all bulls in the control group (6/6) had attained puberty (scrotal circumference > or = 28 cm), whereas a smaller proportion (P < 0.05) had reached puberty in G2 (2/5) and G6 (1/6). Bulls in G2 and G6 also had a lesser (P < 0.05) testis weight compared with the control group. Total volume of seminiferous epithelium and total daily sperm production in G2 and G6 were only half that observed in the control group. Spermatids were observed in less than 50% of seminiferous tubules in G2, G6, and G7 compared with 82% in the control group (P < 0.05). Staining for GATA-4 was specific for and abundant in the Sertoli cell nucleus in both pre- and postpubertal bulls, and no other cell nucleus inside the seminiferous tubule was positive for GATA-4. Total number of Sertoli cells was not affected by treatment (P = 0.45), but nuclear volume was smaller in G2 and G6 (P < 0.05) compared with the control group. In conclusion, treatment of Zebu bulls with deslorelin had no apparent beneficial effect on testis development and delayed puberty when treatment was initiated at 3 mo of age. Staining for GATA-4 was a useful method for identifying and quantifying Sertoli cell nuclei in both pre- and postpubertal bulls.

Animals↗
PubMed1989

Sequential study of the histopathology and cellular and humoral immune response during the development of an autoimmune orchitis in Wistar rats.

Wistar rats immunized with an homologous testicular homogenate (TH) and complete Freund's adjuvant, followed by i.v. injection of Bordetella pertussis, developed an autoimmune orchitis (EAO). Animals were studied at 7, 16, 30, 50, and 80 days (d) after the first immunization. An important lesion of the testis only appeared at 50 d, increasing in severity and incidence (77%) at 80 d. Lesions were characterized by a prevalent aspermatogenesis with tubular atrophy and mild interstitial mononuclear infiltrates. Delayed-type hypersensitivity response (DTH) against TH was detected early at 7 d and, except for 16 d, it increased with time, reaching a maximum at 80 d. A good temporal relationship between DTH and histopathology was found. Circulating antibodies to TH, detected by ELISA, were only present in 64% of the animals with testis lesion, while no deposits of IgG or C3 in the seminiferous tubules were seen. We describe a sequence of immunological events, concomitant with pathological changes of the testis, during the development of a severe EAO in Wistar rats.

Animals↗
PubMed1994

SRY protein enhances transcription of Fos-related antigen 1 promoter constructs.

In mammals, testis determination is under the control of the chromosome Y-linked SRY gene. Sry is expressed in the fetal mouse just before development of the testis and shows germ-cell-dependent expression in the adult mouse. SRY protein contains a high-mobility-group (HMG)-box DNA-binding domain, and potential target sequences have been identified. The fos-related antigen 1 (fra-1) gene is closely related to the protooncogene c-fos and encodes a component of transcription factor AP-1. Fra-1 is expressed during spermatogenesis, and the promoter of the rat fra-1 gene contains several potential binding sites for members of the HMG-box family of DNA-binding proteins. We demonstrate that purified SRY protein binds strongly to one of the putative fra-1 HMG-box response elements and that SRY enhances the transcription of rat fra-1 promoter constructs in cotransfection experiments. These results suggest that the function of HMG-box transcription factors may be mediated, in part, by activation of members of the AP-1 transcription factor family.

Amino Acid Sequence↗
PubMed2004

Expression and role of PDGF-BB and PDGFR-beta during testis morphogenesis in the mouse embryo.

The role played by PDGF in testis morphogenesis is still incompletely understood. The present study investigates the expression and potential role of platelet-derived growth factor-BB (PDGF-BB) and its receptor, PDGF receptor beta (PDGFR-beta), during mouse testis cord formation, and the possibility that the growth factor may be involved in the migration to the gonad of mesenchymal cells of mesonephric origin. Studies from this laboratory have previously shown that mesenchymal cells that migrate from the mesonephros into the gonad, to form peritubular myoid cells and most of the intertubular cells, can be identified by the presence on their surface of the p75 neurotrophin receptor (p75NTR), and can be isolated to near-purity by immunomagnetic selection with anti-p75NTR antibody. We show here that mesonephric p75NTR(+) cells also bear the PDGFR-beta, and are able to migrate and proliferate in vitro in response to PDGF-BB. PDGF-BB is expressed at higher levels in male than female developing gonads, suggesting a role for this factor in testis development. Such a role is further supported by the observation that addition of PDGF-BB to serum-free medium is sufficient to allow organ-cultured male 11.5 days post-coitum urogenital ridges to form testis cords. Finally, we show that mesonephric cell motility and growth induced by exposure to PDGF-BB involve mitogen-activated protein kinases (MAPK) and phosphatidylinositol-3 kinase (PI3-K) pathways, as MAPK inhibitor U0126 and PI3K inhibitor Ly294002 inhibit migration and proliferation in vitro assays. The present findings support the hypothesis that the PDGF/PDGFR system plays a key role in testis morphogenesis in the mouse embryo.

Animals↗
PubMed2001

Infancy is not a quiescent period of testicular development.

Postnatal evolution of the testis in most laboratory animals is characterized by the close continuity between neonatal activation and pubertal development. In higher primates, infancy, a long period of variable duration, separates birth from the beginning of puberty. This period has been classically considered as a quiescent phase of testicular development, but is actually characterized by intense, yet inapparent activity. Testicular volume increases vigorously shortly after birth and in early infancy due to the growth in length of seminiferous cords. This longitudinal growth results from active proliferation of infantile Sertoli cells which otherwise display a unique array of functional capabilities (oestrogen and anti-müllerian hormone secretion, increase of FSH receptors and maximal response to FSH). Leydig cells also show recrudescence after birth, possibly determined by an active gonadotrophic-testicular axis which results in increased testosterone secretion of uncertain functional role. This postnatal activation slowly subsides during late infancy when periodic phases of activation of the hypothalamo-pituitary-testicular axis are paralleled by incomplete spermatogenic spurts. The beginning of puberty is marked by the simultaneous reawakening of Leydig cell function and succeeding phases of germ cell differentiation/degeneration which ultimately lead to final spermatogenic maturation. The marked testicular growth in this stage is due to progressive increase at seminiferous tubule diameter. Sertoli cells, which have reached mitotic arrest, develop and differentiate, establishing the seminiferous tubule barrier, fluid secretion and lumen formation, and acquiring cyclic morphological and metabolic variations characteristic of the mature stage. All of these modifications indicate that, far from being quiescent, the testis in primates experiences numerous changes during infancy, and that the potential for pubertal development and normal adult fertility depends on the successful completion of these changes.

Animals↗