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PubMed1995

The follicle-stimulating hormone (FSH) beta- and common alpha-subunits are expressed in mouse testis, as determined in wild-type mice and those transgenic for the FSH beta-subunit/herpes simplex virus thymidine kinase fusion gene.

Testicular expression of the endogenous FSH beta-subunit (FSH beta) and common alpha-subunit (C alpha) genes, as well as a Herpes simplex virus type 1 thymidine kinase (tk) transgene, driven by a 2.3-kilobase fragment of the bovine GSH beta promoter, were studied at messenger RNA and protein level in normal and transgenic mice. A major 3.8-kb species of FSH beta messenger RNA was demonstrated i the normal mouse testis by Northern hybridization. This was longer than the main 1.7-kb FSH beta transcript detected in the pituitary gland. Reverse transcription-polymerase chain reaction, followed by Southern hybridization, demonstrated FSH beta and tk expression in the pituitary gland and gonads of adult normal and transgenic mice, respectively. The C alpha expression was detected by reverse transcription-polymerase chain reaction in the pituitary gland and testis. During development, testicular transcription of the FSH beta and tk genes was initiated simultaneously a few days after birth. Immunocytochemistry of adult testes showed stage-specific positive reaction with FSH beta, C alpha, and tk antisera in the pachytene spermatocytes and type B spermatogonia, but not in Sertoli cells. Positive reaction with these antisera was also seen in the interstitial tissue. These results demonstrate testicular expression of the endogenous FSH subunit genes and confirm that the testicular expression of the FSH beta /tk transgene reflects or its subunits play a paracrine or autocrine role in the regulation of testicular function.

Animals↗
PubMed2000

The P450 aromatase (P450 arom) gene is asymmetrically expressed in a critical period for gonadal sexual differentiation in the chick.

Steroid hormones appear to play an important role in gonadal sex differentiation of birds. Here we studied the steady-state level of the P450 arom mRNA by reverse transcriptase polymerase chain reaction (RT-PCR) in the left and the right presumptive ovary and testis of developing chicken embryos. The gonads were evaluated every hour during the undifferentiated period, at 144-156 h of incubation (h/i), and every 24 h after sexual differentiation at 168 and 192 h/i. Activity of P450 arom was determined by estrone production from [3H]androstenedione at 144-192 h/i. Moreover, morphological development of the gonad was also examined by light microscopy. Results show that onset of P450 arom mRNA and its protein activity were simultaneously detected in the left and the right ovaries at 147 h/i. Asymmetric function of P450 arom gene expression was observed at 156 h/i when morphological gonadal differentiation is first recognized. Biotransformation of [3H]androstenedione to estrone was also asymmetrically detected between the left and right gonad at 156 h/i and asymmetry was maintained throughout the analyzed stages. It is proposed that there is a gene in birds that is asymmetrically expressed in the undifferentiated stage of the female and the male gonad. In the female this gene could promote P450 arom gene expression, increasing estrogen production, which in turn could induce ovarian cortex proliferation and expression of other structural estrogen-regulated genes involved in ovarian sexual determination.

Androstenedione↗
PubMed1956

An electron microscope study of spermatid differentiation in the toad, Bufo arenarum Hensel.

The differentiation of the spermatids of Bufo arenarum has been described from a study of electron micrographs of thin sections of testis. The development of the acrosome from the Golgi complex takes place in much the same manner as in mammalian spermatogenesis but no acrosome granule is formed. A perforatorium is described for the first time in this species. It is formed by a convergence of dense filaments that arise between the nuclear membrane and the head cap. During maturation of the spermatid the chromatin undergoes striking physicochemical alterations. Fine chromatin granules uniformly dispersed in the karyoplasm are replaced by larger and larger aggregates and these ultimately coalesce to form a very dense sperm head. Two centrioles of cylindrical form are situated very near the base of the sperm head. The longitudinal fibrils of the tail flagellum take origin from one, and the dense fibrous substance of the undulating membrane is closely related to the other. Phase contrast cinematographic observations on the swimming movements of living toad sperm, when considered in relation to the fine structural components of the tail, suggest that there is a contractile component in the undulating membrane as well as in the axial fibrils. The differences in the structure of mammalian and amphibian sperm tails are discussed in relation to differences in the character of their movements.

Acrosome↗
PubMed1999

Apoptosis and mitosis in gonocytes of the rat testis during foetal and neonatal development.

This study was undertaken to determine the extent of apoptosis and mitosis in the various testicular cell types throughout rat development from foetal day 14.5 to postnatal days 9-10. Apoptotic activity was studied by detecting DNA fragmentation (TUNEL method) in situ. A TUNEL-positive reaction was detected in gonocytes, while none of the other testicular cells were labelled. The morphology of the TUNEL-positive gonocytes was characteristic of apoptotic cells and was different from that observed in experimentally induced necrosis. The percentage of stained gonocytes peaked on day 15.5-16.5 post-conception (dpc), decreased thereafter and no TUNEL-positive gonocytes were found from foetal day 18.5 onwards. On postnatal day 2, apoptosis resumed and increased to reach a maximum on day 7. Mitosis in the gonocytes, as evaluated by the immunodetection of 5-bromo-2'-deoxyuridine (BrdU) incorporation, was present during the same developmental periods but the ratio of BrdU-positive/TUNEL-positive gonocytes was much greater in the foetal period than in the neonatal period. In an organotypic culture system, the changes in the apoptotic and mitotic activities of the gonocytes in testicular explants from foetuses on days 18.5 and 20.5 or from neonates on day 3, cultured for two days were similar to those observed in vivo. Addition of LH or FSH did not influence either apoptosis or mitosis in the germ cells. These results suggest that both apoptosis and mitosis of gonocytes are independent of gonadotrophins and are mainly controlled by intratesticular factors.

Animals↗
PubMed1998

Sertoli cells of the mouse testis originate from the coelomic epithelium.

During mouse development, the gonad begins to form shortly before 10. 5 days postcoitum (dpc) on the ventromedial side of the mesonephros. The XY gonad consists of germ cells and somatic cells. The origin of the germ cells is clearly established; however, the origin of the somatic cells, especially the epithelial supporting cell lineages, called Sertoli cells, is still unclear. Sertoli cells are the first somatic cell type to differentiate in the testis and are thought to express Sry, the male sex-determining gene, and to play a crucial role in directing testis development. Previous data have suggested that the somatic cells of the gonad may arise from the mesonephric tubules, the mesonephric mesenchyme, or the coelomic epithelium. Immunohistochemical staining of the gonad at 11.5 dpc showed that the basement membrane barrier under the coelomic epithelium is discontinuous, suggesting that cells in the coelomic epithelium at this stage might move inward. To test this possibility directly, cells of the coelomic epithelium were labeled using the fluorescent lipophilic dye, DiI. We show that when labeled at tail somite 15-17 stages, corresponding to 11.2-11.4 dpc, the coelomic epithelial cells of both sexes migrated into the gonad. In XY gonads, the migrating coelomic epithelial cells became Sertoli cells, as well as interstitial cells. This ability of the coelomic epithelium to give rise to Sertoli cells was developmentally regulated. When labeled at tail somite 18-20 stages, corresponding to 11.5-11.7 dpc, the coelomic epithelial cells no longer became Sertoli cells. Instead, cells that migrated into the gonad stayed outside testis cords, in the interstitium. Migration gradually decreased and ceased by tail somite 30 stage, corresponding to 12.5 dpc, after testis cords had formed and the basement membrane layer underlying the coelomic epithelium had thickened to form the tunica albuginea. In XX gonads, coelomic epithelial cells also migrated into the gonad, but there was no obvious fate restriction during the same developmental period. Taken together, our data show that the coelomic epithelium is a source of Sertoli cells as well as other somatic cells of the gonad in the developing mouse testis.

Animals↗
PubMed1999

Sry-negative XX sex reversal in purebred dogs.

The gene responsible for testis induction in normal male mammals is the Y-linked Sry. However, there is increasing evidence that other genes may have testis-determining properties. In XX sex reversal (XXSR), testis tissue develops in the absence of the Y chromosome. Previous polymerase chain reaction (PCR) assays indicated that autosomal recessive XXSR in the American cocker spaniel is Sry-negative. In this study, genomic DNA from the breeding colony of American cocker spaniels and from privately owned purebred dogs were tested by PCR using canine primers for the Sry HMG box and by Southern blots probed with the complete canine Sry coding sequence. Sry was not detected by either method in genomic DNA of affected American cocker spaniels or in the majority (20/21) of affected privately owned purebred dogs. These results confirm that the autosomal recessive form of XXSR in the American cocker spaniel is Sry-negative. In combination with previous studies, this indicates that Sry-negative XXSR occurs in at least 15 dog breeds. The canine disorder may be genetically heterogeneous, potentially with a different mutation in each breed, and may provide several models for human Sry-negative XXSR. A comparative approach to sex determination should be informative in defining the genetic and cellular mechanisms that are common to all mammals.

Amino Acid Sequence↗
PubMed1990

Photomanipulation of sexual maturation and breeding cycle of the steppe polecat (Mustela eversmanni) and other techniques for more rapid propagation of the species.

Twenty steppe polecats were divided into 2 groups, each consisting of 4 males and 6 females, and subjected to either a natural photoperiod (controls) or alternating periods of short (8 h light/16 hr dark for 8-9 weeks) and long days (16 h light/8 h dark for 16-20 weeks). The experimental photoperiod significantly accelerated sexual maturation in both sexes, with males developing maximal testis size within 57 days and females breeding after an average of 52 days exposure to 16L/8D. Males in the experimental group completed 2 1/2 testicular cycles and participated in mating during 3 successive breeding seasons during the 18 month period whereas males in the control group completed a single testicular cycle and only had an opportunity to mate during a single breeding season. Females in the experimental group produced 3 litters whereas females in the control group only gave birth to a single litter. Litter size averaged 6.9 +/- 2.0 (n = 23) and did not significantly differ with age, parity, or treatment. Pseudopregnant females returned to estrus within 12 days after the expected date of parturition, were bred, and gave birth to kits. Polecats which were subjected to the experimental photoperiods completed more molting cycles and underwent more photoperiod-induced changes in body weight than those in the control group. Death or removal of kits within 8 days after birth resulted in 12/12 females returning to estrus within 6-26 days. Eleven of these females were remated and gave birth to kits. Eight domestic ferrets readily accepted neonatal polecat kits and 5 successfully reared kits, although kit survival was quite poor.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

The influence of epididymal agenesis on the development and maturation of the testis: experimental model and clinical correlations.

The August X Copenhagen (ACI) rat provides an excellent model to study the effect of congenital epididymal anomalies on testicular function. Despite epididymal absence, testicular maturation and function are unchanged until puberty. At puberty, with increased testicular fluid and spermatozoa output, involution of germinal epithelium occurs. This involution is similar to the changes seen with ligation of the efferent ductules of the epididymis. These findings suggest that in this mammalian model the testis functions normally until the pubertal period. At that time, because of proximal epididymal agenesis and failure to reabsorb testicular secretions, intratesticular hydrostatic pressure increases with rapid germinal epithelial atrophy. Clinical correlations are made in patients with epididymal abnormalities, especially in association with undescended testis.

Animals↗
PubMed1991

Testicular effects of the Leydig cell toxicant ethane dimethanesulphonate given to neonatal rats.

Neonatal rats were injected with either 50 mg/kg ethane dimethanesulphonate (EDS) or vehicle on days 1 to 5 inclusive or on day 1 alone. Studies were made on days 6, 28, and 63 of testicular structure; related endocrinologic parameters were measured in the day 1 to 5 treated animals only. Leydig cells and their activities were identified by cell counts using sections stained for 3 beta-hydroxysteroid dehydrogenase, hCG binding to LH receptors in testicular homogenates, and assays of intratesticular testosterone, plus pituitary and/or serum concentrations of testosterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH). Given on days 1 to 5, EDS reduced Leydig cell populations estimated by morphometry and 125I-HCG binding, and testicular and body weights between days 6 and 63, and permanently retarded the development of the seminiferous epithelium. Decreases of serum and intratesticular testosterone occurred with homeostatic rises in FSH and LH. Injection on day 1 reduced Leydig cell numbers only on day 6 although body weight remained retarded. The data illustrate the susceptibility of the developing rat testis to the cytotoxicant EDS; whether this is related to withdrawal of androgen production or nonspecific cytotoxicity remains to be evaluated.

Animals↗
PubMed1998

Sperm parameters after early left varicocele treatment.

OBJECTIVE: We evaluated whether early treatment for left varicocele can improve sperm parameters. DESIGN: Patient follow-up and comparison with control groups. SETTING: Surgical department of a Children's Hospital and a university infertility-care center. PATIENT(S): Nineteen patients who underwent surgery for left varicocele as adolescents (mean +/- SD, 14.11 +/- 1.59 years) were followed up as adults (mean +/- SD, 19.37 +/- 1.16 years). MAIN OUTCOME MEASURE(S): A testicular examination was performed and varicocele staging was done at the time of surgery. Andrologic examination and semen analysis were done 2-8 years later. Semen results were compared with those of two age-matched control groups of 19 healthy, randomly selected subjects and 19 unoperated patients suffering from left varicocele of the same degree. RESULT(S): The mean values of sperm parameters in the patient study group were similar to those of the healthy controls except that the sperm concentration was significantly lower. However, sperm motility and morphology mean values in the patient study group were significantly higher than those of the unoperated patients. CONCLUSION(S): This study indicates that surgery in adolescence can be useful, possibly because the testis is developing at that age. Large-scale, double-blind controlled trials on early treatment of left varicocele are needed to identify possible markers of disease severity.

Adolescent↗
PubMed1991

Gonadal differentiation: a review of the physiological process and influencing factors based on recent experimental evidence.

The sexual differentiation of a gonad is determined in normal embryology by the presence or absence of the TDF gene, a short segment of DNA localized near the tip of the short arm of the Y chromosome. Under the stimulus of this gene, the somatic cells of the genital ridge differentiate into Sertoli cells and secrete anti-müllerian hormone. This hormone inhibits the germ cells from entering meiosis and may well also trigger the formation of the primary sex cords. Once the Sertoli cells are formed, further differentiation of the gonad is independent of the TDF presence, although this gene may further contribute to the normal functioning of the male gonad. In true hermaphroditism the normal regulation of the gonadal differentiation is missing. Gonadal differentiation may revert to a more primitive evolutionary level at which the rate of growth of the gonad determines its sexual direction. When this exceeds a certain threshold a testis may develop despite the absence of the TDF gene.

Animals↗
PubMed2002

Effect of 17beta-estradiol on the reproduction of Japanese medaka (Oryzias latipes).

Estrogenic compounds such as 17beta-estradiol (E2) and its analogs are present in the aquatic environment and can adversely affect the reproductive systems of aquatic organisms. Although E2 has been detected at a maximum concentration of 64 ng/l in effluents of sewage treatment works (STWs), few reports address the associated effects on reproduction in fish. Therefore, we exposed adult medaka (Oryzias latipes) to mean measured E2 concentrations of 29.3, 55.7, 116, 227, and 463 ng/l for 21 d and assessed the effects on the egg number and fertility of paired medaka during the exposure period. In addition, we determined the hepatic vitellogenin (Vtg) concentration and histologically assessed the gonads of these fish. The number of egg produced and fertility of the paired medaka exposed to 463 ng/l E2 were significantly less compared with those of the control fish. Males in all treatment groups had developed testis-ova. Males treated with E2 concentrations = 55.7 ng/l contained relating great concentrations of hepatic Vtg. Therefore, although only the greatest E2 concentration tested in our study affected fecundity and fertility, effects of E2 were observed on induction of Vtg and testis-ova in male medaka exposed to environmentally relevant concentrations of E2.

Animals↗
PubMed1982

Kaposi's sarcoma following chemotherapy for testicular cancer in a homosexual man: demonstration of cytomegalovirus RNA in sarcoma cells.

A 35-year-old white Jewish homosexual man who had undergone surgery and chemotherapy for an embryonal carcinoma of the testis subsequently developed Kaposi's sarcoma. The neoplasm involved the skin as well as visceral tissues. Tissue derived from a biopsy specimen of one of the skin lesions was used in the in situ hybridization technique for the detection of genetic material. Cytomegalovirus messenger RNA was identified in the neoplastic Kaposi cells in the skin. The significance of this finding is discussed.

Cytomegalovirus↗