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PubMed2000

Absence of correlation between in situ expression of cytochrome P450 17alpha hydroxylase/lyase and 3beta-hydroxysteroid dehydrogenase/(Delta5-4) isomerase messenger ribonucleic acids and steroidogenesis during pubertal development in the rat testis.

Changes in expression of Leydig cell 3beta-hydroxysteroid dehydrogenase (3betaHSD) and 17alpha-hydroxylase/C17-20 lyase (P450(17alpha)) messenger RNA (mRNA) during pubertal development have not been well characterized in the rat. In the present study, expression of 3betaHSD and P450(17alpha) were determined in frozen sections of testes of immature (days 21 and 28), pubertal (days 45 and 60) and adult (day 90) rats by in situ hybridization using digoxigenin-labeled riboprobes and quantified densitometrically. Measures of steroidogenesis in this study, 3betaHSD and P450(17alpha) enzyme activities per testis and plasma testosterone concentration, increased during pubertal development, peaking at 45-60 days of age. Expression of 3betaHSD protein, a marker for Leydig cell function, was abundantly immunolocalized to the interstitial compartment of the testis. Quantified densitometrically, the amount of 3betaHSD protein did not vary significantly during pubertal development. Transcripts of 3betaHSD and P450(17alpha) were expressed abundantly by clusters of immature Leydig cells in immature animals. However, in contrast to measures of steroidogenesis during pubertal development, mRNA of 3betaHSD and P450(17alpha) decreased to undetectable levels at the age of 45 and 60 days, respectively. The decline in mRNA of 3betaHSD and P450(17alpha) was confirmed by Northern analysis. Expression of 3betaHSD and P450(17alpha) transcripts rebounded in the adult at 90 days and were comparable to levels of expression observed in immature animals. These results show that during pubertal development the steady-state accumulation of mRNA of 3betaHSD and P450(17alpha) are not correlated with accumulation of 3betaHSD protein, enzyme activities of 3betaHSD and P450(17alpha), or testosterone secretion. Possible explanations of the depletion of transcripts during pubertal development include: specific inhibition of transcription, increased mRNA instability, or high translational activity.

Androgens↗
PubMed1984

Onset of the response to chorionic gonadotropin in the chick embryo testis.

The stage of development of the chick embryo testis when it begins to respond to gonadotropin stimulation was investigated. The testosterone secretion in vitro, measured by radioimmunoassay, was employed to evaluate the response to hCG in testis from 8 to 16 days of incubation. At 8 to 10 days of the chick embryo development, the testis secreted testosterone, but no increment in the steroid production has been observed after hCG treatment. On the contrary, at 12, 14, and 16 days a clear increase in testosterone secretion has been demonstrated when hCG was added to the culture medium. The absence of hCG response before 12 days of incubation agrees with the hypothesis of an early independence period between testis and adenohypophysis during embryonic development.

Animals↗
PubMed1997

Sequences 5' of the basement membrane laminin beta 1 chain gene (LAMB1) direct the expression of beta-galactosidase during development of the mouse testis and ovary.

The murine LAMB1 gene encoding laminin beta 1 is expressed in the developing male and female gonads and mesonephros. To identify the cis-acting elements regulating the expression of LAMB1, murine transgenic lines were generated by fusing regions of the LAMB1 gene to the Eschericia coli lacZ gene. The p3.9LAM beta gal construct contained approximately 4 kb of 5' flanking sequence and directed beta-galactosidase expression in many different organs including the kidney, mammary gland, and the male and female genital systems, the focus of this report. In male embryos, between gestational ages E 14.5 and birth beta-galactosidase was transiently expressed in the prospermatogonia cells of the testis and in the differentiating epithelial cells in the ductus deferens, ductus epididymis, and seminal vesicles. In female embryos, beta-galactosidase was not detected in the ovary until about 1 week after birth; at this time, beta-galactosidase was expressed by oocytes of primary and secondary follicles. In contrast, transgenic mice carrying the first 0.7 kb of LAMB1 fused to the lacZ gene expressed beta-galactosidase only in the prospermatogonia cells of the testis. Thus, the cis-acting element(s) necessary for the expression of the LAMB1 gene in prospermatogonia cells are located in the first 0.7 kb of LAMB1 5' flanking sequence; element(s) required for expression of the LAMB1 gene in oocytes and epithelial cells of the mesonephric ducts, mesonephric tubules, the ductus deferens, ductus epididymis, and seminal vesicles are located with 4 kb 5' of the transcription initiation site.

Animals↗
PubMed1999

Management consideration in nonpulmonary visceral metastatic seminoma of testis.

To develop a more appropriate therapeutic strategy for treatment of nonpulmonary visceral metastatic testicular seminoma based on the International Germ Cell Consensus Classification, we reviewed the medical records of patients with nonpulmonary visceral metastatic testicular seminoma who were treated over a 20-year period. Only 15 (2.2%) of the 686 cases of testicular seminoma were nonpulmonary visceral metastatic seminoma. The median age of patients was 38 years (range, 22-53 years). Ten (67%) of the patients had an initial diagnosis of supradiaphragmatic or visceral metastatic disease. In addition to nonpulmonary visceral metastasis, all patients had lymph node metastasis as well, the majority of which involved the retroperitoneal lymph nodes. The median and mean progression-free survival durations after chemotherapy for advanced disease were 19 months and 63.7 months, respectively. Six patients (40%) survived, five relapsed after radiation therapy and four died of chemorefractory disease not dependent on the specific regimen. Although the number of cases reviewed in this study was small, we conclude that the choice of chemotherapeutic regimen among the current treatments for nonpulmonary visceral metastatic seminoma of testis primary does not present a different outcome. Therefore, multimodality therapies using new strategies or new agents are well indicated.

Adult↗
PubMed1975

Changes in fine structure accompanying estrogen-induced tumorigenesis of Leydig cells in the mouse testis.

The development of estrogen-induced Leydig cell tumors in cryptorchid BALB/c mice was studied with the electron microscope. Changes in Leydig cell fine structure are apparent by 10 days after the s.c. implantation of a pellet of diethylstibestrol (DES). The smooth endoplasmic reticulum is diminished, and there is an increase in lipid droplets and free polysomes as compared with untreated cryptochid controls. These alterations persist as the Leydig cells proliferate to form focal areas of hyperplasia in the interstitial tissue. During this period of proliferation, activated macrophages containing large residual bodies appear among the Leydig cells. If DES treatment is continued for several months, malignant Leydig cell tumors, result. They are characterized by a nuclear and cytoplasmic pleomorphism of the Leydig cells and a decreased macrophage population. Virus-like particles are rarely seen within the cell during the period of tumorigenesis. Along with the reduction in smooth endoplasmic reticulum in the Leydig cells after DES treatment, evidence from the literature suggests that there is also a decrease in testosterone biosynthesis. However, it is not clear whether these two effect are correlated, since the level of the microsomal enzymes of steroid biosynthesis may vary independently of either the amount of smooth endoplasmic reticulum or the level of androgen secretion. The increase in lipid droplets seen in Leydig cells after DES treatment suggest the accumulation of precursors from the steroid biosynthetic pathway. The macrophages are though to represent scavenger cells, rather than a primary tumor cell population. The paucity of virus-like particles within altered Leydig cells implies that formed virus is not a prerequisite for tumorigenesis.

Animals↗
PubMed1984

5 Alpha- and 5 beta-reductases for 4-ene-3-ketosteroids and 17 beta-ol-dehydrogenase in epididymis and testis of golden hamster during sexual development.

Homogenates of the epididymis, testis and seminal vesicle from 15, 25, 35 and 60-day old golden hamsters were incubated with [3H]4-androstene-3,17-dione and NADPH and enzyme activity was estimated. In the testis, activities of 5 alpha- and 5 beta-reductases were the highest (32 +/- 4 and 68 +/- 13 (SD) nmol/100 mg protein/h, respectively) at 25 days of age, moderately high at 35 days and very low (1-3 and 5-6, nmol/100 mg protein/h, respectively) at 15 and 60 days. In the epididymis, 5 alpha-reductase activities increased with age during sexual development by up to 50-fold and reached the maximum value (40 +/- 11 nmol/100 mg protein/h) at 60 days. The 5 alpha-reductase activities in the seminal vesicle were found to be relatively low (0.5-1 nmol/100 mg protein/h), compared with those in the epididymis and testis. Activities of 5 beta-reductase in the epididymis and seminal vesicle were very low (0.1-0.5 nmol/100 mg protein/h) at all ages. These results indicate the existence of a marked, but transient, increase in 5 alpha- and 5 beta-reductase activities during immature period in the testis of golden hamster. In the epididymis, however, 5 alpha-reductase activity increases with age during sexual maturation, while 5 beta-reductase activity is almost undetectable at all ages.

17-Hydroxysteroid Dehydrogenases↗
PubMed2006

Testicular xenografts: a novel approach to study cytotoxic damage in juvenile primate testis.

The underlying primary damage to the testis caused by chemotherapeutic regimens during childhood is largely unknown. Xenografting of monkey testes was successfully applied in maturation of juvenile testis to the point of complete spermatogenesis. This allows us to manipulate developing primate testis without direct treatment of patients. This new model is validated establishing the effects of cytotoxic treatment in the immature primate testis. Male castrated nude mice received eight s.c. grafts of juvenile monkey testicular tissue and, 28 weeks later, were injected with busulfan (38 mg/kg, i.p.) or vehicle. Graft numbers, size, and histology were examined. Grafts showed pubertal induction of spermatogenesis to the level of pachytene spermatocytes at point of busulfan treatment and further progressed to the level of round spermatids in control samples at 4 weeks. Busulfan treatment caused a statistically significant decrease in the number of seminiferous tubules containing germ cells. Type B spermatogonia and more advanced stages of spermatogenesis were depleted. A statistically significant decrease to pretreatment level was observed in the number of type A pale and centrally located spermatogonia. Busulfan did not affect type A dark spermatogonia. Occasionally, elongating spermatids were detected in busulfan-treated grafts. Observations show that busulfan selectively destroys differentiating spermatogonia whereas some of the spermatocytes present at the moment of cytotoxic insult are able to continue differentiation. Data indicate that xenografting of testicular monkey tissue is a valid approach to detect the busulfan-induced germ cell damage and serves as a powerful experimental tool to study cytotoxic effects in developing primate testis.

Animals↗
PubMed1990

Expression of a candidate sex-determining gene during mouse testis differentiation.

The development of a eutherian mammal as a male is a consequence of testis formation in the embryo, which is thought to be initiated by a gene on the Y chromosome. In the absence of this gene, ovaries are formed and female characteristics develop. Sex determination therefore hinges on the action of this testis-determining gene, known as Tdy in mice and TDF in humans. In the past, several genes proposed as candidates for Tdy/TDF have subsequently been dismissed on the grounds of inappropriate location or expression. We have recently described a candidate for Tdy, which maps to the minimum sex-determining region of the mouse Y chromosome. To examine further the involvement of this gene, Sry, in testis development, we have studied its expression in detail. Fetal expression of Sry is limited to the period in which testes begin to form. This expression is confined to gonadal tissue and does not require the presence of germ cells. Our observations strongly support a primary role for Sry in mouse sex determination.

Animals↗
PubMed1999

Differential localization of inhibin subunit proteins in the ovine testis during fetal gonadal development.

Inhibins and activins are dimeric proteins that are involved in cell proliferation, apoptosis, and differentiation in a number of systems and have previously been detected in fetal testes of many species. This study used immunohistochemistry to examine the localization of inhibin alpha-, betaA-, and betaB- subunits during ovine testicular development from days 40-135 of gestation. Localization of inhibin betaA- and betaB-subunit messenger RNAs was confirmed by in situ hybridization. The results showed that there was differential localization of inhibin alpha-, betaA-, and betaB-subunits to specific cells in the ovine fetal testis from 40 days of gestation. All three inhibin subunits were present in Sertoli cells throughout gestation, whereas the rete epithelium and gonocytes did not express inhibin alpha-subunit. These data suggest that the fetal Sertoli cells have the capacity to produce all forms of inhibins and activins, i.e. inhibin A and B, and activins A, AB, and B, whereas the rete testis epithelial cells can only synthesize activin A. In the interstitium, the fetal Leydig cells expressed all three inhibin subunits, but this was restricted to the period between 40 and 90 days of gestation. Thereafter, inhibin alpha-subunit immunoreactivity was not observed in fetal Leydig cells, which suggests that only activin ligands are produced by Leydig cells during late gestation. Collectively, the data demonstrate that fetal ovine testes have the potential to produce the full repertoire of inhibins and activins from very early in testicular differentiation. The distinct and restricted localization of the various subunits to specific cells suggests that specific dimeric proteins have particular roles in the development and function of the fetal testis.

Animals↗
PubMedDate not supplied

Signaling at the crossroads of gonad development.

In mammals, the gonads arise as bipotential primordia that are capable of developing as either testes or ovaries. Expression of the Y-linked gene Sry in the XY gonad initiates testis differentiation; in the absence of Sry, ovarian pathways prevail. Although the molecular targets of SRY are not known, many of the early cellular and morphological events that occur downstream of Sry have been characterized. These include increased cell proliferation, Sertoli cell differentiation, testis cord formation, development of a testis-specific vasculature and differentiation of interstitial lineages. Recently, several of the molecular signals that direct these processes have been identified. In addition, the pathways that suppress features of testis development in the XX gonad are being elucidated.

Animals↗
PubMed1980

Loose connective tissue of rat rete testis. Fine structure, postnatal development and effect of efferent duct ligation.

Fine structure, postnatal development and reaction to efferent duct ligation of the loose connective tissue of the rat rete testis were studied by light and electron microscopy. The loose connective tissue of adult rats consists of elongate fibroblasts in a homogenous ground substance, together with some Leydig cells, lymphocytes, macrophages and mast cells. During postnatal development this tissue increases in amount, while the interstitial areolar tissue decreases. The "looseness" of the tissue becomes more evident between days 22 and 27, and may reflect an increase in hydration. Efferent duct ligation for 15 min to five days has no effect on the histological appearance of the tissue.

Animals↗
PubMed1984

Cytoplasmic filaments in fetal and neonatal pig testis.

Leydig cells in developing fetal pig testis contained during the fetal regressive phase large accumulations of intermediate filaments. Before and after this period these filaments were arranged in a criss-cross fashion. In the pig as well as in the dog testis these filaments have been characterized as vimentin. Within the vimentin aggregates occasionally a weak positive actin reaction was seen in pig but not in dog Leydig cells. Microfilaments were hardly observed. Most Sertoli cells contained a layer of actin microfilaments close to the basal cell membrane. In the lower cell compartment and around the nucleus (intermediate) vimentin filaments could be observed in a criss-cross configuration.

Aging↗
PubMed1989

Development of the inhibitory guanine nucleotide-binding regulatory protein in the rat testis.

The functional development of the inhibitory guanine nucleotide-binding regulatory protein (Gi) and anti-diuretic hormone (ADH) activity was investigated in rat testes. Adult (90-day-old), adolescent (40-day-old), prepubertal (23-day-old), and fetal (20.5 days of gestation) testis cells were cultured with 100 ng/ml pertussis toxin for 24 h. The cells were then cultured with human chorionic gonadotropin (hCG), the ADH agonist arginine vasotocin (AVT), or a combination of the two. Testis cells from rats 23, 40, and 90 days of age that were incubated with hCG increased testosterone production when compared with controls. Preincubation of the cells from postnatal rats with pertussis toxin significantly increased hCG-stimulated testosterone secretion when compared to cells preincubated in medium only at all three ages. AVT suppressed hCG-stimulated testosterone secretion, but this suppression was partially reversed in cells from all postnatal ages preincubated with pertussis toxin. Fetal testis cells showed no response to preincubation with pertussis toxin, even when levels were increased to 400 ng/ml or when pertussis toxin treatment was continued throughout the culture period. AVT also had no effect on fetal testis cells. These results indicate that the Gi protein and AVT are not functional in fetal testes but are active from prepubertal stages of development through maturity.

Animals↗
PubMed1993

Mutations of the p53 gene do not occur in testis cancer.

To characterize the role of p53 in the development of testis cancer, we looked for mutations in the coding sequences of the p53 gene. DNA was obtained both from familial and sporadic testis cancer specimens, as well as from peripheral blood from members of a testis cancer kindred. Mutations in the p53 gene were screened using a combination of constant denaturant gel electrophoresis and single-strand conformational polymorphism analysis, 2 screening methods that can detect single base changes. Abnormalities detected by these methods were confirmed by sequencing of the corresponding cloned polymerase chain reaction products. All conserved regions of the p53 coding sequences were examined, encompassing all previously reported sites of mutations. No mutations were found in any of 22 germ cell cancers of the testis or in the germline DNA of 17 members of the testis cancer family. This is in striking contrast to most other human cancers, in which mutations of p53 are the most commonly described molecular event associated with tumorigenesis. We conclude that dysfunction of tumor suppressor gene or genes other than p53 may prove to play an important role in the development of germ cell cancers of the testis.

Genes, p53↗
PubMed1988

Postnatal development of the tubular lamina propria and the intertubular tissue in the bovine testis.

The postnatal development of intertubular cells and vessels and of the tubular lamina propria was studied in three locations of perfusion-fixed bovine testes from 31 animals ranging from 4 to 78 weeks. The postnatal morphological differentiation of the testis is not uniform, regional differences have to be considered. The intertubular cell population is composed of mesenchyme-like cells, fibrocytes, Leydig cells, peritubular cells and mononuclear cells. In 4- and 8-week-old testes mesenchyme-like cells are the dominating element. These pluripotent cells proliferate by frequent mitoses and are the precursors of Leydig cells, contractile peritubular cells and fibrocytes. Morphologically differentiated Leydig cells are encountered throughout the entire period of postnatal development. In 4-week-old testes degenerating fetal and newly formed postnatal Leydig cells are seen in juxtaposition to each other. From the 8th week on, only postnatal Leydig cells are present. Between 16 and 30 weeks large-scale degeneration of prepuberal Leydig cells is observed. The Leydig cells that survive this degenerative phase constitute the long-lasting adult population. 20-30% (numerically) of all intertubular cells at all ages are free mononuclear cells. These are found as lymphocytes, plasma cells, monocytes, macrophages and light intercalated cells (LIC). The latter are monocyte-derived, Leydig cell-associated typical cells of the bovine testis. The differentiation of the two main components of the tubular lamina propria, (i) basal lamina and (ii) peritubular cell sheath, seems to be effected rather independent from each other and also from hormonal signals important for the development of the germinal cells. The laminated basal lamina reaches nearly 3 micron at 16 weeks and is later on continuously reduced. At 25 weeks the peritubular cells have transformed into contractile myofibroblasts. At this period the germinal epithelium is still in a prepuberal state.

Aging↗
PubMed2002

Expression of a novel reticulon-like gene in human testis.

Identification of genes that are specifically expressed in the adult testis or the fetal testis is important for the study of genes related to the development of the testis. In this study, a human testis cDNA microarray was established. PCR products of 9216 clones from a human testis cDNA library were dotted on a nylon membrane; mRNA from adult and fetal testes were purified and probes were prepared by a reverse transcription reaction with testis mRNA as template. The microarray was hybridized with probes of adult and fetal testes, and 96.8 and 95.4% of clones were positive, respectively. In total, 731 clones were differentially expressed: 592 were highly expressed in adult testis and 139 were highly expressed in fetal testis. Among these genes, a new reticulon (Rtn)-like gene was detected and named Rtn-T. Rtn-T was highly expressed in adult human testis. The cDNA of Rtn-T contains 3491 bp and the putative protein had 968 amino acids. This protein is homologous to the six known members of the Rtn family (KIAA0886, Rtn xL, reticulon 4a, Nogo-A, Nogo-A short form, and brain my043) but was different at the 5' end. All homologues originate from one gene, and result from both different promotor regions and different splicing. Rtn-T lacks the first exon and contains a second exon that is lacking in the other homologues. Rtn-T is shorter than KIAA0886, Rtn xL, reticulon 4a and Nogo-A, but longer than the Nogo-A short form and brain my043. Sequence analysis showed that Rtn-T protein has two hydrophobic regions that may be membrane-spanning domains. Expression profiles showed that Rtn-T is specifically and strongly expressed in testis. The results of the present study indicate that the Rtn-T gene is differentially expressed in adult and fetal testes and encodes a membrane protein that may have a function in testis development.

Adult↗