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PubMed1989

Absence of development of late steroidogenic lesions in rat testis during the end of fetal life.

In the rat during the last 4 days of fetal life, the production of testosterone by the testis does not increase, whereas the plasma level of biological LH-like activity rises sharply. The present study was designed to test whether this phenomenon is attributed to the development of defects in the activity of the enzyme 17 alpha-hydroxylase and C17,20-lyase (called late steroidogenic lesions) during the end of fetal life. As this occurrence would lead to an age-related decrease in the ratio testosterone/progesterone, the testicular productions of these two steroids were evaluated on 18.5, 20.5, and 21.5 days postconception. Three different measurements were performed: (a) the in vivo testicular contents; (b) the in vitro secretions during a 120-min incubation in the presence or in the absence of 100 ng/ml ovine LH; (c) the testicular contents after these incubations. These measurements never revealed a decrease in the ratio testosterone/progesterone as a function of fetal age. It would appear that late steroidogenic lesions do not develop during the end of fetal life in the rat.

Animals↗
PubMed1986

Alterations in activities of calmodulin and heat-stable calmodulin-binding protein in rat testis.

Effects of postnatal development, surgical cryptorchidism, and hypophysectomy on the activity of calmodulin and of a 32,000-molecular weight (32) calmodulin-binding protein (Ono et al., J. Biol. Chem. 259: 9011-9016, 1984) were examined in rat testis. In adult rats, approximately 95% of their activities distributed in seminiferous tubule preparation, and most of them were in the 105,000-g supernatant. Both activities were low early in the development, but the calmodulin activity increased between 25 and 45 days of age, and the 32 K calmodulin-binding protein activity increased between 35 and 45 days of age. In contrast, surgical cryptorchidism caused a rapid decline in their activities in the abdominal testis, whereas their activities in a scrotal testis did not decline. Hypophysectomy similarly resulted in a gradual decline in their activities. Replacement of follicle-stimulating hormone or testosterone for 7 days from 30 days after hypophysectomy did not quantitatively restore either the testes weight or the activities of the proteins. The results indicate a primary distribution of both proteins in mature germ cells.

Animals↗
PubMed2002

Bax-dependent spermatogonia apoptosis is required for testicular development and spermatogenesis.

Bax is a multidomain, proapoptotic member of the Bcl-2 family that is required for normal spermatogenesis in mice. Despite its proapoptotic function, previous results found that Bax-deficient mature male mice demonstrate increased cell death and dramatic testicular atrophy. The present study examined the role of Bax during the normal development of the testis to determine whether the increased cell death in mature mice could be explained by decreased apoptosis earlier in development. Consistent with this hypothesis, testicular atrophy is preceded by increased testicular weight and hypercellular tubules in immature Bax-deficient mice. TUNEL staining at Postnatal Day (P) 7 and morphological quantitation between P5 and P15 demonstrates decreased germ cell apoptosis in Bax-deficient mice. By P15, increased numbers of type A spermatogonia, and at P12 and P15, an increase in intermediate type spermatogonia were noted in Bax-deficient animals. By P25, the number of basal compartment cells was greatly increased in Bax-deficient animals compared with controls such that four or five layers of preleptotene spermatocytes were routinely present within the basal compartment of the testis. Although the Sertoli cell barrier was significantly removed from the basement membrane, it appeared intact as judged by the hypertonic fixation test. During late pubertal development, massive degeneration of germ cells took place, including many of those cell types that previously survived in the first wave of spermatogenesis. The data indicate that Bax is required for normal developmental germ cell death in the type A spermatogonia, specifically dividing (A(2), A(3), and A(4)) spermatogonia, at a time at which the number of spermatogonia is regulated in a density-dependent manner. The massive hyperplasia that occurs in Bax-deficient mice subsequently results in Bax independent cell death that may be triggered by overcrowding of the seminiferous epithelium.

Animals↗
PubMed2002

The murine BTB/POZ zinc finger gene Znf131: predominant expression in the developing central nervous system, in adult brain, testis, and thymus.

The Znf131/ZNF131 protein belongs to the superfamily of POK proteins containing a BTB/POZ domain in its N-terminal part and 5 typical C2H2 zinc fingers and an additional C2HC zinc finger structure in its C-terminal region. In mouse and human two alternatively spliced transcripts are expressed from the Znf131/ZNF131 gene, resulting from intraexonic splicing. While the longer transcript encodes for three double zinc finger structures the shorter transcript lacks the region coding for the first zinc finger. Although the murine Znf131 gene is ubiquitously expressed, expression analysis applying whole mount in situ hybridization showed a predominant expression in the developing central nervous system with strongest signals in the forebrain, midbrain, and hindbrain areas and in the neural tube. Further dominant expression was seen in embryonic limb buds. In human adult tissues a predominant expression of ZNF131 was seen in different brain areas, i.e., the occipital and temporal lobe, the nucleus caudatus, hippocampus, and the cerebellum as well as in testis and thymus. Therefore, it is possible that Znf131/ZNF131 plays a role during development and organogenesis as well as in the function of the adult central nervous system.

Alternative Splicing↗
PubMed2004

Molecular markers for the assessment of postnatal male germ cell development in the mouse.

BACKGROUND: A proliferation marker, proliferating cell nuclear antigen (PCNA), a Sertoli cell specific transcription factor, GATA-1 and the male germ cell specific, RNA binding motif (RBM), were used to identify different cellular populations during postnatal development of the mouse testis. METHODS: Immunohistochemistry, RT-PCR and real-time quantitative RT-PCR (QRT-PCR) were used. RESULTS: PCNA was expressed in pre-Sertoli and germ cells on the day of birth. Both pre-meiotic germ cells and spermatocytes expressed RBM throughout postnatal development. RBM-positive cell counts and QRT-PCR of RBM showed that average level of RBM per cell is highest in juvenile males between 14 and 21 days. From 42 days onward, there was a dramatic decrease in RBM expression in individual pre-meiotic and meiotic germ cells. CONCLUSIONS: These markers were used to correlate cell proliferative capability, gene expression profile and anatomic location within the developing mouse testis. The majority of germ cells start active proliferation once they have migrated to the basement membrane or immediately before. RBM is more highly expressed during the first wave of spermatogenesis versus subsequent waves, suggesting that there may be a change in the activity of RBM.

Animals↗
PubMed1993

Laparoscopy in pediatric urology.

Laparoscopy has been used in pediatric urology for the diagnosis of nonpalpable testes for more than fifteen years. Expansion of pediatric urologic applications of laparoscopic surgical techniques is inevitable with the recent explosion of urologic laparoscopy. While the needs are distinct and at times divergent from those in the adult population, many benefits may be realized with this developing technology in children. Refinement of diagnostic capabilities as well as interventional procedures for the undescended testis are being developed. Increased use for varicocele treatment and intersex evaluation can be expected. Potential applications of laparoscopic techniques for the pediatric urologist include nephrectomy for various benign diseases, ureteral surgery for reflux, bladder autoaugmentation, and hernia repair. Laparoscopic possibilities are limited only by imagination and technology. A skeptical approach is justified and judicious application of these technologies in children is essential. Just as the child is not a small adult, pediatric laparoscopy is not just the use of smaller instruments.

Child↗
PubMed1990

Long-term effects of prepubertal testicular vessel ligation on testicular function in the rat.

To determine the effects of unilateral testicular vein and artery ligation in the immature rat on the function and final location of the testis at adulthood, 10-day-old male rats underwent either a sham operation or unilateral ligation of these vessels of the still undescended testis. Testicular location, blood flow, size and histology as well as ventral prostate weights were measured 50 days later at adulthood. At age 60 days, it was determined that all testes were descended into the scrotum, and there were no differences in testis and ventral prostate weights, intratesticular sperm counts and mean seminiferous tubular area between the control and sham operated animals. However, there was an 18% reduction in testicular blood flow (ml. per 100 gm. per minute +/- standard error of mean) in the operated animals when compared to the sham (20.43 +/- 1.10 versus 16.69 +/- 0.74, p less than 0.02). These data indicate that although there is a slight but significant reduction in testicular blood flow at adulthood when the testicular artery and vein are ligated early in life, this diminution is not sufficient to alter the ultimate location, testicular weight and spermatogenic function of the testis. This would suggest that after ligation of the main testicular vessels to the immature testis, the collateral blood supply is able to compensate with time to allow normal growth and development of the testis. These experimental observations provide additional support for the 2-staged approach to the high undescended testis whereby the testicular vessels are initially ligated and a subsequent procedure is performed to place the undescended testis into the scrotum.

Animals↗
PubMed1992

Development and cytodifferentiation of peritubular myoid cells in the rat testis.

The cytodifferentiation of peritubular myoid cells was studied in developing rats from fetal day 18 through approachment of puberty. The parameters taken into consideration were 1) the presence of desmin, a component of intermediate filaments in contractile cells; 2) the expression of alkaline phosphatase, a cell surface enzyme present in no other cell type of the seminiferous tubule; 3) the expression of the smooth muscle specific isoform of alpha-actin, a marker of terminal differentiation in smooth muscle cells; 4) cell proliferation rate, evaluated in radioautography as labeling index after incorporation of 3H-thymidine in short-term organ culture; and 5) cytoarchitectural changes detected with scanning electron microscopy. By means of immunofluorescence and cytochemistry it was observed that the three markers are expressed early during life, long before the onset of the first spermatogenic wave; in particular desmin is already present in fetal samples and alkaline phosphatase activity appears a few days after birth, whereas alpha-smooth muscle isoactin is first detected around birth. As for myoid cell replication, the high prenatal labeling index was found to drop soon after birth and to further slow down during the first month of postnatal life, suggesting that myoid cell proliferation is not a major factor in peritubular expansion. SEM examination of developing peritubulum has shown that, when approaching puberty, the myoid cell undergoes a dramatic change in cytoarchitecture, consisting in extreme flattening and cytoplasmic expansion resulting in an apparent increase in peritubular surface.

Actins↗
PubMed1994

The requirement of the testis in establishing the sensitivity of the canine prostate to develop benign prostatic hyperplasia.

A long-term study on the requirement of the testis in establishing the sensitivity of the canine prostate to develop benign prostatic hyperplasia (BPH) was conducted using 23 aging beagles both with and without their testes. The dogs had received long-term restoration of testosterone and estrogen through silicone implants. When young beagles (0.5 to 1 year of age) were castrated and normal serum testosterone and estrogen levels restored during aging to 5 years, only 50% of these dogs developed BPH in the absence of their testes as opposed to 100% BPH development in intact controls. In addition, two-thirds of the prostates in the treated groups were remarkably reduced in size, being smaller than any prostate observed in the intact controls. If, following castration, the steroid restoration was withheld for 4 years during aging and subsequently administered starting at 5 years of age and continuing for a 6-month period, none of the animals developed complex BPH. Moreover, two-thirds of the prostate glands were reduced in size by more than 60% and were atrophied in spite of the maintenance of normal prostatic tissue dihydrotestosterone levels. Regardless of the time of steroid restoration to a castrate beagle, the periurethral zone of the canine prostate exhibits various degrees of atrophy indicating functional regions within the canine prostate that are sensitive to the requirements of the testes during aging. This study implicates the importance of the testis in increasing the probability and/or sensitivity for the full development of canine BPH.

Aging↗
PubMed2002

Developmental, stage-specific, and hormonally regulated expression of growth hormone secretagogue receptor messenger RNA in rat testis.

Recent evidence from our research suggested the direct role of ghrelin in the control of testicular function. However, the pattern of expression and hormonal regulation of the gene encoding its cognate receptor (i.e., the growth hormone-secretagogue receptor [GHS-R]) in the male gonad remains to be fully elucidated. In this paper, overall expression of GHS-R mRNA in rat testis was compared with that of the functional receptor form, namely GHS-R type 1a, in different developmental and experimental settings. In addition, cellular distribution of GHS-R within adult testis tissue was assessed. Our analyses demonstrated persistent expression of the GHS-R gene in rat testis throughout postnatal development. In contrast, testicular expression of GHS-R type 1a mRNA remained undetectable before puberty and sharply increased thereafter. In adult testis, GHS-R1a mRNA expression presented a scattered pattern of cellular distribution, including Sertoli and Leydig cells that also showed specific GHS-R1a immunoreactivity. Expression of total GHS-R and specific GHS-R1a mRNAs was detected in isolated seminiferous tubule preparations, with varying levels throughout the defined stages of the spermatogenic cycle. In addition, testicular expression of total GHS-R and GHS-R1a mRNAs was up-regulated by exposure to ghrelin in vitro and after stimulation with FSH in vivo. In conclusion, our data demonstrate that expression of the GHS-R gene in rat testis takes place in a developmental, stage-specific, and hormonally regulated manner. Divergent expression of total GHS-R and type 1a specific mRNAs was detected at certain stages of postnatal development and spermatogenic cycle, thus raising the possibility that, in addition to net changes in GHS-R gene expression, the balance between receptor subtypes may represent a novel mechanism for the tuning of ghrelin sensitivity in rat testis.

Animals↗
PubMed2004

The murine testicular transcriptome: characterizing gene expression in the testis during the progression of spermatogenesis.

One of the most promising applications of microarrays is the study of changes in gene expression associated with the growth and development of mammalian tissues. The testis provides an excellent model to determine the ability of microarrays to effectively characterize the changes in gene expression as an organ develops from birth to adulthood. To this end, a developmental testis gene expression time course profiling the expression patterns of approximately 36 000 transcripts on the Affymetrix MGU74v2 GeneChip platform at 11 distinct time points was created to gain a greater understanding of the molecular changes necessary for and elicited by the development of the testis. Additionally, gene expression profiles of isolated testicular cell types were created that can aid in the further characterization of the specific functional actions of each cell type in the testis. Statistical analysis of the data revealed 11 252 transcripts (9846 unique) expressed differentially in a significant manner. Subsequent cluster analysis produced five distinct expressional patterns within the time course. These patterns of expression are present at distinct chronological periods during testis development and often share similarities with cell-specific expression profiles. Analysis of cell-specific expression patterns produced unique and characteristic groups of transcripts that provide greater insight into the activities, biological and chronological, of testicular cell types during the progression of spermatogenesis. Further analysis of this time course can provide a distinct and more definitive view into the genes implicated, known and unknown, in the maturation, maintenance, and function of the testis and the integrated process of spermatogenesis.

Animals↗
PubMed1977

Congenital testicular lymphangiectasis.

Testicular lymphangiectasis are described for the first time in a patient with bilateral inguinal cryptorchidism. A great number of irregular lymphatic channels was observed within the parenchyma and the tunica vasculosa in both testes. Large and numerous anastomosis between the lymphatic vessels of these two areas could also be seen. The MTD and the TFI of the left testis were normal. Both parameters were very low in the right testis. The association of this fact with the greater development of the lymphatic vessels in this testis strongly supports the idea that testicular lymphangiectasis interfere mechanically with the testis tubular development.

Biopsy↗
PubMed1994

[Effects of low doses of desmopressin (DDAPV) on gonadal and adrenal development, and on the testicular function and sperm motility].

The present study proved that desmopressin (DDAVP) (1 microgram DDAVP/12 h/5 días) does not affect ovary, testis and adrenal development in immature Wistar rats (17 days old), because the DDAVP does not modify the weight of the aforementioned organs as compared with the control group. Nevertheless, the male adults Wistar rats (80 days old) showed lower serum testosterone concentrations than the control group, after injection of 4 micrograms/day (2 micrograms/12 h) or 8 micrograms/day (4 micrograms/12 h) of DDAVP during a 5 days period time. Moreover, paradoxical significant lower concentrations of serum testosterone were found in 4 micrograms DDAVP/day-treated rats than in 8 micrograms DDAVP/day-treated ones. The former also showed a decreased number of spermatozoa as compared with the latter and with the control group. The percentage of mobile spermatozoa was lower in rats treated with both concentrations of DDAVP as compared with the control group. Therefore, desmopressin does not delay gonadal and adrenal growth in immature rats, but, at low doses, it affects the testicular function and the mobility of the spermatozoa in male adult rats.

Adrenal Glands↗
PubMed2005

Germline niche transplantation restores fertility in infertile mice.

BACKGROUND: Stem cells interact closely with their microenvironment or niche, and abnormalities in niche compromise the self-renewing tissue. In testis, for example, Sertoli cells interact with germ cells, and defects in Sertoli cells compromises spermatogenesis, leading to male infertility. However, it has not been possible to restore spermatogenesis from endogenous stem cells in infertile testis with environmental defects. METHODS AND RESULTS: When healthy Sertoli cells from infertile white spotting (W) mouse were transplanted into the seminiferous tubules of infertile Steel (Sl) mouse testis that had defective Sertoli cells, spermatogenesis occurred from Sl stem cells in the recipient testis. On average, 1.1% of the recipient tubules showed spermatogenesis. Furthermore, in a microinsemination experiment with germ cells that developed in the testis, we obtained four normal offspring from 114 successfully injected oocytes. CONCLUSIONS: This study demonstrates that defects in male germline microenvironment can be corrected by Sertoli cell transplantation. Although further improvements are required to enhance the low efficiency of spermatogenesis, the ability to correct environmental defect by niche transplantation has important implications in developing new strategies for treating incurable disorders in self-renewing tissues.

Animals↗
PubMed1984

Differentiation of the rat testis between 20 and 120 days of age.

The differentiation of the seminiferous epithelium was studied in 20-120-day-old Sprague-Dawley rats. Body weights and the weights of the testes, seminal vesicles, and kidneys were determined. The best way of defining the development of the testis was to denote the most differentiated germ cell present. Spermatogenesis is complete at 56 days of age, but the testis continues to grow up to 108 days of age. The development of certain parameters has been calculated, and it is very important to define the age of the animals in experimental studies and to include sufficient numbers of controls.

Aging↗
PubMed1993

Experimental testicular germ cell tumorigenesis in mouse strains with and without spontaneous tumours differs from development of germ cell tumours of the adult human testis.

The aim of this study was to undertake a morphological analysis of the earliest stages of experimentally induced (by genital ridge grafting) germ cell tumours in mouse strains with (129/Sv-ter) and without (MA) spontaneous tumorigenesis. Genital ridges from fetuses aged 12 or 13 days from 129/Sv-ter and MA were transplanted into the testes of adult 129/Sv-ter. The results show clearly that experimentally induced carcinoma-in-situ in mouse testes differs considerably from its human counterpart, found in patients with and without testicular germ cell tumours, and considered to be the precursor for all kinds of germ cell tumours of the adult testis apart from spermatocytic seminoma. The results indicate that development of testicular germ cell tumours is different in man and the mouse.

Adult↗
PubMed1998

Sex in the 90s: SRY and the switch to the male pathway.

In mammals the male sex determination switch is controlled by a single gene on the Y chromosome, SRY. SRY encodes a protein with an HMG-like DNA-binding domain, which probably acts as a local organizer of chromatin structure. It is believed to regulate downstream genes in the sex determination cascade, although no direct targets of SRY are clearly known. More genes in the pathway have been isolated through mutation approaches in mouse and human. At least three genes, SRY itself, SOX9, and DAX1, are dosage sensitive, providing molecular evidence that the sex determination step operates at a critical threshold. SRY initiates development of a testis from the bipotential cells of the early gonad. The dimorphic male and female pathways present a rare opportunity to link a pivotal gene in development with morphogenetic mechanisms that operate to pattern an organ and the differentiation of its cells. Mechanisms of testis organogenesis triggered downstream of SRY include pathways of cell signaling controlling cell reorganization, cell proliferation, cell migration, and vascularization.

Amino Acid Sequence↗
PubMed1997

Developmental expression of H3.3A variant histone mRNA in mouse.

Cloning and characterization of H3.3A variant histone expression has recently been reported to be associated with meiotic development in mouse testis and ovary. Using Northern analysis and in situ hybridization, the pattern of H3.3A expression was studied during the development of different tissues. In addition to the differential expression detected in male and female meiosis, H3.3A was found to be highly expressed in preantral follicles of adult ovaries and in the basal regions of seminiferous epithelium corresponding to spermatogonia. Different patterns of expression were observed in somatic tissues, which also differed with respect to the developmental stage of the tissue. The lowest expression was detected in adult skeletal muscle. High expressions were found in foetal liver and spinal cord. These different expressions might reflect a possible function of H3.3A in cell differentiation as detected in MEL cells.

Animals↗