Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “testis development”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,135 records · Page 63Linked to original sources
PubMed2001

Gonadal steroidogenesis in response to estradiol-17beta administration in the sea bream (Sparus aurata L.).

The sea bream (Sparus aurata) is a protandrous hermaphrodite teleost fish in which estrogen administration induces testicular regression without influencing ovarian development. To analyze the changes in steroidogenesis of fish treated with two levels of estrogen (2 and 10 mg. kg(-1)) and untreated control fish, fragments of gonads were incubated with tritiated 17-hydroxyprogesterone and the metabolites identified. The ability to extract radioactivity decreased with incubation time and was lower in gonads containing a larger proportion of ovarian tissue. The difference in steroidogenic capacity between control and estrogen-treated groups was generally quantitative rather than qualitative and paralleled the observed histological changes. The same metabolites were identified in all three groups, but estrogen treatment caused a marked inhibition of 5beta-reduction, 3alpha-reduction, side-chain cleavage, and 11beta-hydroxylation. The main androgens identified were 11beta-hydroxy-4-androstene-3,17-dione and 3alpha-hydroxy-5beta-androstane-3,17-dione, and the synthesis of both steroids was inhibited by estrogen treatment. Of the more polar pregnanes, 5beta-pregnane-3alpha,17,20alpha-triol and 5beta-pregnane-3alpha,17,20beta-triol were detected in significant amounts, but only the latter appeared to be associated with development of the testis (in the untreated fish). A feature of sea bream gonadal steroidogenesis less common in other teleosts was the presence of 6alpha- and 6beta-hydroxylation.

Animals↗
PubMed2005

Mutant meiotic chromosome core components in mice can cause apparent sexual dimorphic endpoints at prophase or X-Y defective male-specific sterility.

Genetic modifications causing germ cell death during meiotic prophase in the mouse frequently have sexually dimorphic phenotypes where oocytes reach more advanced stages than spermatocytes. To determine to what extent these dimorphisms are due to differences in male versus female meiotic prophase development, we compared meiotic chromosome events in the two sexes in both wild-type and mutant mice. We report the abundance and time course of appearance of structural and recombination-related proteins of fetal oocyte nuclei. Oocytes at successive days post coitus show rapid, synchronous meiotic prophase development compared with the continuous spermatocyte development in adult testis. Consequently, a genetic defect requiring 2-3 days from the onset of prophase to reach arrest registers pachytene as the developmental endpoint in oocytes. Pachytene spermatocytes, on the other hand, which normally accumulate during days 4-10 after the onset of prophase, will be rare, giving the appearance of an earlier endpoint than in oocytes. We conclude that these different logistics create apparent sexually dimorphic endpoints. For more pronounced sexual dimorphisms, we examined meiotic prophase of mice with genetic modifications of meiotic chromosome core components that cause male but not female sterility. The correlations between male sterility and alterations in the organization of the sex chromosome cores and X-Y chromatin may indicate that impaired signals from the XY domain (XY chromosome cores, chromatin, dense body and sex body) may interfere with the progression of the spermatocyte through prophase. Oocytes, in the absence of the X-Y pair, do not suffer such defects.

Animals↗
PubMed2001

Establishment of the urogenital junction in the male bovine embryo: an ultrastructural study.

The ultrastructure of the developing extratesticular rete testis, the efferent ductules and the establishment of the urogenital junction were studied in bovine embryos and fetuses of 41 through 95 days post conceptionem. The efferent ductules originate as a new set of secondary mesonephric tubules from the dorsal aspect of the nephric giant corpuscle and grow in the direction of the Wolffian duct. Cytological differentiation of the efferent ductules proceeds in a proximo--distal direction. At about 50-60 days, the simple columnar epithelium of the proximal portions of the efferent ductules already consists of the two typical cell types, i.e. reabsorptive principal cells with an endocytotic apparatus and a brush-border and ciliated cells. The lumen of the proximal portion is temporarily filled with intraductular blood vessels and perivascular tissue which may represent vestigial rudiments of glomeruli associated with the efferent ductules. At 50 to 60 days, the extratesticular rete still has a blastema--like appearance and consists of irregular cells with abundant glycogen. Extensions of the extratesticular rete come into contact with the efferent ductules and create the first end-to-side anastomoses with the latter. Somewhat later, the separating basal laminas vanish and invading rete cells intermingle with the epithelium of the efferent ductules, thus establishing the urogenital junction.

Animals↗
PubMed1986

Determination of apo and holo retinoic acid-binding protein levels in retinoid-responsive transformed cells by high-performance size-exclusion chromatography.

A method to measure the endogenous levels of apo and holo cellular retinoic acid-binding proteins was developed using calf testis cytosol as the source of retinoic acid-binding protein. [3H]Retinoic acid-retinoic acid-binding protein complexes were assayed by high-performance size-exclusion chromatography. Preincubation of cytosol with 10 mM p-hydroxymercuribenzoate at 4 degrees C resulted in complete inhibition of retinoic acid binding to apo retinoic acid-binding protein. In addition, total dissociation of preformed holo retinoic acid-binding protein complexes was noted within 20 min after mercurial addition. Thus, p-hydroxymercuribenzoate converted the total pool of cellular retinoic acid-binding protein (apo plus holo) to mercurial-protein complexes unable to bind retinoic acid in vitro. Mercurial inhibition of retinoic acid-retinoic acid-binding protein complex formation was totally reversed upon the addition of 50 mM dithiothreitol. Total cytosolic retinoic acid-binding protein was determined from specific retinoic acid binding after treatment with p-hydroxymercuribenzoate and dithiothreitol. Apo cellular retinoic acid-binding protein concentration was measured by determining specific radioligand binding prior to p-hydroxymercuribenzoate treatment, and correcting for exchange of endogenously bound retinoid with exogenous tritiated retinoic acid. Holo cellular retinoic acid-binding protein concentration was derived from the difference between total and apo retinoic acid-binding protein concentrations. Using this method, we have demonstrated that retinoid-responsive EJ and T24 human bladder carcinoma cell lines and AT3A and AT3B rat pancreatic acinar carcinoma cell lines lack detectable levels of either apo or holo cellular retinoic acid-binding protein. These results established that retinoid inhibition of transformed bladder and acinar cell proliferation in culture was mediated by a cellular retinoic acid-binding protein-independent mechanism.

Animals↗
PubMed1989

Cellular localization of fibronectin gene expression in the seminiferous tubule.

The cellular location of fibronectin expression within the seminiferous tubule was investigated in order to better understand testicular cell functions and cell-cell interactions. Peritubular cells were shown to actively synthesize and secrete fibronectin in culture by the detection of a radiolabeled 220 kDa secreted protein that is immunologically similar to fibronectin and by the quantitation of fibronectin in peritubular cell conditioned medium with a fibronectin enzyme-linked immunosorbent assay. Sertoli cells did not produce detectable levels of fibronectin when assayed by either of these procedures. A 6.5 kb fibronectin messenger RNA was detected in freshly isolated or cultured peritubular cells, but no fibronectin gene expression was detected in Sertoli cells or developing germinal cells. Combined results imply that the peritubular cells are the only apparent site of fibronectin expression within the seminiferous tubule. During the development of the testis the levels of fibronectin expression increased to a maximum at early puberty (15-day-old rats) and then slowly declined. The results demonstrate that fibronectin can be utilized as a unique functional and biochemical marker for peritubular cells when compared to other cell types in the seminiferous tubule. Production of fibronectin by peritubular cells provides an example of the ability of peritubular cells and Sertoli cells to cooperate in the production of individual components of the basement membrane of the seminiferous tubule. This cellular interaction is an example of a mesenchymal/stromal-epithelial interaction which is postulated to be important for the physiology of many tissues.

Animals↗
PubMed2004

Evolutionary origin of the medaka Y chromosome.

Genetic sex determination in an XX-XY chromosome system can be realized through a locus on the Y chromosome that makes the undifferentiated gonad develop into a testis. Although this mechanism is widespread, only in two cases so far have the corresponding master male sex-determining genes been identified. One is Sry, which initiates testes determination in most mammals. The other is dmrt1bY (syn. dmy), from the fish medaka, Oryzias latipes. The mammalian Y is roughly estimated to be over 200 million years old. The medaka Y may be considerably younger. A comparative analysis of the genus Oryzias revealed that one sister species of the medaka has dmrt1bY on a homologous Y chromosome, whereas in another closely related species only a non-sex-linked pseudogene is present. In all other species, dmrt1bY was not detected. The divergence time for the different species was determined with mitochondrial DNA sequences. The timing was confirmed by independent calculations based on dmrt1 sequences. We show that the medaka sex-determining gene originated approximately 10 million years ago. This makes dmrt1bY and the corresponding Y chromosome the youngest male sex-determining system, at least in vertebrates, known so far.

Animals↗
PubMed2004

Peri- and postnatal developmental toxicity of the fluoroquinolone antibacterial DW-116 in rats.

DW-116 is a fluoroquinolone antibacterial developed by Dong-Wha Pharmaceutical Industry Co. The aim of this study is to determine the potential adverse effects of this chemical on pregnancy, delivery and lactation of dams and on peri- and postnatal development of F1 offspring. The test chemical was orally administered to pregnant rats from day 16 of pregnancy, through parturition and throughout the period of lactation up to weaning (postnatal day 21) at dose levels of 0, 10, 50, or 250 mg/kg/day. The progeny were examined at birth and subsequently to weaning. Mortality, body weight change, physical signs of postnatal development (pinna detachment, incisor eruption, fur development, eye opening, testis descent and vaginal opening) and behavioral function (righting reflex, negative geotaxis, grip-strength, pupillary reflex, acoustic startle response, rotating rod test, open field test and water-filled T-maze test) were evaluated. When the exposed offspring reached maturity (11 weeks old) their reproductive capacity was assessed. Maternal toxicity was observed only in the highest dose group and was limited to decreased food consumption during the late stage of pregnancy. However, this change was not observed during the lactation period. There were no adverse effects on mortality, clinical signs, body weight, necropsy findings, organ weight of dams in any treatment group. No adverse effects on the offspring were seen with the low and middle doses tested, but the highest dose increased postnatal mortality. The number of stillborn was also increased at the highest dose but the difference was not statistically significant. Meanwhile, no treatment-related effects were observed in clinical sign, developmental and behavioral landmarks and necropsy findings at any dose levels tested. There were no treatment-related effects on the mating of the F1 generation and resulting F2 offspring. The results of this study indicate that the peri- and postnatal administration of DW-116 to female rats results in an increase in postnatal mortality at a minimally maternotoxic dose, i.e., 250 mg/kg/day. Under the experimental conditions, the no-observed-adverse-effect level for peri- and postnatal developmental toxicity was considered to be 50 mg/kg/day.

Administration, Oral↗
PubMed2006

Sex determination and sex reversal.

Sex determination in mammals is based on a genetic cascade that controls the fate of the gonads. Gonads will then direct the establishment of phenotypic sex through the production of hormones. Different types of sex reversal are expected to occur if mutations disrupt one of the three steps of gonadal differentiation: formation of the gonadal primordia, sex determination, and testis or ovary development.

Animals↗
PubMed2004

The transcription factor Sox9 is degraded by the ubiquitin-proteasome system and stabilized by a mutation in a ubiquitin-target site.

Sox9 is a transcription factor that is critical for chondrogenesis, testis determination, and development of several other organs in vertebrates. Thus the levels of Sox9 protein and its activity may be tightly regulated. Here we show that inhibitors of the 26S proteasome increase both the levels of Sox9 protein and its transcriptional activity measured with Col2a1 promoter/enhancer construct in RCS cells and C3H10T1/2 cells. Indeed, in intact cells ubiquitination assays indicate that Sox9 is multiply ubiquitinated. The K398A mutation, which was introduced in a potential ubiquitin-binding site, increases the stability of Sox9 protein and its transcriptional activity of Col2a1, Col11a2, and AMH promoter/enhancer constructs without affecting the subcellular localization and the DNA binding efficiency of Sox9. Pulse-chase experiments show that the increased Sox9 levels resulting from treatment with the MG132 proteasome inhibitor or from the K398A mutation produce stabilization of the protein. Our in vitro studies indicate that the ubiquitin-proteasome proteolytic system degrades Sox9 and regulates its transcriptional activity.

Animals↗
PubMed1988

Abdominal wall defects and cryptorchidism: an animal model.

Intra-abdominal pressure has been implicated in the mechanism of testicular descent. Boys born with abdominal wall defects reportedly have an increased incidence of cryptorchidism. To examine this relationship further a rat model was developed. The rat testis normally descends postnatally on or about day 21. In this study newborn male rats underwent surgical excision of all anterior abdominal musculature from the umbilicus to the xiphoid, while a control group had a sham procedure. In both groups steel wire was inserted into both testes as radiological markers to monitor descent. Animals were explored on day 28 to confirm the position of the testes. A total of 36 animals survived all sections of the protocol. Eight animals had adhesions and were dropped from the study. The results of 17 rats in the experimental group and 11 in the control group revealed that the surgically created abdominal wall defect did not result in cryptorchidism. This finding suggests that an intact anterior abdominal wall is not a prerequisite for testicular descent in the rat.

Abdominal Muscles↗
PubMed1982

The surgical management of acute bacterial epididymitis with emphasis on epididymotomy.

During the course of acute bacterial epididymitis of nonvenereal origin, severe epididymal inflammation and edema can produce compression of adjacent branches of the spermatic vessels, which can compromise the testicular vascular system. Scrotal fixation over the involved testicle heralds this event and indicates actual or impending epididymal suppuration. At this crucial moment either surgical decompression of the epididymis or epididymectomy is indicated to prevent ischemia of the testis and subsequent development of gangrenous epididymo-orchitis with testicular slough. Between 1956 and 1980, 14 epididymotomies were done, which resulted in salvage of 12 testicles (86 per cent). During the same period 10 patients with acute epididymitis had progression of the disease to gangrenous epididymo-orchitis, which necessitated orchiectomy. Epididymotomy can prevent progression of acute epididymitis to gangrenous epididymo-orchitis in many instances and is believed to have a role in the management of this troublesome affliction.

Acute Disease↗
PubMed1980

A case of polyorchidism with testicular teratoma.

A patient with duplication of the testis who presented initially with torsion of a right inguinal testis is described. Subsequently, a malignant teratoma of the trophoblastic type (choriocarcinoma) developed in the scortal testis on the right side. This scrotal testis was impalpable initially but a normal testis was present on the left side. The patient died of cerebral and pulmonary metastases of the teratoma.

Child↗
PubMed2002

Y chromosome genes and male infertility.

Normal spermatogenesis is a complex process that depends on many factors. Genetics plays a major role in many of these factors including providing a normal hormonal milieu, the development of the testis and ductal system, and control of the stepwise maturation of sperm in the testis. The Y chromosome plays a key role in testis determination and control of spermatogenesis. Understanding how these genes work together can elucidate of the exact cause of infertility in some patients once thought to have idiopathic infertility. It is not only important that patients understand the cause of their infertility. Using sperm from these men to attain pregnancies by assisted reproductive techniques will probably result in infertile male offspring. Additional consequences are currently unknown but are the topic of research investigations.

Chromosomes, Human, Y↗
PubMed1998

Expression of murine H1 histone genes during postnatal development.

Murine genes encoding the seven H1 histone isoforms H1.1-H1.5, H1(o) and H1t have been isolated and sequenced. We have established expression patterns of these genes in several tissues during postnatal development. For that analysis, RNase protection assay rather than Northern blot hybridization was used, since the sequences of these genes are highly similar and would cross-hybridize under Northern blot conditions. Expression patterns of H1.1 to H1.5 and H1(o) were determined in tissues of animals at days 5, 9 and 20 after birth and of adult mice. In addition, RNA was analyzed in three mouse cell lines (NIH3T3, P19, TM4). Transcription of the subtype genes H1.2 and H1.4 was found in all tissues and cell lines studied. The most varied expression patterns were obtained with the H1.1 subtype. H1.1 mRNA was found at high concentrations in thymus and spleen throughout development and in testis beginning with a low expression in 5-day-old animals and increasing levels in testis RNA from 9- and 20-day-old and adult mice. H1(o) mRNA was found primarily in highly differentiated tissues with concentrations decreasing from 5-day-old to adult animals.

3T3 Cells↗
PubMed1997

Molecular characterisation of ovarian cathepsin D in the rainbow trout, Oncorhynchus mykiss.

In fish, cathepsin D, an aspartyl protease, is believed to mediate the processing of yolk proteins in the oocyte. Cathepsin D, therefore, is vital for the production of a viable egg. This study set out to isolate and sequence the cDNA encoding cathepsin D, and to determine the developmental expression of the message in the ovary and subsequently during embryogenesis in the rainbow trout, Oncorhynchus mykiss. The full-length trout cathepsin D cDNA is 1847 base pairs (bp) long, encoding a protein of 400 amino acids (aa). The sequence consists of a putative signal peptide of 18 aa, a prosequence extending 46 aa and a mature peptide of 336 aa. The deduced sequence of rainbow trout ovarian cathepsin D shows significant homology with cathepsin D in mammals (human; 81% aa similarity), in the chicken (80% aa similarity) and in Xenopus (74% aa similarity). Our data support the contention that the primary structure of cathepsin D is highly conserved across the vertebrate phyla, from mammals to fish. Unlike cathepsin Ds in other species, however, rainbow trout cathepsin D appears to have only one putative N-glycosylation site, rather than two. The mRNA for 'ovarian' cathepsin D was expressed in both ovarian and non-ovarian tissues (liver, muscle, spleen and testis). During the development of the ovary, the highest expression levels of cathepsin D mRNA were seen at around the onset of vitellogenesis, a time when the oocytes are starting to sequester large quantities of yolk proteins. Northern hybridisation did not detect cathepsin D mRNA in either unfertilised eggs, or in fertilised eggs until after gastrulation, indicating that there is little, if any, de novo synthesis of this message at these stages of development. However, the mRNA for cathepsin D was detectable at the eyed embryo stage, and the expression of the gene increased towards the end of embryonic development.

Amino Acid Sequence↗
PubMed1999

NIMA-related kinases: isolation and characterization of murine nek3 and nek4 cDNAs, and chromosomal localization of nek1, nek2 and nek3.

The Aspergillus NIMA kinase plays a key role in controlling entrance into mitosis, and recent evidence suggests that mammalian NIMA-related kinases perform similar functions. We report here the cloning of the mouse nek3 and nek4 genes. Mouse nek3 is probably the ortholog of the partially sequenced, human nek3, whereas murine nek4 cDNA is probably the ortholog of human STK2. Nek4 is highly conserved between mouse and human, whereas Nek3 is somewhat less conserved (96.5 and 88% identity in the kinase domains, respectively). Northern analysis shows preferential expression of nek3 in mitotically active tissue, whereas nek4 is highly abundant in the testis. Within the developing testicular germ cells, in-situ analysis demonstrated that nek1, 2 and 4 exhibit differential patterns of expression, suggesting overlapping, but non-identical functions. Linkage analysis, using the mouse recombinant inbred strain panel (BXD), was used to localize nek1, 2 and 3. nek1 was mapped between Cpe and D8Mit8 on chromosome 8 at around 32cM, nek2 was mapped to the distal region of chromosome 1, and nek3 was mapped to the most centromeric region of chromosome 8.

Amino Acid Sequence↗
PubMed1998

The use of testosterone as a male contraceptive.

Testosterone functions as a contraceptive by suppressing secretion of the pituitary gonadotropins luteinizing hormone and follicle stimulating hormone. Low levels of these hormones decrease endogenous testosterone secretion from the testis and deprive developing sperm of the signals required for normal maturation. Interference with sperm maturation causes a decline in sperm production and can lead to reversible infertility in men, raising the possibility that testosterone could be utilized in a commercially available contraceptive. To this end, testosterone has been studied alone and in combination with either gonadotropin releasing hormone analogues or progestins in efforts to improve its contraceptive efficacy. In this chapter, we will review efforts to use testosterone to create a safe, convenient, efficacious contraceptive method for men.

Contraception↗
PubMed2000

Surveillance for stage I testicular germ cell tumours: results and cost benefit analysis of management options.

Between 1979 and 1996 303 men with stage I testicular germ cell tumours (120 seminoma and 183 non-seminomatous germ cell tumours (NSGCT)) were enrolled onto a programme of surveillance. In our institutions the frequency of computed tomography (CT) scans is reduced compared with other centres. For all 303 men, the median follow-up is 5.1 years (range: 0.1-21.7 years) and there have only been 3 deaths (1 from disease, 1 from neutropenic sepsis and 1 from secondary leukaemia). 52/183 (28%) patients with NSGCT and 18/120 (15%) patients with seminoma have relapsed. The relapse-free survival at 5 years is 82% for seminoma and 69% for NSGCT (Logrank P=0.004). All men who relapsed, except 1 man with NSGCT, were in the International Germ Cell Cancer Collaborative Group good or intermediate prognosis group at relapse. Half of the seminoma relapses presented with symptoms and 31% of the NSGCT relapses. The remaining relapses were detected serologically or radiologically by the surveillance programme. 5 men (2%) on surveillance, 3 with initial diagnosis of seminoma and 2 with NSGCT, have developed second contralateral testis tumours (all stage I seminomas). In a well motivated centre a policy of surveillance for stage I testicular germ cell tumours (both NSGCT and seminoma) is associated with a low mortality rate (3/303, 1%) and may have the advantage of sparing overtreatment with potentially toxic therapies in this group of young men.

Adolescent↗