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Selective expression of the scaffold protein JSAP1 in spermatogonia and spermatocytes.

Scaffold proteins of mitogen-activated protein kinase (MAPK) intracellular signal transduction pathways mediate the efficient and specific activation of the relevant MAPK signaling modules. Previously, our group and others have identified c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinase-associated protein 1 (JSAP1, also known as JNK-interacting protein 3) as a scaffold protein for JNK MAPK pathways. Although JSAP1 is expressed in the testis in adults, its expression during development has not been investigated. In addition, it is unknown which types of cells in the testis express the scaffold protein. Here, we examined the expression of JSAP1 in the testis of mice aged 14 days, 20 days, 6 weeks, and 12 weeks by immunohistochemistry and Western blotting. The specificity of the anti-JSAP1 antibody was evaluated from its reactivity to exogenously expressed JSAP1 and a structurally related protein, and by antigen-absorption experiments. The immunohistochemical analyses with the specific antibody showed that the JSAP1 protein was selectively expressed in the spermatogonia and spermatocytes, but not in other cell types, including spermatids and somatic cells, during development. However, not all spermatogonia and spermatocytes were immunopositive either, especially in the 12-week-old mouse testis. Furthermore, we found by Western blotting that the expression levels of JSAP1 protein vary during development; there is high expression until 6 weeks after birth, which approximately corresponds to the end of the first wave of spermatogenesis. Collectively, these results suggest that JSAP1 function may be important in spermatogenic cells during early postnatal development.

Adult↗

NXP-1, a human protein related to Rad21/Scc1/Mcd1, is a component of the nuclear matrix.

Nuclear matrix is a complex intranuclear network supposed to be involved in the various nuclear functions. In order to identify the nuclear matrix proteins, we isolated a cDNA clone from a human placenta cDNA library. This clone was partially represented a known cDNA clone HA1237. HA1237 encoded a 631-amino-acid peptide, which we designated NXP-1. NXP-1 was related to yeast Rad21/Scc1/Mcd1, Xenopus XRAD21, and mouse PW29, and identical with HR21spA isolated from a human testis cDNA library. We developed a polyclonal antibody to the purified NXP-1 bacterially expressed as a fusion protein with GST. Western blot analysis with anti-NXP-1 polyclonal antibody showed nuclear matrix localization of NXP-1 in HeLa cells. Indirect immunofluorescence staining also showed nuclear and nuclear matrix localization of the NXP-1. Results of in vitro binding assays employing nuclear matrix preparations indicated that the N-terminal region (16-128 amino acid) of NXP-1 has an important role in nuclear matrix distribution.

Amino Acid Sequence↗

[Investigation of toxicity through human cases and animal experiments--study of bromopropanes].

In 1995, workers in a Korean electronic factory exhibited oligospermia or amenorrhea. We investigated the toxicity of 2-bromopropane used as an alternative to chlorofluorocarbons in the factory in animal experiments, and clarified that exposure to 2-bromopropane depletes spermatogenic cells in male rats and oocytes in female rats. Subsequently, we investigated the neurotoxicity of 2-bromopropane on the basis of the reported neuropathy in the Korean workers exposed to 2-bromopropane. For comparison, we employed 1-bromopropane, which is now used as a new alternative to chlorofluorocarbons. The results showed that 1-bromopropane is more neurotoxic than 2-bromopropane, causing harm to reproductive organs by inhibiting spermiation in the testis and impairing follicular development in the ovary. Shortly after the initial investigation of 1-bromopropane in animals, human cases were reported in the United States. Neurologic abnormalities in Chinese workers exposed to 1-bromopropane were also reported, such as the elongation of distal latency and lowered sense of vibration in the lower limbs. Thus, these serial studies revealed that 1-bromopropane is neurotoxic, but its dose-response relationship in humans remains unknown. In the investigation of 2-bromopropane toxicity, initial animal studies were designed on the basis of human studies, while in research on 1-bromopropane, animal studies preceded human studies and contributed to the prediction of toxicity in humans. However, the use of animal model is limited in its ability to predict the toxicity of chemicals introduced depending on species differences. Further studies should focus more on the differences and commonality between animals and humans in response to toxic agents.

Animals↗

Follicle-stimulating hormone regulates both Sertoli cell and spermatogonial populations in the adult photoinhibited Djungarian hamster testis.

The hormones that regulate spermatogonial development are ill defined, in part due to lack of appropriate experimental models. The photoinhibited hamster model provides a rich source of spermatogonia, thus making it an ideal model to study their control. This study aimed to assess the effects of FSH, in the absence of testosterone, on the reinitiation of Sertoli cell and spermatogonial development in the photosensitive adult Djungarian hamster. Hamsters raised under long photoperiods (LD, 16L:8D) were exposed to short photoperiods (SD, 8L:16D) for 11 wk, leading to suppression of gonadotropins and regression of testicular function. Groups of 10 animals then received FSH alone or in combination with the antiandrogen, flutamide, for 7 days. Two control groups maintained either under long or short photoperiods were treated with vehicle. Sertoli and germ cell number were then determined using the optical disector (sic) stereological technique. The number of Sertoli cells, type A spermatogonia, type B spermatogonia/preleptotene spermatocytes, and leptotene/zygotene spermatocytes were suppressed in SD controls to 66%, 34%, 19%, and 10% (all P < 0.01) of long-day control values, respectively. Later germ cell types were not detected. FSH treatment, with or without flutamide, increased Sertoli cell number (P < 0.01) to normal long-day values. Similarly, FSH treatment in the absence/presence of flutamide increased type A spermatogonia, type B spermatogonia/preleptotene spermatocytes, and leptotene/zygotene spermatocytes to approximately 85%, 69%, and 80% (all P < 0.01) of long-day controls, respectively. Our data demonstrate that the reinitiation of spermatogonial maturation in this model is dependent on FSH in the presence of an antiandrogen. Surprisingly, the adult Sertoli cell population in this model is also hormone dependent. This naturally occurring model provides a unique opportunity to understand the mechanisms (apoptotic and/or proliferative) by which FSH regulates Sertoli and germ cell development in the adult animal.

Androgen Antagonists↗

Development of interstitial cells in experimentally sex-reversed gonads of genetically female chick embryos.

A testis graft implanted in young genetically female embryos induced a male gonadal differentiation. The interstitial cell percentage and actual content were strongly lowered in masculinized gonads compared to normal female embryos and became similar to those observed in the normal developing embryonic testis. This effect was enhanced by the association of a graft and an antiestrogenic drug, and was not observed after administration of the drug alone. This inhibiting influence of the graft on interstitial cell formation may be considered as resulting in an inhibition of estrogen production. Its possible causative role in gonadal masculinization is discussed in the light of previous and present results.

Animals↗

Expression of a testis-specific form of TBP-related factor 2 (TRF2) mRNA during mouse spermatogenesis.

The gene encoding TATA-binding protein-related factor 2 (TRF2/TLF/TLP/TRP), essential for the progress of spermiogenesis, is abundantly expressed in mammalian testis. A sequence database search revealed that mouse TRF2 is encoded by two mRNAs containing the same protein-coding region and different 5'-untranslated regions. Northern blot analysis using DNA probes specific for the 5'-untranslated regions demonstrated that these two mRNAs are distinguished from each other by the expression patterns: ubiquitous and testis-specific expression. The ubiquitously expressed form of TRF2 mRNA was present at a very low level throughout testicular development, whereas expression of the testis-specific form was first detectable in the 14-day-old testis, and the mRNA level abundantly increased at the later stages of testicular development. Western blot analysis indicated that the TRF2 level increases during testicular development, which is consistent with the expression pattern of the testicular form of TRF2 mRNA. Thus, the presence of the testis-specific form of TRF2 mRNA may account for overexpression of the TRF2 gene in the testis.

5' Untranslated Regions↗

Reversal of vasectomy.

Vasovasostomy to reverse a previous vasectomy for sterilization was attempted for 27 men, the procedure being technically impossible in only one case. A testicular biopsy was performed at the time of operation and a number were investigated for cell-mediated immunity to sperm and for the presence of circulating sperm-agglutinating and cytotoxic antibodies. The first 17 cases have been studied and of these there have been 11 pregnancies, ten of which have already come to term with the birth of normal infants, including one set of twins. Of the rest, two are known to have oligozoospermia and four have been lost to follow-up, although two of them were euspermic when last examined. In spite of these encouraging results, it is considered that there are no grounds for alterning the present basis of vasectomy counseling which is that the operation is likely to be irreversible.

Adult↗

Molecular cloning and characterization of mouse EBAG9, homolog of a human cancer associated surface antigen: expression and regulation by estrogen.

We previously identified a human estrogen-responsive gene, EBAG9 (ER-binding fragment-associated antigen9) (Watanabe, T. et al., Mol. Cell. Biol. 18, 442-449, 1998). It was later reported as RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) that induced apoptosis and suppressed the growth of several cells such as activated T cells (Nakashima, M. et al., Nat. Med. 5, 938-942, 1999). Here, we have isolated both cDNA and genomic DNA of mouse EBAG9/RCAS1. Mouse EBAG9 gene spans about 30 kb in genomic DNA and consists of 7 exons. Mouse EBAG9 cDNA encodes a protein that contains the transmenbrane segment and coiled-coil domain. An alignment between the predicted mouse and human EBAG9 shows a high degree of homology at the amino acid level (98%). Northern and Western blot analyses demonstrate that EBAG9 is expressed in several tissues including the heart, brain, spleen, liver, kidney, and testis, and also in developing embryo. In the uterus, a target organ for estrogen, the EBAG9 was shown to be upregulated in vivo by 17beta-estradiol. To determine the biological action of mouse EBAG9, NIH3T3 fibroblastic cells were incubated with recombinant EBAG9 protein, resulting in suppression of cell growth. These findings suggest that EBAG9 is an in vivo estrogen-responsive gene that inhibits the cell growth.

3T3 Cells↗

A carcinoid occurring in the testis.

Carcinoids of the testis are rare tumours developing in three different ways: 1. It may differentiate within a teratoma, 2. it may be a metastasis of a "loco alieno" seated carcubiud abd 3. it may represent a real primary carcinoid. The observation of a primary testicular carcinoid in a man aged 55 years afforded the opportunity to study such a tumor for the first time by electron microscopic and fluorescence microscopic methods. Thereby, it could bw shown, that this testicular carcinoid corresponds to the carcinoids of the lower small gut. According to the specific ultrastructure of the intracytoplasmic granules it must derive histogenetically from an EC-cell. At the moment it cannot be decided whether the primary testicular carcinoid represents an autochthonous tumor of the male gonad or solely a teratoma with one-sided differentiation in the sense of a simplified teratoma.

Carcinoid Tumor↗

Respiratory syncytial virus, a rare cause of severe pneumonia following bone marrow transplantation.

Mixed alveolar interstitial pneumonia is a much-feared complication in bone marrow transplant recipients because it carries a high mortality. Many cases in which an etiological agent is identified are due to fungi or cytomegalovirus; rarely, other infectious agents such as Pneumocystis carinii or (para)influenzavirus are involved. In this report we describe a patient who received intense chemotherapy followed by autologous bone marrow transplantation for relapse of testis seminoma and who developed a severe alveolar interstitial pneumonia caused by respiratory syncytial virus in the early posttransplant period. The patient fully recovered after treatment with ribavirin.

Adult↗

Initial experiences of a testicular sperm extraction programme for assisted reproduction in Ireland.

BACKGROUND: The technique aspirating spermatozoa from the testis is a new development in male infertility treatment. It is appropriate for infertile couples where the male has azoospermia but is still producing live motile spermatozoa in the testes. AIM: To describe the initial experiences of a testicular sperm extraction programme (TESE) coupled with intracytoplasmic sperm injection (ICSI) in 18 men during 1998. METHODS: Spermatozoa were obtained by direct aspiration from the testes using a 16 gauge needle with cannula and negative suction under local anaesthetic. All samples obtained were to be cryopreserved for use in a subsequent ICSI cycle. RESULTS: All five men with congenital bilateral absence of the vas deferens to be carriers of cystic fibrosis gene mutations. No gene deletions were found in their wives. No other cyto or molecular genetic abnormalities were otherwise found. Twenty one procedures were carried out. The mean number of aspirations was 1.72. Eleven samples from 10 men had sperm suitable for ICSI post-freeze. Post-procedure pain was the universal side-effect. Eight couples had a single attempt at ICSI, two couples two each. Fertilisation rate was 71.4%. Two pregnancies were achieved. CONCLUSION: TESE may give hope in selected cases of azoospermia of fathering a child without the involvement of a third party.

Adult↗

Spermatocytic seminoma.

A case is reported of a forty-four-year-old man with spermatocytic seminoma with no evidence of metastasis for twelve years. This patient is the second to have undergone retroperitoneal lymph node dissection and the third to have histopathologic examination of these lymph nodes. Review of 52 cases of spermatocytic seminoma disclosed 70 per cent of patients were over fifty years of age; none developed in a cryptorchid testis, none occurred in associated with teratoma, and there was no histopathologic evidence of metastasis. Whether or not radiation therapy is necessary is questionalbe. Prognosis appears to be good if not better than in classic seminoma. Available data indicate that spermatocytic and classic seminoma are two distinct neoplasms with different histogenesis and pathologic, clinical, and biologic features.

Adult↗

The juvenile three-spined stickleback (Gasterosteus aculeatus L.) as a model organism for endocrine disruption. I. Sexual differentiation.

Juvenile three-spined stickleback (Gasterosteus aculeatus L.) is introduced as a unique model organism for both androgenic and oestrogenic endocrine action. Intersex is often used as an indicator for disruption of sexual differentiation in fish exposed to different kinds of effluents from human activities. In wild fish it has exclusively been reported in terms of feminisation due to xenoestrogens in the environment. The assumption that the intersex individuals are feminised genetic males can only be proven by genetic sex identification of the intersexual individuals. Intersex and gonadal sex reversal were induced in three-spined sticklebacks by treatment with natural and synthetic steroid hormones. Juvenile sticklebacks were exposed to three nominal concentrations of 17 beta-oestradiol (E2); i.e. 0.01, 1.0 and 10.0 microg/L; which were administered to the water either continuously from hatching to the end of the experiment (39-58 days post hatch), during the first 2 weeks after hatching only, from 14 days after hatching onwards, or during the chorionated embryo stage until hatching. Other groups were exposed to 17 alpha-ethinylestradiol (EE2) at 0.05 microg/L and 17 alpha-methyltestosterone (MT) at 1.0 microg/L (nominal concentrations). MT was applied continuously, during the first 2 weeks post hatch only, or from 14 days after hatching onwards. Gonad histology was examined and the genetic sex was identified with male sex-linked PCR markers. Treatment with oestrogens caused feminisation at the two highest E2 concentrations and with EE2. Exposure to E2 before hatching had no effect. Intersexual individuals from oestrogen treatments were genetic males. The genetic sex marker identified apparent total reversal of the gonad type of genetic males. Treatment with MT did not reveal a clear picture, since intersex was observed in both genetic females and males. MT also caused severe testis abnormalities, mainly the development of large branched cavities with unidentified origin. The process of sex differentiation is most sensitive to the influence of external steroids during the first 2 weeks after hatching. A lower incidence of intersex could also be induced in sticklebacks exposed from 14 days after hatching by E2 treatment, but not with MT. The combination of gonad histopathology with genetic sex identification in juvenile sticklebacks is suggested as a tool for detecting endocrine disruption in laboratory studies, and might become very useful in field surveys.

Analysis of Variance↗

Short-type PB-cadherin promotes survival of gonocytes and activates JAK-STAT signalling.

Neonatal development of the rat testis involves a number of critical events including re-entry of gonocytes into the cell cycle and eventual loss of many of these cells and their progeny via apoptosis. Since surviving gonocytes give rise to subsequent generations of germ cells, regulation of their fate is critical for adult testicular function. Here, we have identified a role for short-type PB-cadherin (STPB-C) in promoting survival of gonocytes in neonatal rats and we have linked its expression to the JAK-STAT signaling pathway. These findings were obtained with varied approaches including use of transgenic rats overexpressing STPB-C which were studied with protein microarrays and other techniques, direct examination of germ cell apoptosis and survival in gonocyte-Sertoli cell co-cultures, and direct study of the JAK-STAT pathway in these models and in L cells transfected with STPB-C. These data provide new information on the regulation of gonocyte fate and exciting new evidence supporting a link between the JAK-STAT pathway and cadherin-based cell-cell interactions.

Animals↗

Sox9 is required for notochord maintenance in mice.

Sox9 encodes a HMG-box transcription factor that has been implicated in numerous developmental processes including chondrogenesis, formation of cardiac valves, and neural crest, testis and spinal cord development. Here we show that Sox9 is expressed in the notochord and the sclerotome during mouse development suggesting that the gene may play additional roles in the development of the axial skeleton. We used ubiquitous mosaic inactivation of a conditional Sox9 allele by Cre/loxP-mediated recombination in the mouse to screen for novel functions of Sox9, and revealed that its absence results in severe malformations of the vertebral column. Besides its established role in chondrogenesis, Sox9 is required for maintaining the structural integrity of the notochord. Mutant embryos establish a normal notochord; however, starting from E9.5, the notochord disintegrates in a cranial to caudal manner. The late requirement in notochord development uncovered a function of notochord-derived signals in inducing segmentation of the ventral sclerotome and chondrogenesis. Thus, Sox9 is required for axial skeletogenesis by regulating notochord survival and chondrogenesis.

Animals↗