Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “mouse testis”

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 163 records · Page 9Linked to original sources
PubMed1995

Characterization of a novel spermatogenic cell antigen specific for early stages of germ cells in mouse testis.

To study the mechanism of spermatogenesis during the premeiotic phase, a hybridoma producing monoclonal antibody (mAb) specific for early stages of spermatogenic cells was obtained. In immunohistochemical staining of adult testis, this mAb, designated as EE2, was able to react with type A to B spermatogonia and early meiotic cells, but not with Sertoli cells, Leydig cells, and other somatic tissues. Precursor cells of type A spermatogonia (gonocytes) were also positive for EE2 in perinatal mouse testis. The antigenic molecule recognized by mAb EE2 was a novel glycoprotein with molecular weight of 114 kDa, which had affinity with Con A and WGA lectins, and was susceptible to N-glycanase, suggesting the presence of asparagine-linked sugar chains. Furthermore, EE2 antigen was found to localize on the germ cell surface. The specific expression of this antigenic molecule suggests that it may play an important role in early spermatogenesis, of which only a little information is available at present.

Animals↗
PubMed2000

Expression of the leptin receptor during germ cell development in the mouse testis.

Leptin, a recently identified hormonal product of the ob gene, is known to regulate appetite, body metabolism, and reproductive functions. We investigated the expression of the leptin receptor (Ob-R) in testes from different age groups. The messenger RNA for Ob-R was found in testes from all age groups using RT-PCR. Using immunohistochemistry, we observed age- and stage-dependent distribution of the Ob-R in mouse testis. In testis of 5-day-old mice, its expression was mainly in type A spermatogonia. In the 20- and 30-day-old testis, Ob-R expression was in the spermatocytes; in the adult testis, it was specific to spermatocytes in stages IX and X of the cycle of the seminiferous epithelium. Five main immunoreactive proteins were detected using Western blot (220, 120, 90, 66, and 46 kDa). The 120-kDa protein was evident only in 20-day-old and older testes, whereas the 90-kDa band was present only in the 5- and 10-day-old testis. Leptin treatment induced phosphorylation of signal transducer and activator of transcription-3 in cultured seminiferous tubules from adult and 5-day-old testes. Our results show for the first time age- and stage-specific localization of a functional Ob-R in testicular germ cells. We hypothesize a direct role for leptin, through phosphorylation of signal transducer and activator of transcription-3, in proliferation and differentiation of germ cells, which may partially explain the infertility observed in leptin-deficient mice.

Aging↗
PubMed2005

The telomerase activity of adult mouse testis resides in the spermatogonial alpha6-integrin-positive side population enriched in germinal stem cells.

Testis is one of the organs with the most telomerase activity in the adult. This activity protects chromosomes from telomere attrition and ensures the transmission of full-length chromosomes to progeny. Little is known about telomerase activity during adult germ cell differentiation, however. We demonstrate here that the telomerase activity of adult mouse testis resides in the alpha6-integrin-positive Side Population containing spermatogonia and enriched in spermatogonial stem cells. The telomerase activity of these cells fell upon entry into meiosis and during the subsequent spermiogenesis. In addition, the telomerase activity of cells in various stages of differentiation was unaffected by aging and, notably, remained high in the alpha6-integrin-positive Side Population.

Age Factors↗
PubMed2003

The protein of a new gene, Tctex4, interacts with protein kinase CK2beta subunit and is highly expressed in mouse testis.

Casein kinase 2 (CK2) is a ubiquitous, multifunctional eukaryotic serine/threonine kinase that phosphorylates an array of proteins. CK2 is a heterotetramer composed of two catalytic (alpha,alpha(')) and two regulatory (beta) subunits. CK2 plays an essential role in regulatory pathways in cell transformation and proliferation. But the role and function of the individual subunits of CK2, which are not in the holoenzyme, are not yet clear. Northern blot analysis reveals the highest CK2beta activity in mouse testicles and brain. By employing a yeast two-hybrid screen to identify the proteins that interact with CK2beta, we have isolated a cDNA clone encoding a 14-kDa protein with homology to dynein light chains and have designated it as Tctex4. CK2beta interacts specifically with Tctex4 both in a yeast two-hybrid system and in an in vitro interaction assay. Northern blot and in situ hybridization showed that Tctex4 is a novel gene that is expressed in mouse testis.

Amino Acid Sequence↗
PubMed2006

Expression of hedgehog signalling components in adult mouse testis.

Hedgehog (Hh) signalling is known to regulate many aspects of normal development as well as being upregulated in various cancers. Signalling is mediated by the Gli family of zinc finger transcription factors. Based on observations that deletion of one of the three Hh genes, Dhh, leads to male infertility, we hypothesized that regulated expression of Hh signalling components would be a feature of adult spermatogenesis. We used in situ hybridization to characterise Gli gene expression in juvenile and adult mouse testes. In the first wave of spermatogenesis, mRNAs encoding all three Glis are detected in spermatogonia and Sertoli cells. In adult mouse testes, these transcripts are observed in spermatogonia and spermatocytes, with reduced signal intensity in round spermatids. The mRNAs encoding key effectors of Hh signalling, Ptc2, Smo, and Fu, are also most apparent in spermatogonia, spermatocytes, and to a lower extent in round spermatids. In contrast, mRNA encoding SuFu, a negative regulator of Hh signalling, was most predominant in round spermatids and the protein is evident in round and elongating spermatids, suggesting that SuFu protein may switch off Hh signalling in haploid germ cells. Overall, the coordinated expression pattern of these genes in adult mouse testis indicates a role for Hh signalling in spermatogenesis.

Animals↗
PubMed1992

In situ localization of male germ cell-associated kinase (mak) mRNA in adult mouse testis: specific expression in germ cells at stages around meiotic cell division.

Biochemical analysis of the male germ cell-associated kinase (mak) gene, which was isolated recently by using weak cross-hybridization with the v-ros tyrosine kinase gene, revealed that the gene was highly expressed in mammalian testicular germ cells, but not in ovarian cells. In order to identify the cells which express the mak gene in more detail, we localized mak mRNA in frozen sections of mouse testis by non-radioactive in situ hybridization. In this study, we utilized thymine-thymine (T-T) dimerized mak cDNA as a haptenic, non-radioactive probe, and the signal was detected enzyme-immunohistochemically by using an anti-T-T antibody. As a result, mak mRNA was localized intensely in late pachytene (stage X) and diplotene (stage XI) spermatocytes, and faintly in dividing spermatocytes (stage XII) and early round spermatids (stage I-II), suggesting that the gene may play an important role in the phase around meiotic cell division, but not throughout the entire meiosis.

Animals↗
PubMed1994

Structural analysis of transcripts for the protein L-isoaspartyl methyltransferase reveals multiple transcription initiation sites and a distinct pattern of expression in mouse testis: identification of a 5'-flanking sequence with promoter activity.

The gene encoding the protein L-isoaspartyl-(D-aspartyl) methyltransferase (protein carboxyl methyltransferase, PCMT) is widely expressed in bacteria and eucaryotic cells. An antisense probe encompassing the first exon of the murine PCMT gene [E. A. Romanik, C. L. Ladino, S. C. D'Ardenne, and C. M. O'Connor (1992) Gene 118, 217-222] was used in ribonuclease protection assays to identify the initiation sites for PCMT transcription in mouse testis, brain, and liver tissues. Two major initiation sites, 155-157 nucleotides (nt) and 119 nt upstream from the ATG initiation codon, were identified in all tissues in addition to several minor sites. The locations of the initiation sites in testicular RNA were confirmed using ligation-mediated 5'-rapid amplification of cDNA ends (RACE). These initiation sites are situated at the 3'-end of a 407-bp genomic sequence which is sufficient to drive the expression of a firefly luciferase gene in transient transfection assays with NIH/3T3 cells. The 407-bp sequence resembles a housekeeping gene promoter in its high G+C content, lack of a TATA box and the presence of multiple potential binding sites for the transcription factors Sp1 and ETF. Alternative splicing in the C-terminal encoding sequence and in the 3'-untranslated regions of PCMT transcripts generates three distinct classes of mRNAs which were cloned from testicular poly(A)+ RNA using 3'-RACE. Transcript splicing either 38 nt downstream or 7 nt upstream from the termination codon in exon 7 produces mRNAs encoding PCMT isozymes with -RWK or -RDEL, respectively, at their C-termini. The predominant transcript in testis, which is not detected in somatic tissues by Northern blotting and which may be specific to germ cells, is not spliced within exon 7 and also encodes the -RWK isozyme.

3T3 Cells↗
PubMed1994

Developmental and cell type specificity of LINE-1 expression in mouse testis: implications for transposition.

The LINE-1, or L1, family of interspersed repeated DNA constitutes roughly 10% of the mammalian genome. Its abundance is due to duplicative transposition via an RNA intermediate, L1-encoded proteins, and reverse transcription. Although, in principle, transposition may occur in any cell type, expression and transposition of a full-length functional element in the germ line are necessary to explain the evolutionary genetics of L1. We have found differential expression of L1 protein and RNA in germ and somatic cells of the mouse testis during development. Of particular interest is the coexpression of full-length, sense-strand L1 RNA and L1-encoded protein in leptotene and zygotene spermatocytes at postnatal day 14 of development. Expression in meiotic prophase precedes the strand breakage that occurs during chromosomal recombination; this offers an avenue for L1 insertion into new locations in chromosomal DNA in a cell type that ensures L1 propagation in future generations.

Aging↗
PubMed1995

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

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

Animals↗
PubMed2003

Proliferation and differentiation of spermatogonial stem cells in the w/wv mutant mouse testis.

Mutations in the dominant-white spotting (W; c-kit) and stem cell factor (Sl; SCF) genes, which encode the transmembrane tyrosine kinase receptor and its ligand, respectively, affect both the proliferation and differentiation of many types of stem cells. Almost all homozygous W or Sl mutant mice are sterile because of the lack of differentiated germ cells or spermatogonial stem cells. To characterize spermatogenesis in c-kit/SCF mutants and to understand the role of c-kit signal transduction in spermatogonial stem cells, the existence, proliferation, and differentiation of spermatogonia were examined in the W/Wv mutant mouse testis. In the present study, some of the W/Wv mutant testes completely lacked spermatogonia, and many of the remaining testes contained only a few spermatogonia. Examination of the proliferative activity of the W/Wv mutant spermatogonia by transplantation of enhanced green fluorescent protein (eGFP)-labeled W/Wv spermatogonia into the seminiferous tubules of normal SCF (W/Wv) or SCF mutant (Sl/Sld) mice demonstrated that the W/Wv spermatogonia had the ability to settle and proliferate, but not to differentiate, in the recipient seminiferous tubules. Although the germ cells in the adult W/Wv testis were c-kit-receptor protein-negative undifferentiated type A spermatogonia, the juvenile germ cells were able to differentiate into spermatogonia that expressed the c-kit-receptor protein. Furthermore, differentiated germ cells with the c-kit-receptor protein on the cell surface could be induced by GnRH antagonist treatment, even in the adult W/Wv testis. These results indicate that all the spermatogonial stem cell characteristics of settlement, proliferation, and differentiation can be demonstrated without stimulating the c-kit-receptor signal. The c-kit/SCF signal transduction system appears to be necessary for the maintenance and proliferation of differentiated c-kit receptor-positive spermatogonia but not for the initial step of spermatogonial cell differentiation.

Animals↗
PubMed1988

Treatment with an LHRH agonist or hCG increases interstitial fluid volume and permeability to Evans blue in the mouse testis.

Treatment of adult mice with 1 microgram of an LHRH-agonist or with 5 i.u. hCG, subcutaneously, resulted in an increase in the permeability to intravenously injected Evans blue into the testicular interstitial space and in the volume of testicular interstitial fluid. These changes are probably related to an increase in vascular permeability but, in contrast to the situation in rats, this was accompanied neither by an accumulation of polymorphonuclear leucocytes in testicular blood vessels nor by the formation of large inter-endothelial cell gaps in postcapillary venules. The mechanisms mediating the gonadotrophin-induced increase in vascular permeability in the mouse testis thus remain unknown.

Animals↗
PubMed1990

Identification of interleukin-1 receptors in mouse testis.

The cytokine interleukin-1 (IL-1) has been reported to alter reproductive functions through both effects in brain and direct actions at the level of the gonads. To further define the role of IL-1 at the gonads, we have used 125I-labeled recombinant human IL-1 to identify and characterize IL-1 receptors in crude membrane preparations of mouse (C57BL/6) testis and to study the distribution of IL-1-binding sites using autoradiography. In preliminary homogenate binding and autoradiographic studies, [125I]IL-1 alpha showed significantly higher specific binding than [125I]IL-1 beta. Thus, [125I]IL-1 alpha was used in all subsequent assays. The binding of [125I]IL-1 alpha was linear over a broad range of membrane protein concentrations, saturable, and reversible, and on Scatchard analysis revealed an equilibrium dissociation constant (Kd) of 82 +/- 4 pM and a maximum number of binding sites (Bmax) of 10.8 +/- 1.5 fmol/mg protein. In competition studies, IL-1 alpha, IL-1 beta, and a weak IL-1 beta analog IL-1 beta+ inhibited [125I]IL-1 alpha binding to mouse testis in parallel with their relative bioactivities in immune assays, with inhibitory binding affinity constant (Ki) values of 14.2 +/- 1.7, 88.8 +/- 5.7, and 7183.3 +/- 603 pM, respectively; rat/human CRF and human tumor necrosis factor showed no effect on [125I]IL-1 alpha binding. In autoradiographic studies, IL-1 receptors were heterogeneously distributed, with highest densities present in the luminal border of the epididymis and interstitial areas of the testis. After hypophysectomy, the testes were significantly atrophied, and homogenate binding and autoradiographic studies showed that while the total number of binding sites per testis was significantly decreased in hypophysectomized mice in proportion to the reduction in testicular mass, there was no apparent change in the relative density of IL-1 receptors. These data provide the first identification of IL-1 receptors in testis and provide further support for a physiological role for IL-1 to alter reproductive functions through a direct effect at the gonads.

Animals↗
PubMed2000

Molecular cloning and biochemical characterization of a new mouse testis soluble-zinc-metallopeptidase of the neprilysin family.

Because of their roles in controlling the activity of several bio-active peptides, members of the neprilysin family of zinc metallopeptidases have been identified as putative targets for the design of therapeutic agents. Presently, six members have been reported, these are: neprilysin, endothelin-converting enzyme (ECE)-1 and ECE-2, the Kell blood group protein, PHEX (product of the phosphate-regulating gene with homologies to endopeptidase on the X chromosome) and X-converting enzyme (XCE). In order to identify new members of this important family of peptidases, we designed a reverse transcriptase-PCR strategy based on conserved amino acid sequences of neprilysin, ECE-1 and PHEX. We now report the cloning from mouse testis of a novel neprilysin-like peptidase that we called NL1. NL1 is a glycoprotein that, among the members of the family, shows the strongest sequence identity with neprilysin. However, in contrast with neprilysin and other members of the family which are type II integral membrane proteins, NL1 was secreted when expressed in cultured mammalian cells, likely due to cleavage by a subtilisin-like convertase at a furin-like site located 22 amino acid residues in the C-terminus of the transmembrane domain. The recombinant enzyme exhibited neprilysin-like peptidase activity and was efficiently inhibited by phosphoramidon and thiorphan, two inhibitors of neprilysin. Northern blot analysis and in situ hybridization showed that NL1 mRNA was found predominantly in testis, specifically in round and elongated spermatids. This distribution of NL1 mRNA suggests that it could be involved in sperm formation or other processes related to fertility.

Amino Acid Sequence↗
PubMed1999

An in vitro tubule assay identifies HGF as a morphogen for the formation of seminiferous tubules in the postnatal mouse testis.

We have been working with a recently immortalized Sertoli cell line, SF7, that appears to produce sleeves, or hollow tubules, when cultivated on a layer of growth factor-reduced Matrigel (GFR-Matrigel) in medium supplemented with serum. We tried to determine which components of GFR-Matrigel and serum provide the environment needed for tubule formation. While laminin and collagen IV were essential for the formation of flat cords, none of the basement membrane constituents, when taken alone or in combination, would support the formation of tubules in minimal culture medium. Moreover, none of the growth factors present in GFR-Matrigel could induce tubulogenesis. Recently, much attention has been focused upon the role of hepatocyte growth factor (HGF) and its receptor c-met in the induction of tubulogenesis by epithelial cells. Therefore, we investigated the expression of HGF/c-met in the mouse testis at different postnatal stages and in the adult and evaluated the contribution of HGF/c-met in the production of Sertoli cell tubules by SF7 and primary Sertoli cells in vitro. Our results confirm that laminin and collagen IV are essential for the formation of testicular cords and reveal that HGF/c-met are necessary for the further remodeling of these cords into tubules.

Animals↗
PubMed2004

Embryonic mouse testis development: role of platelet derived growth factor (PDGF-BB).

Platelet-derived growth factors (PDGFs) are paracrine growth factors mediating epithelial-mesenchymal interactions and exerting multiple biological activities which include cell proliferation, motility, and differentiation. As previously demonstrated, PDGFs act during embryonic development and recently, by culturing male genital ridges, we have demonstrated that PDGF-BB is able to support in vitro testicular cord formation. In the present paper, we report that PDGF-BB is present during embryonic testis development and, in organ culture, induces cord formation although with reduced diameters compared with the cords formed in the genital ridges cultured in the presence of HGF. Moreover we have analyzed the roles exerted by this growth factor during the morphogenesis of the testis. We demonstrate by immunohistochemical experiments that PDGF-BB and its receptors are synthesized by the male UGRs isolated from 11.5 and 13.5 dpc embryos and by Western blot that the factor is secreted in a biologically active form by testicular cells isolated from 13.5 dpc embryos. The biological roles of the factor have also been studied and we demonstrate that PDGF-BB acts as a migratory factor for male mesonephric cells whose migration is a male specific event necessary for a normal testicular morphogenesis. In addition we demonstrate that during testicular development, PDGF-BB induces testicular cell proliferation being in this way responsible for the increase in size of the testis. Finally we demonstrate that PDGF-BB is able to reorganize dissociated testicular cells inducing the formation of large cellular aggregates. However the structures formed in vitro under PDGF-BB stimulation never had a cord-like morphology similar to the cord-like structures formed in the presence of HGF (Ricci et al., 2002, Mech Dev 118:19-28), suggesting that this factor does not act as a morphogenetic factor during testicular development. All together the data presented in this paper demonstrate that PDGF-BB and its receptors (alpha- and beta-subunits) are present during the crucial ages of embryonic mouse testis morphogenesis and indicate the multiple roles exerted by this factor during the development of the male gonad.

Animals↗
PubMed2004

[Establishment of animal model for in vitro spermatogenesis by heterotopic grafting of neonatal mouse testis].

OBJECTIVE: To establish an in vitro model for the development of mouse spermatogenic cells into sperm by using the immunodefective mouse as the incubator. METHODS: Tissue grafting was performed using testis from 1-2 days old Kun-ming mice as donor tissue and immunodefective mice as recipients; the expression of TESK1 mRNA in grafts was determined by RT-PCR and the spermatogenesis further observed with histological analysis of grafts. RESULTS: Molecular biological and histological analyses showed that grafts post-grafting not only expressed TESK1 mRNA as in normal mouse testis, but also exhibited similarities in the structure of seminiferous tubules and component of spermatogenic cells, including sperms. CONCLUSION: Spermatogenic cells heterotopically grafted in vitro could continuously grow and complete spermatogenesis and finally develop into sperm.

Animals↗
PubMed1997

Effect of retinoid status on the messenger ribonucleic acid expression of nuclear retinoid receptors alpha, beta, and gamma, and retinoid X receptors alpha, beta, and gamma in the mouse testis.

The testicular gene expression of the retinoic acid receptors, RAR alpha, -beta, and -gamma, was studied in normal mice and in vitamin A-deficient mice after the administration of all-trans-retinoic acid (ATRA). All three types of RARs were expressed in normal and/or vitamin A-deficient testes. Only the expression of RAR beta messenger RNA was transiently induced within 24 h after ATRA injection. ATRA-induced RAR beta expression was also found in purified Sertoli cells, suggesting that these cells mediate at least part of the effect of retinoids on germ cells. When an equimolar amount of retinol was administered instead of ATRA, no induction of RAR beta was seen at the point of maximal induction by ATRA, suggesting that the effect of retinol was delayed and probably less. The related nuclear receptors, RXR alpha, -beta, and, for the first time, gamma, were also shown to be present in the mouse testis. Upon administration of ATRA, messenger RNA expression of RXR alpha and -beta did not change significantly. The expression of RXR gamma was too low to allow quantification. Finally, the effect of the retinoid metabolism inhibitor liarozole on ATRA-induced proliferation of A spermatogonia was examined. The labeling index of A spermatogonia, 24 h after the administration of 0.25 mg ATRA, was significantly lowered by liarozole due to a shift of the maximal 5-bromo-deoxyuridine incorporation to an earlier point (20 h). This indicates that liarozole delays retinoid metabolism, thereby increasing the actual ATRA concentration, and more importantly, that ATRA by itself is an active retinoid in spermatogenesis. Apparently, ATRA does not need to be metabolized to 4-oxo-RA, which was previously shown to be a more potent inducer of spermatogonial proliferation than ATRA, to be effective.

Animals↗
PubMed1978

Glucose-6-phosphate dehydrogenase activity in somatic and germinal cells of the mouse testis.

The activity of G6PD was examined by spectrophotometric and electrophoretic assays in cell fractions from the testes of mice at different ages (5-62 days). (1) The G6PD activity of the cells of the seminiferous tubule was as high or higher than that of the interstitial tissue. (2) The high G6PD activity of the testis of the immature mouse was mainly due to a high specific activity of the Sertoli cells which declined with age. (3) The G6PD activity was more easily lost during culture from the germinal cells than from the interstitial or Sertoli cells. (4) All the cell types of the testis contained G6PD and hexose-6-phosphate dehydrogenase. The functional significance of the high G6PD activity in the Sertoli cells of immature mice is not at present understood.

Animals↗