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 883 records · Page 49Linked to original sources
PubMed1999

Expression of peroxisome proliferator-activated receptor alpha messenger ribonucleic acid and protein in human and rat testis.

Peroxisome proliferator-activated receptor a (PPARalpha), a member of the steroid hormone receptor superfamily, has been linked to lipid homeostasis and tumorigenesis in tissues with high expression of receptor protein. On the other hand, the role of PPARalpha in tissues with a lower expression is not well known. Here we demonstrate the localization of PPARalpha messenger RNA (mRNA) and protein in developing and adult rat testis. Additionally, we demonstrate the expression of PPARalpha protein in adult human testis. Our experiments with Northern analysis, in situ hybridization and immunocytochemistry reveal a complex distribution of PPARalpha in tubular and interstitial cells of both adult and developing rat testis. The overall expression is rather low but may be modified by exogenous or endogenous stimuli. An up-regulation of PPARalpha mRNA could be observed after stimulation with FSH. In the developing rat testis, a clear expression of PPARalpha mRNA was present from the first days after birth. Additionally, PPARalpha mRNA and protein increased toward adulthood. In adult human testis PPARalpha immunoreactivity (IR) was present in interstitial Leydig cells and tubular cells. In the seminiferous epithelium of adult human testis the expression of PPARalpha-IR could be seen in meiotic spermatocytes, spermatids and myoid peritubular cells. The findings of our study suggest that PPARalpha may be involved in the regulation of growth and differentiation of tubular and interstitial cells in rat and human testis.

Adult↗
PubMed2003

Sexually dimorphic expression of multiple doublesex-related genes in the embryonic mouse gonad.

The only molecular similarity shown so far for sexual regulatory genes among different phyla involves doublesex (dsx) of Drosophila, mab-3 and mab-23 of Caenorhabditis elegans, and Dmrt1 of vertebrates. These genes encode DM domain transcription factors (DM = dsx and mab-3) and are required for sexual differentiation. In the case of dsx and mab-3, the two genes control analogous aspects of sexual development, bind similar DNA sequences, and are capable of functional substitution in vivo. All three phyla have multiple DM domain genes, but it is unknown how many of these are involved in sexual development. Mammals, for example, have at least seven DM domain genes, but embryonic expression has only been examined in detail for Dmrt1(dsx- and mab-3 related transcription factor 1). We have identified additional murine DM domain genes and have examined their expression in the mouse embryo, with emphasis on the developing gonad. At least three murine DM domain genes in addition to Dmrt1 are expressed in the embryonic gonad: Dmrt4 is expressed at similar levels in gonads of both sexes; Dmrt3 is more highly expressed in males; and Dmrt7 is more highly expressed in females. Expression of three other genes is low or absent in the embryonic gonad. Two of these, Dmrt5 and Dmrt6, are expressed primarily in the brain, and the third, Dmrt2, is expressed in presomitic mesoderm and developing somites. Our data suggest that multiple DM domain genes may be involved in mammalian sexual development, and that they may function in both testis and ovary development.

Animals↗
PubMed2006

The expression of neurotrophins and their receptors in the prenatal and adult human testis: evidence for functions in Leydig cells.

Previous studies have demonstrated local functions for neurotrophins in the developing and mature testis of rodents. To examine whether these signaling molecules are present and also potentially active in the human testis, we characterized immunohistochemically the expression and cellular localization of the known neurotrophins and their receptors during prenatal testicular development as well as in the adult human testis. Results obtained revealed the presence of nerve growth factor (NGF), brain-derived neurotrophic factor, neurotrophin-3 and 4, as well as neurotrophin receptors p75(NTR), TrkA, TrkB, and TrkC during testis morphogenesis. These proteins were also detectable in the adult human testis, and their local expression could be confirmed largely by immunoblot and RT-PCR analyses. Remarkably, the Leydig cells were found to represent the predominant neurotrophin/receptor expression sites within both fetal and adult human testes. Functional assays performed with a mouse tumor Leydig cell line revealed that NGF exposure increases cellular steroid production, indicating a role in differentiation processes. These findings support previously-recognized neuronal characteristics of Leydig cells, provide additional evidence for potential roles of neurotrophins during testis morphogenesis and in the mature testis, and demonstrate for the first time a neurotrophin-induced functional activity in Leydig cells.

Aged↗
PubMed2003

Colocalization of WT1 and cell proliferation reveals conserved mechanisms in temperature-dependent sex determination.

During vertebrate development the gonad has two possible fates, the testis or the ovary. The choice between these fates is made by a variety of sex-determining mechanisms, from the sex-determining gene on the Y chromosome (Sry) in mammals, to nongenetic temperature-dependent systems in many reptiles. Despite the differences in the mechanisms at the top of the sex-determining cascade, the resulting morphology and many genes involved in early testis and ovarian development are common to most vertebrates, leading to the hypothesis that the underlying processes of sex determination are conserved. In this study, we examined the early steps of gonad development in the red-eared slider turtle (Trachemys scripta), a species that uses the temperature of egg incubation to determine sex. A dramatic increase in cell proliferation was observed in the male gonad during the earliest stages of sex determination. Using the localization of Wilms' Tumor suppressor 1 (WT1), we determined that this proliferation increase occurred in a population that contained pre-Sertoli cells. The proliferation of pre-Sertoli cells has been documented during sex determination in both mice and alligators, suggesting that proliferation of this cell type has an important role in vertebrate testis organogenesis and the determination of male fate.

Animals↗
PubMed2006

Spermatogenesis in testis xenografts grafted from pre-pubertal Holstein bulls is re-established by stem cell or early spermatogonia.

Xenografting of testis explants into recipient mice has resulted in successful restoration of spermatogenesis in several species. Most studies have utilized neonatal donor tissue, although a few have used prepubertal testes. In Holstein bulls, prepubertal development of the testis occurs between 16 and 32 weeks of age. The purpose of the present study was to determine the optimal age during prepubertal development of Holstein bulls for testis grafting. Explants of testis tissue from Holstein bulls between 12 and 32 weeks of age (2 bulls/age; 6 ages) were subcutaneously grafted into castrated or intact immunocompromised mice (n=8/age), then recovered after 75 and 173 days (n=4 mice/grafting period) and evaluated histologically for spermatogenic progression. Seminiferous tubules were assigned a score based on the most advanced type of germ cell present within the tubule and the average for all tubules scored (n=25) within an explant was calculated. Scores for all explants per mouse (n=6) were averaged to give a single spermatogenic progression score per mouse. No difference in spermatogenic progression of grafts between intact and castrated recipients was observed. Spermatocytes were observed in testis grafts from bulls of all ages 75 days post-grafting. At 173 days, the spermatogenic progression score for explants derived from 20 weeks bulls was greater than all ages except 12 weeks donors (p<0.05), with 8% of tubules containing spermatids. Donor material from bulls older than 20 weeks had lesser spermatogenic progression scores largely attributed to the greater number of atrophic tubules in grafts from older donors. Grafts from 28 and 32 weeks donors showed signs of degeneration by 75 days post-grafting, with 30 and 55% atrophic tubules, respectively, and lesser spermatogenic efficiency scores. By 173 days post-grafting, 72% of tubules in explants from 32 weeks donors were atrophic. The results of the present study suggest that the early stages of prepubertal development are optimal for testis grafting while advanced spermatogenesis in the donor tissue prior to grafting had a negative effect on graft development. Spermatogenesis within the grafts apparently needs to be re-established by spermatogonial stem cells or early spermatogonia.

Age Factors↗
PubMed1981

Postnatal development and differentiation of contractile cells within the rabbit testis.

This study has been determined the postnatal development and differentiation of smooth muscle cells within the rabbit testicular capsule and within the peritubular tissue surrounding seminiferous tubules. Smooth muscle cells within the tunica albuginea are not identifiable at birth by light microscopy but by electron microscopy myocytes in early stages of development may be shown to be present. It is not until 42 to 49 days postnatum that smooth muscle cells can be identified by light microscopy. Differentiation of smooth muscle cells within the capsule is completed by 128 days postnatum. At this time, the muscle is arranged in two organized layers, a superficial layer of longitudinally oriented cells and a deeper layer of circularly arranged cells. At birth, the peritubular tissue consists of two to four layers of undifferentiated cells and, during the first postnatal week, the tissue becomes more condensed and generally is arranged in two cellular layers. Cells of the inner layer contain small bundles of microfibrils whereas cells of the outer layer are fibroblast in nature. Differentiation of the peritubular tissue is completed by 112 days postnatum. At this stage, it consists of four layers, two acellular and two cellular. The inner cellular layer, composed of attentuated myoid cells, possesses a basal lamina on both surfaces and is surrounded by two delicate connective tissue lamellae. The myoid cells of the peritubular tissue thus achieve structural maturity at approximately the same time postnatally as do those within the testicular capsule, which corresponds to the time when spermatogenesis becomes established. The relative contributions of the myoid cells in the peritubular tissue and within the testicular capsule to the movement of non-motile spermatozoa out of the testis and the possible significance of the peritubular tissue as a component of the permeability barrier are discussed in relation to the present findings.

Animals↗
PubMed1992

Basic fibroblast growth factor (bFGF) gene expression and protein production during pubertal development of the seminiferous tubule: follicle-stimulating hormone-induced Sertoli cell bFGF expression.

The potential role of basic fibroblast growth factor (bFGF) as a mediator of cell-cell interactions in the growth and development of the testis was examined. Nuclease protection analysis was used to evaluate bFGF gene expression in the testis and other male reproductive tract tissues. bFGF expression was evident in seminal vesicle, prostate, epididymis, and, at low levels, testis of 20-day-old rats. The developmental expression of bFGF in whole testis and isolated somatic cells types was determined. Mesenchymal-derived peritubular cells and epithelial-like Sertoli cells were isolated from prepubertal, midpubertal, and late pubertal rat testes. In whole testis, bFGF expression is predominant early in prepubertal testicular development and decreases with sexual maturity. Both freshly isolated peritubular and Sertoli cells express bFGF at relatively constant levels during pubertal development, with a slight suppression at the late pubertal stages. Freshly isolated mature Leydig cells also expressed low levels of bFGF. Cultured Sertoli and peritubular cells produced bFGF-like proteins, including 18- and 24-kilodalton forms. Interestingly, FSH increased Sertoli cell bFGF gene expression and protein production. Previously, FSH and bFGF have been shown to stimulate immature Sertoli cell growth. The results of the current study suggest that the ability of FSH to regulate testis and Sertoli cell proliferation may in part be indirectly mediated through the local production and action of bFGF. bFGF has also previously been shown to localize in developing germinal cells. Therefore, FSH-induced Sertoli cell bFGF expression may mediate Sertoli-germinal cell interactions involved in the control of the spermatogenic process. Observations demonstrate the presence of bFGF at a time coinciding with active growth of the somatic cell populations of the seminiferous tubule. Potential roles for bFGF in the seminiferous tubule to consider include angiogenesis of the tubule, prepubertal Sertoli cell proliferation, and mediating Sertoli-germinal cell interactions.

Animals↗
PubMed2002

A novel promoter is involved in the expression of estrogen receptor alpha in human testis and epididymis.

The role of estrogens in the development and physiology of the male reproductive tract remains provocative, with a growing body of evidence suggesting that estrogens are able to influence normal testis development and physiology, through their classical receptors, estrogen receptor (ER)-alpha and ER-beta. We describe the identification and characterization of a new promoter that is involved in the expression of ER-alpha in the epididymis and in testis. This promoter lies on chromosome 6q25.1, approximately 16 kb upstream of the first coding exon of ER-alpha. Sequence analysis indicates that this promoter has a conventional TATA box and GC box but no upstream CAAT sequence. Alternative splicing results in at least two species of mRNA encoding ER-alpha being synthesized from this promoter. Transcription profiling of human tissues shows that, among those tested, this promoter is predominantly active only in testis and epididymal tissues. Transient transfection assays using this new promoter in a number of cell lines indicate that the region we have identified functions as a promoter and that tissue-specific regulation is likely to be dependent on inhibitory sequences greater than 1 kb upstream of the transcription start site.

Aged↗
PubMed2003

Outer dense fibers serve as a functional target for Cdk5.p35 in the developing sperm tail.

Cdk5 is ubiquitously expressed in all tissues, but its activators, p35 and p39, are principally found in brain, and Cdk5 activity has mostly been associated with brain development, particularly neuronal differentiation and migration. Here we show that the p35 transcript and protein are also present in the testis, and an active Cdk5.p35 complex exists in this tissue as well. Cdk5 and p35 are prominently observed in elongating spermatid tails, particularly over the tail outer dense fibers (ODF). The appearance of Cdk5.p35 proceeds from the proximal to the distal end of elongating spermatids, coinciding with the proximal to distal assembly of ODF along the length of the tail axoneme. Incidentally, increased Cdk5.p35 activity is observed in isolated elongating spermatids and at a time when elongating spermatids appear in the developing testis, suggesting a role for Cdk5.p35 in spermiogenesis. The presence of Cdk5 and p35 in ODF isolated from rat sperm tails implies a strong association among these proteins. In vitro ODF phosphorylation by Cdk5.p35 and decreased in vivo sperm tail ODF phosphorylation in p35-deficient mice indicate that Cdk5.p35 is an integral component of ODF and that ODF is a functional Cdk5.p35 target in the testis. Our results demonstrate for the first time that Cdk5.p35 may participate in the regulation of sperm tail development via a mechanism involving ODF phosphorylation. Apparently, as in brain development, Cdk5.p35 plays a part in testis development.

Animals↗
PubMed1992

Oocyte numbers are reduced in developing mouse ovaries cultured in testis-conditioned medium.

Reduced numbers of oocytes were present in fetal ovaries of 13 d post coitum (dpc) mice, cultured for 4 d in medium conditioned (-CM) for 2 d by 13 dpc testes, compared with ovaries maintained in standard unconditioned medium. This effect was abolished by heat-inactivation of the testis-CM. Electrophoretic analysis of conditioned media revealed differences between testis-CM and ovary-CM. Ovarian differentiation was otherwise unaffected by the testis-CM and gonadal volume was not significantly reduced. Organisation of ovigerous cords proceeded, even though the full complement of oocytes was absent, and connective tissue septa developed normally between the small cords. The reduction in oocyte numbers occurred without any inhibition of müllerian duct development. Since others, using transgenic mice, have shown, that higher concentrations of antimüllerian hormone are required to decrease oocyte numbers than are necessary for duct regression, our results suggest that an additional factor is involved in producing this modified effect.

Animals↗
PubMed1992

Torsion of a malignant undescended testis mimicking appendicitis.

Testicular maldescent is known to be associated with later development of malignancy. The maldescended testis is prone to other complications--in particular, torsion. We report an unusual coincidence of both malignancy and torsion of an intra-abdominal testis which closely simulated a ruptured appendix abscess. This case demonstrates that an intra-abdominal testis can develop acute life-threatening complications which should be considered in any patient with acute abdominal symptoms who has an 'absent' testis.

Adult↗
PubMed1985

Seminoma in an atrophic testis.

A rare case of a seminoma developing in an atrophic testis is described and the role of testicular atrophy in tumorigenesis is discussed.

Adult↗
PubMed2002

Tissue-specific transcriptional regulation of the cholesterol biosynthetic pathway leads to accumulation of testis meiosis-activating sterol (T-MAS).

Lanosterol 14alpha-demethylase (CYP51) produces follicular fluid meiosis-activating sterol (FF-MAS), which is converted further to testis meiosis-activating sterol (T-MAS). MAS are intermediates in the cholesterol biosynthetic pathway, with the ability to trigger resumption of oocyte meiosis in vitro. In contrast to the liver, where pre- and post-MAS genes are upregulated coordinately at the level of transcription by a cholesterol feedback mechanism through sterol regulatory element-binding proteins (SREBP), regulation differs in the testis. Genes encoding pre-MAS enzymes [HMG-CoA synthase (SYN), HMG-CoA reductase (RED), farnesyl diphosphate synthase (FPP), squalene synthase (SS), and CYP51] are upregulated during sexual development of the testis, although not all genes are turned on at the same time. Furthermore, two post-MAS genes, C-4 sterol methyl oxidase and sterol Delta(7)-reductase, are expressed at low levels and are not upregulated either in rat or human. This transcriptional discrepancy seems to be SREBP independent. Besides cAMP/cAMP-responsive element modulator, other unknown transcription factors control expression of individual cholesterogenic genes during spermatogenesis. HPLC analysis shows an 8-fold increase in T-MAS during development of rat testis whereas MAS is barely detectable in livers of the same animals. We propose that the lack of a coordinate transcriptional control over the cholesterol biosynthetic pathway contributes importantly to overproduction of the signaling sterol T-MAS in testis.

Animals↗
PubMed2000

Incidence of testicular lesions in a population of tree shrews (Tupaia belangeri).

BACKGROUND AND PURPOSE: The sexual activity of male tree shrews is socially influenced; therefore, the testicular lesions in adult male tree shrews were of interest. METHODS: The testes of 229 adult and 9 subadult male tree shrews were obtained during routine necropsy and were subjected to light microscopy. At one time, 138 animals were experimentally exposed to social conflicts. RESULTS: Hypospermatogenesis (testicular inactivity) was observed in social stress-exposed males up to two years of age. Seasonality of hypospermatogenesis could not be statistically supported. Testicular atrophy, observed in 21 animals, was neither stress- nor age-related; it developed unilaterally, with the left testis preferred. Testicular tumors developed in animals older than 2 years, with increasing frequency particularly of Leydig cell tumors in animals more than four year old. CONCLUSION: Testicular lesions were more frequently found in male tree shrews than they were observed in nonhuman primates kept at the German Primate Center. Connections to social stress were statistically supported, particularly with respect to hypospermatogenesis. Testicular tumors, in contrast, were distinctly age related.

Age Factors↗
PubMedDate not supplied

Postnatal changes in the calcium binding proteins of mouse testis.

To define the changes in calcium-binding proteins (CBPs) of mouse testis during postnatal development, testicular protein extracts were analyzed by mobility shift after Ca2+ binding (MSACB) in the 2-dimensional SDS-PAGE. In the adult testis extracts, 29 kinds of protein spots showed mobility shift in the gel containing Ca2+. Among them, 2 spots showed nonspecific mobility shift and 4 spots showed Zn2+ shift. Drastic changes in expression of high-Mr CBPs (Mr > 25 kDa) were observed in testis 3 weeks after birth, suggesting that their expressions were developmentally changed. There was no obvious difference in the qualitative patterns of CBP between 4-week-old testis and adult testis. There was a large mass of CBPs (Mr = 20-25 kDa) expressed constitutively in testis throughout the postnatal development. Degree of MSACB (Mr on the diagonal line/Mr of shifted point in Ca2+ gel) of each spot was in the range of 1.1-1.7 in 12% acrylamide gel. These results suggest that changes in CBPs of testis are closely related with progression of spermatogenesis in mouse testis.

Animals↗
PubMed2006

Multiple alternative splicing of mouse Dmrt1 during gonadal differentiation.

Evolutionarily conserved Dmrt1 encodes a transcriptional regulator that is expressed exclusively in the gonads and is required for testis differentiation. Here we report that four transcripts of the mouse Dmrt1 were generated in developing gonads and adult testis by alternative splicing. Dmrt1 a encodes the known protein with 374 amino acids. Dmrt1 b, Dmrt1 c, and Dmrt1 d encode predicted proteins with 212, 257, and 194 amino acids, respectively. Dmrt1 a2 and Dmrt1 a3 have anterior alternative polyadenylation signals in 3'UTR than the known Dmrt1 transcript (Dmrt1 a1). Dmrt1 a2 lacks 18 nucleic acids in 3'UTR. Interestingly, Dmrt1 b lacks exon5, Dmrt1 c lacks exon3, and Dmrt1 d lacks both exon1 and exon2 which encode DM domain. RT-PCR showed that all of Dmrt1 transcripts were only detectable in adult testis. However, during gonadogenesis, the multiple alternatively spliced transcripts all had gonad-specific and sexually dimorphic expression profiles. Northern blot and real time fluorescent quantitative RT-PCR further indicated that the expression of Dmrt1 a was dominantly higher than those of Dmrt1 b, c, and d, although they showed a similar up and down pattern of expression during embryo development. The expression of Dmrt1 transcripts climbed up to a climax at 13.5dpc in both male and female gonad. Afterwards, expression in male gonad decreased to a low level and maintained, whereas female one reduced rapidly until undetectable in adult ovary. These results provide new insight into roles of regulation at level of splicing of the Dmrt1 in governing sex differentiation.

Alternative Splicing↗
PubMed1975

An angiographic study of the fox testis in various stages of sexual activity.

The arteries and veins of the fox testis were studied using an angiographic technique. The postnatal development of the testis involved only minor modification of the vasculature. In the non-breeding season both the arteries and veins of the adult fox testis undergo extensive spiralization which completely disappears during the breeding season. When the sequence of morphological changes in blood vessels are related to available data on changes in testicular size, blood flow and connective tissue content, it is obvious that the vascular spiralization is passive and related to shrinkage of the organ and dose not primarily influence the testicular blood flow.

Angiography↗