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Impaired estrogen production by Leydig cells of the naturally retained testis in unilaterally cryptorchid boars and stallions.

Estrogen production in vitro was compared for Leydig cells from cryptorchid and scrotal testes in boars and stallions. Animals with natural and experimental cryptorchidism were used. Purified Leydig cells were prepared from testes of mature animals by collagenase treatment and Percoll density gradients. After incubation for 3 hours (1 X 10(6) cells), estrone sulfate and estrone in the media were measured by direct radioimmunoassay. Androstenedione and testosterone in media extracts also were determined. Cells from the abdominal testis of unilateral cryptorchid boars and stallions showed impaired estrogen production compared with that of the contralateral scrotal testis. Surgical translocation of the scrotal testis to the abdominal cavity in four unilaterally cryptorchid, prepubertal boars did not result in a reduced capacity for estrogen secretion by Leydig cells examined after puberty. Cells from the naturally retained testis in each of these four animals produced practically no estrogen. In a naturally bilateral cryptorchid stallion, there was a high rate of estrogen secretion by both testes. It was concluded that the scrotal testis of a unilaterally cryptorchid animal exerts a suppressive influence on estrogen formation by the abdominal testis.

Androstenedione↗

Prolonged suppression of rat testis function by a depot formulation of Zoladex, a GnRH agonist.

A sustained-release formulation of a potent gonadotropin-releasing hormone (GnRH) agonist, Zoladex (D-Ser(But),6 Aza Gly10-GnRH; ICI 118,630; goserelin), was administered subcutaneously (3.6 mg/depot) to male rats once every 28 days for 2-24 wk to determine the extent to which pituitary-testis function could be suppressed and whether suppression was maintained throughout the period of treatment. Administration of Zoladex resulted in sustained decreases in weight of the testis, epididymis, seminal vesicles and prostate gland. The decreases were apparent within 2 wk of initiating treatment. Patchy degeneration of the seminiferous tubules and atrophy of the Leydig cells were observed, but did not progress beyond the degree observed after 1 month of treatment. Serum and testis testosterone were markedly depressed after 2 wk of treatment, as was testis [125I]hCG binding. Serum gonadotropins were also reduced by treatment. Serum androgen binding protein (ABP) was elevated, testis ABP content remained unchanged, and epididymal ABP content was reduced. The changes are consistent with the hypothesis that this compound affects both the anterior pituitary gland and the testis. These findings indicate that depot delivery systems are a convenient way to administer GnRH analogs for sustained treatment schedules.

Androgen-Binding Protein↗

A game of cat and mouse: xenografting of testis tissue from domestic kittens results in complete cat spermatogenesis in a mouse host.

Loss of genetic diversity because of infertility or the premature death of valuable individuals is a significant problem in the conservation of rare and endangered felid species, as well as in the maintenance of lines of cats used to study inherited feline and human disease. Attempts to overcome loss of genetic diversity have focused on freezing sperm; however, sperm cannot be collected from immature males. Previously, we reported completion of spermatogenesis in testis tissue from newborn pigs and goats grafted ectopically into host mice. The objective of this study was to extend the technique of testis tissue xenografting to the domestic cat as a model for felid species. Testes from 1- to 5-week-old domestic shorthaired kittens (n = 9) were cut into small fragments (about 0.5-1 mm3 each), and up to 8 fragments were grafted under the back skin of each castrated immunodeficient host mouse (n = 16). Histologic examination of the testis xenografts was performed between 5 and 54 weeks posttransplantation. At the time of grafting, the seminiferous cords of the donor testis tissue contained only immature Sertoli cells and gonocytes. At 14 weeks after grafting, tubular expansion was evidently caused by the proliferation of Sertoli cells and tubular lumen formation. By 18 weeks after transplantation, the seminiferous epithelium contained spermatocytes, and by 20 weeks, round spermatids were the most advanced types of germ cells. By 36 weeks after transplantation, xenografts of cat testis tissue had completed spermatogenesis. These results demonstrate the potential of xenografting to achieve full spermatogenesis in testis tissue from kittens. Therefore, sperm production in a mouse host can provide an alternative for germ line preservation from immature felids where sperm cryopreservation is not an option.

Animals↗

Structural and functional analysis of the rat testis-specific histone H1t gene.

A 6.86 kb rat genomic DNA fragment containing the testis-specific histone H1t gene and the histone H4t gene has been sequenced. S1-nuclease protection analyses of total cellular RNA from rat liver and testis showed that histone H1t mRNA was present only in testis. Examination of various highly enriched populations of rat testis cell types revealed that H1t mRNA was found exclusively in a fraction enriched in pachytene spermatocytes. When protein, DNA interactions within the proximal promoter region of the histone H1t gene were examined by electrophoretic mobility shift assays, only minor differences were found in mobility shift patterns of the H1t promoter in assays comparing binding of nuclear proteins from pachytene spermatocytes and early spermatids. However, major differences in binding were observed upon comparing nuclear proteins from rat pachytene spermatocytes to liver. Comparison of binding patterns of rat testis, rat hepatoma H4 cells, HeLa cells, and COS-1 cells also revealed dramatic differences. Transcriptional activity of the histone H1t promoter was examined by measuring H1t promoted chloramphenicol acetyltransferase (CAT) mRNA levels in transient expression assays in transfected rat hepatoma H4 cells, HeLa cells, and COS-1 cells. These assays revealed that the histone H1t promoted CAT gene functioned poorly in HeLa cells and COS-1 cells compared to expression with the parent SV40 promoted vector pSV2CAT. The H1t promoted CAT gene apparently did not work at all in transfected rat hepatoma H4 cells, which is consistent with testis germinal cell specific expression of the histone H1t gene.

Animals↗

Biology of the scrotum. IV. Testis location and temperature sensitivity.

Whereas abdominal temperatures have no effect on spermatogenesis in testicondid mammals but inhibit the process completely in scrotal mammals, the inguinal testes of the naturally cryptorchid musk shrew and degu have been found to display an intermediate response. Twelve to 18 weeks after transposition to the abdomen (and so about 1.5 degrees C above its normal inguinal temperature) the weight of the testis was reduced by 27% (musk shrew) and 52% (degu). Nonetheless, spermatogenesis continued in both, though at a lower rate and with a greater proportion of abnormal spermatozoa formed. The ultrastructural anomalies evident in some spermatids of the degu testis transposed to the abdomen were reminiscent of those seen commonly in the germinal epithelium of "normal" men. Natural cryptorchids may thus be useful models in which to discover whether spermatogenesis at a temperature somewhat above the norm for the species compromises the ability of fertilizing spermatozoa to support normal development. The fact that deep-body temperature induces only a partial suppression of function in the inguinal testis of natural cryptorchids shows that there is no, absolute distinction between the scrotal and ascrotal states among mammals with respect to the temperature sensitivity of the testis. That visible sensitivity seems more likely to reflect the adaptation of the metabolically dynamic germinal epithelium to function optimally at the temperature of the location to which the testis migrates, rather than any fundamental incompatability between spermatogenesis and the temperature imposed by homeothermy. External migration of the testis itself may originally have helped the sperm storage region of the associated epididymis to project from and so attain a cooler environment than that beneath the body surface.

Animals↗

A specific androgen-binding protein (ABP) in Necturus testis and its zonal distribution.

The urodele amphibian Necturus maculosus has a zoned testis, which is advantageous for separating Leydig cells from germinal elements and for studying stage-dependent biochemical changes. Using [3H]testosterone (T) in a standard binding assay and dextran-coated charcoal (DCC) or Sephadex LH-20 to separate free and bound steroids, we identified an androgen-binding protein (ABP) in Necturus testis cytosols. This protein was of high affinity (Kd = 10(-9) M) and was saturable (Bmax = 10(-9) M) and specific for androgen (T; 5 alpha-dihydrotestosterone, DHT) but could be distinguished from the androgen receptor of Necturus testis by its relative abundance (300-550 fmol/mg protein), short half-time of dissociation (3 min at 22 degrees C), inability to adhere to DNA-cellulose, and absence from nuclear extracts. Additionally, when analyzed on sucrose gradients, the ABP of Necturus testis sedimented at 6-7 S in both low or high ionic strength buffers. In that estradiol (E2) is a poor competitor for T-binding, this protein resembles a sex steroid-binding protein previously identified in urodele serum but differs from the ABP and testosterone-estradiol-binding globulin (TEBG) of rodents, humans, goldfish, and sharks. It is differentially distributed within the testis, with the highest levels in immature lobular regions composed of Sertoli cells and germ cells in premeiotic stages and lower levels in regions composed primarily of Leydig cells. The cellular source and function of this protein in Necturus testis remain to be determined.

Androgen-Binding Protein↗

An in vitro system for the long-term tissue culture of juvenile rainbow trout (Oncorhynchus mykiss) testis.

In vitro cultivation of fish gonad fragments continues to be an important experimental approach to answer both fundamental and applied scientific questions. The aim of the present investigation was to test whether juvenile rainbow trout (Oncorhynchus mykiss) testes cultured for a week or more were physiologically competent. Trout testis fragments (approximately 1 mm2) were placed on pieces of flat, culture plate insert filter, in a drop of liquid medium (modified Leibovitz's L-15), and floated on the medium surface in a multi-well culture plate. Culture plates were covered and incubated in air at 15 degrees C. Three different endpoints were used to test whether cultured testis fragments remained healthy and functional. First, a comparison of the histological appearance of testis fragments cultured in vitro for different periods up to 8 days with intact testes indicated that no differences were evident. Secondly, testis fragments incubated in medium supplemented with bovine calf serum (BCS) at concentrations of 2.5% and 25% BCS had significantly greater proliferation of interstitial and spermatocyst cells as measured by nuclear 5-bromo-2'-deoxyuridine incorporation. Finally, testis fragments cultured for 5 days and transplanted back into the donor fish underwent precocious sexual maturity in response to a regime of salmon pituitary extract injections and produced fertile sperm as determined by their ability to successfully fertilize eggs. These experiments demonstrate the utility of this method for in vitro culture of juvenile rainbow trout testis fragments.

Animals↗

Extracellular matrix abnormalities in testis and epididymis of XXSxr ("sex-reversed") mice.

Sex-reversed (Sxr) is a duplication of the sex-determining region of the Y chromosome, which gets transposed to a paternal X chromosome. Chromosomally female (XX) zygotes that receive this XSxr chromosome develop as apparent males. Previous work on XXSxr mice (called pseudomales) showed extracellular matrix (ECM) ultrastructural abnormalities in the epididymis and testis. This study examined the biochemical nature of these abnormalities. More hydroxyproline (an indicator of collagen) was noted in the pseudomale testis and epididymis compared to normal male tissues. Western blot analysis showed increased collagen IV in the pseudomale testis and epididymis. In both the hydroxyproline and collagen IV studies, the epididymis was found to contain higher levels of these substances than the testis for both genotypes. There also appeared to be increased messenger RNA for tissue inhibitor of metalloproteinases (Timp), a regulator of collagen, in the pseudomale testis. Data from these studies seem to indicate that the XXSxr genotype influences ECM deposition and/or turnover and exerts a direct genetic influence on the development of the testis and epididymis. According to the existing paradigm of mammalian sexual development, the epididymis is expected to be normal in the presence of adequate androgenization and independent of chromosomal and genetic sex. The results presented here differ from what would be predicted by this paradigm.

Animals↗

Galactosyl receptor in human testis and sperm is antigenically related to the minor C-type (Ca(2+)-dependent) lectin variant of human and rat liver.

Galactosyl receptor, a cell surface Ca(2+)-dependent lectin with binding affinity for galactose, was evaluated by immunoblotting, immunoprecipitation, Northern blotting, and immunocytochemistry in human liver, testis, and sperm. Polyclonal antisera raised against the minor asialoglycoprotein receptor variant of rat hepatocytes (designated rat hepatic lectin-2/3, RHL-2/3), and its human liver-equivalent (designated H2), recognize native galactosyl receptor in the testis and sperm in immunoblotting, immunoprecipitation, and immunocytochemical experiments. An equivalent to the major hepatocyte asialoglycoprotein receptor variant (rat RHL-1 and human H1) was not detected. Human testis and sperm galactosyl receptor was resolved, after immunoprecipitation and immunoblotting, as a single protein component of molecular mass 50 kD. The single protein component in human testis and sperm contrasted with the doublet nature of rat testis and sperm galactosyl receptor, consisting of two components of molecular masses of 54 and 49 kD. Northern blotting experiments using radiolabeled H1 and H2 cDNA probes confirmed the presence of H2 mRNA and the lack of H1 mRNA in the human testis. Immunocytochemical studies detected specific antigenic sites on the entire surfaces of spermatogenic cells. However, immunoreactivity in epididymal and ejaculated sperm was confined to head surfaces overlying the acrosome. Results from these studies, and from previous studies in the rat, suggest that the testis/sperm galactosyl receptor is a C-type Ca(2+)-dependent lectin with possible roles in cell-cell interaction during spermatogenesis and sperm-zona pellucida binding at fertilization.

Animals↗

The matricellular protein SPARC is internalized in Sertoli, Leydig, and germ cells during testis differentiation.

The gene encoding the matricellular protein secreted protein, acidic and rich in cysteine (SPARC) was identified in a screen for genes expressed sex-specifically during mouse gonad development, as being strongly upregulated in the male gonad from very early in testis development. We present here a detailed analysis of SPARC gene and protein expression during testis development, from 11.5 to 15.5 days post coitum (dpc). Section in situ hybridization analysis revealed that SPARC mRNA is expressed by the Sertoli cells in the testis cords and the fetal Leydig cells, found within the interstitial space between the testis cords. Immunodetection with anti-SPARC antibody showed that the protein was located inside the testis cords, within the cytoplasm of Sertoli and germ cells. In the interstitium, SPARC was present intracellularly within the Leydig cells. The internalization of SPARC in Sertoli, Leydig, and germ cells suggests that it plays an intracellular regulatory role in these cell types during fetal testis development.

Animals↗

The detection of cytochrome P450 2E1 and its catalytic activity in rat testis.

Cytochrome P450 2E1 participates in the bioactivation of a wide variety of environmental and occupational pollutants. Such reactions may lead to the production of active carcinogenic metabolites. The presence of P450 2E1 in the testis and prostate has not yet been reported. In the present study, cytochrome P450 2E1 mRNA has been identified in the rat prostate and testis by reverse transcription PCR, southern blotting, and DNA sequencing. P450 2E1 protein from rat testis could be detected with immunoblot analysis, but was not detected in the prostate. The hydroxylation of p-nitrophenol, known to be mediated by P450 2E1, was demonstrated by HPLC measurement of product formation in microsomal fractions from the rat testis, but again not from prostate. Exposure of rats to pyridine resulted in a 2.9-fold increase of p-nitrophenol hydroxylation by testicular microsomes. Diethyldithiocarbamate, a selective mechanism-based inhibitor of P450 2E1, or a P450 2E1 monoclonal antibody, caused marked inhibition of testicular microsomal p-nitrophenol hydroxylase activity. These results indicate that cytochrome P450 2E1 is present in the rat testis, and that it is elevated by the treatment of the animals with pyridine. Thus, the presence and inducibility of cytochrome P450 2E1 in the testis may be of significance in the bioactivation of environmental chemicals to genotoxic metabolites.

Animals↗

Localization of estrogen receptor alpha and beta RNA in germinal and nongerminal epithelia of the channel catfish testis.

The germinal epithelium of the anterior region of the channel catfish testis is the site of spermatogenesis, whereas the nongerminal epithelium of the posterior region (seminal vesicle) may play a role in the regulation of seminal fluid composition. The available information indicates that estrogens play a physiological role in the regulation of spermatogenesis and seminal fluid composition in vertebrates. However, the cellular distribution of estrogen receptor (ER) gene expression in the teleost testis is poorly understood. Therefore, the objective of this study was to determine the presence and cellular distribution of ERalpha and ERbeta transcripts in germinal and nongerminal epithelia of the mature testis of channel catfish. RT-PCR of whole-testis RNA extracts showed that ERalpha and ERbeta RNAs are present in the mature testis. In situ hybridization of histological sections of the germinal epithelium showed that primary spermatocytes contain little or no ERalpha or ERbeta RNA. However, both ER transcripts were present in secondary spermatocytes and spermatids and their levels were relatively high in mature sperm. The columnar epithelium of the seminal vesicle also contained ERalpha and ERbeta RNA. The ER RNAs in epithelial cells of the seminal vesicle were not evenly distributed throughout the cytoplasm but seemed to concentrate in their apical region, near the nucleus. In conclusion, ERalpha and ERbeta genes are coexpressed in germinal and nongerminal epithelia of the mature testis of channel catfish and seem to be developmentally regulated in spermatocytes. These observations are consistent with the concept that estrogens, via interaction with ERalpha and ERbeta, participate in the regulation of male gamete development and fertility.

Animals↗

Effects of elevated temperature on the epididymis and testis: experimental studies.

The effects of temperature on the male tract have been examined in the rat, rabbit and hamster, as well as other species that include a naturally cryptorchid rodent, the degu, and an insectivore, the musk shrew. In principle, a small increase in the temperature of the testis does not destroy the germinal epithelium; however, it reduces testis weight and sperm production and brings a greater incidence of morphologically abnormal spermatids and spermatozoa. This demonstrates that the testis can be partially suppressed yet remain functional in the face of moderate elevation in its ambient temperature. Selective imposition of abdominal temperature on the epididymis alone does not suppress sperm maturation there, and bilaterally cryptepididymal males remain fertile for long periods. However, deep body temperature changes at least the ionic and protein composition of cauda fluid by virtue of effects on the cauda epithelium, and it eliminates the special ability of the cauda to store and prolong the life of spermatozoa. Additionally, deep body temperature also immediately curtails the storage capacity of the cauda epididymidis, an effect that is reflected in a reduced diameter and apparently length of that segment of the cauda as well as vas deferens, which contracts during orgasm to provide the bulk of the ejaculate. One consequence of this, notwithstanding a normal sperm production by the testis, is a much smaller number of spermatozoa in the first ejaculate, and an atypically steep decline in the number in subsequent ejaculates produced by cryptepididymal males. Further effects of deep body temperature on the epididymis are seen in significantly faster (rabbit) sperm transport through it, and a reduction in the time required for capacitation of (hamster) spermatozoa, in vitro and in vivo. Man's scrotal surface temperature is chronically elevated by several degrees in the clothed state. Although observations are lacking for human "control" populations, certain of the temperature-related phenomena described in animals are nevertheless suggested variably in different measurable functions of the human male reproductive tract. These include a relatively low number produced/gm of testis and a poorer quality of spermatozoa released from it, a rapid epididymal transport and minimally developed sperm storage system in the cauda epididymidis. Finally, the character of the ejaculated spermatozoa in several respects may imply an imminent state of capacitation. In all, this circumstantial evidence makes it seem possible that the human epididymis as well as the testis often exists in a state of temperature-induced partial suppression.

Animals↗

Current concepts of radiation treatment of carcinoma in situ of the testis.

During a recent international workshop on carcinoma in situ and cancer of the testis held in November 1992, there was consensus about the management of the contralateral testis in patients with unilateral testicular cancer [20]. Such men should be offered a biopsy of the contralateral testis. This consensus was based on (1) the high prevalence of carcinoma in situ (CIS) in the contralateral testis found not only in Danish men but also in studies from other countries and (2) the possibility of eradicating the CIS and thereby preventing the development of invasive cancer by means of localized irradiation with preservation of testosterone production in the testis. The aim of this paper is to outline the present status of the radiation treatment of CIS of the testis.

Antineoplastic Combined Chemotherapy Protocols↗

Distribution and fine structure of the lymphatic system in the human testis.

The distribution of lymph vessels in the human testis was investigated using ink injection methods, and light and electron microscopy. Lymph capillaries occur in the septula testis but are absent in the intertubular tissue. They consist of endothelial cells provided with an incomplete basal lamina and anchoring filaments of the adjacent connective tissue. Frequently, the endothelial cells are separated by gaps measuring up to 2 micron. The lymph capillaries of the septula testis are connected to lymph vessels in the rete testis and tunica albuginea. These vessels have occasional smooth muscle cells and valves. At the posterior margin of the testis, the network of lymph vessels merges into collecting ducts, which together with vessels derived from the rete testis are drained by the lymphatic system in the spermatic cord.

Endothelium↗

Expression of the preoptic regulatory factor-1 and -2 genes in rat testis. Developmental and hormonal regulation.

Hormone-responsive peptides play a vital role in development and regulation of testicular function. The preoptic regulatory factors, porf-1 and porf-2, were originally discovered in the rat brain, but are also expressed in the rat and human testis. In the brain expression is age-related, hormone-responsive, region- specific, and gender-related, suggesting that porf-1 and porf-2 are involved in gender-specific brain development and function. Tissue-specific porf-1 and porf-2 mRNAs are also found in the testis and hypophysectomy may alter testicular porf-2 expression. It was thus of interest to further examine porf-1 and porf-2 expression in the testis to evaluate their potential as hormone-responsive peptides that regulate testicular development and function. Testicular expression of both porf-1 and -2 was analyzed as a function of maturational stage, aging and hypophysectomy by the solution hybridization/nuclease protection assay, and cellular location determined by in situ hybridization histochemistry. Expression was quantitatively compared in normal male rats at 15, 30 and 60 d (n = 4) and at 2, 6, 12, and 24 mo of age (n = 5). During development porf-1 is expressed at a constant level at 15, 30 and 60 d, then declines significantly with advancing age; levels at 24 mo are only 20% of those seen at 2 mo (p < 0.05). In contrast, porf-2 expression is highest at 15 d of age and steadily declines at 30 and 60 d, plateaus in the mature adult (6 and 12 mo), then exhibits an additional significant decline in the aged 24 mo animals (6 vs 24 mo, p < 0.05). Hypophysectomy of young adult rats at day 42 results in increased testicular expression 12 d later of both porf-1 (p < 0.05) and porf-2(p < 0.005) compared to intact 54-d-old rats (n = 5). In situ hybridization histochemistry confirms that both porf-1 and porf-2 are expressed in the mature testis at 60 d of age. Porf-2 mRNA is localized to immature germ cells including spermatogonia and primary spermatocytes. Porf-1 mRNA is associated with mature sperm and at low levels in the Sertoli cell cytoplasm surrounding spermatocytes. These data suggest that porf-2 is a pituitary hormone-responsive factor in the developing testis and that both porf-1 and porf-2 have cell-type specific functions in the germ cell compartment of the mature testis

Aging↗

Immunocytochemical localization of testis ecdysiotropin in the pupa of the gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae).

Antiserum against testis ecdysiotropin isolated from the gypsy moth, Lymantria dispar, reacted with neurons in the protocerebrum, optic and antennal lobes, subesophageal, thoracic and abdominal ganglia, as well as in nerve tracts extending through the optic lobes, tritocerebrum, and interganglionic connectives of the pupal stage of these insects. Testis ecdysiotropin is a peptide required by immature moths to initiate production of testes ecdysteroid, which is necessary for the development of the male reproductive system and initiation of spermatogenesis. Antiserum against testis ecdysiotropin also detected an accumulation of testis ecdysiotripic-like material between the inner and outer testis sheaths of pupae. The localization of this peptide in the imaginal disks of the last larval stage, cells and nerve fibers in the optic and antennal lobes of the pupa of both sexes, as well as in the testes during development of the adult reproductive system indicates that testis ecdysiotropin has a much larger impact on adult metamorphosis than development of the reproductive system and initiation of gametogenesis. Although this peptide may have a modulatory role in the central nervous system (CNS), it may also initiate a cascade of activity required for the development of the adult nervous system, in addition to its role in reproduction.

Abdomen↗

A novel gene, RSD-3/HSD-3.1, encodes a meiotic-related protein expressed in rat and human testis.

The expression of stage-specific genes during spermatogenesis was determined by isolating two segments of rat seminiferous tubule at different stages of the germinal epithelium cycle delineated by transillumination-delineated microdissection, combined with differential display polymerase chain reaction to identify the differential transcripts formed. A total of 22 cDNAs were identified and accepted by GenBank as new expressed sequence tags. One of the expressed sequence tags was radiolabeled and used as a probe to screen a rat testis cDNA library. A novel full-length cDNA composed of 2228 bp, designated as RSD-3 (rat sperm DNA no.3, GenBank accession no. AF094609) was isolated and characterized. The reading frame encodes a polypeptide consisting of 526 amino acid residues, containing a number of DNA binding motifs and phosphorylation sites for PKC, CK-II, and p34cdc2. Northern blot of mRNA prepared from various tissues of adult rats showed that RSD-3 is expressed only in the testis. The initial expression of the RSD-3 gene was detected in the testis on the 30th postnatal day and attained adult level on the 60th postnatal day. Immunolocalization of RSD-3 in germ cells of rat testis showed that its expression is restricted to primary spermatocytes, undergoing meiosis division I. A human testis homologue of RSD-3 cDNA, designated as HSD-3.1 (GenBank accession no. AF144487) was isolated by screening the Human Testis Rapid-Screen arrayed cDNA library panels by RT-PCR. The exon-intron boundaries of HSD-3.1 gene were determined by aligning the cDNA sequence with the corresponding genome sequence. The cDNA consisted of 12 exons that span approximately 52.8 kb of the genome sequence and was mapped to chromosome 14q31.3.

Adult↗