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PubMed2005

Sertoli cell proliferation in the adult testis--evidence from two fish species belonging to different orders.

Germ cell survival and development critically depend on the cells' contact with Sertoli cells in the vertebrate testis. Fish and amphibians are different from mammals in that they show a cystic type of spermatogenesis in which a single germ cell clone is enclosed by and accompanied through the different stages of spermatogenesis by an accompanying group of Sertoli cells. We show that in maturing and adult testes from African catfish and Nile tilapia, Sertoli cell proliferation occurs primarily during spermatogonial proliferation, allowing the cyst-forming Sertoli cells to provide the increasing space required by the growing germ cell clone. In this regard, coincident with a dramatic increase in cyst volume and number of germ cells per cyst, in Nile tilapia, the number of Sertoli cells per cyst was strikingly increased from primary spermatogonia to spermatocyte cysts. In both African catfish and Nile tilapia, Sertoli cell proliferation is strongly reduced when germ cells have proceeded into meiosis, and stops in postmeiotic cysts. We conclude that Sertoli cell proliferation is the primary factor responsible for the increase in testis size and sperm production observed in teleost fish. In mammals, Sertoli cell proliferation in the adult testis is not observed under natural conditions. However, on the level of the individual spermatogenic cyst--similar to mammals--Sertoli cell proliferation ceases when germ cells have entered meiosis and when tight junctions are established between Sertoli cells. This suggests that fish are valid vertebrate models for studying Sertoli cell physiology.

Age Factors↗

PubMed2001

Development of a 950-gene DNA array for examining gene expression patterns in mouse testis.

BACKGROUND: Over the past five years, interest in and use of DNA array technology has increased dramatically, and there has been a surge in demand for different types of arrays. Although manufacturers offer a number of pre-made arrays, these are generally of utilitarian design and often cannot accommodate the specific requirements of focused research, such as a particular set of genes from a particular tissue. We found that suppliers did not provide an array to suit our particular interest in testicular toxicology, and therefore elected to design and produce our own. RESULTS: We describe the procedures used by members of the US Environmental Protection Agency MicroArray Consortium (EPAMAC) to produce a mouse testis expression array on both filter and glass-slide formats. The approaches used in the selection and assembly of a pertinent, nonredundant list of testis-expressed genes are detailed. Hybridization of the filter arrays with normal and bromochloroacetic acid-treated mouse testicular RNAs demonstrated that all the selected genes on the array were expressed in mouse testes. CONCLUSION: We have assembled two lists of mouse (950) and human (960) genes expressed in the mouse and/or human adult testis, essentially all of which are available as sequence-verified clones from public sources. Of these, 764 are homologous and will therefore enable close comparison of gene expression between murine models and human clinical testicular samples.

Adult↗

PubMed2006

Avian transgenerational reproductive toxicity test with in ovo exposure.

Ecological risk assessment of environmental pollutants requires effective laboratory assays and extrapolation of the resultant data to wild species. Because avian reproductive disorder and accumulation of persistent compounds in wild birds and their eggs have long been observed in polluted regions, we have developed an assay for investigating whether pollutants accumulated in eggs impair the reproduction of the exposed birds and the survival of the next generation using the Japanese quail. A typical estrogenic compound, diethylstilbestrol (DES), dissolved in olive oil was injected into the air-chamber of fertilized eggs on day 10 of incubation. After sexual maturation of hatched chicks, we mated pairs of male and female quails following an observation period of egg production and collected their eggs. The collected eggs were incubated and checked for the fertility and hatchability, and then the hatchlings were raised and observed in growth for 3 weeks. A dosage of 5 ng/g per egg of DES caused eggshell thinning in eggs laid by exposed females and reduction in eggshell strength. DES also induced shortening of the left oviduct and unexpected development of the right oviduct, while testis weight was reduced symmetrically. The ability of quail pairs to produce offspring was significantly diminished by exposure of females to DES independently of exposure of males, which mainly arose from production of abnormal and inviable eggs. Fertility of normal-shelled eggs and hatchability of fertilized eggs were unchanged regardless of treatments. External morphological abnormalities, which were mostly unopened toes of the foot, were frequently observed in hatchlings from exposed males independently of exposure of females. Additionally, we attempted to extrapolate the experimental results to the northern bobwhite and to predict population trends for quails in a polluted habitat using a population projection model composed of a combination of a Leslie matrix and the logistic equation. In the event of accumulation of an estrogenic compound equivalent to a dosage of 5 ng/g DES in quail eggs, the average population size was predicted to decrease by 20.2% after 1 year, to approximately half after 4 years, and to a fifth after 14 years. When observed weakening of individuals and the risk of egg breakage are taken into consideration, the decline in population was further accelerated. The proposed assay appears to be suitable not only for assessing adverse effects of chemicals on avian reproduction but for population projection of affected wild birds.

Abnormalities, Drug-Induced↗

PubMed1997

Immunohistochemical analysis of androgen effects on androgen receptor expression in developing Leydig and Sertoli cells.

Leydig and Sertoli cells are both targets of androgen action in the testis. Androgen exerts contrasting effects on the two cell types partially inhibiting steroidogenesis in adult Leydig cell and stimulating adult Sertoli cell functions required to support spermatogenesis. The developmental changes in the messenger RNA (mRNA) levels of androgen receptor (AR) also differ between Leydig and Sertoli cells, with Leydig cell AR mRNA being highest on day 35 postpartum, whereas Sertoli cell AR mRNA levels are highest on day 90. The purpose of the present study was to determine if the concentrations of AR in Leydig and Sertoli cells are differentially regulated during development using quantitative immunostaining. AR protein levels were measured in rat testes after hormonal treatments at three developmental stages: on days 21, 35, and 90 postpartum. At each age, five groups of animals were treated for 4 days with: 1) vehicle; 2) LHRH antagonist (NalGlu, 0.3 mg/kg BW.day) to suppress endogenous levels of androgen that accompany inhibition of LH and FSH secretion; 3) NalGlu + LH (0.2 mg/kg BW.day); 4) NalGlu + testosterone (T, at 7.5 mg/kg BW.day); and 5) NalGlu + MENT (a potent synthetic androgen, 7 alpha-methyl-19-nortestosterone, 0.7 mg/kg BW.day). AR protein was visualized by immunohistochemistry and measured by computer-assisted image analysis in Leydig and Sertoli cells using frozen sections of tests. After NalGlu treatment, AR levels in Leydig cells declined sharply to 42% and 31% of vehicle control (P < 0.01) in the 21 and 35 days postpartum age groups, respectively, but in 90-day-old rats there was no change. AR levels were partially maintained by exogenous LH, and completely maintained by exogenous androgen treatments in Leydig cells from 21- and 35-day-old rats, whereas in Leydig cells from 90-day-old rats, AR levels were unaffected in all treatment groups. In contrast, after NalGlu treatment, the AR concentration in Sertoli cells from 90-day-old rats were reduced to 32% of control (P < 0.01). Moreover, in Sertoli cells from 90-day-old rats, AR levels were partially maintained by LH and completely maintained by androgens. A similar trend was observed on day 35. On day 21, however, AR levels in immature Sertoli cells were unaffected in all treatment groups. These results indicate that androgen maximally stimulates AR levels in immature Leydig cells but is without significant effect in adult Leydig cells. In contrast, AR levels in Sertoli cells are more sensitive to androgen regulation in adult compared with immature animals. These findings indicate that there are distinct mechanisms controlling AR concentrations in Leydig and Sertoli cells during the development of the testis.

Androgens↗

PubMed2003

Cellular localization of pituitary adenylate cyclase-activating polypeptide in the rat testis.

Several growth factors are critical regulators of testicular development. Recently, pituitary adenylate cyclase-activating polypeptide (PACAP) has been shown to promote the differentiation and proliferation of various cell types and to stimulate the release of vascular endothelial growth factor during tissue growth. The present study aimed to evaluate the possible expression of PACAP in immature and adult rat testes by Northern blot analysis, in situ hybridization, and immunohistochemistry. PACAP transcripts were detected in both immature and adult tissues, but the level of PACAP expression depended on the age of the animal. It was expressed in the peritubular and interstitial cells of the 14-day-old testis and in seminiferous tubules of the 90-day-old-testis. It was strongly expressed in blood vessels at 14 days, moderately at 28 days and only weakly at 90 days. These results suggest that PACAP contributes to the growth and differentiation of peritubular and interstitial cells, and of blood vessels, during testicular development.

Animals↗

PubMed1980

Morphology of the rat rete testis in experimental autoimmune orchitis.

The role of the rete testis and related structures in the development of experimental autoimmune orchitis (EAO) was studied in adult inbred Sprague-Dawley rats. Histology and electron microscopy showed focal perivascular infiltration and an increase in the number of mast cells and polymorphonuclears. Often there were vacuolated macrophages. These changes were first observed two weeks after the beginning of immunization, but they did not clearly precede lesions in seminiferous tubules. Increased amounts of cellular debris appeared in rete cavities, suggesting damage to germinal epithelium. Lanthanum tracer studies of immunized rats showed local lesions in the blood-testis barrier of the seminiferous tubules but did not indicate spreading of lesions from the rete testis. Efferent duct ligation of immunized rats for 24 h did not increase the frequency of lesions. The present observation do not support the theory that the rete testis is the route of spreading of EAO.

Animals↗

PubMed1998

Neural crest-specific and general expression of distinct metalloprotease-disintegrins in early Xenopus laevis development.

Metalloprotease-disintegrins are a family of membrane-anchored glycoproteins that have been implicated in diverse cellular processes, including fertilization and myoblast fusion, release of TNFalpha from the plasma membrane, and neurogenesis. Here we report the cloning of cDNAs encoding three full-length (xMDC9, xMDC11b, and xMDC13), and one partial (xMDC11a) metalloprotease-disintegrin from the amphibian Xenopus laevis, and the analysis of their expression during early X. laevis development and in adult tissues. The most notable finding was the highly localized and specific expression pattern of xmdc11a at the tailbud stage in the cranial neural crest and in a subset of neural tube cells in the trunk region. In contrast, expression of the closely related xmdc11b was not detectable during the early stages of X. laevis development, and remained low in the adult tissues examined here. Distinct expression patterns were also observed for two other highly related X. laevis genes, xmdc13 and adam13 (Alfandari et al., 1997). While adam13 is expressed in the somitic mesoderm and in neural crest cells, but not in adult testis, xmdc13 expression is low and ubiquitous in the developing embryo, but is clearly present in adult testis. Finally, xmdc9, the putative orthologue of human and mouse mdc9, was found at all stages of development, and in all tissues examined, suggesting a function that may be utilized by most or all cells. The noteworthy features of these four xmdc genes and the implications of their distinct spatial and temporal expression patterns are discussed.

Amino Acid Sequence↗

PubMed2006

Larger testes and higher inhibin B levels in Finnish than in Danish newborn boys.

CONTEXT: Recent studies showed that male reproductive health problems, such as cryptorchidism, hypospadias, testicular cancer, and low sperm quality, are more prevalent in Denmark than in Finland. OBJECTIVES: We hypothesized that, if fetal testicular dysgenesis contributed to these observations, differences in gonadal development and the hypothalamus-pituitary-testis axis would already be detectable perinatally. Thus, we investigated healthy newborn boys in both countries. DESIGN: This was a prospective, longitudinal population-based study. SETTING: Two primary obstetric centers were included at the University Hospitals of Copenhagen, Denmark, and Turku, Finland. PARTICIPANTS: The participants of the study included 633 Danish and 1044 Finnish boys, born at term with appropriate weight for gestational age. INTERVENTIONS: Ultrasound determination of testis size at 0, 3, and 18 months and blood sampling (n = 727) at 3 months were analyzed. MAIN OUTCOME MEASURES: Testicular volume and reproductive hormones were measured. RESULTS: Testis volume was significantly higher at all ages in Finnish than in Danish boys (medians, 98 vs. 95, 185 vs. 119, and 188 vs. 136 mm(3), respectively; P < 0.00001). Testis growth from birth to 3 months was larger in Finnish than in Danish boys (mean, 75 vs. 26 mm(3); P < 0.0001). Serum hormone levels were higher in Finnish than Danish boys for inhibin B (median, 456 vs. 385 pg/ml; P < 0.0001), FSH (1.33 vs. 1.21 IU/liter; P < 0.036), and SHBG (143 vs. 136 nmol/liter; P < 0.022). Inhibin B was significantly positively correlated to testicular volume (r = 0.25; P < 0.006). CONCLUSIONS: The larger testes and higher inhibin B levels most likely represent a bigger volume of seminiferous tubules in Finnish compared with Danish boys. Although this phenomenon may be attributable to a genetic difference between the two countries, it may also reflect environmental factors influencing testicular development.

Adult↗

PubMed1985

The role of germinal epithelium and spermatogenesis in the privileged survival of intratesticular grafts.

The testis is an immunologically privileged site. Since earlier studies excluded testicular steroid production as an essential factor, the present study evaluates the role of germ cells and spermatogenesis in the privileged survival of allografts within the testis. We used a Sertoli cell-only testis model and adolescent unilateral cryptorchidism in inbred rats to eliminate germ cells and spermatogenesis selectively. Parathyroid allografts were implanted into these sites, normal testes and beneath the renal capsule (a nonprivileged site) in appropriately matched controls. With at least 15 rats in each group, privileged allograft survival was shown to be unaffected by eliminating germ cells and spermatogenesis (p less than .005). Experimental evidence suggests the presence of an active process which incidentally permits privileged allograft survival within the testis, but which exists teleologically to protect the developing sperm from autoimmune attack. This is in addition to the passive anatomical separation provided by the blood-testis barrier. Our cumulative data strongly implicates the Sertoli cell in this process.

Animals↗

PubMed1995

Sexual differentiation of chimeric chickens containing ZZ and ZW cells in the germline.

The developmental fate of male and female cells in the ovary and testis was evaluated by injecting blastodermal cells from Stage X (Eyal-Gliadi and Kochav, 1976: Dev Biol 49:321-337) chicken embryos into recipients at the same stage of development to form same-sex and mixed-sex chimeras. The sex of the donor was determined by in situ hybridization of blastodermal cells to a probe derived from repetitive sequences in the W chromosome. The sex of the recipient was assigned after determination of the chromosomal composition of erythrocytes from chimeras at 10, 20, 40, and 100 days of age. If the sex chromosome complement of all of the erythrocytes was the same as that of blastodermal cells from the donor, the sex of the recipient was assumed to be the same as that of the donor. Conversely, if the sex-chromosome complement of a portion of the erythrocytes of the chimera differed from that of the donor blastodermal cells, the sex of the recipient was assumed to differ from that of the donor. Injection of male blastodermal cells into female recipients produced both male and female chimeras in equal proportions whereas injection of female cells into male recipients produced only by male chimeras. One phenotypically male chimera developed with a left ovotestis and a right testis although sexual differentiation was usually resolved into an unambiguous sexual phenotype during development when ZZ and ZW cells were present in a chimera. Donor cells contributed to the germline of 25-33% of same-sex chimeras whereas 67% of male chimeras produced by injecting male donor cells into female recipients incorporated donor cells into the germline. When ZW cells were incorporated into chimeric males, W-chromosome-specific, DNA sequences were occasionally present in DNA extracted from semen. To examine the potential of W-bearing spermatozoa to fertilize ova, males producing ZW-derived offspring and semen in which W-chromosome-specific DNA was detected by Southern analysis were mated to sex-linked albino hens. Since sex-linked albino female progeny were not obtained from this mating, it was concluded that the W-bearing sperm cells were unable to fertilize ova. The production of Z-derived, but not W-derived, offspring from ZW spermatogonia indicates that female primordial germ cells can become spermatogonia in the testes. In the testes, ZW spermatogonia enter meiosis I and produce functional ZZ spermatocytes. The ZZ spermatocytes complete the second meiotic division, continue to differentiate during spermiogenesis, and leave the seminiferous tubules as functional spermatozoa. By contrast, the WW spermatocytes do not appear to complete spermiogenesis and, therefore, spermatozoa bearing the W-chromosome are not produced. When cells from male embryos were incorporated into a female chimera, ZZ "oogonia" were included within the ovarian follicles and the chromosome complement of genetically male oogonia was processed normally during meiosis. Following ovulation, the male-derived ova were fertilized and produced normal offspring. This is the first reported evidence that genetically male avian germ cells can differentiate into functional ova and that genetically female germ cells can differentiate into functional sperm.

Animals↗

PubMed2001

[Undescended testicular tumor found by torsion of the testis: a case report].

A 37-year-old man was admitted with a painful mass in his left inguinal region. He had an undescended testis on the left side. Six months earlier, he had noted that his left inguinal testis was larger, and he had suddenly developed pain in the left inguinal region. The levels of AFP, hCG beta and LDH were normal. We diagnosed a left undescended testicular tumor and torsion of the left testis. Left inguinal high orchiectomy showed a torsion of the left testis and histopathological examination of the specimen revealed seminoma.

Adult↗

PubMed2005

[The application of gonadotropin in treatment of male central hypogonadism].

OBJECTIVE: To observe the efficacy of human chorionic gonadotrophin (hCG) and hCG plus human menopausal gonadotropin (HMG) for central hypogonadism in male patients. METHODS: 64 men with central hypogonadism were recruited in this study, including 19 patients with Kallmann syndrome, 41 patients with idiopathic hypogonadotrophic hypogonadism (IHH) and 4 patients with hypogonadism after brain surgery. 33 patients were treated with hCG 1500 IU intramuscularly twice a week, whereas 31 patients were treated with intramuscular hCG 1500 IU plus HMG 75 IU twice a week, for at least 6 months. RESULTS: After treatment, all patients felt stronger physically and 42/64 patients developed beard, pubes or armpit hair. The testis volume enlarged significantly [(3.08 +/- 2.44) ml vs (8.92 +/- 5.37) ml, P < 0.001], and serum follicle-stimulating hormone, luteinizing hormone and testosterone concentrations were higher significantly than those before treatment (P < 0.05). 6/64 patients underwent spermatorrhea and 2 patient were found to have spermatogenesis. If judged by the testis volume, 52 patients (81.2%) were effective and 12 patients were ineffective. CONCLUSIONS: For male patients with the central hypogonadism, hCG and hCG plus HMG can promote the pubertal development and maturation of second sex characteristics, as well as enhance the physical strength; in some patients both androgen production and spermatogenesis can be achieved.

Adolescent↗

PubMed1995

The effect of the excision of future scrotal skin on testicular descent in neonatal rats: a new experimental model of cryptorchidism.

The ingunoscrotal skin of neonatal rats was widely excised on either the right or left side to examine the role of the scrotum in testicular descent. At the age of 10 days, gubernacular migration was observed to be significantly inhibited on the operated side in comparison with that on the nonoperated side. At the age of 60 to 90 days, 12 of 17 testes on the operated side were located in the superficial inguinal position, 2 were in the perineum, and another 3 had descended into the contralateral nonoperated scrotum. All the testes descended into the scrotum on the nonoperated side and in the normal control rats. Though the histological development was remarkably inhibited in the cryptorchid testis, the contralateral descended testis did show the same histological appearance as that of the control testes in 90-day-old rats. This new model of cryptorchidism is considered to provide a simple technique for investigating the mechanism of testicular descent and the impaired development of the testes in cryptorchidism.

Animals↗

PubMed2003

Exposure to the environmental estrogen bisphenol A differentially modulated estrogen receptor-alpha and -beta immunoreactivity and mRNA in male mouse testis.

We examined the effects of bisphenol A (0.5 microg/ml or 50 microg/ml) in the drinking water on estrogen receptor (ER) alpha and beta proteins and mRNA in the testis of young mice following 8-weeks of oral administration of bisphenol A utilizing immunohistochemistry and semiquantitative reverse transcription polymerase chain reaction amplification (RT-PCR). ER beta was clearly localized in the nuclei of spermatogonia and/or spermatocytes. ER beta immunopositive cell numbers per testis section were significantly decreased in the 50 microg/ml bisphenol A-treated group compared with control and the 0.5 microg/ml bisphenol A-treated group. The number of ER alpha positive cells in the testis was significantly lower than ER beta positive cells in control group. ER alpha immunopositive cell numbers per testis section were markedly increased in the 50 microg/ml bisphenol A-treated group compared with the control and the 0.5 microg/ml bisphenol A-treated group. ER beta mRNA expression was significantly decreased in the 50 microg/ml bisphenol A-treated group compared with the control and the 0.5 microg/ml bisphenol A-treated group. In contrast, ER alpha mRNA expression was markedly increased in the 50 microg/ml bisphenol A-treated group compared with the control and the 0.5 microg/ml bisphenol A-treated group. The existence of ER alpha and beta in the testis suggests that estrogens directly affect germ cells during testicular development and spermatogenesis, and differential modulation of ER alpha and beta in the testis could be involved in the effects of bisphenol A.

Animals↗

PubMed1985

Descent of the testis in the fetal calf. A summary of the anatomy and process.

The descent of the testis in the fetal calf is reviewed, and the role in that process of the swelling reaction of the gubernaculum testis is discussed. The testes of 30 Dutch Friesian fetuses were examined by dissection and light microscopy of sections prepared from chemically and frozen-fixed specimens. The gubernaculum remains unattached to the scrotal fasciae until descent is completed. Shortening of the intra-abdominal gubernaculum and displacement of the testis begins at fetal week 11; the swelling reaction of the gubernaculum occurs between weeks 14 and 15. The testis is at the deep inguinal ring by week 15, and by week 20 it is in the scrotal position and the gubernaculum has regressed. It is proposed that the swelling of the gubernaculum dilates the vaginal ring and enlarges the inguinal canal. The clinical importance of these anatomical relationships and changes is discussed.

Animals↗

PubMed1999

Developmentally regulated expression of cyclin D3 and its potential in vivo interacting proteins during murine gametogenesis.

To begin to assess the function of the cell cycle regulator cyclin D3 during gametogenesis, the present study examined its expression, interacting partners, and associated kinase activity in the murine testis and ovary. In the early stages of postnatal testicular development, cyclin D3 protein was detected in spermatogonia and Leydig cells. In the adult testis, cyclin D3 was also expressed in terminally differentiating spermatids. In the embryonic ovary, detection of cyclin D3 was limited to somatic cells. In the postnatal ovary, its localization was predominantly in the nuclei of oocytes in primordial and small follicles, a localization that diminished with oocyte growth. Cdk4 and p27 were expressed in a similar subset of testicular and ovarian cells, suggesting that they may regulate cyclin D3 function during testicular and ovarian development in a cell type-specific manner. Cyclin D3-associated kinase activity was detected in immature, but not adult, testes and ovaries. These observations suggest unique roles for cyclin D3 in the control of cell division and differentiation in the germ line and the differential regulation of mitotic and meiotic cell cycles during male and female gametogenesis.

Animals↗

PubMed2001

Perforin-independent expression of granzyme B and proteinase inhibitor 9 in human testis and placenta suggests a role for granzyme B-mediated proteolysis in reproduction.

Granzyme B (graB) plays a pivotal role in cytotoxic lymphocyte granule-mediated apoptosis through cleavage of intracellular proteins in target cells. Proteinase inhibitor-9 (PI-9) is a potent inhibitor of graB and is highly expressed in cytotoxic lymphocytes. Here, we show by immunohistochemistry that PI-9 is also abundantly expressed in human testicular Sertoli cells and placental syncytial trophoblasts. Postulating that PI-9 protects these tissues from graB-producing auto- or allo-reactive cytotoxic lymphocytes, we also stained sections for graB. Unexpectedly, graB was observed in non-cytotoxic cells in both tissues. In the adult human testis, graB was present in spermatogenic cells within the seminiferous tubule, and this was verified by in-situ hybridization and reverse transcription-polymerase chain reaction (RT-PCR). Immunohistochemical analysis of term placentae demonstrated graB in syncytial trophoblasts, and this was confirmed by RT-PCR on primary trophoblasts from term placenta. Perforin, which is co-produced with graB by activated cytotoxic lymphocytes and is required for graB release into the target cell, was not detected in either testis or placenta. We postulate that, in these organs, graB has a perforin-independent role, involving hydrolysis of extracellular matrix components. In the testis, graB may facilitate migration of developing germ cells, while in the placenta, it may contribute to extracellular matrix remodelling during parturition.

Animals↗

PubMed1999

Identification and characterization of TESK2, a novel member of the LIMK/TESK family of protein kinases, predominantly expressed in testis.

In this study we present the cDNA sequence of a novel putative protein kinase, denoted TESK2. The open reading frame of TESK2 encodes a putative 555-amino-acid protein, including a protein kinase consensus sequence in the N-terminal half. The protein kinase domain of TESK2 is structurally similar to the kinase domain of the protein serine/threonine kinase TESK1 (64% identity) and to those of the LIMK1 and LIMK2 kinases (42 and 39% identity, respectively). TESK2, together with TESK1, constitutes a second subgroup of the LIMK/TESK family of protein kinases, as revealed by phylogenetic analysis of the protein kinase domains. Chromosomal localization of human TESK2 was assigned to 1p32. Expression analysis of human TESK2 revealed a single mRNA species of 3.0 kb predominantly expressed in testis and prostate and low expression in most other tissues examined. Rat testicles expressed a single species of TESK2 mRNA of approximately 3.5 kb. However, the transcript was first detectable in rat testis after day 30 of postnatal development and was predominantly expressed in round spermatids. These observations suggest that TESK2 plays an important role in spermatogenesis.

Amino Acid Sequence↗