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PubMed2002

Diethylstilbestrol attenuates antioxidant activities in testis from male mice.

It has been reported that acute exposure to diethylstilbestrol (DES) induces apoptosis in the testis, and antioxidants play a role in preventing DES-induced tissue damage. In this study, the effect of chronic exposure to DES on the antioxidants was examined in the testis and liver. Eight-week old male ICR mice were treated subcutaneously with various doses of DES for 20 days. Morphologically apparent apoptotic changes, 4-hydroxy-2-nonenal-positive cells and TUNEL-positive DNA-fragmentation, were demonstrated in the testis, but were minimal in the liver. Activities of antioxidants such as glutathione (GSH) peroxidase and GSH S-transferase decreased in both the liver and testis. The activity of Mn-superoxide dismutase (SOD) decreased in the liver but increased in the testis. The activity of Cu, Zn-SOD decreased in the liver but was unchanged in the testis. On Western and Northern blots, gamma-glutamylcysteine synthetase (gamma-GCS), a rate limiting enzyme of GSH synthesis, was increased in the liver dependent on the dose of DES. However, the expression of gamma-GCS was reduced in the testis. Since quinones, metabolites of DES, generate reactive oxygen species, which damage DNA, antioxidants are important to prevent the damage. The data suggest that antioxidant activities are impaired by DES, and the levels of GSH are related to DES-induced apoptosis in the testis.

Animals↗
PubMed1994

Glutathione S-transferases in rat testis microsomes: comparison with liver transferase.

Glutathione S-transferases in testis microsomes were purified from rats and compared with the liver microsomal transferase. When microsomal fractions were prepared from rat testis by the same method as used for liver microsomes, testis microsomal glutathione S-transferase activity was increased 2-fold by N-ethylmaleimide as compared to a 7-fold increase in that of the liver transferase. In contrast to the single glutathione S-transferase in liver microsomes, at least three isozymes of glutathione S-transferase were separated from testis microsomes on hydroxylapatite column chromatography. The major fraction exhibiting glutathione S-transferase activity from the testis microsomes was shown to contain a member of the Mu family. The second fraction with transferase activity contained one of the Alpha class, and the third and smallest fraction was found to contain the liver microsomal form of glutathione S-transferase. Since the GSH S-transferase of the Mu family is present in the cytosol, we isolated the GSH S-transferase from testis cytosol, it being suggested that the major GSH S-transferase in testis microsomes is the cytosolic transferase. These results indicate that testis microsomes contain mainly the cytosolic form of glutathione S-transferase, and that the activity of the liver microsomal form of the transferase is very low.

Animals↗
PubMed2003

NYD-SP16, a novel gene associated with spermatogenesis of human testis.

By hybridizing human adult testis cDNA microarrays with human adult and embryo testis cDNA probes, a novel human testis gene NYD-SP16 was identified. NYD-SP16 expression was 6.44-fold higher in adult testis than in fetal testis. NYD-SP16 contains 1595 base pairs (bp) and a 762-bp open reading frame encoding a 254-amino acid protein with 73% amino acid sequence identity with the mouse testis homologous protein. The NYD-SP16 gene was localized to human chromosome 5q14. The deduced structure of the NYD-SP16 protein contains one transmembrane domain, which was confirmed by GFP/NYD-SP16 fusion protein expression in the cytomembrane of the transfected human choriocarcinoma JAR cells, suggesting that it is a transmembrane protein. Multiple tissue distribution indicated that NYD-SP16 mRNA is highly expressed in the testes and pancreas, with little or no expression elsewhere. Further analysis of abnormal expression in infertile male patients revealed complete absence of NYD-SP16 in the testes of patients with Sertoli-cell-only syndrome and variable expression in patients with spermatogenic arrest. Homologous gene expression in mouse testis was confirmed in spermatogenic cells by in situ hybridization. The results of cDNA microarray, in situ hybridization, and semiquantitative polymerase chain reaction in mouse testis of different stages indicated that NYD-SP16 expression is developmentally regulated. These results suggest that the putative NYD-SP16 protein may play an important role in testicular development/spermatogenesis and may be an important factor in male infertility.

Adult↗
PubMed2006

Testis morphometry, duration of spermatogenesis, and spermatogenic efficiency in the wild boar (Sus scrofa scrofa).

The wild boar is a natural inhabitant of Europe, Asia, and North Africa and is phylogenetically the ancestor of the domestic pig. Because of its phylogenetic and economic importance, this species is an interesting model for studying testis function in boars. Therefore, the present study was performed to investigate the testis structure, spermatogenic cycle length, and Sertoli cell (SC) and spermatogenic efficiencies in eight adult wild boars. Each spermatogenic cycle lasted 9.05 days, and the total duration of spermatogenesis was estimated as lasting approximately 41 days. The percentages of testis volume occupied by seminiferous tubules and by Leydig cells were 87% and 6%, respectively. The mean number of SCs per gram of testis was 42 million. The SC (round spermatids per SC) and spermatogenic (daily sperm production per gram of testis) efficiencies were 6.6 cells and 28.6 million, respectively. In general, the testis structure, overall germ cell associations at the different stages of the seminiferous epithelium cycle, and duration of spermatogenesis in the wild boar were similar to those in domestic pigs. Probably because of the small size of Leydig cells (400 microm3), their number per gram of testis (157 million) was the highest among investigated mammalian species. Although the SC efficiency in wild boars was low, their spermatogenic efficiency was comparable to that observed in domestic pigs, mainly because of the higher number of SCs per gram of testis in wild boars. These data suggest that SCs became more efficient during evolution, genetic selection, and domestication in pigs.

Animals↗
PubMed1987

Developmental regulation of calmodulin, actin, and tubulin RNAs during rat testis differentiation.

Postnatal testis differentiation involves transition through neonatal, pre-meiotic, meiotic, haploid, and mature stages. We have examined the qualitative and quantitative changes in rat testis RNAs that specifically hybridize to cDNAs encoding the cytoskeletal proteins, calmodulin, beta-actin, alpha- and beta-tubulin at ages corresponding to each of these developmental periods. We compared the species and relative levels of specific RNAs from testes of animals engaged in normal spermatogenesis with RNA from germ cell-depleted, Sertoli cell-enriched (SCE) testis. Distinct developmental patterns of expression of the specific RNAs were found with each of the cDNAs in the two animal models. A 2.2 kb (kilobase) actin RNA and a 2.7 kb beta-tubulin RNA are maximal at 5-10 days of age, suggesting these RNAs are required by somatic and germ cells in the postnatal phase prior to puberty. Between 19 and 29 days, when pachytene spermatocytes appear in significant numbers, there is a slight increase in the 2.2-kb actin RNA, but a 4- to 10-fold increase in RNAs hybridizing to cDNAs for calmodulin, alpha- and beta-tubulin. These changes are much less pronounced in the SCE testis than in the normal testis, indicating increases in these RNAs are related to germinal cell maturation. The germ cell-related increase in 1.8-kb beta-tubulin RNA appears to reflect a developmental "switch" in the gene from which the RNA is derived. This hypothesis is based on the observation that the ratio of hybridization of a chicken brain beta-tubulin cDNA versus a rat spleen beta-tubulin cDNA to the 1.8-kb RNA band increases more than 40-fold between 5 and 29 days of age in normal testis, but is constant in SCE testis. These data suggest that a specific beta-tubulin gene is activated in maturing germ cells. Analogously, a 2.1-kb alpha-tubulin RNA is found only in maturing normal testis and increases as spermatids are produced. A 2.0-kb beta-tubulin RNA, not found in normal testes, is maximal in maturing SCE testes, suggesting this RNA is of somatic cell origin. All of the RNA species studied, except the 2.0-kb beta-tubulin RNA, decrease between 5 and 19 days in SCE testes, as Sertoli cell mitotic activity wanes, indicating that their levels may be regulated by the developmental signals that influence mitosis.

Actins↗
PubMed1992

Impaired detoxification of reactive oxygen and consequent oxidative stress in experimentally cryptorchid rat testis.

The effect of experimental cryptorchidism on the level of oxidative stress and antioxidant functions in rat testis was studied. Adult male Sprague-Dawley rats were rendered unilaterally cryptorchid (by suturing one testis to the abdominal wall) and killed 1, 3, or 7 days after the operation. As an indicator of oxidative stress, lipid peroxidation was measured by the diene conjugation method in testis homogenates. The activities of the antioxidant enzymes were determined either in the 10,000 x g supernatant fraction (glutathione [GSH] peroxidase, GSH transferase, hexose monophosphate shunt) or in crude testis homogenates (superoxide dismutase, catalase). An expected reduction (48%) in weight of the abdominal testes was evident by postoperative Day 7. The catalytic activities per testis of superoxide dismutase (Cu/Zn form) and catalase were found to decrease in cryptorchidism. The effect was seen on the first postoperative day and was most profound on Day 7 after surgery. The principal antioxidant enzyme, superoxide dismutase, was most sensitive to cryptorchidism, the activity in the abdominal testes being 74% or 85% (per gram of tissue or per whole testis, respectively; p less than 0.01). After impairment of the reactive oxygen detoxifying capacity, lipid peroxidation was increased in the abdominal testis by 46% (p less than 0.01) on postoperative Day 7. Slight concomitant increases were detected in the activities of GSH-peroxidase (p less than 0.01), GSH-transferase (p less than 0.001), and the hexose monophosphate shunt (p less than 0.001). This effect was seen only when calculated per gram of tissue, not per whole testis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Effects of short photoperiod on ATPase activities in the testis of the immature Siberian hamster.

The effects of changes in photoperiod length upon body weight; spleen, thymus, and testis weights; testis protein content; testis cation pump enzyme activities; and plasma testosterone were studied in the developing Siberian hamster, Phodopus sungorus. Male hamsters were exposed to a cycle of 16L:8D (long-day), until Day 18 when half were switched to a 10L:14D (short-day) cycle, until killed 0, 2, 4, 7, 10, 12, or 15 days later. Body weight and relative testis weight (expressed as percentage of body weight) increased steadily during the first week of exposure. After 10 days, the long-day hamsters consistently weighed more (p less than 0.05). Relative testis weights in the short-day group began to decrease (p less than 0.005) within 10 days and continued to decline. Testis homogenate K(+)-pNPPase- (as a measure of Na+,K(+)-ATPase) and Mg(2+)-pNPPase-specific activities closely paralleled testis weight, with the short-day animals (p less than 0.05) differing after 10 days. Plasma testosterone levels remained below adult levels through exposure Day 15, but were relatively lower (p less than 0.05) in the short-day group after 10 days. Spleen weights were similar for the long- and short-day groups. The short-day group had larger thymus weights after 12 days (p less than 0.05), but thymus enzyme activities did not differ between the two groups. We conclude that cation pump activities in the Siberian hamster testis are significantly affected by changes in photoperiod length.

Adenosine Triphosphatases↗
PubMed1994

Response of alpha 2-macroglobulin messenger ribonucleic acid expression to acute inflammation in the testis is different from the response in the liver and brain.

Recent studies from this laboratory have shown that Sertoli cells derived from 20-day-old rats and cultured in vitro synthesize and secrete a nonspecific protease inhibitor that is structurally and immunologically similar to serum alpha 2-macroglobulin (alpha 2-MG). In contrast to its serum homologue, the testicular alpha 2-MG is not an acute-phase protein in the rat since its protein concentration in the rete-testis fluid does not increase in response to inflammation. In the present study we examined the expression of alpha 2-MG mRNA in the rat testis in comparison to that in the brain and liver following induced inflammation. alpha 2-MG mRNA in the testis did not respond to induced inflammation, whereas its protein concentration in serum and its mRNA level in the brain and liver increased significantly in 20-day-old inflamed rats. In 8-day-old rat testis, where the blood-testis barrier is not yet formed, alpha 2-MG mRNA expression also did not respond to induced inflammation. The mRNA expression of clusterin, another authentic Sertoli cell protein whose secretion appears to be closely related to cell-cell interactions in the seminiferous epithelium, was shown to be unaffected by induced inflammation in the testis, brain, and liver. In view of the unexpected differential expression of alpha 2-MG mRNA to induced inflammation in the testis and liver, we sought to examine whether Sertoli cell alpha 2-MG would respond to FSH and testosterone (T), the major regulators of testicular function. Interestingly, expression of alpha 2-MG and clusterin mRNA in the Sertoli cell was not regulated by FSH, T, or a combination of FSH and T. Since there is an intimate morphological relationship between Sertoli cells and germ cells, we next examined the effect of germ cell-conditioned medium (GCCM) on Sertoli cell alpha 2-MG and clusterin mRNA expression. It was noted that GCCM caused a dose-dependent stimulation of alpha 2-MG and inhibition of clusterin mRNA expression in Sertoli cells, respectively. Therefore, our studies have shown that the regulatory mechanism that modulates the expression of alpha 2-MG mRNA in the rat testis is different from its counterpart in the brain and liver.

Aging↗
PubMed1994

Expression of heat shock factor 2 in mouse testis: potential role as a regulator of heat-shock protein gene expression during spermatogenesis.

We have examined the expression and function of heat shock transcription factor 2 (HSF2) in spermatogenic cells of mouse testis. The results of in situ RNA hybridization analysis, RNA filter hybridization, and reverse transcription-polymerase chain reaction (RT-PCR) analysis indicate that HSF2 mRNA expression in testis is subject to developmental and cell type-dependent, as well as stage-dependent, regulation. Localized expression of HSF2 mRNA in testis first appears between Day 14 and Day 21 of postnatal development. In adult testis, HSF2 mRNA is found at highest levels in spermatocytes and round spermatids. Immunocytochemical staining and gel mobility shift analysis demonstrate that HSF2 protein is localized to the nuclei of spermatocytes and round spermatids and that this transcription factor exists in testis in a constitutively active DNA-binding state. We further demonstrate that the constitutive HSF2 DNA-binding activity present in testis is able to interact with promoter sequences of the hsp70.2 gene, a testis-specific member of the hsp70 gene family. Taken together, our results show that the expression and functional properties of HSF2 are regulated in spermatogenic cell types of the mouse testis, supporting a role for this transcription factor as a regulator of hsp gene expression during spermatogenesis.

Animals↗
PubMed1995

Testis-brain RNA-binding protein, a testicular translational regulatory RNA-binding protein, is present in the brain and binds to the 3' untranslated regions of transported brain mRNAs.

Previous studies have demonstrated that a phosphoprotein in testis binds to transcript c, a sequence containing two highly conserved elements, Y and H, in the 3' untranslated region (UTR) of mouse protamine 2 mRNA (mP2) and represses its translation in vitro. When gel-retardation assays were performed with cytoplasmic extracts prepared from seven different mouse tissues, we found that brain in addition to testis contains a protein that binds to transcript c. Both the testis and brain proteins are found exclusively in the nonpolysomal fractions of their postmitochondrial extracts. The testis and brain proteins appear to be identical according to numerous criteria: the complexes they form with transcript c have identical mobility in native gels, identical optimal pH, identical lability to increased salt concentrations, identical chromatographic properties, identical molecular sizes as judged from UV crosslinking, and identical peptide mapping as revealed by V8 digestion of the UV crosslinked protein-RNA complexes. In addition to binding to the same conserved sequence in the 3'UTR of mP2, the phosphoprotein from testis and brain, hereafter called testis-brain RNA-binding protein (TB-RBP), also specifically binds to a similar sequence in the 3'UTR of brain Tau mRNA. Since TB-RBP binds to the 3'UTRs of several translationally regulated mRNAs in testis and since numerous transported brain mRNAs also contain the same conserved binding elements, we propose that TB-RBP plays a role in mRNA storage, translocation, and/or localization in brain and testis.

Ammonium Sulfate↗
PubMed1996

Effects of transient prepubertal 6-N-propyl-2-thiouracil treatment on testis development and function in the domestic fowl.

It has been well established that thyroid hormones play an important role in regulating the onset of puberty and reproductive function in birds. In mammals it has been shown that transient hypothyroidism induced with the reversible goitrogen 6-N-propyl-2-thiouracil (PTU) can result in tremendous increases in testis size and sperm production and that the timing of hypothyroidism must correspond to the period of Sertoli cell proliferation. As the period of Sertoli cell proliferation is not precisely known in the fowl, an experiment was conducted to determine whether chicken testes have a similar window of sensitivity to PTU treatment. Broiler breeder male chicks (Peterson) were placed in floor pens at one day of age and reared according to the breeder's management guide for the entire 28-wk duration (controls) or up to the point of dietary treatment with PTU (0.1% w:w) for 6 wk that began at 2-wk intervals (2-8, 4-10, 6-12, 8-14, and 10-16 wk of age); after treatment, birds were returned to feed restriction and photostimulated at 20 wk of age. Birds were bled and killed, and testes were collected at 4-wk intervals. At 28 wk, one testis was fixed for histological examination and one was immediately placed in liquid N2 for sperm counts. Treatment with PTU from 6 to 12 wk of age resulted in a 96% increase in mean testis weight at 28 wk of age (treated 39.3 +/- 4.1 g per testis vs. control 20.0 +/- 1.6 g per testis). These testes exhibited normal morphology and increased relative sperm production. Treatment with PTU from either 8 to 14 or 10 to 16 wk of age resulted in approximately a 35% increase in testis mass at 28 wk of age relative to the control value (27.2 +/- 2.0 g and 27.7 +/- 3.6 g vs. 20.0 +/- 1.6 g per testis, respectively). However, both of these groups clearly demonstrated precocious puberty and abnormal spermatogenesis. These results suggest that appropriately timed PTU treatment may result in permanent increases in testis size and sperm production in the domestic fowl.

Animals↗
PubMed2001

Mesenchymal cell precursors of peritubular smooth muscle cells of the mouse testis can be identified by the presence of the p75 neurotrophin receptor.

In the mouse embryo, at approximately 11.5 days postcoitum (dpc), cells migrate from the mesonephros into the developing testis to contribute to the somatic population of the interstitial compartment (i.e., peritubular myoid cells, Leydig cells, and endothelial cells). Studies from this laboratory have shown that the interstitial population of mesenchymal cells in fetal and newborn mouse testis express the p75 neurotrophin receptor (p75NTR, formerly known as the low-affinity nerve growth factor receptor); part of the cell population progressively congregates around testis cords, later to be replaced by contractile peritubular myoid cells, which express smooth muscle cell markers. In the present study, we show that the migrating cells and the p75NTR-expressing cells are the same population. We also show that the neurotrophin receptor is a useful endogenous marker to follow cell migration within the urogenital ridge and to identify and isolate mesenchymal precursors of myoid cells. A time-course immunolocalization study of the location of p75NTR-bearing cells within the urogenital ridge of mouse embryos between 10.5 and 12.5 dpc showed that the interstitium of the fetal testis was progressively occupied by p75NTR+ cells. The progressive increase of p75NTR expression within the developing testis was confirmed by immunoblot analysis of proteins isolated from the fetal gonads. Organ cultures of isolated testes or testis-mesonephros grafts confirmed that p75NTR+ cells do not appear in the testis unless a mesonephros is attached to it. Cells bearing the p75NTR receptor, purified from 12.5-dpc male mouse mesonephroi by immunomagnetic sorting, were able to differentiate in vitro into myoid cells. Immunofluorescence analysis of postnatal testis sections confirmed the presence around the tubules of cells coexpressing p75NTR and alpha-smooth muscle actin. The ability to identify and purify precursors of myoid cells may be of considerable help for studying the mechanisms regulating their differentiation.

Animals↗
PubMed2000

Proximal insertion of gubernaculum testis in normal human fetuses and in boys with cryptorchidism.

PURPOSE: We determine how the proximal gubernaculum testis is attached to the testis and epididymis in human fetuses, and compare these data with findings in boys who had undergone surgery for cryptorchidism. MATERIALS AND METHODS: We analyzed 280 testes and epididymides with the gubernacula of 140 well preserved, fresh human fetuses ranging from 10 to 35 weeks after conception with no detectable congenital malformations and 36 undescended testes of 28 boys 2 to 15 years old (mean age 6.8) who had undergone surgery for cryptorchidism. In both groups the different conformations of the relationship among the proximal gubernaculum, testis and epididymis were classified according to a system used for patients with cryptorchidism. In group A the gubernaculum is attached to the testis and epididymis, in group B the gubernaculum is attached only to the testis with a tail disjunction epididymal anomaly, in group C the gubernaculum is attached only to the testis with total disjunction of the epididymis, in group D the gubernaculum is attached only to the epididymal tail and in group E there are no attachments among gubernaculum, testis and epididymis. RESULTS: Of the 280 fetal testes studied 194 (69.2%) were in the abdomen, 38 (13. 57%) in the inguinal canal and 48 (17.14%) in the scrotum. There were 277 cases (98.9%) in group A and 3 (1.1%) in group B. Of the 36 undescended testes analyzed 2 (5.6%) were abdominal and 34 (94.4%) were inguinal. There were 26 cases (72.2%) in group A, 8 (22.2%) in group B and 2 in group D. CONCLUSIONS: In fetuses without congenital malformations or epididymal alterations, such as tail disjunction or elongated epididymis, the proximal portion of the gubernaculum was attached to the testis and epididymis in all cases. In undescended testes there was an increased incidence of paratesticular structure malformations accompanied by gubernacular attachment anomalies compared to the testes in normal fetuses.

Abdomen↗
PubMed2002

The single testis: paternity after presentation as unilateral cryptorchidism.

PURPOSE: We determine if paternity is reduced among men with monorchidism (absent or removed testis) compared to men with unilateral cryptorchidism corrected during childhood by orchiopexy and controls. The group of men with an absent testis was determined among males presenting during childhood with only 1 descended testis. MATERIALS AND METHODS: Data were obtained by medical record review and a detailed questionnaire. Only men who had been successful at or attempted paternity for whom we had complete data were included in the study from the entire cohort of 584 men with former cryptorchidism, 23 with absent testis, 26 treated with orchiectomy and 706 controls. RESULTS: Percentages of men reporting success after attempting paternity did not differ among men with an absent testis (15 of 15, 100%), treated with orchiectomy (17 of 20, 85.0%), with corrected unilateral cryptorchidism (313 of 349, 89.7%) and controls (412 of 442, 93.2%). There was no difference for a subgroup of men with cryptorchidism judged to have an atrophic testis at orchiopexy (17 of 20, 85%) or those who underwent orchiectomy at initial attempted orchiopexy (8 of 10, 80%) and men who had subsequently undergone orchiopexy (9 of 10, 90.0%). Paternity was also not reduced in the group of men with only 1 testis (32 of 35, 91.4%) (monorchism plus orchiectomy) compared to either the corrected unilateral cryptorchid group or the control group. Of 637 testes 183 were recorded as impalpable on examination before surgery and 23 testes were absent, including 7 recorded as palpable. In fact, 12.1% (23 of 190) of testes that should have been recorded as impalpable were absent. CONCLUSIONS: This study failed to indicate that paternity is diminished among men with a single testis compared with the general population, regardless of the origin of the loss. About 12% of unilateral impalpable testes judged to be impalpable on examination before surgery were found to be absent after surgical exploration.

Adolescent↗
PubMed2004

Structural evidence against hormonal therapy for cryptorchid testis: abnormal gubernacular attachment.

PURPOSE: Various factors are involved in testicular descent, and no single factor is elucidated as the cause of cryptorchidism. We prospectively observed the locations of gubernacular attachments in the cryptorchid testis. MATERIALS AND METHODS: From April 1996 to June 2002, 639 boys underwent surgical correction of cryptorchid testis. Those with complete records of testicular locations and gubernacular attachments were analyzed. RESULTS: A total of 639 boys underwent 732 surgical corrections of inguinal testis (425, 58%), high scrotal testis (165, 23%) and impalpable abdominal testis (142, 19%). Impalpable abdominal testes had gubernacular attachment to either the lateral or upper scrotum in 36 cases (25%) or around the inguinal ring in 83 (58%). The gubernaculum was attached to the bottom of the scrotum in 21 inguinal testes (5%), to the lateral or upper scrotum in 132 (31%) or around the inguinal ring in 268 (63%). In cases of high scrotal testis the gubernaculum was attached usually to the bottom of the scrotum (28, 17%), to the lateral or upper scrotum (109, 66%) or around the inguinal ring (26, 16%). CONCLUSIONS: The locations of distal gubernacular attachments in the cryptorchid testis were usually abnormal (93%). In these cases the possible testicular descent induced by hormonal therapy may either be insufficient or unable to prevent future ascent. Thus, early surgical correction rather than hormonal therapy is warranted in boys with cryptorchid testis.

Child↗
PubMed2000

Gene discovery using computational and microarray analysis of transcription in the Drosophila melanogaster testis.

Identification and annotation of all the genes in the sequenced Drosophila genome is a work in progress. Wild-type testis function requires many genes and is thus of potentially high value for the identification of transcription units. We therefore undertook a survey of the repertoire of genes expressed in the Drosophila testis by computational and microarray analysis. We generated 3141 high-quality testis expressed sequence tags (ESTs). Testis ESTs computationally collapsed into 1560 cDNA set used for further analysis. Of those, 11% correspond to named genes, and 33% provide biological evidence for a predicted gene. A surprising 47% fail to align with existing ESTs and 16% with predicted genes in the current genome release. EST frequency and microarray expression profiles indicate that the testis mRNA population is highly complex and shows an extended range of transcript abundance. Furthermore, >80% of the genes expressed in the testis showed onefold overexpression relative to ovaries, or gonadectomized flies. Additionally, >3% showed more than threefold overexpression at p <0.05. Surprisingly, 22% of the genes most highly overexpressed in testis match Drosophila genomic sequence, but not predicted genes. These data strongly support the idea that sequencing additional cDNA libraries from defined tissues, such as testis, will be important tools for refined annotation of the Drosophila genome. Additionally, these data suggest that the number of genes in Drosophila will significantly exceed the conservative estimate of 13,601.

Animals↗
PubMed2006

Morphological evaluation of the radioprotective effects of melatonin against X-ray-induced early and acute testis damage in Albino rats: an animal model.

Irradiation has profound effects on the reproductive function. Our knowledge about radioprotective effects of melatonin against X-ray-induced testis damage is rudimentary. In this investigation, we hypothesized that melatonin can minimize germ-cell depletion and morphological features of cell damage in testis following X-ray irradiation (XRI). To examine these effects, and to test our hypothesis, an animal model comprised of 60 Albino rats was established. The animals were divided into five groups: Group 1, non-irradiated; Group 2, X-ray irradiated (XRI, 8 Grays); Group 3, XRI pretreated with solvent (ethanol and phosphate-buffered saline); Group 4, non-irradiated group treated with melatonin and Group 5, XRI pretreated with melatonin. The testes were evaluated for both histological (light microscopy) and ultrastructural changes (transmission electron microscopy). Histologically, there were marked depletions (66%) of the germinal epithelial cells, in XRI group (Groups 2 and 3), whereas these changes were almost absent in XRI testis of animals pretreated with melatonin (Group 5). The number of spermatogenic cells in XRI testis of animals pretreated with melatonin (Group 5) was comparable (95%) to that of non-irradiated group (Groups 1 and 4) but significantly (P < 0.05) higher than those in XRI testis (34%, Groups 2 and 3). Ultrastructurally, XRI testis (Groups 2 and 3) showed features of apoptosis (condensation of the nuclei, vacuolization of the cytoplasm, increased cytoplasmic density and apoptotic bodies). These features were absent in XRI testis of animals pretreated with melatonin (Group 5). Also, this Group showed features of an increased metabolic activity (large acrosomal vesicle, prominent Golgi, increased mitotic activity, increased complement of cytoplasmic organelles and appearance of nucleoli-like bodies). There was a minimal depletion of the Sertoli and Leydig cells following XRI. Also, morphological features of apoptosis were infrequent in these cells. Administration of melatonin (MEL) prior to irradiation can protect testis against its destructive effects. The protective effects include amelioration of germ-cell depletion and apoptotic changes. The clinical ramifications of these observations mandate further studies.

Animals↗
PubMed1977

Changes in the sequence diversity of polyadenylated cytoplasmic RNA during testis differentiation in rainbow trout (Salmo gairdnerii).

We have compared the sequence diversity of polyadenylated cytoplasmic RNA derived from naturally maturing trout testis at three different stages of spermatogenesis, by performing hybridization experiments between cDNA synthesized on a template of polyadenylated RNA and a vast excess of polyadenylated RNA. Polyadenylated RNA from early testis has a base sequence complexity of 7.2x10(9) daltons. As testis maturation proceeds, there is a decrease in the complexity of polyadenylated mRNA sequences in testis cells and the relative abundance of individual mRNAs varies over a more narrow range. Heterologous hybridization reactions demonstrate that a substantial fraction of polyadenylated RNA sequences present in early testis cytoplasm is absent from late testis cytoplasm. Nevertheless, all the sequences of late testis mRNA are represented in the population of early testis mRNA molecules.

Aging↗