Are male germ cells of the arid-zone hopping mouse (Notomys alexis) sensitive to high environmental temperatures?

2011 ◽  
Vol 59 (4) ◽  
pp. 249 ◽  
Author(s):  
H. Wechalekar ◽  
B. P. Setchell ◽  
E. Peirce ◽  
C. Leigh ◽  
W. G. Breed
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Arid Zone ◽  
Core Body Temperature ◽  
Mammalian Species ◽  
Whole Body ◽  
Testicular Artery ◽  
Male Germ Cells ◽  
Environmental Temperatures ◽  
Body Heat

In most mammalian species, the temperature of scrotal testes is several degrees lower than that of core body temperature due to the presence of a counter-current heat exchange between the coiled testicular artery and the pampiniform plexus of veins. Here we ask: have hopping mice developed a highly efficient cooling mechanism within their scrotal sac and/or germ cell resistance to high environmental temperatures? To investigate this, adult male sexually mature Notomys alexis were used to determine: (1) the temperature of the testes; (2) the extent of coiling of the testicular artery; (3) the effect of artificially induced cryptorchidism on spermatogenesis up to three weeks after surgery; and (4) the effect of whole body heat exposure of 37−38°C for 8 h per day for three consecutive days on germ cell apoptosis. The results showed that in hopping mice the testicular artery, unlike that in most other mammalian species, is not coiled although the temperature in the scrotum was found to be ~2°C lower than that of the abdomen. In cryptorchid males, 21 days after surgery, testes weights were reduced in three of five individuals but there was no statistically significant decrease after 16 h exposure to whole body heat (P = 0.07). Nevertheless, some impairment of spermatogenesis was evident in both the cryptorchid testes and in the testes after whole body heating. These results show that in hopping mice developing male germ cells are susceptible to degeneration when testes are exposed to high environmental temperatures. Thus adaptations of Notomys alexis to the arid zone have not involved any special adaptations for male germ cell survival in a hot environment. Behavioural adaptations may play a pivotal role in maintaining maximal male fertility in such extreme environmental conditions.

437. Whole body heat stress induces selective germ cell apoptosis in mice

2008 ◽  
Vol 20 (9) ◽  
pp. 117 ◽  
Author(s):  
H. Wechalekar ◽  
B. P. Setchell ◽  
W. G. Breed ◽  
M. Ricci ◽  
C. Leigh ◽  
...  
Keyword(s):  
Heat Stress ◽  
Germ Cell ◽  
Germ Cells ◽  
Wilcoxon Test ◽  
Whole Body ◽  
Seminiferous Tubules ◽  
Heat Treated ◽  
Significant Difference ◽  
Whole Body Heat Stress ◽  
Body Heat

Introduction: In scrotal mammals, heat stress (43°C/ 20 min) to the scrotum results in germ cell death in the testes1, abnormal spermatozoa, and infertility2 whereas two days of whole body heating (36°C, 12 h/ day) reduces testes weight, sperm numbers and fertility3. The aim of the present study was to determine the intratesticular effects of whole body heating on germ cell maturation and apoptosis. Methods: C57BL/6 mice (n = 16) were housed at 37–38°C for 8 h/ day for 3 days while controls (n = 4) were kept at 23–24°C. Animals from heat treated (n = 4), and control groups (n = 1) were sacrificed at 16 h, 7, 14 and 21 days post exposure to heat. Testes were weighed and analysed by t-test. In testes from each animal, two sections 70µm apart were end labelled for TdT-mediated-dUTP nick (TUNEL). Apoptosis was determined in 200 seminiferous tubules by a colour threshold set in the particle analysis program (Olympus).The tubules were staged as I-VI (early), VII-VIII, IX-X and XI-XII (late) and results analysed using Wilcoxon test. Results: The weights of testes were significantly reduced in heat-treated animals (P < 0.05) at 16 h, 7 and 14 days with no significant difference at 21 days. Apoptosis was significantly higher in the heat-treated group in stages I-VI and XI-XII at 16 h, 7 and 14 days (P < 0.05). In addition, in stages VII-VIII and IX-X apoptosis was significantly higher at 16 h (P < 0.05) with no statistical difference between other time intervals. By day 21, the levels of apoptosis did not differ significantly from the controls in any of the stages (P > 0.05).Conclusion: Whole body heat stress can induce stage and cell specific degeneration of the germ cells in the seminiferous epithelium. The germ cells undergoing apoptosis are spermatogonia, primary spermatocytes and early spermatids. In addition, heat stress produces significant apoptosis of germ cells in the hormone dependent stages VII-VIII immediately after heat stress. (1) Rockett, J.C. et al. (2001) Biol. Reprod. 65:229–239. (2) Banks, S. et al. (2005) Reproduction 129:505–514. (3) Yaeram, J. et al. (2006) Reprod. Fert. Dev. 18:647–653.

sp42, the boar sperm tyrosine kinase, is a male germ cell-specific product with a highly conserved tissue expression extending to other mammalian species

1996 ◽  
Vol 109 (4) ◽  
pp. 851-858
Author(s):  
G. Berruti ◽  
B. Borgonovo
Keyword(s):  
Tyrosine Kinase ◽  
Western Blot ◽  
Germ Cell ◽  
Molecular Mass ◽  
Germ Cells ◽  
Mammalian Species ◽  
Tissue Expression ◽  
Spermatogenic Cells ◽  
Male Germ Cells ◽  
Boar Spermatozoa

sp42, a tyrosine kinase of 42 kDa originally found in ejaculated boar spermatozoa, is so far the only tyrosine protein kinase to have been purified from mature male germ cells. We have developed and characterized rabbit polyclonal antibodies specifically directed against the boar sperm enzyme, which has been here purified to homogeneity. Anti-sp42 serum and sp42 affinity-purified antibodies work very well in western blot, immunoprecipitation and immunocytochemistry, and do not inhibit sp42 catalytic activity. Immunoblotting analyses reveal the presence of sp42 both in maturing boar epididymal (caput, corpus and cauda segment) spermatozoa and in testicular spermatogenic cells, thus establishing that the protein is effectively expressed in the germ cells and is not a sperm-associated protein secreted by the epididymal epithelium or male accessory glands. This finding is further strengthened by the fact that sp42 is not glycosylated, since different lectins fail to bind to sp42 and treatment of sp42 with different deglycosylation enzymes does not result in a reduction of the molecular mass of sp42. When different boar tissues are immunoscreened in western blot analysis, the results are all sp42-negative. The extension of the study to other mammalian species (human, mouse and rat) demonstrates that proteins immunologically related to boar sp42, which share the same molecular mass and tyrosine kinase activity, are both expressed in spermatogenic cells and maintained in mature sperm cells. Intriguingly, when a wide spectrum of somatic mouse and rat tissues is probed with sp42-antiserum, no tissue presents anti-sp42 immunoreactivity. Immunocytochemistry shows that in boar spermatozoa sp42 is confined to the tail mid-piece, while by immunohistochemistry carried out on sections of adult rat testis the appearance time of the kinase appears to be consistent with a post-meiotic synthesis in haploid spermatids. Altogether, these results demonstrate that boar sp42 is a new male germ cell-specific gene product, with highly conserved tissue expression extended to other mammalian species, and suggest a possible role played by the cytoplasmic tyrosine kinase in the cell signalling network specific to haploid male germ cells.

scholarly journals Overexpression of peroxisomal testis-specific 1 protein induces germ cell apoptosis and leads to infertility in male mice

2011 ◽  
Vol 22 (10) ◽  
pp. 1766-1779 ◽  
Author(s):  
Karina Kaczmarek ◽  
Maja Studencka ◽  
Andreas Meinhardt ◽  
Krzysztof Wieczerzak ◽  
Sven Thoms ◽  
...  
Keyword(s):  
Cell Death ◽  
Germ Cell ◽  
Germ Cells ◽  
Specific Gene ◽  
Male Mice ◽  
Terminal Part ◽  
Male Germ Cells ◽  
Germ Cell Apoptosis ◽  
Induced Apoptosis

 Peroxisomal testis-specific 1 gene (Pxt1) is the only male germ cell–specific gene that encodes a peroxisomal protein known to date. To elucidate the role of Pxt1 in spermatogenesis, we generated transgenic mice expressing a c-MYC-PXT1 fusion protein under the control of the PGK2 promoter. Overexpression of Pxt1 resulted in induction of male germ cells’ apoptosis mainly in primary spermatocytes, finally leading to male infertility. This prompted us to analyze the proapoptotic character of mouse PXT1, which harbors a BH3-like domain in the N-terminal part. In different cell lines, the overexpression of PXT1 also resulted in a dramatic increase of apoptosis, whereas the deletion of the BH3-like domain significantly reduced cell death events, thereby confirming that the domain is functional and essential for the proapoptotic activity of PXT1. Moreover, we demonstrated that PXT1 interacts with apoptosis regulator BAT3, which, if overexpressed, can protect cells from the PXT1-induced apoptosis. The PXT1-BAT3 association leads to PXT1 relocation from the cytoplasm to the nucleus. In summary, we demonstrated that PXT1 induces apoptosis via the BH3-like domain and that this process is inhibited by BAT3.

217 PROTEIN-INDUCED TRANSDIFFERENTIATION INTO MALE GERM CELL-LIKE LINEAGE FROM CHICKEN FETAL BONE MARROW STEM CELLS

2012 ◽  
Vol 24 (1) ◽  
pp. 220
Author(s):  
J. M. Yoo ◽  
J. J. Park ◽  
K. Gobianand ◽  
J. Y. Ji ◽  
J. S. Kim ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Retinoic Acid ◽  
Germ Cell ◽  
Germ Cells ◽  
Cultured Cells ◽  
Male Germ Cell ◽  
Male Germ Cells ◽  
Germ Cell Differentiation ◽  
Transgenic Chickens

Bone marrow (BM)-derived stem cells are capable of transdifferentiation into multilineage cells like muscle, bone, cartilage, fat and nerve cells. In this study, we investigated the capability of mesenchymal stem cells (MSC) derived from BM into germ cell differentiation in the chicken. Chicken MSCs were isolated from BM of day 20 fertilized fetal chicken with Ficoll-Paque Plus. Isolated cells were cultured in advance-DMEM (ADMEM) supplemented with 10% fetal bovine serum and antibiotics. Once confluent, cells were subcultured until five passages. The cultured cells showed fibroblast-like morphology. The cells had positive expressions of Oct4, Sox2 and Nanog. Two induction methods were conducted to examine the ability of transdifferentation into male germ cells. In group 1, MSC were cultured in ADMEM containing retinoic acid and chicken testicular extracts proteins for 10 to 15 days. In group 2, MSC were permeabilized by streptolysin O and treated with chicken testicular protein extracts. In both treatment groups, MSC were cultured in ADMEM containing retinoic acid for 10 to 15 days. We found that chicken MSC had a positive expression of pluripotent proteins such as Oct4, Sox2, Nanog and a small population of chicken MSC seem to transdifferentiate into male germ cell-like cells. These cells expressed early germ cell markers and male germ-cell-specific markers (Dazl, C-kit, Stra8 and DDX4) as analysed by reverse transcription-PCR and immunohistochemistry. These results demonstrated that chicken MSC may differentiate into male germ cells and the same might be used as a potential source of cells for production of transgenic chickens. This study was carried out with the support of Agenda Program (Project No. PJ0064692011), RDA and Republic of Korea.

377 SPERMATOZOA RETRIEVED FROM MALE MICE FROZEN FOR 15 YEARS CAN PRODUCE NORMAL OFFSPRING

2007 ◽  
Vol 19 (1) ◽  
pp. 304
Author(s):  
N. Ogonuki ◽  
K. Mochida ◽  
H. Miki ◽  
K. Inoue ◽  
T. Iwaki ◽  
...  
Keyword(s):  
Germ Cells ◽  
Mammalian Species ◽  
The Body ◽  
Freezing And Thawing ◽  
Abdominal Incision ◽  
Closely Related Species ◽  
Male Germ Cells ◽  
Testicular Spermatozoa ◽  
One Year ◽  
Normal Offspring

Cryopreservation of male germ cells is a strategy to conserve animal species and strains of animals valuable to biomedical research. However, to minimize damage that may occur during freezing and thawing, complex cryopreservation protocols that have been optimized for the stage and species of male germ cells are usually employed. Recently, we have found that mouse male germ cells can be cryopreserved at -80�C by freezing the whole epididymides and testes without cryoprotectant for at least one year (Ogonuki et al. 2006 Reprod. Fertil. Dev. 18, 286 abst). This study was undertaken to determine whether mouse male germ cells retrieved from the bodies of mice frozen at -20�C for 15 years could produce normal offspring by microinsemination. Mature males of BALB/c-nude and C3H/He (8 weeks of age) were euthanized by overdose of pentobarbital on February 20 and March 8, 1991, respectively, and kept in a -20�C freezer. The frozen body was thawed about 15 years after freezing (February 2006) by putting it in a water bath until the outer surface of the body was softened. The body was then removed from the water, and the testes were isolated through an abdominal incision. Testicular spermatozoa were collected from the testes and microinseminated into B6D2F1 oocytes. Within 24 h after sperm injection, over 80% of oocytes developed into 2-cell embryos. Apparently normal pups were born after embryo transfer in both strains of mice at rates of 21% (17/81) and 12% (12/97) per transfer, respectively. Two pups from the BALB/c-nude group died shortly after Caesarian section due to respiratory failure, but others grew normally and were proven to be fertile when they matured (at least 19 mice out of 20 mice tested). We further mated these F1 offspring and confirmed that the nude gene was safely propagated. The present study demonstrates that spermatozoa can retain their fertilizing ability in frozen whole bodies for longer than we anticipated. If spermatozoa of extinct mammalian species (e.g. woolly mammoth) can be retrieved from animal bodies that were kept frozen in permanent frost, live animals might be restored by injecting them into oocytes from females of closely related species.

scholarly journals Cannabinoid Receptors Signaling in the Development, Epigenetics, and Tumours of Male Germ Cells

2019 ◽  
Vol 21 (1) ◽  
pp. 25 ◽  
Author(s):  
Marco Barchi ◽  
Elisa Innocenzi ◽  
Teresa Giannattasio ◽  
Susanna Dolci ◽  
Pellegrino Rossi ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Cannabinoid Receptors ◽  
Endocannabinoid System ◽  
Male Reproduction ◽  
Metabolizing Enzymes ◽  
Male Germ Cells ◽  
Testicular Tumours ◽  
Germ Cell Differentiation ◽  
Degradative Enzymes

Endocannabinoids are natural lipid molecules whose levels are regulated by specific biosynthetic and degradative enzymes. They bind to and activate two main cannabinoid receptors type 1 (CB1) and type 2 (CB2), and together with their metabolizing enzymes form the “endocannabinoid system” (ECS). In the last years, the relevance of endocannabinoids (eCBs) as critical modulators in various aspects of male reproduction has been pointed out. Mammalian male germ cells, from mitotic to haploid stage, have a complete ECS which is modulated during spermatogenesis. Compelling evidence indicate that in the testis an appropriate “eCBs tone”, associated to a balanced CB receptors signaling, is critical for spermatogenesis and for the formation of mature and fertilizing spermatozoa. Any alteration of this system negatively affects male reproduction, from germ cell differentiation to sperm functions, and might have also an impact on testicular tumours. Indeed, most of testicular tumours develop during early germ-cell development in which a maturation arrest is thought to be the first key event leading to malignant transformation. Considering the ever-growing number and complexity of the data on ECS, this review focuses on the role of cannabinoid receptors CB1 and CB2 signaling in male germ cells development from gonocyte up to mature spermatozoa and in the induction of epigenetic alterations in these cells which might be transmitted to the progeny. Furthermore, we present new evidence on their relevance in testicular cancer.

scholarly journals Proteomic and metabolomic analyses uncover sex-specific regulatory pathways in mouse fetal germline differentiation†

2020 ◽  
Vol 103 (4) ◽  
pp. 717-735
Author(s):  
Yohei Hayashi ◽  
Masaru Mori ◽  
Kaori Igarashi ◽  
Keiko Tanaka ◽  
Asuka Takehara ◽  
...  
Keyword(s):  
Oxidative Phosphorylation ◽  
Germ Cell ◽  
Germ Cells ◽  
Cell Development ◽  
Nucleotide Synthesis ◽  
Male Germ Cells ◽  
Regulatory Pathways ◽  
Germ Cell Development ◽  
Germ Cell Differentiation ◽  
Germline Differentiation

Abstract Regulatory mechanisms of germline differentiation have generally been explained via the function of signaling pathways, transcription factors, and epigenetic regulation; however, little is known regarding proteomic and metabolomic regulation and their contribution to germ cell development. Here, we conducted integrated proteomic and metabolomic analyses of fetal germ cells in mice on embryonic day (E)13.5 and E18.5 and demonstrate sex- and developmental stage-dependent changes in these processes. In male germ cells, RNA processing, translation, oxidative phosphorylation, and nucleotide synthesis are dominant in E13.5 and then decline until E18.5, which corresponds to the prolonged cell division and more enhanced hyper-transcription/translation in male primordial germ cells and their subsequent repression. Tricarboxylic acid cycle and one-carbon pathway are consistently upregulated in fetal male germ cells, suggesting their involvement in epigenetic changes preceding in males. Increased protein stability and oxidative phosphorylation during female germ cell differentiation suggests an upregulation of aerobic energy metabolism, which likely contributes to the proteostasis required for oocyte maturation in subsequent stages. The features elucidated in this study shed light on the unrevealed mechanisms of germ cell development.

scholarly journals TEX14 Interacts with CEP55 To Block Cell Abscission

2010 ◽  
Vol 30 (9) ◽  
pp. 2280-2292 ◽  
Author(s):  
Tokuko Iwamori ◽  
Naoki Iwamori ◽  
Lang Ma ◽  
Mark A. Edson ◽  
Michael P. Greenbaum ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Intercellular Bridge ◽  
Male Germ Cells ◽  
Physical Separation ◽  
Targeted Deletion ◽  
Intercellular Bridges ◽  
Daughter Cells ◽  
Stable Component ◽  
Evolutionarily Conserved

ABSTRACT In somatic cells, abscission, the physical separation of daughter cells at the completion of cytokinesis, requires CEP55, ALIX, and TSG101. In contrast, cytokinesis is arrested prior to abscission in differentiating male germ cells that are interconnected by TEX14-positive intercellular bridges. We have previously shown that targeted deletion of TEX14 disrupts intercellular bridges in all germ cells and causes male sterility. Although these findings demonstrate that intercellular bridges are essential for spermatogenesis, it remains to be shown how TEX14 and other proteins come together to prevent abscission and form stable intercellular bridges. Using a biochemical enrichment of male germ cell intercellular bridges, we identified additional bridge proteins, including CEP55. Although CEP55 is highly expressed in testes at the RNA level, there is no report of the presence of CEP55 in germ cells. We show here that CEP55 becomes a stable component of the intercellular bridge and that an evolutionarily conserved GPPX3Y motif of TEX14 binds strongly to CEP55 to block similar GPPX3Y motifs of ALIX and TSG101 from interacting and localizing to the midbody. Thus, TEX14 prevents the completion of cytokinesis by altering the destiny of CEP55 from a nidus for abscission to an integral component of the intercellular bridge.

scholarly journals Identification of a candidate c-mos repressor that restricts transcription of germ cell-specific genes.

1995 ◽  
Vol 15 (10) ◽  
pp. 5369-5375 ◽  
Author(s):  
W Xu ◽  
G M Cooper
Keyword(s):  
Germ Cell ◽  
Somatic Cell ◽  
Binding Site ◽  
Germ Cells ◽  
Phosphoglycerate Kinase ◽  
3T3 Cells ◽  
Male Germ Cells ◽  
Nuclear Extracts ◽  
Genes Encoding ◽  
Nih 3T3

The c-mos proto-oncogene is specifically expressed in female and male germ cells. Previous studies identified a negative regulatory element (NRE) upstream of the c-mos promoter that suppresses c-mos transcription in transfected NIH 3T3 cells. In this study, we used gel shift assays to detect proteins in nuclear extracts of NIH 3T3 cells that bind to the c-mos NRE in a sequence-specific manner. One protein was found to bind to a region of the NRE which was shown by site-directed mutagenesis to be required for suppression of c-mos transcription. This factor was present in nuclear extracts of several somatic cell lines and tissues but not in male germ cells in which c-mos is transcribed, suggesting that it is a somatic cell repressor of c-mos transcription. The binding site of the candidate repressor within the c-mos NRE consists of sequences related to putative NREs identified in two other male germ cell-specific genes (encoding protamine 2 and phosphoglycerate kinase 2). The c-mos repressor bound and could be UV cross-linked to these protamine 2 and phosphoglycerate kinase 2 gene sequences as a protein with an apparent molecular mass of approximately 30 kDa. The repressor binding site is also conserved in two other germ cell-specific genes (encoding testis-specific cytochrome c and heat shock-like protein 70), suggesting that the c-mos repressor may be generally involved in suppressing transcription of germ cell-specific genes in somatic cells.

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