scholarly journals Infertility Caused by Inefficient Apoptotic Germ Cell Clearance in Xkr8-Deficient Male Mice

2019 ◽  
Vol 40 (3) ◽  
Author(s):  
Yahiro Yamashita ◽  
Chigure Suzuki ◽  
Yasuo Uchiyama ◽  
Shigekazu Nagata
Keyword(s):  
Germ Cells ◽  
Sertoli Cells ◽  
Tyrosine Kinase Receptor ◽  
Apoptotic Cells ◽  
Male Mice ◽  
Phosphatidylserine Receptor ◽  
Cell Clearance ◽  
Fluorescence And Electron Microscopy ◽  
Sperm Counts ◽  
Wild Type Male

ABSTRACT During spermatogenesis, up to 75% of germ cells in the testes undergo apoptosis and are cleared by Sertoli cells. X-linked XK blood group-related 8 (Xkr8) is a plasma membrane protein that scrambles phospholipids in response to apoptotic signals, exposing phosphatidylserine (PtdSer). Here, we found that Xkr8−/− male mice were infertile due to reduced sperm counts in their epididymides. Apoptotic stimuli could not induce PtdSer exposure in Xkr8−/− germ cells. Consistent with the hypothesis that PtdSer functions as an “eat-me” signal to phagocytes, cells expressing phosphatidylserine receptor TIM4 and MER tyrosine kinase receptor efficiently engulfed apoptotic wild-type male germ cells but not Xkr8−/− germ cells. Fluorescence and electron microscopy revealed Sertoli cells carrying engulfed and degenerated dead cells. However, many unengulfed apoptotic cells and residual bodies and much cell debris were present in Xkr8−/− testes and epididymides. These results indicate that Xkr8-mediated PtdSer exposure is essential for the clearance of apoptotic germ cells by Sertoli cells. There was no apparent inflammation in Xkr8−/− testes, suggesting that the unengulfed apoptotic cells may have undergone secondary necrosis, releasing noxious materials that affected the germ cells. Alternatively, failure to engulf the apoptotic germ cells may have caused the Sertoli cells to starve and lose their ability to support spermatogenesis.

scholarly journals Basigin null mutant male mice are sterile and exhibit impaired interactions between germ cells and Sertoli cells

2013 ◽  
Vol 380 (2) ◽  
pp. 145-156 ◽  
Author(s):  
Jiajia Bi ◽  
Yanfen Li ◽  
Fengyun Sun ◽  
Anja Saalbach ◽  
Claudia Klein ◽  
...  
Keyword(s):  
Germ Cells ◽  
Sertoli Cells ◽  
Null Mutant ◽  
Male Mice ◽  
Mutant Male

scholarly journals A mitochondrial mechanism is involved in apoptosis of Robertsonian mouse male germ cells

Reproduction ◽  
2008 ◽  
Vol 135 (6) ◽  
pp. 797-804 ◽  
Author(s):  
Valeria Merico ◽  
Gabriela Diaz de Barboza ◽  
Chiara Vasco ◽  
Ruben Ponce ◽  
Valeria Rodriguez ◽  
...  
Keyword(s):  
Germ Cells ◽  
Sertoli Cells ◽  
Histological Evaluation ◽  
Male Mice ◽  
Male Germ Cells ◽  
Intrinsic Mechanism ◽  
Pachytene Spermatocytes ◽  
Calbindin D ◽  
Tunel Labelling ◽  
Dependent Mechanism

The aim of this study was to determine whether the intrinsic mechanism of apoptosis is involved in the death of germ cells in Robertsonian (Rb) heterozygous adult male mice. Testes from 5-month-old Rb heterozygous CD1×Milano II mice were obtained and compared with those from homozygous CD1 (2n=40) and Milano II (2n=24) mice. For histological evaluation of apoptosis, TUNEL labelling and immunohistochemistry were used to localise Bax and cytochrome c. Expression of calbindin D28k (CB), an anti-apoptotic molecule, was also analysed by immunohistochemistry and immunoblotting. Testicular ultrastructure was visualised by electron microscopy. Morphology and cell associations were abnormal in the Rb heterozygous seminiferous epithelium. An intense apoptotic process was observed in tubules at stage XII, mainly in metaphase spermatocytes. Metaphase spermatocytes also showed Bax and cytochrome c redistributions. Mitochondria relocated close to the paranuclear region of spermatocytes. CB was mainly expressed in metaphase spermatocytes, but also in pachytene spermatocytes, spermatids and Sertoli cells at stage XII. The co-localisation of CB and TUNEL labelling was very limited. Sixty per cent of metaphase spermatocytes were apoptotic and calbindin negative, while 40% were calbindin positive without signs of apoptosis. Ten per cent of the Bax- and cytochrome c-positive cells were also calbindin positive. These data suggest that apoptosis of the germ cells in heterozygous mice occurs, at least in part, through a mitochondrial-dependent mechanism. Calbindin overexpression might prevent or reduce the apoptosis of germ cells caused by Rb heterozygosity, which could partially explain the subfertility of these mice.

scholarly journals Effects of W (c-kit) gene mutation on gametogenesis in male mice: agametic tubular segments in Wf/Wf testes

Development ◽  
1992 ◽  
Vol 114 (4) ◽  
pp. 861-867 ◽  
Author(s):  
U. Koshimizu ◽  
D. Watanabe ◽  
Y. Tajima ◽  
Y. Nishimune
Keyword(s):  
Stem Cell ◽  
Embryonic Development ◽  
Germ Cells ◽  
Seminiferous Tubule ◽  
Primordial Germ Cells ◽  
Mutant Mice ◽  
Tyrosine Kinase Receptor ◽  
Male Mice ◽  
Kit Gene ◽  
Development And Differentiation

Mutations of the W (c-kit) gene, which encodes a transmembrane tyrosine kinase receptor, affect the development and differentiation of many types of stem cell. Most homozygous W mutant mice are sterile, due to a lack of germ cells arising during embryonic development, but one of the notable exceptions is Wf/Wf mice, which are fully fertile in both sexes. In order to elucidate the effects of the Wf mutation on spermatogenesis, postnatal spermatogenesis in Wf/Wf mice was histologically examined. The number of gonocytes at birth was significantly reduced and small portions of agametic seminiferous tubule segments were observed in mutant mice. It is suggested that this is due to a deficiency of primordial germ cells (PGC). Other than the agametic tubules, there was no evidence of reduced spermatogenesis after birth. These results indicate that the function of the W (c-kit) gene is more necessary for the development of PGC than for postnatal germ cells.

scholarly journals Transient Reduction of DNA Methylation at the Onset of Meiosis in Male Mice

2017 ◽  
Author(s):  
Valeriya Gaysinskaya ◽  
Brendan F. Miller ◽  
Godfried W. van der Heijden ◽  
Kasper D. Hansen ◽  
Alex Bortvin
Keyword(s):  
Dna Methylation ◽  
Quality Control ◽  
Germ Cells ◽  
Extended Period ◽  
S Phase ◽  
Male Mice ◽  
Wild Type ◽  
Genome Wide ◽  
Wild Type Male

AbstractThe quality of germ cells depends on successful chromatin organization in meiotic prophase I (MPI). To better understand the epigenetic context of MPI we studied the dynamics of DNA methylation in wild-type male mice. We discovered an extended period of genome-wide transient reduction of DNA methylation (TRDM) during early MPI. Our data show that TRDM arises by passive demethylation in the premeiotic S phase highlighting the abundance of hemimethylated DNA in MPI. Importantly, TRDM unmasks a deficit in retrotransposon LINE-1 DNA methylation contributing to its expression in early MPI. We propose that TRDM facilitates meiosis and gamete quality control.

Freeze-etch observations on the tight junctions of sertoli cells grown in organ culture with FSH

1978 ◽  
Vol 36 (2) ◽  
pp. 340-341
Author(s):  
Rita Meyer ◽  
Zoltan Posalaky ◽  
Dennis Mcginley
Keyword(s):  
Organ Culture ◽  
Tight Junctions ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Barrier Function ◽  
Cell Junction ◽  
Intramembranous Particles ◽  
Junctional Complexes ◽  
Oriented Parallel

The Sertoli cell tight junctional complexes have been shown to be the most important structural counterpart of the physiological blood-testis barrier. In freeze etch replicas they consist of extensive rows of intramembranous particles which are not only oriented parallel to one another, but to the myoid layer as well. Thus the occluding complex has both an internal and an overall orientation. However, this overall orientation to the myoid layer does not seem to be necessary to its barrier function. The 20 day old rat has extensive parallel tight junctions which are not oriented with respect to the myoid layer, and yet they are inpenetrable by lanthanum. The mechanism(s) for the control of Sertoli cell junction development and orientation has not been established, although such factors as the presence or absence of germ cells, and/or hormones, especially FSH have been implicated.

Development of Testis Cords and the Formation of Efferent Ducts in Xenopus laevis: Differences and Similarities with Other Vertebrates

2021 ◽  
pp. 1-14
Author(s):  
Yuanyuan Li ◽  
Jinbo Li ◽  
Man Cai ◽  
Zhanfen Qin
Keyword(s):  
Cell Proliferation ◽  
Xenopus Laevis ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Testis Development ◽  
Larval Stages ◽  
Efferent Ducts ◽  
Steroidogenic Cells ◽  
Testis Cord ◽  
Anterior Posterior

The knowledge of testis development in amphibians relative to amniotes remains limited. Here, we used Xenopus laevis to investigate the process of testis cord development. Morphological observations revealed the presence of segmental gonomeres consisting of medullary knots in male gonads at stages 52–53, with no distinct gonomeres in female gonads. Further observations showed that cell proliferation occurs at specific sites along the anterior-posterior axis of the future testis at stage 50, which contributes to the formation of medullary knots. At stage 53, adjacent gonomeres become close to each other, resulting in fusion; then (pre-)Sertoli cells aggregate and form primitive testis cords, which ultimately become testis cords when germ cells are present inside. The process of testis cord formation in X. laevis appears to be more complex than in amniotes. Strikingly, steroidogenic cells appear earlier than (pre-)Sertoli cells in differentiating testes of X. laevis, which differs from earlier differentiation of (pre-)Sertoli cells in amniotes. Importantly, we found that the mesonephros is connected to the testis gonomere at a specific site at early larval stages and that these connections become efferent ducts after metamorphosis, which challenges the previous concept that the mesonephric side and the gonadal side initially develop in isolation and then connect to each other in amphibians and amniotes.

scholarly journals Kindlin-2 in Sertoli cells is essential for testis development and male fertility in mice

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Xiaochun Chi ◽  
Weiwei Luo ◽  
Jiagui Song ◽  
Bing Li ◽  
Tiantian Su ◽  
...  
Keyword(s):  
Sertoli Cells ◽  
Male Fertility ◽  
Nuclear Translocation ◽  
Hippo Pathway ◽  
Reproductive Organs ◽  
Male Reproduction ◽  
Barrier Structure ◽  
Male Mice ◽  
Sperm Development

AbstractKindlin-2 is known to play important roles in the development of mesoderm-derived tissues including myocardium, smooth muscle, cartilage and blood vessels. However, nothing is known for the role of Kindlin-2 in mesoderm-derived reproductive organs. Here, we report that loss of Kindlin-2 in Sertoli cells caused severe testis hypoplasia, abnormal germ cell development and complete infertility in male mice. Functionally, loss of Kindlin-2 inhibits proliferation, increases apoptosis, impairs phagocytosis in Sertoli cells and destroyed the integration of blood-testis barrier structure in testes. Mechanistically, Kindlin-2 interacts with LATS1 and YAP, the key components of Hippo pathway. Kindlin-2 impedes LATS1 interaction with YAP, and depletion of Kindlin-2 enhances LATS1 interaction with YAP, increases YAP phosphorylation and decreases its nuclear translocation. For clinical relevance, lower Kindlin-2 expression and decreased nucleus localization of YAP was found in SCOS patients. Collectively, we demonstrated that Kindlin-2 in Sertoli cells is essential for sperm development and male reproduction.

scholarly journals Expression of beta-nerve growth factor and its receptor in rat seminiferous epithelium: specific function at the onset of meiosis.

1992 ◽  
Vol 117 (3) ◽  
pp. 629-641 ◽  
Author(s):  
M Parvinen ◽  
M Pelto-Huikko ◽  
O Söder ◽  
R Schultz ◽  
A Kaipia ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Sertoli Cells ◽  
Seminiferous Epithelium ◽  
Receptor Protein ◽  
Tyrosine Kinase Receptor ◽  
Specific Expression ◽  
Nerve Growth ◽  
Ngf Receptor

beta-Nerve growth factor (NGF) is expressed in spermatogenic cells and has testosterone-downregulated low-affinity receptors on Sertoli cells suggesting a paracrine role in the regulation of spermatogenesis. An analysis of the stage-specific expression of NGF and its low affinity receptor during the cycle of the seminiferous epithelium in the rat revealed NGF mRNA and protein at all stages of the cycle. Tyrosine kinase receptor (trk) mRNA encoding an essential component of the high-affinity NGF receptor was also present at all stages. In contrast, expression of low affinity NGF receptor mRNA was only found in stages VIIcd and VIII of the cycle, the sites of onset of meiosis. The low-affinity NGF receptor protein was present in the plasma membrane of the apical Sertoli cell processes as well as in the basal plasma membrane of these cells at stages VIIcd to XI. NGF was shown to stimulate in vitro DNA synthesis of seminiferous tubule segments with preleptotene spermatocytes at the onset of meiosis while other segments remained nonresponsive. We conclude that NGF is a meiotic growth factor that acts through Sertoli cells.

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