While hallmarks of rodent spermatogonia stem cell biomarkers' heterogeneity have recently been identified, their stage and subset distributions remain unclear. Furthermore, it is currently difficult to accurately identify subset-specific SSC marker distributions due to the poor nuclear morphological characteristics associated with fixation in 4% paraformaldehyde. In the present study, testicular cross-sections and whole-mount samples were Bouin fixed to optimize nuclear resolution and visualized by immunohistochemistry (IHC) and immunofluorescence (IF). The results identified an expression pattern of PLZF^highc-KIT^pos in A₁ spermatogonia, while A₂-A₄-differentiating spermatogonia were PLZF^lowc-KIT^pos. Additionally, this procedure was used to examine asymmetrically expressing GFRA1 and PLZF clones, asymmetric A_pr and false clones were distinguished based on the presence or absence of TEX14, a molecular maker of intercellular bridges, despite having identical nuclear morphology and intercellular distances that were <25 μm. In conclusion, this optimized Bouin fixation procedure facilitates the accurate identification of spermatogonium subsets based on their molecular profiles and is capable of distinguishing asymmetric and false clones. Therefore, the findings presented herein will facilitate further morphological and functional analysis studies and provide further insight into spermatogonium subtypes.
Animals ; Cell Differentiation ; Fluorescent Antibody Technique ; Gene Expression Regulation/genetics* ; Glial Cell Line-Derived Neurotrophic Factor Receptors/genetics* ; Immunohistochemistry ; Male ; Mice ; Mice, Inbred C57BL ; Promyelocytic Leukemia Zinc Finger Protein/genetics* ; Proto-Oncogene Proteins c-kit/genetics* ; Seminiferous Tubules/cytology* ; Spermatogenesis ; Spermatogonia/metabolism* ; Testis/cytology* ; Tissue Fixation ; Transcription Factors/genetics*

Nanos2, a member of the Nanos2 gene family, is a specific gene in male germ cells and encodes an evolutionarily conserved RNA binding protein expressed in male primordial germ cells (PGCs) during the embryonic period as well as in the spermatogonial stem cells (SSCs) of the testis. In the embryonic period, Nanos2 promotes the development of male PGCs and inhibits them from meiosis. In the process of spermatogenesis, Nanos2 suppresses the differentiation of SSCs in the testis and maintains the stability of the SSC pool. The knockout of Nanos2 may cause the disappearance of germ cells and sterility in male mice while its overexpression in the testis may lead to accumulation of SSCs in seminiferous tubules. Besides, Nanos2 is involved in the degradation of specific RNAs and possibly associated with some diseases of the male reproductive system. This review focuses on the recent progress in the studies of Nanos2 in the male reproductive system.
Animals ; Cell Differentiation ; Gene Knockout Techniques ; Male ; Meiosis ; Mice ; RNA ; metabolism ; RNA-Binding Proteins ; genetics ; metabolism ; Spermatogenesis ; physiology ; Spermatogonia ; Spermatozoa ; Testis ; cytology

Objective: To investigate the role of pH2AX in the reversibility of mouse testicular reproductive function impaired by single heat stress. METHODS: Twenty-four C57 male mice were randomly divided into heat stress and control groups and immersed in water at 43℃ and 25℃, respectively, for 15 minutes. At 1, 7, and 14 days of heat exposure, all the mice were sacrificed and their testis tissues collected for determining the apoptosis of the germ cells by TUNEL and measuring the expression level of the pH2AX protein by immunohistochemistry and Western blot. RESULTS: The highest percentage of apoptotic cells were found in the seminiferous tubules of the mice in the heat stress group on the 1st day of the exposure and almost no apoptosis was observed at 7 and 14 days. The pH2AX protein was expressed in the nuclei of the basement membrane of adjacent seminiferous tubules. Compared with the control group, the expression of pH2AX was significantly increased on the 1st day of exposure (0.47 ± 0.02 vs 1.61 ± 0.04, P <0.01), then decreased at 7 days (0.85 ± 0.03) in comparison with that on the 1st day (P <0.01), and again elevated at 14 days (1.72 ± 0.02) as compared with either those at 1 and 7 days (P <0.01) or that of the control (P <0.01). CONCLUSIONS Heat stress causes dynamic changes of the pH2AX expression in the testis of the mouse, which are associated with heat stress-induced proliferation and division of the testicular spermatogenic cells.
Animals ; Apoptosis ; Blotting, Western ; Heat Stress Disorders ; complications ; Histones ; metabolism ; Hot Temperature ; Immunohistochemistry ; In Situ Nick-End Labeling ; Male ; Mice ; Mice, Inbred C57BL ; Random Allocation ; Seminiferous Tubules ; cytology ; Spermatozoa ; cytology ; metabolism ; Testis ; Time Factors

OBJECTIVETo study the pattern of CGG repeat instability within germline cells derived from two male fetuses affected with Fragile X syndrome (FXS).

METHODSThe length and methylation status of CGG repeats within the testes of a fetus carrying a full FXS mutation and another fetus carrying mosaicism FXS mutation were analyzed with Southern blotting and AmplideX FMR1 PCR. Immunohistochemistry was also applied for the measurement of FMR1 protein (FMRP) expression within the testes.

RESULTSFor the fetus carrying the full mutation, Southern blotting analysis of the PCR product has detected an expected band representing the full mutation in its brain and a premutation band of > 160 CGG repeats in its testis. Whereas the pattern of premutation/full mutation in mosaic testis was similar to that in peripheral blood and no sign of contracted fragment was found other than a band of about 160 CGG repeats. Immunohistochemistry assay with a FMRP-specific antibody demonstrated a number of FMRP-positive germ cells, which suggested a contraction from full mutation to premutation alleles.

CONCLUSIONThis study has clarified the instability pattern of CGG repeat and expression of FMRP protein within the testes of fetuses affected with FXS, confirming that the CGG repeat can contract progressively within the germline. The FMRP expression in the testis is consistent with spermatogonium proliferation, and thus the contraction from full mutation to unmethylated premutations may occur for the requirement of FMRP expression during spermatogenesis. The better understanding of FMRP function during germ cell proliferation may elucidate the mechanism underlying the contraction of full FXS mutation in male germline.

Abortion, Eugenic ; Blotting, Southern ; Brain ; embryology ; metabolism ; DNA Methylation ; Fatal Outcome ; Fetus ; cytology ; metabolism ; Fragile X Mental Retardation Protein ; genetics ; metabolism ; Fragile X Syndrome ; diagnosis ; genetics ; Humans ; Immunohistochemistry ; Male ; Mosaicism ; Mutation ; Polymerase Chain Reaction ; Spermatozoa ; metabolism ; Testis ; cytology ; embryology ; metabolism ; Trinucleotide Repeat Expansion ; genetics

OBJECTIVETo study on the expression patterns of proteins associated with cell junctions in the developing mouse testes.

METHODThe expression levels of reproductive related cell lines spermatogonia cell line GC1 spg, spermatocyte cell line GC2 spg, leydig cell line TM3, and sertoli cell line TM4, primary sertoli cells, and 1-6-week mouse testes were analyzed using Western blot.

RESULTSThe sertoli cell junction-associated membrane proteins adhesion molecule A, Occludin and Claudin, and the sertoli-germ cell junction-associated membrane proteins junctional adhesion molecule C, Nectin-3, and E-cadherin were stage-specific in the seminiferous tubules in the mouse testes. The adaptor proteins associated with cell juctions zonula occludens-1, zonula occludens-2, Afadin, Β-catenin, and CD2-associated protein were not stage-specific in the seminiferous tubules in the mouse testes.

CONCLUSIONSIn the seminiferous tubules in the mouse testes, the membrane proteins associated with cell junctions are stage-specific. However, the expressions of adaptor proteins associated with cell junctions do not obviously change.

Adaptor Proteins, Signal Transducing ; metabolism ; Animals ; Cdh1 Proteins ; metabolism ; Cell Adhesion Molecules ; metabolism ; Cell Line ; Cytoskeletal Proteins ; metabolism ; Humans ; Intercellular Junctions ; metabolism ; Male ; Membrane Proteins ; metabolism ; Mice ; Microfilament Proteins ; metabolism ; Nectins ; Seminiferous Tubules ; cytology ; metabolism ; Sertoli Cells ; cytology ; Testis ; cytology ; Zonula Occludens-1 Protein ; metabolism ; Zonula Occludens-2 Protein ; metabolism ; beta Catenin ; metabolism

OBJECTIVETo investigate the effects of single heat stress treatment on spermatogenic cells in mice.

METHODSWe randomly divided 36 C57 male mice into a control and a heat stress treatment group and submerged the lower part of the torso in water at 25 °C and 43 °C, respectively, both for 15 minutes. At 1, 7, and 14 days after treatment, we obtained the testicular organ indexes, observed the changes in testicular morphology by HE staining, and determined the location and expression levels of the promyelocytic leukemia zinc finger (PLZF) and synaptonemal comlex protein-3 (SCP-3) in the testis tissue by immunohistochemistry and Western blot.

RESULTSThe testicular organ index was significantly lower in the heat stress treatment than in the control group (P < 0.05). Compared with the controls, the heat shock-treated mice showed loosely arranged spermatogenic cells scattered in the seminiferous tubules at 1 day after heat stress treatment, atrophied, loosely arranged and obviously reduced number of spermatogenic cells at 7 days, and relatively closely arranged seminiferous tubules and increased number and layers of spermatogenic cells at 14 days. The number of SCP-3 labelled spermatocytes obviously decreased in the heat stress-treated animals at 1 and 7 days and began to increase at 14 days. The PLZF protein expression was significantly reduced in the heat stress treatment group at 1 day as compared with that in the control (0.19 ± 0.12 vs 0.64 ± 0.03, P < 0.01), but elevated to 0.77 ± 0.02 at 7 and 14 days, even remarkably higher than in the control animals (P < 0.01).

CONCLUSIONHeat stress treatment can induce short-term dyszoospermia in mice, which can be recovered with the prolonged time after treatment.

Animals ; Blotting, Western ; Hot Temperature ; Immunohistochemistry ; Male ; Mice ; Nuclear Proteins ; metabolism ; Promyelocytic Leukemia Protein ; Seminiferous Tubules ; cytology ; Spermatocytes ; cytology ; pathology ; Testis ; metabolism ; Transcription Factors ; metabolism ; Tumor Suppressor Proteins ; metabolism

ObjectiveTo explore the feasibility of inducing human umbilical cord mesenchymal stem cells (HUMSCs) to differentiate into Leydig cells in the interstitial tissue of the rat testis.

METHODSHUMSCs were obtained by tissue blocks culture attachment and their purity and multi-lineage differentiation ability were verified by flow cytometry and chondrogenic/adipogenic/osteogenic differentiation. Then the HUMSCs were marked by CM-Dil and transplanted into the interstitial tissue of the rat testis. At 4 and 8 weeks after transplantation, the survival and differentiation status of the HUMSCs were observed by immunofluorescence staining and flow cytometry. The suspension of the rat Leydig cells was obtained at 8 weeks for determining the expression of the Leydig cell marker 3β-HSD in the HUMSCs, the cells labeled with CM-Dil were sorted and cultured, and the medium collected after 3 days of culture for measurement of the testosterone level.

RESULTSThe expression of the Leydig cell marker CYPllal was not observed in the HUMSCs at 4 weeks but found at 8 weeks after transplantation and the differentiation rate of 3β-HSD was about 14.5% at 8 weeks. CM-Dil labeled cells survived after sorting and testosterone was detected in the medium.

CONCLUSIONSHUMSCs are likely to differentiate into Leydig cells in the interstitium of the rat testis.

Animals ; Biomarkers ; metabolism ; Carbocyanines ; Cell Differentiation ; Cholesterol Side-Chain Cleavage Enzyme ; metabolism ; Feasibility Studies ; Humans ; Leydig Cells ; cytology ; metabolism ; Male ; Mesenchymal Stromal Cells ; cytology ; Rats ; Testis ; cytology ; Time Factors ; Umbilical Cord ; cytology

To monitor the trans-differentiation from adult stem cells to germ cells, we analyzed the vasa expression of goat testicular tissues in different ages and constructed the germ cell specific reporting vector pVASA-EGFP. The expression of vasa was verified by RT-PCR and immunofluorescence. The vector pVASA-EGFP was constructed by molecular technology, then transfected into goat bone mesenchymal stem cells (BMSCs) by Lipofectamine 2000. Moreover, we observed the expression of the vector through green fluorescent protein (GFP). Immunofluorescence results show that Vasa was expressed in all groups of goat testicular tissues, RT-PCR results show that the levels of vasa mRNA in 3-month group and 10-month group were significantly higher than that in 10-day group. Sequencing and restriction enzyme results show that the vector was successfully constructed. After transfection and RA treatment, GFP expression was observed, which proved the validity of our reporting system. All the results proved that vasa was expressed in different ages in goat testicular tissues, and the vector pVASA-EGFP is efficient in monitoring the trans-differentiation in vitro, which paves the way for further characterization and screening of the trans-differentiation of goat BMSCs.
Animals ; Cell Transdifferentiation ; Genes, Reporter ; Genetic Vectors ; Germ Cells ; cytology ; Goats ; Green Fluorescent Proteins ; Male ; Mesenchymal Stromal Cells ; RNA, Messenger ; Testis ; metabolism ; Transfection

OBJECTIVETo isolate, identify and culture human spermatogonial stem cells (SSC) and then obtain purified and enriched human SSCs for research and application.

METHODSWe detected the expression of CD90 in the human testis using the immunofluorescence technique and isolated human testicular spermatogenic cells by two-step enzymatic digestion, followed by differential plating and magnetic-activated cell sorting (MACS) with CD90 as an SSC marker. Then we identified the isolated CD90-positive spermatogenic cells by RT-PCR and immunocytochemistry, and meanwhile cocultured them with Sertoli cells in SG medium in vitro.

RESULTSThe isolated CD90-positive cells showed a relatively homogeneous characteristic in size and morphology and expressed the genes specific for human SSCs, with high expressions (90.5%) of GFRA1, GPR125, and UCHL1. After coculture with Sertoli cells in the SG medium for 2 weeks, the isolated CD90-positive cells maintained a good activity.

CONCLUSIONCD90 can be regarded as a speci- fic marker for human SSCs and used to obtain highly enriched human SSCs by differential plating and MACS. Furthermore, the isolated human SSCs can be cultured in SG medium in vitro.

Adult Stem Cells ; cytology ; Biomarkers ; metabolism ; Cell Separation ; methods ; Cell Shape ; Cell Size ; Coculture Techniques ; Glial Cell Line-Derived Neurotrophic Factor Receptors ; metabolism ; Humans ; Immunohistochemistry ; Male ; Receptors, G-Protein-Coupled ; metabolism ; Sertoli Cells ; Spermatogonia ; cytology ; Testis ; metabolism ; Thy-1 Antigens ; isolation & purification ; metabolism ; Ubiquitin Thiolesterase ; metabolism

OBJECTIVETo investigate the impact of in utero exposure to di-n-butyl phthalate (DBP) on the apoptosis of testicular cells in the pubertal male rat offspring.

METHODSTen pregnant SD rats were randomly divided into a control and an experimental group to be treated intragastrically with olive oil (1 ml per day) and DBP (500 mg per kg of body weight per day) respectively between gestation days 12 and 19. At the pubertal age (postnatal day 45, PND 45), the testes of the male rat offspring were removed for observation of the cell structure under the transmission electron microscope and the development of different spermatogenetic cells by HE staining. The apoptosis of testicular cells was detected by the TUNEL method, the expressions of the apoptosis-regulating proteins Bcl-2, Bcl-XL, Bax and p53 were determined by immunohistochemistry and Western blot, and the data obtained were compared between the two groups by t-test.

RESULTSTransmission electron microscopy revealed increased apoptosis and vacuolization of testicular cells in the PND-45 rat offspring, HE staining showed markedly decreased numbers of different spermatogenetic cells, TUNEL manifested significantly increased apoptosis of testicular cells in the experimental group as compared with the control (12.00 ± 5. 22 vs 3.17 ± 1.47, P < 0.01), and immunohistochemistry and Western blot exhibited remarkably higher expressions of Bax and p53 in the former than in the latter group (P < 0.05).

CONCLUSIONIn utero exposure to DBP can increase the apoptosis of germ cells and Sertoli cells, induce the vacuolization of testicular cells, and significantly elevate the expressions of the apoptosis-promoting proteins Bax and p53 in the pubertal male rat offspring.

Animals ; Apoptosis ; Body Weight ; Dibutyl Phthalate ; adverse effects ; Female ; Immunohistochemistry ; In Situ Nick-End Labeling ; Male ; Pregnancy ; Prenatal Exposure Delayed Effects ; Rats ; Rats, Sprague-Dawley ; Sertoli Cells ; cytology ; pathology ; Spermatogenesis ; Testis ; cytology ; pathology ; Tumor Suppressor Protein p53 ; metabolism ; bcl-2-Associated X Protein ; metabolism