• Applied Microscopy
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• v.39 no.3
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• pp.219-226
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• 2009

The ultrastructure of spermatogenesis and sperm in Cichlasoma managuensis belonging to Cichlidae was investigated by light and electron microscopes. The testis of C. managuensis contained numerous testicular cysts, and spermatogenesis was synchronized in these testicular cysts. In the case of spermatogonia, the nucleus was comparatively large ellipsoidal, and mitochondria showed a marked development. The size of primary spermatocyte was smaller than that of spermatogonia, and that of secondary spermatocyte was smaller than that of primary spermatocyte. The chromatin of spermatocyte was highly condensed according to their development. The nucleus with electron-dense was round shape. In spermiogenesis, flagella started to be formed and chromatin was more condensed. The mitochondria were rearranged in a middle piece. The sperm was formed by loss of cytoplasm. The head of mature sperm was a spherical shape and had not acrosome. The microtubules of flagella were arranged 9+2 structure. Also, the tail of sperm have lateral fins.

• Toxicological Research
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• v.14 no.2
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• pp.193-203
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• 1998

The toxicity of DA-125. a new anthracycline anticancer agent, on the male reproductive system was studied in Sprague-Dawley rats. Forty male rats were rando$m\ell$y assigned to Jour groups with ten rats in each group and given single intraveneous doses of DA-125 at dose levels of 0. 12.5. 25. and 50 mg/kg body weight. On day 56 after treatment the animals were allowed to mate. and their male reproductive Junctions and organs were examined in detail. Copulated females were sacrificed on day 20 of gestation for examination of embryo-fetal development. One out of ten rats in the 50 mg/kg group died on day 12 after treatment. Clinical signs such as emaciation. sedation, anorexia. swelling. dark material around eye. alopecia. and diarrhea were observed in the 25 and/or 50 mg/kg groups. Reduction in the body weight gain. decrease in the absolute weights of testes. epididymis and seminal vesicles. and/or decrease in the number of testicular sperm heads were also found. Although histopathological changes such as atrophy of seminiferous tubules. loss or decrease of spermatogenic cells. exfoliation of spermatogenic cells. vacuolization of Sertoli cells. decrease of sperm. and/or increase of necrotic spermatogenic cells in epididymal ducts were observed. no adverse effects on the motility and morphology of epididymal sperm. copulation index. fertility index. and embryo-fetal development were detected in the 25 and 50 mg/kg groups. There were no evidences of male reproductive toxicity in the 12.5 mg/kg group. These results show that single intravenouse doses of DA-125 produce significant dose-related testicular atrophy. histopathological changes. and oligozoospermia in rats and $LD_{10}$ for DA-125 appears to be 50 mg/kg body weight.

• Journal of Animal Science and Technology
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• v.54 no.3
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• pp.157-163
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• 2012

The male reproduction is precisely controlled by a number of intrinsic and extrinsic factors. These factors usually involve in expressional regulation of various molecules influencing on sperm production in the testis. A number of ways are employed to control the transcription of specific genes, including epigenetic modifications of DNA and histone molecules. DNA methylation of CpG dinucleotides is a commonly used regulatory mechanism for testicular genes associated with the fertility. Previous studies have demonstrated the infertility induced by improper DNA methylation of these genes. In the present research, we attempted to determine transcriptional expression of some of these genes in the rat testis at different postnatal ages using real-time PCR analysis. These genes include neurotrophin 3 (Ntf3), insulin-like growth factor II (Igf2), JmjC-domain-containing histone demethylase 2A 1 (Jhm2da), paired box 8 transcription factor (Pax8), small nuclear ribonucleoprotein polypeptide N (Snrpn), and 5,10-methylenetetrahydrofolate reductase (Mthfr). The expression levels of Ntf3, Igf2, and Snrpn genes were the highest at the neonatal age, followed by transient decreases at the prepubertal age. Expression of Jhm2da and Mthfr genes were continuously increased from the neonate to 1 year of age. The levels of Pax8 mRNA at the early ages were higher than those at the later ages of postnatal development. These findings suggest that expression of some fertility-associated testicular genes in the rat during postnatal period could be differentially regulated by the control of the degree of DNA methylation.

• International Journal of Stem Cells
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• v.17 no.3
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• pp.298-308
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• 2024

Sine oculis homeobox 1 (Six1) is an important factor for embryonic development and carcinoma malignancy. However, the localization of Six1 varies due to protein size and cell types in different organs. In this study, we focus on the expression and localization of Six1 in male reproductive organ via bioinformatics analysis and immunofluorescent detection. The potential interacted proteins with Six1 were also predicted by protein-protein interactions (PPIs) and Enrichr analysis. Bioinformatic data from The Cancer Genome Atlas and Genotype-Tissue Expression project databases showed that SIX1 was highly expressed in normal human testis, but low expressed in the testicular germ cell tumor sample. Human Protein Atlas examination verified that SIX1 level was higher in normal than that in cancer samples. The sub-localization of SIX1 in different reproductive tissues varies but specifically in the cytoplasm and membrane in testicular cells. In mouse cells, single cell RNA-sequencing data analysis indicated that Six1 expression level was higher in mouse spermatogonial stem cells (mSSCs) and differentiating spermatogonial than in other somatic cells. Immunofluorescence staining showed the cytoplasmic localization of Six1 in mouse testis and mSSCs. Further PPIs and Enrichr examination showed the potential interaction of Six1 with bone morphogenetic protein 4 (Bmp4) and catenin Beta-1 (CtnnB1) and stem cell signal pathways. Cytoplasmic localization of Six1 in male testis and mSSCs was probably associated with stem cell related proteins Bmp4 and CtnnB1 for stem cell development.

• Development and Reproduction
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• v.14 no.3
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• pp.199-205
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• 2010

A neurotoxin, 6-hydroxydopamine (6-OHDA) has been widely used to create animal model for Parkinson's disease (PD). The present study was undertaken to examine whether depletion of brain dopamine (DA) stores with 6-OHDA can make alteration in the activities of the testicular steroidogenesis in adult rats. Young adult male rats (3 months old) were received a single dose of 6-OHDA (200 ${\mu}g$ in 10 ${\mu}{\ell}$/animal) by intracerebroventricular (icv) injection, and sacrificed after two weeks. The mRNA levels of steroidogenesis-related enzymes were measured by qRT-PCRs. Serum testosterone levels were measured by radioimmunoassay. Single icv infusion of 6-OHDA significantly decreased the mRNA levels of CYP11A1 (control:6-OHDA group=$1:0.68{\pm}0.14$ AU, p<0.05), CYP17 (control:6-OHDA group=$1:0.72{\pm}0.13$ AU, p<0.05). There were no changes in the mRNA levels of $3{\beta}$-HSD (control:6-OHDA group=$1:0.84{\pm}0.08$ AU) and $17{\beta}$-HSD (control: 6-OHDA group=$1:0.63{\pm}0.20$ AU), though the levels tended to be decreased in the 6-OHDA treated group. Administration of 6-OHDA decreased significantly the mRNA level of StAR when compared to the level of saline-injected control animals (control:6-OHDA group=$1:0.72{\pm}0.08$ AU, p<0.05). Treatment with single dose of 6-OHDA remarkably lowered serum testosterone levels compared to the levels of control group (control:6-OHDA group=$0.72{\pm}0.24:0.13{\pm}0.03ng/m{\ell}$, p<0.05). Taken together with our previous study, the present study demonstrated that the activities of hypothalamus-pituitary-testis hormonal axis could be negatively affected by blockade of brain DA biosynthesis, and suggested the reduced reproductive potential might be resulted in the animals. More precise information on the testicular steroidogenic activities in PD patients and PD-like animals should be required prior to the generalization of the sex steroid hormone therapy to meet the highest standards for safety and efficacy.

• Development and Reproduction
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• v.25 no.1
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• pp.15-24
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• 2021

Benzo[a]pyrene (B[a]P) is a potent carcinogen and is classified as an endocrine-disrupting chemical. In mammalian testes, Sertoli cells support spermatogenesis. Therefore, if these cells are negatively affected by exposure to xenotoxic chemicals, spermatogenesis can be seriously disrupted. In this context, we evaluated whether mouse testicular TM4 Sertoli cells are susceptible to the induction of cytotoxicity-mediated cell death after exposure to B[a] P in vitro. In the present study, while B[a]P and B[a]P-7,8-diol were not able to induce cell death, exposure to BPDE resulted in cell death. BPDE-induced cell death is accompanied by the activation of caspase-3 and caspase-7. Depolarization of the mitochondrial membrane and cytochrome c release from mitochondria were observed in benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE)-treated cells. These results indicate that TM4 cells are susceptible to apoptosis in a caspase-dependent manner. Western blot and reverse transcription-polymerase chain reaction (RT-PCR) analyses showed that aryl hydrocarbon receptor (AhR) expression was almost undetectable in TM4 cells and that its expression was not altered after B[a]P treatment. This indicates that TM4 cells are nearly AhR-deficient. In TM4 cells, the CYP1A1 protein and its activity were not present. From these results, it is clear that AhR may be a prerequisite for CYP1A1 expression in TM4 cells. Therefore, TM4 cells can be referred to as CYP1A1-deficient cells. Thus, TM4 Sertoli cells are believed to have a rigid and protective cellular machinery against genotoxic agents. In conclusion, it is suggested that tolerance to B[a]P cytotoxicity is associated with insufficient AhR and CYP1A1 expression in testicular Sertoli cells.

• Animal Bioscience
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• v.35 no.4
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• pp.544-555
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• 2022

Objective: Spermatozoa are produced within the seminiferous tubules after sexual maturity. The expression levels of mRNAs and lncRNAs in testicular tissues are different at each stage of testicular development and are closely related to formation of the extracellular matrix (ECM) and spermatogenesis. Therefore, we set out to study the expression of lncRNAs and mRNAs during the different developmental stages of the goat testis. Methods: We constructed 12 RNA libraries using testicular tissues from goats aged 3, 6, and 12 months, and studied the functions of mRNAs and lncRNAs using the gene ontogeny (GO) and Kyoto encyclopedia of genes and genomes (KEGG) databases. Relationships between differentially expressed genes (DEGs) were analyzed by lncRNA-mRNA co-expression network and protein-protein interaction network (PPI). Finally, the protein expression levels of matrix metalloproteinase 2 (MMP2), insulin-like growth factor 2 (IGF2), and insulin-like growth factor-binding protein 6 (IGFBP6) were detected by western blotting. Results: We found 23, 8, and 135 differentially expressed lncRNAs and 161, 12, and 665 differentially expressed mRNAs that were identified between 3 vs 6, 6 vs 12, and 3 vs 12 months, respectively. GO, KEGG, and PPI analyses showed that the differential genes were mainly related to the ECM. Moreover, MMP2 was a hub gene and co-expressed with the lncRNA TCONS-0002139 and TCONS-00093342. The results of quantitative reverse-transcription polymerase chain reaction verification were consistent with those of RNA-seq sequencing. The expression trends of MMP2, IGF2, and IGFBP6 protein were the same as that of mRNA, which all decreased with age. IGF2 and MMP2 were significantly different in the 3 vs 6-month-old group (p<0.05). Conclusion: These results improve our understanding of the molecular mechanisms involved in sexual maturation of the goat testis.

• Development and Reproduction
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• v.7 no.1
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• pp.35-40
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• 2003

Gonadotropin releasing hormone(GnRH), which is secreted from the hypothalamus, has a pivotal role in the reproduction of mammals. Golden hamsters are seasonal breeding mammal and their sexual activity is determined by photoperiod(length of light per day). Long photoperiod(LP, $\leq$ 12.5 hours of light) maintains the reproductive activity and short photoperiod(SP, $\leq$ 12 hours of light) suppresses it. In order to investigate in detail, the sexual activity was individually examined in SP-housed male golden hamsters received a vector at three different concentrations which contains rat GnRH cDNA. The gonadal regression was significantly(P<0.05) accelerated by the highest concentrations of the vector at 8 and 10 weeks after the treatment in comparison to the other groups. In the light of pulsatile release of GnRH in maintaining reproductive activity, the vector containing GnRH cDNA might secrete the GnRH in a constant high level. These results suggest that the GnRH-containing vector might desensitize the anterior pituitary, leading to acceleration or testicular regression.

• Development and Reproduction
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• v.17 no.1
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• pp.37-43
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• 2013

Cynomorium songaricum (CS) has been used in traditional Korean medicine in treating male impotence and sexual dysfunction. We investigated the effects of aqueous CS extract on the reproductive activity of golden hamsters whose spermatogenetic capacity is active in summer and inactive in winter. The animals were divided into 5 groups: long photoperiod (LP) control, short photoperiod (SP) control, and SP animals treated with low, middle, or high concentrations of CS. The animals were orally ingested with low (0.5 g/kg), middle (1.0 g/kg), or high (2.5 g/kg) concentrations of the aqueous extracts for 8 weeks on the daily basis. The control animals received the vehicle. As results, the LP control animals showed active testicular function but SP control animals displayed remarkably reduced testicular weights. The outcomes of the reproductive activity from low and middle concentrations of CS treatments were identical and marked as low dose. The consequences were a partial blocking of regressing activity by SP. On the other hand, the animals treated with high dose of CS extract showed remarkable significance in comparison to the SP control, indicative of a complete blocking effect of the CS on the regressing testes by SP. There were a dose-dependent effects of the CS on the sexual function. These results suggest that the CS extract promotes the male fertility by strengthening the spermatogenesis in the golden hamsters.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.12
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• pp.1826-1835
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• 2019

Objective: Testicular growth and development are strongly influenced by androgen. Although both testis weight and plasma testosterone level are inherited traits, the interrelationship between them is not fully established. Males of DDD/Sgn (DDD) mice are known to have extremely heavy testes and very high plasma testosterone level among inbred mouse strains. We dissected the genetic basis of testis weight and analyzed the potential influence of plasma testosterone level in DDD mice. Methods: Quantitative trait loci (QTL) mapping of testis weight was performed with or without considering the influence of plasma testosterone level in reciprocal $F_2$ intercross populations between DDD and C57BL/6J (B6) mice, thereby assessing the influence of testosterone on the effect of testis weight QTL. Candidate genes for testis weight QTL were investigated by next-generation sequencing analysis. Results: Four significant QTL were identified on chromosomes 1, 8, 14, and 17. The DDDderived allele was associated with increased testis weight. The $F_2$ mice were then divided into two groups according to the plasma testosterone level ($F_2$ mice with relatively "low" and "high" testosterone levels), and QTL scans were again performed. Although QTL on chromosome 1 was shared in both $F_2$ mice, QTL on chromosomes 8 and 17 were identified specifically in $F_2$ mice with relatively high testosterone levels. By whole-exome sequencing analysis, we identified one DDD-specific missense mutation Pro29Ser in alpha tubulin acetyltransferase 1 (Atat1). Conclusion: Most of the testis weight QTL expressed stronger phenotypic effect when they were placed on circumstance with high testosterone level. High testosterone influenced the QTL by enhancing the effect of DDD-derived allele and diminishing the effects of B6-derived allele. Since Pro29Ser was not identified in other inbred mouse strains, and since Pro29 in Atat1 has been strongly conserved among mammalian species, Atat1 is a plausible candidate for testis weight QTL on chromosome 17.