Testicular Development Research Articles

Adaptive divergence in reproductive seasonality and underlying physiological features fit Rattus norvegicus to live as opportunistic breeders.

How organisms respond to complex environments is one of the unsolved problems in ecology. Life history patterns of a species provide essential information on how different populations may respond and adapt to environmental changes. Compared to typical seasonal breeders, which have limited distributions, the worldwide distribution of brown rats (Rattus norvegicus) across highly complex and divergent habitats suggests they exhibit exceptional adaptiveness. However, the difference in physiological mechanisms by which brown rats respond and adapt to markedly different environments is seldom investigated. Here, we reveal a significant divergence in reproductive seasonality and environmental responses between two brown rat subspecies: one subspecies, R. n. caraco, lives in the temperate zone, and another subspecies, R. n. norvegicus, lives in the subtropical region. Although R. n. caraco displayed a significantly higher reproductive seasonality than R. n. norvegicus, both subspecies adapted to sub-optimal breeding conditions mainly by regulating the seminal vesicle rather than testis development. Especially in responding to severe winter conditions in high-latitude regions, bodyweight-dependent recovery of testicular development in adults enables R. n. caraco to initiate reproduction more rapidly when conditions are suited. These findings elucidate a regulatory process of how brown rats live as opportunistic breeders by benefiting from enhanced semen production.

Characterization of a novel and testis-specific zinc finger protein during sexual development of Pacific white shrimp Litopenaeus vannamei.

Since females grow faster in penaeid shrimp, all-female aquaculture was proposed. Environmental conditions in the Pacific white shrimp did not found to affect genetic sex determination (ZZ/ZW system). The androgenic gland (AG)-secreting insulin-like androgenic gland hormone (IAG) is a key controlling factor in crustacean male differentiation. However, functional sex reversal (neo-male) in penaeid shrimp has not yet been achieved by manipulating the IAG-sexual switch. Therefore, understanding the molecular mechanisms of gonadal differentiation may help build appropriate tools to generate neo-male (ZW) for all-female breeding. This study describes the potential role of the novel penaeid-specific testicular zinc finger protein (pTZFP) in the gonads of Pacific white shrimp. First, pTZFP transcripts show a male-bias expression pattern in undifferentiated gonads, which is then exclusively expressed in the testis and absent or slightly expressed in the ovary and other tissues. Besides, the knockdown of pTZFP in undifferentiated males results in smaller testes but no sex reversal. Immunohistochemical (IHC) staining of proliferating cell nuclear antigen (PCNA) further confirmed that the smaller testes in pTZFP-deficient males are due to the lower proliferating activity of spermatogonia. These data reveal that pTZFP may be involved in testicular development but have fewer effects on gonadal differentiation. Moreover, testicular pTZFP transcription levels were not reduced with estradiol-17β (E2) administration or AG excision. Therefore, our data suggest that pTZFP may regulate testicular development through downstream genes regulating spermatogonia proliferation. Moreover, our data provide an appropriate molecular marker for identifying the sex of undifferentiated gonads.

Interaction of CTCF and CTCFL in genome regulation through chromatin architecture during the spermatogenesis and carcinogenesis.

The zinc finger protein CTCF is ubiquitously expressed and is integral to the regulation of chromatin architecture through its interaction with cohesin. Conversely, CTCFL expression is predominantly restricted to the adult male testis but is aberrantly expressed in certain cancers. Despite their distinct expression patterns, the cooperative and competitive mechanisms by which CTCF and CTCFL regulate target gene expression in spermatocytes and cancer cells remain inadequately understood. In this review, we comprehensively examine the literature on the divergent amino acid sequences, target sites, expression profiles and functions of CTCF and CTCFL in normal tissues and cancers. We further elucidate the mechanisms by which CTCFL competitively or cooperatively binds to CTCF target sites during spermatogenesis and carcinogenesis to modulate chromatin architecture. We mainly focus on the role of CTCFL in testicular and cancer development, highlighting its interaction with CTCF at CTCF binding sites to regulate target genes. In the testis, CTCF and CTCFL cooperate to regulate the expression of testis-specific genes, essential for proper germ cell progression. In cancers, CTCFL overexpression competes with CTCF for DNA binding, leading to aberrant gene expression, a more relaxed chromatin state, and altered chromatin loops. By uncovering the roles of CTCF and CTCFL in spermatogenesis and carcinogenesis, we can better understand the implications of aberrant CTCFL expression in altering chromatin loops and its contribution to disease pathogenesis.

Androgen blockage impairs proliferation and function of Sertoli cells via Wee1 and Lfng

BackgroundAndrogens are essential hormones for testicular development and the maintenance of male fertility. Environmental factors, stress, aging, and psychological conditions can disrupt androgen production, impacting the androgen signaling pathway and consequently spermatogenesis. Within the testes, testosterone is produced by Leydig cells and acts on Sertoli cells by activating the androgen receptor (AR), which then translocates to the nucleus to function as a transcription factor. Despite clinical correlations between low testosterone levels and diminished sperm quality, the precise mechanism remains unclear.MethodsThis study explores the hypothesis that reduced androgen levels impair Sertoli cell function by disrupting AR transcriptional regulation. Using an androgen blockade model with enzalutamide, we investigated the impact of low androgen levels on AR target genes in Sertoli cells through ChIP-seq and RNA-seq assays.ResultsOur results reveal that androgen blockage increases AR enrichment on the promoter region of Wee1, promoting Wee1 expression, while decreasing binding to the promoter region of Lfng, inhibiting its expression. Increased WEE1 protein inhibits Sertoli cell proliferation, whereas reduced LFNG affects Notch modification, leading to decreased production of glial cell line-derived neurotrophic factor (GDNF), a key growth factor for spermatogonial stem cell self-renewal.ConclusionsThese findings provide new insights into the molecular mechanisms by which low androgen levels interfere with Sertoli cell functions, offering novel perspectives for the clinical treatment of male reproductive disorders.

Neonatal undernutrition induced by litter size expansion alters testicular parameters in adult Wistar rats.

Several models of maternal undernutrition reveal impairment of testicular development and compromise spermatogenesis in male offspring. The expansion of the litter size model, valuable for studying the impact of undernutrition on early development, has not yet been used to evaluate the consequences of early undernutrition in the adult male reproductive system. For this purpose, pups were raised in either normal litter (ten pups/dam) or large litter (LL; sixteen pups/dam). On postnatal day 90, sexual behaviour was evaluated or blood, adipose and reproductive tissues were collected for biochemical, histological and morphological analysis. Adult LL animals were lighter and thinner than controls. They showed increased food intake, but decrease of retroperitoneal white adipose tissue weight, glycaemia after oral glucose overload and plasma concentration of cholesterol. Reproductive organ weights were not altered by undernutrition, but histopathological analysis revealed an increased number of abnormal seminiferous tubules and number of immature spermatids in the tubular lumen of LL animals. These animals also showed reduction in total spermatic reserve and daily sperm production in the testes. Undernutrition decreased the number of Sertoli cells, and testosterone production was increased in the LL group. Mitochondrial activity of spermatozoa remained unchanged between experimental groups, suggesting no significant impact on the energy-related processes associated with sperm function. All animals from both experimental groups were considered sexually competent, with no significant difference in the parameters of sexual behaviour. We conclude that neonatal undernutrition induces histological and physiological testicular changes, without altering sperm quality and sexual behaviour of animals.

Integration analysis of transcriptome and metabolome revealed the potential mechanism of spermatogenesis in Tibetan sheep (Ovis aries) at extreme high altitude

Testis has an indispensable function in male reproduction of domestic animals. Numerous genes and metabolites were related to testicular development and spermatogenesis. However, little is known about the biological regulation pathways associated with fecundity in male Tibetan sheep. In this study, Testes were collected from Huoba Tibetan sheep (HB, 4614 m) and Gangba Tibetan sheep (GB, 4401 m) at extreme high altitude, and Alpine Merino sheep (AM, 2500 m, control group) at medium-high altitude, investigating the genes and metabolites levels of them. The histological analysis of testicular tissue using hematoxylin-eosin (HE) staining was performed for Tibetan sheep and Alpine Merino sheep, and the testes of them were analyzed by transcriptomics and metabolomics to explore the potential mechanism of testicular development and spermatogenesis. The statistical results showed that the cross-sectional area of testicular seminiferous tubules, diameter of seminiferous tubules, and spermatogenic epithelium thickness were significantly smaller in HB and GB than in AM (P < 0.05). Overall, 5648 differentially expressed genes (DEGs) and 336 differential metabolites (DMs) were identified in three sheep breeds, which were significantly enriched in spermatogenesis and other related pathways. According to integrated metabolomic and transcriptomic analysis, glycolysis/gluconeogenesis, AMPK signaling pathway, and TCA cycle, were predicted to have dramatic effects on the spermatogenesis of Tibetan sheep. Several genes (including Wnt2, Rab3a, Sox9, Hspa8, and Slc38a2) and metabolites (including L-histidinol, Glucose, Fumaric acid, Malic acid, and Galactose) were significantly enriched in pathways related to testicular development and spermatogenesis, and might affect the reproduction of Tibetan sheep by regulating the acrosome reaction, meiotic gene expression, and the production of sex hormones. Our results provide further understanding of the key genes and metabolites involved in testicular development and spermatogenesis in Tibetan sheep.

8509 Molecular and Reproductive Assessment in Ames strain under or not Hormonal Replacement

Abstract Disclosure: B.V. Azevedo: None. N. Trigueiro: None. J.M. Marques: None. V. Yariwake: None. L. Tamashiro: None. R. Cruz: None. M.M. Veras: None. L. Carvalho: None. Introduction: The Ames lineage, a mouse model with a mutation in the Prop1 gene, exhibits GH, TSH, and PRL deficiencies along with low levels of gonadotropins. This has prompted an investigation into aging and reproductive restoration after hormone replacement reported in the literature. Aims: The present study aims to analyze the pathophysiologic mechanisms in the reproductive system and fertility restoration. Methods: This is a prospective study approved by the ethical committee for animal use at the University of Sao Paulo Medical School. An isogenic Ames lineage was categorized into four groups: 1) Ames wild-type mice, 2) untreated Ames dwarf mice with sexual maturity, 3) untreated Ames dwarf mice without sexual maturity, and 4) Ames dwarf mice under hormonal treatment. Male Ames dwarf mice received treatment with levothyroxine and human recombinant GH, starting at 30 days postnatal (dp) for 40 days, followed by weekly applications until 90 dp. At the time of euthanasia, a set of analyses were conducted on animals from each group to characterize sexual maturation, fertility, and tissue collection for reproductive parameter analyses, such as seminiferous tubule morphology by histology, testicular weight, gonadosomatic index, and spermogram analysis. Additionally, pituitary RNAseq was performed using the poly-A tail capture method with the Illumina stranded mRNA prep kit and sequenced on the NextSeq 2000. Results: Treated dwarf mice exhibited fertility restoration, an increase in testicular volume with an improvement of testicular function, and complete spermatogenesis. Untreated Ames dwarf mice were infertile, but those that reached sexual maturity without hormonal replacement showed improvements in reproductive parameters, such as enhanced testicular development, maturation of some seminiferous tubules, increased testicular weight, and improvement in the spermogram compared to immature Ames dwarf mice. Transcriptome analyses revealed distinct patterns of all Ames dwarf mice groups and the wild-type. It was observed a decrease in Fshb expression in the group without sexual maturation compared to the wild-type group. Additionally, Prl and Slc6a12 were upregulated in the spontaneously sexually mature Ames dwarf compared to the non-restored Ames dwarf mice. Conclusion: GH and levothyroxine treatment in the Ames lineage are effective in restoring fertility and improving reproductive parameters in male Ames dwarf mice. However, sexually mature Ames dwarf mice without treatment presented improvements in reproductive and molecular parameters despite remaining infertile. These findings provide valuable insights into the complex interaction among hormonal replacement, modulating mechanisms, and sexual maturity. Presentation: 6/2/2024

8509 Molecular and Reproductive Assessment in Ames strain under or not Hormonal Replacement

Abstract Disclosure: B.V. Azevedo: None. N. Trigueiro: None. J.M. Marques: None. V. Yariwake: None. L. Tamashiro: None. R. Cruz: None. M.M. Veras: None. L. Carvalho: None. Introduction: The Ames lineage, a mouse model with a mutation in the Prop1 gene, exhibits GH, TSH, and PRL deficiencies along with low levels of gonadotropins. This has prompted an investigation into aging and reproductive restoration after hormone replacement reported in the literature. Aims: The present study aims to analyze the pathophysiologic mechanisms in the reproductive system and fertility restoration. Methods: This is a prospective study approved by the ethical committee for animal use at the University of Sao Paulo Medical School. An isogenic Ames lineage was categorized into four groups: 1) Ames wild-type mice, 2) untreated Ames dwarf mice with sexual maturity, 3) untreated Ames dwarf mice without sexual maturity, and 4) Ames dwarf mice under hormonal treatment. Male Ames dwarf mice received treatment with levothyroxine and human recombinant GH, starting at 30 days postnatal (dp) for 40 days, followed by weekly applications until 90 dp. At the time of euthanasia, a set of analyses were conducted on animals from each group to characterize sexual maturation, fertility, and tissue collection for reproductive parameter analyses, such as seminiferous tubule morphology by histology, testicular weight, gonadosomatic index, and spermogram analysis. Additionally, pituitary RNAseq was performed using the poly-A tail capture method with the Illumina stranded mRNA prep kit and sequenced on the NextSeq 2000. Results: Treated dwarf mice exhibited fertility restoration, an increase in testicular volume with an improvement of testicular function, and complete spermatogenesis. Untreated Ames dwarf mice were infertile, but those that reached sexual maturity without hormonal replacement showed improvements in reproductive parameters, such as enhanced testicular development, maturation of some seminiferous tubules, increased testicular weight, and improvement in the spermogram compared to immature Ames dwarf mice. Transcriptome analyses revealed distinct patterns of all Ames dwarf mice groups and the wild-type. It was observed a decrease in Fshb expression in the group without sexual maturation compared to the wild-type group. Additionally, Prl and Slc6a12 were upregulated in the spontaneously sexually mature Ames dwarf compared to the non-restored Ames dwarf mice. Conclusion: GH and levothyroxine treatment in the Ames lineage are effective in restoring fertility and improving reproductive parameters in male Ames dwarf mice. However, sexually mature Ames dwarf mice without treatment presented improvements in reproductive and molecular parameters despite remaining infertile. These findings provide valuable insights into the complex interaction among hormonal replacement, modulating mechanisms, and sexual maturity. Presentation: 6/2/2024

Deficiency in the Rab25 gene leads to a decline in male fertility and testicular injury: Impact on the regulation of germ cell proliferation and apoptosis

BackgroundRab25 is a member of the Rab family, functioning as a regulatory molecule in intracellular transport. Although its involvement in cellular functions and disease development is well-established, its precise roles in male reproductive physiology remain elusive. MethodsTo explore the specific roles of Rab25 in testicular development and spermatogenesis, we established the Rab25−/− mouse model and Rab25 knockdown germ cell line (GC-2). We compared the fertility, sperm analysis, and testicular tissues between Rab25−/− and wild-type male mice. To delve deeper into potential mechanisms, we employed immunohistochemistry, TUNEL assay, Western Blotting, CCK-8 assay, etc. to evaluate cell proliferation and apoptosis in testicular tissues and GC-2 cells. ResultsOur findings indicated that Rab25 was expressed in germ cells and Leydig cells in the testes. Although the weight of Rab25−/− mice testes exhibited no significant changes, fertility was compromised, with a decrease in sperm quantity and reduced motility. HE staining revealed a disorganized arrangement of germ cells and vacuolization. Additionally, chromatin marginalization and nuclear pyknosis were observed in the Rab25−/− mice. In both Rab25−/− mice testes and Rab25 knockdown GC-2 cells, we found that germ cell proliferation was reduced, while apoptosis was increased. ConclusionsIn conclusion, our study proposes that Rab25 plays a vital role in spermatogenesis by regulating the proliferation and apoptosis of germ cells.

Study of Histological Changes of Testis in Rats of Different Ages When Exposed to Frequency 10GHZ Within The X-Band Microwave

This study investigates the impact of 10 GHz microwave exposure, within the X-band range, on rat testicular tissue and sperm development across different age groups. Laboratory rats were divided into a control group of six, which was not exposed to microwaves, and a treatment group of 18, further split into three age-based subgroups (8–12 weeks, 12–16 weeks, and 16–20 weeks), each containing six rats exposed to 10 GHz microwaves for 2.5 hours daily over five weeks. The findings revealed no histological changes in the control group. However, in the treated groups, significant alterations were observed: the youngest group showed a lack of sperm formation and loss of spermatocytes; the middle group displayed malformed sperm and reduced numbers; and the oldest group experienced a decrease in sperm count and minor shape alterations. Additionally, after five weeks, all treated groups exhibited damage to the testicular interstitial tissue, including ruptures and space formation between seminiferous tubules. This study suggests potential risks of microwave exposure on reproductive health and lays the groundwork for future research in this area.

Effect of dietary quercetin on growth performance, blood parameters and testicular development of Hu sheep in summer

Effect of dietary quercetin on growth performance, blood parameters and testicular development of Hu sheep in summer

Low-temperature-induced disruption of reproductive axis and sperm vitality via stress axis in Monopterus albus

The ricefield eel (Monopterus albus) is inherently timid and highly sensitive to stress. Our previous studies have shown that low-temperature weather could significantly affect the sperm vitality of ricefield eels. This study aims to investigate the regulatory mechanism of low-temperature effects on testicular function and sperm vitality in ricefield eels. The ricefield eels were initially reared at low (10 °C) and normal (25 °C) temperatures for 24 h. Low temperatures were found to induce the expression of pituitary pro-opiomelanocortin (POMC) and testes insulin-like growth factor-binding protein 1 (IGFBP1) mRNA expression, suggesting that the reduction in sperm vitality could be attributed to the activation of the stress axis. Moreover, the results indicated a significant decrease in sperm occupancy and count in the testes, along with a reduced percentage of motile sperm. Subsequent transcriptome analysis showed substantial inhibition of reproductive hormone genes (gnrh1, lh, and fsh) in the brain and pituitary, and downregulation of meiosis-related genes (dmc1, rec8, and sycp3) in the testes. These findings suggest that low temperatures might disrupt testicular development and spermatogenesis by inhibiting the reproductive axis. Metabolomics analysis then demonstrated a significant reduction in the levels of metabolites related to glycolysis, fatty acid metabolism, and the tricarboxylic acid (TCA) cycle in the testes after low-temperature treatment. Interestingly, the expression of zona pellucida sperm-binding proteins 3 and 4 (ZP3 and ZP4), which may affect sperm vitality and spermatogenesis, was significantly induced by low temperatures in the testes. In conclusion, these findings suggested that low temperatures might affect testicular function and sperm vitality by simultaneously activating the stress axis and inhibiting the reproductive axis and energy metabolism in the testes.

Transcriptomic Study of Different Stages of Development in the Testis of Sheep.

Numerous genes govern male reproduction, modulating testicular development and spermatogenesis. Our study leveraged RNA-Seq to explore candidate genes and pivotal pathways influencing fecundity in an F1 hybrid of Southdown × Hu sheep testes across four developmental milestones: M0 (0 months old, newborn), M3 (3 months old, sexually immature), M6 (6 months old, sexually mature), and Y1 (1 years old, adult). Histological examination using hematoxylins and eosin staining revealed that the cross-sectional area of the spermatid tubules and the number of supportive cells increased in the other groups, as compared to the M0 group. The cross-sectional area of the vasculature and the number of supporting cells were found to be significantly increased in all other groups in comparison to the M0 group. We conducted GO and KEGG analyses of the differentially expressed genes (DEGs) in the three comparison groups and identified key pathways, including cAMP, MAPK, ECM-receptor interactions, PI3K-Akt, and FOXO signaling, which are closely related to testicular development and spermatogenesis. Notably, alternative splicing (AS) events were markedly elevated in M6 and Y1 stages. Key genes like GATA4, GATA6, SMAD4, SOX9, YAP1, ITGB1 and MAPK1 emerged as significantly enriched in these pathways, potentially orchestrating the transition from immature to mature testes in sheep. These findings offer valuable insights into male reproductive potential and can inform strategies for optimizing animal breeding.

Near-stop in spermatogonia progression and reduced sperm motility in two testis forms of captive North African catfish in Kalasin, Thailand

North African catfish (Clarias gariepinus) is integral to aquaculture, particularly in hybrid production with bighead catfish (Clarias macrocephalus). Recent declines in their production output have been linked to the quality of the parental sperm. This study aimed to evaluate the state of spermatogenesis in two morphological testis forms, normal white testes (CGA_A) and black-brown testes (CGA_B), in captive populations to understand their differences in the cytological processes of spermatogenesis and impact on sperm quality and fertility. We performed computer-assisted sperm analysis (CASA), meiotic chromosome analysis, gene expression profiling, histological examination, and identification of apoptotic cells using the terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). Additionally, microsatellite genotyping was conducted to assess genetic diversity of the populations, showing that similar gene pool patterns were observed between the two populations with the CGA_A and the CGA_B testes. The average sperm motility was 11.15 %. Histologically, the CGA_A testes predominantly contained spermatozoa. By contrast, the CGA_B testes, characterized by black-brown color and harder texture, were composed mainly of spermatocytes and exhibited a higher incidence of apoptotic spermatogonia. Additionally, the CGA_B testes displayed reduced expression of genes essential for normal testicular development. Notably, the CGA_A testes showed significantly higher expression of GtH I, GtH II, Dazl, and Cxcr4b genes and lower levels of Caspase-3 and p53 (p < 0.05). The selective removal of deficient spermatogonia through early apoptosis in CGA_B testes suggest a mechanism contributing to male infertility due to imbalances between the number of germ cells and Sertoli cells. Despite the use of CGA_A testis for fertilization, a hatching rate in the captive populations was 36.43 % over the last three years (2021−2023), substantially lower than that previously reported, indicating the presence of genetic and environmental factors that influence reproductive success in North African catfish. Differences in spermatogenesis between testis forms highlight the need for genetic and environmental strategies to enhance reproductive outcomes in aquaculture.

26 Trace minerals to improve bull fertility

Abstract Bull fertility is paramount for reproductive success in cow-calf production systems and there are a variety of factors that influence bull fertility. Trace mineral requirements and recommendations have been established for growing and finishing steers, as well as lactating and pregnant cows, yet no specific requirements have been established for young or mature beef bulls. Nonetheless, trace minerals have been shown to have an important role in sexual maturation and semen quality of ruminants. Research performed in rams indicates that zinc deficiency results in reduced testicular development, decreased testicular concentrations of testosterone, and impaired development of seminiferous tubules. Deficiency of Zn has also been reported to negatively impact male fertility in humans, where men diagnosed with infertility responded positively to Zn supplementation. In growing bulls, diets with greater concentrations of organic forms of Zn, Cu, and Mn, tended to result in earlier attainment of puberty compared with control diets containing inorganic minerals. Furthermore, greater liver concentrations of Zn have been negatively correlated with sperm acrosomal damage in growing bulls, based on flow cytometry analyses. More recent research indicates that the use of hydroxichloride-based trace minerals results in greater liver concentrations of Zn and Cu compared with sulfate sources. While evidence indicates that trace mineral status has an important role in bull fertility, further research is required to better understand the contributions of trace minerals to semen quality. In addition, investigating the impact of trace mineral sources with greater bioavailability on semen quality may result in the development of practical recommendations that optimize bull fertility.

Familial DMRT1-related non-obstructive azoospermia: a case report.

To report an exceptional case of male-to-male transmission of genetically based non-obstructive azoospermia (NOA) and varicocele through a naturally obtained pregnancy. A father and his son were both diagnosed with NOA after centrifugation and varicocele. The father has no other clinical concerns apart from infertility, detected after many attempts of having another child, but given his urological situation (bilateral varicocele and NOA) assisted reproductive techniques were discouraged. After genetic counseling, several genetic-chromosomal analyses were carried out in the son (karyotype, chromosome Y microdeletions, CFTR screening, NGS infertility panels, and finally array-CGH). After a series of inconclusive tests, array-CGH detected a deletion of 224-283kb (del9p24.3) involving part of the KANK1 and DMRT1 genes, inherited from the father. Haploinsufficiency of DMRT1 was therefore considered the determining factor in the development of azoospermia in the family by a loss of function mechanism. The confirmation of father-to-son transmission of a deletion including DMRT1 represents an important point for clinicians dealing with male infertility, even when complete azoospermia is repetitively detected, and must be of hope for a relevant portion of men. Inclusion criteria for the access to assisted reproductive techniques may also be reconsidered and worthy of a greater number of clinical insights. Finally, since DMRT1 alterations have been associated with NOA and abnormal testicular development, but not specifically with varicocele, further studies are required to validate this issue, as varicocele may have played a crucial role in this case.

MiR-9-5p regulates Sirt1 involved in testicular development and spermatogenesis in mouse

Testicular development and spermatogenesis are critical for male reproduction, with histone (de)acetylation playing a key role in chromatin remodeling within germ cells. Sirt1, a key histone deacetylase, is implicated in chromatin remodeling, but its expression pattern and specific role in testicular development and spermatogenesis need further study. This study comprehensively analyzed Sirt1 expression in adult and juvenile mouse testicular tissues and across various male germ cells, utilizing RT-qPCR, Western blot, immunofluorescence, and cell transfection. GO and KEGG enrichment analyses were performed to elucidate the biological functions and pathways associated with Sirt1 and its related genes. Multiple miRNA databases were utilized to predict miRNAs targeting Sirt1, and their expression levels were validated using RT-qPCR. Lentiviral transfection was used to knockdown candidate miRNAs to assess their functional roles. The results revealed a significant downregulation of Sirt1 expression in adult mouse testicular tissues compared to juvenile tissues, with pronounced variation across diverse male germ cells. Sirt1 was highly expressed in spermatogonia and mature sperm, but comparatively lower in spermatocytes and spermatids. GO and KEGG enrichment analyses highlighted Sirt1's role in key biological processes, including chromatin organization, regulation of cell proliferation, and energy homeostasis, as well as its association with signaling pathways like cellular senescence, the FoxO signaling pathway, and the AMPK signaling pathway. Bioinformatic analysis and subsequent RT-qPCR validation identified miR-9-5p as a miRNA targeting Sirt1. The expression of miR-9-5p was significantly higher in adult mouse testicular tissues compared to juvenile tissues, inversely correlating with Sirt1 levels. Moreover, the knockdown of miR-9-5p led to a notable increase in Sirt1 mRNA and protein expression. In conclusion, Sirt1 is a key player in mouse testicular development and spermatogenesis. The discovery that miR-9-5p negatively regulates Sirt1 suggests a critical regulatory axis that may govern these processes, providing novel insights into male fertility and potential targets for therapeutic intervention.

Immunolocalization of Aquaporin 1, 2, and 9 in Anuran Testis of the Neotropical Pointedbelly Frog Leptodactylus podicipinus.

Many anuran survival strategies involve hydric regulation, and reproduction is not different. The aquaporin (AQP) family plays an important role in water transport and regulation in many tissues, including the male gonad. The testes undergo various stages of change during the reproductive cycle, and water balance is an important factor for ensuring reproductive success. Considering the relevance of water control in testicular development in anurans and the lack of research regarding the tissue localization of AQP in the male gonad, the present study investigated the expression of three AQPs (1, 2, and 9) in the testis of the neotropical anuran species Leptodactylus podicipinus during two different periods of the reproductive cycle (reproductive and non-reproductive). AQP1 and 2 immunoreactions were found in early germ cells, spermatozoa, Leydig cells, and Sertoli cells, which were more frequently expressed within the reproductive period. AQP1 was also found in the testicular blood vessels. AQP9 was identified predominantly in the epithelium of the intratesticular ducts of reproductive-period individuals. This study presents, for the first time, the localization of AQP1, AQP2, and AQP9 in the testes of an anuran species and the differences in their location during two distinct periods of the reproductive cycle.

Seasonal piRNA Expression Profile Changes in the Testes of Plateau Zokor (Eospalax baileyi).

Seasonal reproduction is a mammalian behavior that has developed over an extended evolutionary period and requires animals to respond to external environmental changes to facilitate reproduction. In this study, we investigated the role of PIWI-interacting RNA (piRNA) in the seasonal reproduction of plateau zokors (Eospalax baileyi). piRNA expression profiles in plateau zokor testes during both breeding and non-breeding seasons were examined. The piRNAs had a distinctive ping-pong signature and ranged from 27 to 32 nt with a peak at 30 nt. Testicular piRNAs predominantly aligned to specific genomic regions, including repeat and gene regions. Analysis of the piRNA-mRNA interaction network and functional enrichment of differentially expressed piRNAs targeting mRNAs revealed their association with testicular development and spermatogenesis. Significantly, PIWIL4 is an mRNA gene that interacts with piRNA and exhibits high expression levels within the testes during the non-breeding phase. This study provides a foundation to improve our understanding of piRNA regulatory mechanisms during testicular development and spermatogenesis in seasonally reproducing animals and, specifically, in the plateau zokor.

Histological observations and transcriptome analyses reveal the dynamic changes in the gonads of the blotched snakehead (Channa maculata) during sex differentiation and gametogenesis

BackgroundBlotched snakehead (Channa maculata) displays significant sexual dimorphism, with males exhibiting faster growth rates and larger body sizes compared to females. The cultivation of the all-male population of snakeheads holds substantial economic and ecological value. Nonetheless, the intricate processes governing the development of bipotential gonads into either testis or ovary in C. maculata remain inadequately elucidated. Therefore, it is necessary to determine the critical time window of sex differentiation in C. maculata, providing a theoretical basis for sex control in production practices.MethodsThe body length and weight of male and female C. maculata were measured at different developmental stages to reveal when sexual dimorphism in growth initially appears. Histological observations and spatiotemporal comparative transcriptome analyses were performed on ovaries and testes across various developmental stages to determine the crucial time windows for sex differentiation in each sex and the sex-related genes. Additionally, qPCR and MG2C were utilized to validate and locate sex-related genes, and levels of E2 and T were quantified to understand sex steroid synthesis.ResultsSexual dimorphism in growth became evident starting from 90 dpf. Histological observations revealed that morphological sex differentiation in females and males occurred between 20 and 25 dpf or earlier and 30–35 dpf or earlier, respectively, corresponding to the appearance of the ovarian cavity or efferent duct anlage. Transcriptome analyses revealed divergent gene expression patterns in testes and ovaries after 30 dpf. The periods of 40–60 dpf and 60–90 dpf marked the initiation of molecular sex differentiation in females and males, respectively. Male-biased genes (Sox11a, Dmrt1, Amh, Amhr2, Gsdf, Ar, Cyp17a2) likely play crucial roles in male sex differentiation and spermatogenesis, while female-biased genes (Foxl2, Cyp19a1a, Bmp15, Figla, Er) could be pivotal in ovarian differentiation and development. Numerous biological pathways linked to sex differentiation and gametogenesis were also identified. Additionally, E2 and T exhibited sexual dimorphism during sex differentiation and gonadal development. Based on these results, it is hypothesized that in C. maculata, the potential male sex differentiation pathway, Sox11a–Dmrt1–Sox9b, activates downstream sex-related genes (Amh, Amhr2, Gsdf, Ar, Cyp17a2) for testicular development, while the antagonistic pathway, Foxl2/Cyp19a1a, activates downstream sex-related genes (Bmp15, Figla, Er) for ovarian development.ConclusionsThis study provides a comprehensive overview of gonadal dynamic changes during sex differentiation and gametogenesis in C. maculata, establishing a scientific foundation for sex control in this species.