The cyclin dependent kinase inhibitor P21 CDKN1A has been shown to be upregulated during differentiation and after DNA damage in somatic cells. We examined the expression of P21 CDKN1A and of γ-H2AX during the differentiation of germ cells in normal mouse testis. P21 CDKN1A was normally expressed in in a variable mode in different cell types (spermatogonia, spermatocytes, spermatids, Sertoli cell) located since the basal till the lumen of the seminiferous tubules. Moreover, in agreement with γ-H2AX expression, P21 maybe involved in different cell cycle checkpoints in spermatocytes such as a pre-replication, XY body inactivation, a mid-pachytene and a metaphase I checkpoints. Finally, in comparison to control, the p21 deficient mouse testis show elevated numbers of apoptosis of elongated spermatids within stages VIII-IX but any difference in the number of spermatogonia mitosis.These results suggest that P21 also may take part in the regulation of the differentiation of the male germ cells and may have a role in spermatogonia not related with a mitotic checkpoint.

Many anuran strategies for survival 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 testis undergoes various stages of change during the reproductive cycle, and water balance is an important factor in 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. AQP1 and 2 immunoreactions were found in early germ cells, spermatozoa, Leydig cells, and Sertoli cells, which were strongly associated with the reproductive period. AQP1 was also found in the testicular blood vessels. AQP 9 was identified predominantly in the epithelium of the intratesticular ducts of reproductive period individuals. The study present, for the first time, the localization of AQP1, AQP2, and AQP9 in the testis of an anuran species, and the differences in their location during two distinct periods of the reproductive cycle.

Spermatogenesis is critical for insect reproduction and is regulated by many different genes. In this study, we found that Forkhead transcription factor Fd59a functions as a key factor in spermatogenesis of Drosophila melanogaster. Fd59a contains a conversed Forkhead domain, and it is clustered to the FoxD subfamily with other FoxD members from some insect and vertebrate species. Mutation in Fd59a caused swelling in the apical region of the testis. More importantly, only a few mature sperm were present in the seminal vesicle of Fd59a mutant flies compared to the control flies, and the fertility of Fd59a2/2 mutant males was significantly lower than that of the control flies. Immunofluorescence staining showed that the homeostasis of testis stem cell niche in Fd59a2/2 mutant and Fd59a RNAi flies was disrupted, and apoptosis of sperm bundles was increased. Furthermore, results from RNA-sequencing and qRT-PCR suggest that Fd59a can regulate expression of genes related to reproductive process and cell death. Taken together, our results indicated that Fd59a plays a key role in the spermatogenesis of Drosophila.

The Drosophila spermatogenesis has the renewal of germline stem cells, meiosis of spermatocytes, and morphological transformation of spermatids into mature sperm. We previously demonstrated that Ocnus (ocn) plays an essential role in spermatogenesis. ValRS-m (Valyl-tRNA synthetase, mito-chondrial) gene was downregulated in ocn RNAi testes. By hatchability testing, we found that ValRS-m-knockdown induced complete sterility of male flies. We also concluded that ValRS-m-knockdown inhibited the transition from spermatogonia to spermatocytes and caused accumulated spermatogonia in testes. To understand the intrinsic reason for this destruction, we further conducted transcriptome sequencing analysis in ValRS-m RNAi testes. A total of 7710 dif-ferentially expressed genes (DEGs) were identified to have at least a 2-fold change with a p-value of

Spermatogenesis is a complex, tightly regulated biological process crucial for male fertility in mammals. MicroRNAs (miRNAs) and messenger RNAs (mRNAs) play essential functions in regulating gene expression during spermatogenesis, and their specific roles in Holstein bull testicular development remain unclear. The study analyzed testicular tissues from young and mature Holstein bulls, unveiling the post-sexual maturation transcriptome landscape with a focus on spermatogenesis-associated miRNAs and mRNA profiles. The cDNA libraries from the testicular tissues of three young Holstein bulls (X1, X2, and X3; group YB) and three mature Holstein bulls (D5, D6, and D7; group AB) were established for RNA-sequencing analysis using Illumina high-throughput sequencing technology, followed by bioinformatics analysis. A total of 1114 miRNAs were identified in the X vs. D groups: 683 known miRNAs and 431 novel miRNAs. Notably, 221 known miRNAs exhibit differential expression between the X and D groups, with 118 up-regulated and 103 down-regulated genes. Moreover, a total of 237 previously unidentified novel miRNAs were also observed to exhibit differential expression between X and D, with 77 up-regulated and 160 down-regulated miRNA genes. These miRNA genes were linked to Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways related to male reproduction and spermatogenesis. The DE analysis of miRNA genes identified the top five up-regulated miRNAs (bta-miR-127, bta-miR-495, bta-miR-493, bta-miR-432, and bta-miR-3956) and down-regulated miRNAs (bta-miR-34c, bta-miR-34b, bta-miR-449a, bta-miR-449b, and 23_28233-5p (hsa-miR-6774-3p)) between the young bull and adult bull groups. The miRNA-mRNA network analysis also identified 17_16057-5p, X_45311-3p (cpo-miR-12072-3p), bta-miR-34c, bta-miR-375, 17_15431-5p (eca-miR-8912), 10_2547-3p (isc-miR-5313), bta-miR-449b, and mRNA genes such as BCL2L11, ADAMTSI1, MED1, and PRDM1; these genes were associated with reproductive system development. The mRNA genes (STRB and BCL2L11) and miRNA genes (bta-miR-134, bta-let-7e, bta-miR-181b, and bta-miR-214) were also found to have a significant correlation with the spermatogenic process. Thus, the comprehensive analysis of miRNA and mRNA enhances our knowledge of the regulatory networks involved in testicular development and identifies potential targets for further investigation and manipulation to improve cattle reproductive efficiency and genetic selection.

Androgens are key for pubertal development of the mammalian testis, a phenomenon tightly linked to Sertoli cell maturation. In this review, we discuss how androgen signalling affects Sertoli cell function and morphology by concomitantly inhibiting some processes and promoting others that contribute jointly to the completion of spermatogenesis. We focus on the molecular mechanisms that underlie AMH inhibition by androgens at puberty, as well as on the role androgens have on Sertoli cell tight junction formation and maintenance and, consequently, on its effect on proper germ cell differentiation and meiotic onset during spermatogenesis.

Signaling modules that integrate the diverse extra- and intracellular inputs to control cell proliferation are essential during both development and adult stages to guarantee organism homeostasis. Mobs are small adaptor proteins that participate in several of these signalling pathways. Here we review recent advances unraveling Mob4 cellular functions, a highly conserved non-catalytic protein, that plays a diversity of roles in cell proliferation, sperm cell differentiation and simultaneously is involved in synapse formation and neural development. In addition, the gene is often overexpressed in a wide range of tumors and is linked to poor clinical outcomes. Nevertheless, Mob4 molecular functions remain poorly defined, although it integrates the core structure of STRIPAK, a kinase/phosphatase protein complex, that can act upstream of the Hippo pathway. In this review we focus on the recent findings of Mob4 functions, that have begun to clarify its critical role on cell proliferation and development of tissues and individuals.

Cadherins are a group of membrane proteins responsible for cell adhesion. They are crucial for cell sorting and recognition during the morphogenesis, but also play many other roles such as assuring tissue integrity and resistance to stretching, mechanotransduction, cell signaling, regulation of cell proliferation, apoptosis, survival, carcinogenesis, etc. Within the cadherin superfamily, the E- and N-cadherin have been especially well studied. They are involved in many aspects of sexual development and reproduction, such as germline development and gametogenesis, gonad development and functioning, and fertilization. E-cadherin is expressed in the primordial germ cells, (PGCs) and also participates in PGC migration to the developing gonads where they become enclosed by the N-cadherin-expressing somatic cells. The differential expression of cadherins is also responsible for the establishment of the testis or ovary structure. In the adult testes, the N-cadherin is responsible for the integrity of the seminiferous epithelium, regulation of sperm production, and the establishment of the blood-testis barrier. Sex hormones regulate the expression and turnover of N-cadherin influencing the course of spermatogenesis. In the adult ovaries, E- and N-cadherin assure the integrity of ovarian follicles and the formation of corpora lutea. Cadherins are expressed in the mature gametes, and facilitate the capacitation of sperm in the female reproductive tract, and gamete contact during fertilization. The germ cells and accompanying somatic cells express a series of different cadherins, however, their role in gonads and reproduction is still unknown. In this review, we show what is known and unknown about the role of cadherins in the germline and gonad development, and suggest the topics for future research.