Gene expression dynamics during the gonocyte to spermatogonia transition and spermatogenesis in the domestic yak

Abstract

Background Spermatogenesis is a cellular differentiation process that includes three major events: mitosis of spermatogonia, meiosis of spermatocytes and spermiogenesis. Steady-state spermatogenesis relies on functions of spermatogonial stem cells (SSCs). Establishing and maintaining a foundational SSC pool is essential for continued spermatogenesis in mammals. Currently, our knowledge about SSC and spermatogenesis is severely limited in domestic animals. Results In the present study, we examined transcriptomes of testes from domestic yaks at four different stages (3, 5, 8 and 24 months of age) and attempted to identify genes that are associated with key developmental events of spermatogenesis. Histological analyses showed that the most advanced germ cells within seminiferous tubules of testes from 3, 5, 8 and 24 months old yaks were gonocytes, spermatogonia, spermatocytes and elongated spermatids, respectively. RNA-sequencing (RNA-seq) analyses revealed that 11904, 4381 and 2459 genes were differentially expressed during the gonocyte to spermatogonia transition, the mitosis to meiosis transition and the meiosis to post-meiosis transition. Further analyses identified a list of candidate genes than may regulate these important cellular processes. CXCR4 , a previously identified SSC niche factor in mouse, was one of the up-regulated genes in the 5 months old yak testis. Results of immunohistochemical staining confirmed that CXCR4 was exclusively expressed in gonocytes and a subpopulation of spermatogonia in the yak testis. Conclusions Together, these findings demonstrated histological changes of postnatal testis development in the domestic yak. During development of spermatogonial lineage, meiotic and haploid germ cells are supported by dynamic transcriptional regulation of gene expression. Our transcriptomic analyses provided a list of candidate genes that potentially play crucial roles in directing the establishment of SSC and spermatogenesis in yak. Electronic supplementary material The online version of this article (10.1186/s40104-019-0360-7) contains supplementary material, which is available to authorized users.

Ashwin Gene Expression Profiles in Oocytes, Preimplantation Embryos, and Fetal and Adult Bovine Tissues

“…RNA sequencing of gene expression dynamics during the prospermatogonia-spermatogonia transition and spermatogenesis in this domestic species revealed a transcriptomic signature specific to each process. The total sequences of Wang et al [19] show positive ashwin sequencing, supporting our observation that this gene is expressed during the prospermatogonia-spermatogonia transition and in the spermatogonial differentiation phase. However, the spatiotemporal differences in the distribution of the protein detected by immunohistochemistry in the present work support the hypothesis that ashwin in adult tissue is related more to spermatogenesis function, and that in fetal tissue it is related more to the development and maintenance of spermatogonia.…”

“…The ashwin protein was present in fetal prospermatogonia and adult spermatocytes. A recently published histological analysis demonstrated that spermatogenesis in the domestic yak (Bos grunnies) is comparable to that in Bos taurus [19]. RNA sequencing of gene expression dynamics during the prospermatogonia-spermatogonia transition and spermatogenesis in this domestic species revealed a transcriptomic signature specific to each process.…”

Transcriptome dynamics in developing testes of domestic cats and impact of age on tissue resilience to cryopreservation

“…A deeper understanding of the molecular events happening in testis from infancy to adulthood would contribute greatly to development of male fertility preservation and fertility control in domestic cats and wild felids. Whole transcriptome of testicular tissue during its maturation has been sequenced in several mammalian species, including pig [ 14 ], Mongolian horse [ 15 ], domestic yak [ 16 ], human [ 17 ] and mouse [ 18 ]. Further studies using scRNA-seq were also recently performed for developing testis in human and mouse [ 4 , 5 ].…”

TLR7/8 signalling affects X-sperm motility via the GSK3 α/β-hexokinase pathway for the efficient production of sexed dairy goat embryos

“…Then, their testes and epididymis were collected and fixed in 4% (w/v) paraformaldehyde overnight and embedded in paraffin, as described previously [ 13 , 20 ]; next, the tissue sections of the testis and epididymis were probed with an anti-TLR7 antibody (bs-6601; Bioss Antibodies, Woburn, MA, USA) and anti-TLR8 antibody (ab180610; Abcam, Cambridge, MA, USA) diluted at a ratio of 1:200. After washing with PBS, the antigens (TLR7 and TLR8) were visualised using Cy3-conjugated goat anti-rabbit IgG (ab6939; Abcam), 30 μL fluorescein isothiocyanate-peanut agglutinin (FITC-PNA, 100 μg/mL in PBS), a marker of acrosome in round spermatid and sperm [ 21 ], and 1 μg/mL DAPI, which was used to stain the nuclei. Stained sections were monitored and photographed using an epifluorescence microscope (Nikon Eclipse C1; Nikon, Tokyo, Japan).…”