Comparative testis proteome dataset between cattleyak and yak

Proteomic analysis of giant panda testicular tissue of different age groups

Background

The reproductive ability of male giant pandas has been a major complicating factor in the ex-situ conservation of the species. While it is well known that the testis produces sperm and secretes androgens, a process that requires precise regulation of various proteins, at present, there has been no systematic study on the composition of proteins in the testis of the giant pandas. Therefore, this study aims to apply proteomics to explore the regulation of proteins in the testes of giant pandas.

Methods

Samples from the testes of three giant pandas (22 years, 18 years, 8 days) were studied to assess the protein's function. A label-free quantitative method was used to isolate testicular proteins from each male, 139,039 peptides and 11,435 proteins were obtained.

Results

Gene Ontology (GO) annotates most of the proteins involved in the processes of protein phosphorylation, oxidation-reduction, proteolysis, and signal transduction. KEGG pathway indicated that most of the proteins were involved in the pathway of signal transduction, transport, and catabolism. The protein kinase and WD40 repeats were involved in protein-protein interaction, which in turn regulates gene expression in the testicular tissue of giant pandas.

Conclusions

This study is the first to conduct an in-depth proteomic analysis of testicular tissue in giant pandas. The results revealed the important role of proteins in testicular tissue on spermatogenesis, testosterone production, and testicular microenvironment, providing clues for further research on male giant panda reproduction.

Comparative proteomic analysis of spleen reveals key immune-related proteins in the yak (Bos grunniens) at different growth stages

Spleen plays an indispensable role in the immune system as the largest lymphatic organ in the body. The spleens of yaks at three developmental stages (1 day fetal yak, 15 months juvenile yak and 5 years old adult yak) were sampled and the Tandem mass tag (TMT) quantification method was employed in spleen proteomic analysis. The results showed that 6576 proteins and 529 differentially expressed proteins (DEPs) were identified in the yak spleens at three growth stages. Gene ontology (GO) analysis of DEPs indicated that DEPs were enriched in Oxygen transport, Actin filament movement, DNA replication, Cell cycle process, and Cell macromolecule biosynthesis process, which was conducive to high altitude breathing, protein synthesis and organ growth in yaks. These were indispensable for yak spleen growth and cell metabolism, high altitude adaptation. Those DEPs were further analyzed based on Kyoto encyclopedia of genes and genomes (KEGG) pathways, which principally participated in Th1 and Th2 cell differentiation, NF-kappa B signaling pathway, Phagosome, and Glutathione metabolism. Those pathways were associated with some animal life activities in defense against microbial antigens, indicating that with age, the immune function of the yak's spleen continued to increase. Hemoglobin, Tumor necrosis factor receptor associated factor 1 (TRAF1), T cell receptor (TCR), Macrophage receptor, Fc receptors (FcR), and Gamma-glutamyl transferase (GGT) of DEPs played roles in immune function in yak spleen directly or indirectly. The dynamic changes of Toll like receptor 2 (TLR2), TRAF1 and Heat shock protein 27 (HSP27 or HSPB1) detected by Immunohistochemistry were consistent with those obtained from TMT proteomic. In conclusion, this study provides extensive and functional analyses of the spleen proteome at three developmental stages and will offer a new insight into key proteins involved in the immune function of yak spleen.

Disruption of cell proliferation and apoptosis balance in the testes of crossbred cattle-yaks affects spermatogenic cell fate and sterility

The balance between proliferation, differentiation, and apoptosis is well-coordinated in spermatogenesis for the timely production of appropriate numbers of sperm in animals. Disruption or decrease in sperm production is due to many conditions, including changes in testicular cell fate balance. Interspecies hybridisation of domestic yaks and cattle results in sterility in males because of spermatogenic arrest; however, the underlying mechanisms involved in sterility are still unclear. In the present study, we investigated the proliferation and apoptosis status during the development of yaks and crossbred cattle-yaks using immunohistochemistry of proliferating cell nuclear antigen and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays. Testicular tissues from yaks (immature: 1 year old, mature: 2-3 years old) and backcrossed hybrids (2 year old) were collected and used to investigate the expression of each parameter in testicular cells. During the maturation of yak testes, proliferation and apoptosis became active only in spermatogenic cells, and not in other somatic cells, such as Sertoli cells, myoid cells, and Leydig cells. Furthermore, hybrid cattle-yak testes maintained proliferation ability but less apoptotic ability in spermatogenic cells when compared to yaks of the same age, suggesting that normal spermatogenic cell fate control is disrupted by changes in the balance between proliferation and apoptosis. In addition, Leydig cell proliferation rate was higher than apoptosis rate in the cattle-yak testes, indicating an increased number of Leydig cells, which may affect spermatogenesis through changes in steroidogenesis. Although epigenetic changes may be involved in cattle-yak testes, further studies are needed to clarify the modulation of proliferation and apoptosis to elucidate the mechanisms of infertility in hybrid cattle-yak males.

High-throughput sequencing reveals differential expression of miRNAs in yak and cattleyak epididymis

Cattleyaks (CY) are interspecific hybrids between cattle (Bos taurus) and yak (Bos gruniens, YK) exhibiting the same prominent adaptability and higher performances than YK. MiRNAs have played an important role in the acquisition and maintenance of male fertility in reproduction, where deletion of Dicer in mice germ cells results in infertility. According to a body of evidence, the function of miRNA in the male reproductive system extends from the testis into the epididymis and, as such, regulates gene expression and contributes to regional gene expression variations. Using RNA sequencing on biological replicates, we described differentially expressed miRNAs profiles for tissue from epididymis of YK and CY. In the present study, High-throughput sequencing analysis showed that 55 differentially expressed (DE) miRNAs were identified in the epididymis of YK and CY. Among these, 43 DE miRNAs were upregulated while the remaining 12 DE miRNAs were downregulated between epididymis of YK and CY. Our results showed that the top most important DE miRNAs, bta-miR-449c, bta-miR-539, bta-miR-136, bta-miR-504, bta-miR-31 and bta-miR-222 were found to be involved in the reproductive system of CY. In addition, some targeted genes, Clusterins (CLU), Retinoic Acid Receptor a (RARa) and Hydroxy acyl glutathione Hydrolase (HAGH) and HSPH1 targeted by bta-miR-2411-3p and bta-miR-1298 were involved in the sperm motility, sperm morphology and post-testicular sperm maturation. Furthermore, GO and KEGG analyses were performed to classify the functions of target genes for DE miRNAs. In addition, RT-qPCR validation of the DE miRNAs and its targeted genes revealed that putative miRNAs are involved in the male CY infertility by altering the gene expression. Present findings may not only increase our understanding of the molecular mechanisms regulated by the miRNAs in epididymis, but also provide a valuable information to understand the male infertility mechanism of CY.

Male hybrid sterility in the cattle-yak and other bovines: a review

Hybridization is important for both animal breeders attempting to fix new phenotypic traits and researchers trying to unravel the mechanism of reproductive barriers in hybrid species and the process of speciation. In interspecies animal hybrids, gains made in terms of adaptation to environmental conditions and hybrid vigor may be offset by reduced fertility or sterility. Bovine hybrids exhibit remarkable hybrid vigor compared to their parents. However, the F1 male hybrid exhibits sterility, whereas the female is fertile. This male-biased sterility is consistent with the Haldane rule where heterogametic sex is preferentially rare, absent, or sterile in the progeny of two different species. The obstacle of fixing favorable traits and passing them to subsequent generations due to the male sterility is a major setback in improving the reproductive potential of bovines through hybridization. Multiperspective approaches such as molecular genetics, proteomics, transcriptomics, physiology, and endocrinology have been used by several researchers over the past decade in an attempt to unravel the potential mechanisms underlying male hybrid sterility. However, the mechanism of sterility in the hybrid male is still not completely unravelled. This review seeks to provide an update of the mechanisms of the sterility in the cattle-yak and other bovines.

Proteomic analyses of ram (Ovis aries) testis during different developmental stages

Male reproductive capacity is essential for animal breeding and reproduction. In males, the testes produce sperm and secrete androgen, processes which require precise regulation by multiple proteins. The composition of proteins in the ram testes has not yet been studied systematically, thus, the application of proteomics to explore differential protein regulation during ram testes development is of great significance. In the present study, ram testes were studied at five different developmental phases to assess postnatal differences in protein regulation. Two dimensional electrophoresis (2-DE) was used to separate ram testes proteins at each developmental phase, yielding 45 different proteins, 37 of which were identified by Matrix Assisted Laser Desorption Ionization-Time of Flight-Time of Flight-Mass Spectrometry (MALDI-TOF/TOF-MS). Gene Ontology (GO) was used to specifically annotate the biological process, cellular composition, and molecular function of each identified protein. Most of the identified proteins were involved in structural formation, development, reproduction, and apoptosis of the testicular spermatogenic tissue and spermatozoa. Quantitative real time PCR (qRT-PCR), western blot and immunohistochemical methods were used to verify the proteins, and the results were consistent with that of 2-DE. The proteins that were different in abundance that were identified in this study can be used as biomarkers in future studies of ram reproduction.