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.

Highland animals have unique hair growth mechanisms to allow them to adapt to harsh living environments. Compared with other species, their hair cycle growth is affected by more environmental factors. Yaks, as highland animals, have obvious periodic hair growth characteristics in a year; this biological process is regulated by numerous proteins, but the specific molecular regulatory mechanism is still unclear. Here we analyzed the histological characteristics of yak hair follicles (HFs) at each stage and conducted TMT proteomics research. The protein expression network of yak hair at each stage and the mechanism of the yak HF growth cycle were systematically explored, and the candidate proteins Sfrp1 and Ppard were verified. A total of 3176 proteins were quantifiable and 1142 differentially expressed proteins (DEPs) were obtained at five stages of the yak hair cycle. DEPs enriched in complement activation change, tissue development, lipid metabolism, WNT pathway, VEGF pathway, JAK-STAT pathway, and PPAR pathway may promote the growth of yak hair follicles, such as Serpinf1, Ppard, and Stat3. DEPs enriched in complement system, coagulation, cell adhesion, lipid metabolic process, proliferation of epidermal cells, and estrogen pathway may promote the degeneration of yak hair, such as Sfrp1, Eppk1, and Egfr. Using Protein-Protein Interaction (PPI) analysis, we found that core nodes of DEP networks in yak skin are significantly different at three critical time points in hair follicle development, and lipid metabolism proteins are common core DEP nodes during yak HF growth and degeneration. The expression of Sfrp1 and Ppard in yak hair follicles at different periods showed they are related to yak hair cycle control. This study showed that the protein regulatory network of the yak HF growth cycle is complex and dynamically changing and revealed key candidate proteins that may affect yak hair follicle development. These findings provided detailed data for further understanding of the plateau adaptation mechanism of the yak, which is of great significance to make better use of the yak livestock resources and enhance their economic value.

Background: Healthcare workers’ (HCWs’) knowledge in delivering medical services is significantly influenced by their understanding of zoonotic diseases and the One Health (OH) concept. This study investigates the extent of HCWs’ knowledge and experience regarding zoonosis and the One Health approach in Ghana. Methods: This cross-sectional study involved 182 HCWs at the Tamale Teaching Hospital who completed questionnaires. Logistic regression was conducted to assess associations between socio-demographic factors and knowledge of zoonoses and OH. The correlation between knowledge and self-reported experience with zoonoses was assessed using Spearman’s correlation. Results: While 79.7% of HCWs correctly defined zoonoses, only 18.7% could sufficiently identify zoonotic diseases, and 59.3% were familiar with OH. The most commonly identified zoonotic disease was Ebola (75.3%), while brucellosis (12.1%) was the least recognized. Medical doctors were more likely to report previous encounters with zoonoses. Compared to medical doctors (reference HCWs), knowledge of OH was significantly higher among biomedical scientists (OR = 2.25, 95% CI: 0.72-7.37) and lower among nurses (OR = 0.92, 95% CI: 0.33-2.60). Professional experience of more than 5 years was associated with greater knowledge of rabies and tuberculosis. There was no significant correlation between knowledge of zoonoses and self-reported experience with any of the assessed diseases, except for a weak negative correlation with trypanosomiasis (Spearman’s r = –0.206, P = .005). Conclusions: The majority of HCWs have inadequate knowledge of zoonosis. Although most HCWs are aware of OH, they have limited experience with zoonosis and OH. Curricula for training HCWs should include more courses on zoonosis and arrange refresher training programs for HCWs. Enhancing HCWs’ expertise in zoonotic disease surveillance and detection is crucial for early identification and control of zoonoses, aiding in the prevention of future outbreaks.

• The male hybrid cattle-yak is sterile, while the female is fertile. • The male hybrid sterility was found to be caused by aberrations that occur during spermatogenesis. • Spata22 and its co-localizing partners play a very crucial role during the meiosis phase of spermatogenesis. • Spata22 mRNA and protein were under-expressed in the cattle-yak. • There was extensive cellular depletion, characterized by the absence of advanced-stage germ cells beyond the primary spermatocyte stage in the testes of the cattle-yak.