Expression of genes associated with fertility in the uterus and oviduct of heifers challenged with lipopolysaccharide

Summary Lipopolysaccharide (LPS) endotoxemia has been negatively associated with fertility. This study aimed to investigate the effect of LPS-induced inflammation on gene expression associated with bovine fertility in the uterus and oviduct. Sixteen healthy heifers were divided into two groups. The LPS group (n = 8) received two intravenous (i.v.) injections of 0.5 µg/kg of body weight of LPS with a 24-h interval, and the control group (n = 8) received two i.v. injections of saline solution with the same interval of time. All the animals had the follicular wave synchronized. Three days after the second injection of LPS, all animals were slaughtered and uterine and oviduct samples were collected. Gene expression associated with inflammatory response, thermal and oxidative stresses, oviduct environment quality, and uterine environment quality was evaluated. Body temperature and leucogram demonstrated that LPS induced an acute systemic inflammatory response. In the uterus, the expression of PTGS2 and NANOG genes was downregulated by the LPS challenge. However, no change in expression was observed in the other evaluated genes in the uterus, nor those evaluated in the oviduct. In conclusion, the inflammatory process triggered by LPS did not persist in the uterus and oviduct 3 days after challenge with LPS. Nonetheless, reduction in PTGS2 and NANOG expression in the uterus suggested that, indirectly, LPS may have a prolonged effect, which may affect corpus luteum and endometrial functions.

Fertility-Associated Polymorphism within Bovine ITGβ5 and Its Significant Correlations with Ovarian and Luteal Traits

There is an urgent need to improve bovine fertility, and molecular marker-assisted selection (MAS) can accelerate this process. Genome-wide association studies suggest that Integrin β5 (ITGβ5) might affect fertility in bovines. As a member of the integrins family, ITGβ5 can bind to the extracellular matrix and mediate various cellular processes. In our study, primers spanning six potential insertion/deletion (indel) polymorphisms within the ITGβ5 gene were designed and 696 ovary samples from different individuals, the vast majority not in oestrum were collected for genetic variation detection. A deletion locus, rs522759246, namely P1-D13-bp, was found to be polymorphic. The allele D frequency was 0.152 and the polymorphism information content (PIC) value was 0.224, indicating a low-degree PIC. This locus did not follow the Hardy–Weinberg equilibrium (p = 1.200E-23). Importantly, associations between P1-D13-bp and ovarian morphological traits were established. Polymorphisms of this locus had significant correlations with ovarian width (p = 0.015). The corpus luteum is also linked to fertility and P1-D13-bp was significantly correlated with corpus luteum diameter (p = 0.005). In conclusion, an indel mutation within the bovine ITGβ5 gene was identified, which was significantly associated with several ovarian and luteal traits.

Brahispina – hereditary anomaly reducing the fertility of cattle

Aim. Rigid selection for a limited number of signs of productivity and the use of artificial insemination of cows relatively small number of the best bulls-producers led to a decrease in genetic variability. The study of the genetic structure of the golshtinized cattle population for the FANCI gene, which determines the development of Brachispinal Syndrome (BY), is relevant for the development of livestock breeding in the Republic of Belarus. The negative influence of this recessive genetic defect in the homozygous state leads to embryonic death or calf death in the early postembryonic period. Therefore, the hereditary brachispinal anomaly refers to the haplotype of HHO fertility. Methods. The material is DNA extracted from biological samples of animal tissues (blood, pinch of an ear). The studies were carried out using molecular genetic methods: PCR, sequencing. Results. 325 cattle were screened for mutation сarriers (HH0 (BY) fertility haplotypes). The frequency of carriers of mutations of the FANCI gene associated with bovine fertility in Belarus (HH0 (BYC)) is 3.38 %. Conclusions. Animals-carriers of the mutation are excluded from the selection process. In the future, it is necessary to strictly control the quality of imported pedigree products (material) to the Republic of Belarus.Keywords: haplotypes, fertility, mutations carriers, Brachyspina.

Aquaporin 11 is related to cryotolerance and fertilising ability of frozen–thawed bull spermatozoa

Aquaporins (AQPs) are channel proteins involved in the transport of water and solutes across biological membranes. In the present study we identified and localised aquaporin 11 (AQP11) in bull spermatozoa and investigated the relationship between the relative AQP11 content, sperm cryotolerance and the fertilising ability of frozen–thawed semen. Bull ejaculates were classified into two groups of good and poor freezability and assessed through immunofluorescence and immunoblotting analyses before and after cryopreservation. AQP11 was localised throughout the entire tail and along the sperm head. These findings were confirmed through immunoblotting, which showed a specific band of approximately 50 kDa corresponding to AQP11. The relative amount of AQP11 was significantly (P < 0.05) higher in both fresh and frozen–thawed spermatozoa from bull ejaculates with good freezability compared with those with poorer freezability. In addition, in vitro oocyte penetration rates and non-return rates 56 days after AI were correlated with the relative AQP11 content in fresh spermatozoa. In conclusion, AQP11 is present in the head and tail of bull spermatozoa and its relative amount in fresh and frozen–thawed spermatozoa is related to the resilience of the spermatozoa to withstand cryopreservation and the fertilising ability of frozen–thawed spermatozoa. Further research is needed to elucidate the actual role of sperm AQP11 in bovine fertility.