Pre-implantation factors in cattle – development of an early pregnancy test and their potential to enhance blastocyst quality.

• Applicant: Professorin Dr. Claudia Klein, Ph.D.
• Subject Area: Veterinary Medical Science
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 464899742

Low conception rates and early pregnancy loss are major problems in dairy and beef cattle. Pregnancy diagnosis based on transrectal ultrasonography or a single measurement of Pregnancy Associated Glycoproteins is possible around 30 days after breeding. The current proposal revolves around a group of short peptides secreted by the early embryo referred to as “pre-implantation factors”. Using Luminex technology, a bead-based competitive ELISA will be developed for the detection of two peptides (PIF and HIV-RT) belonging to the group of pre-implantation factors. The resulting ELISA will then be validated for its potential to discriminate non-pregnant and pregnant cows 10 days after breeding. The remainder of the proposed work focuses on vitro embryo production, which is gaining significance in Germany and globally as a means to produce embryos from genetically valuable animals. The pre-implantation factors PIF and HIV-RT will be examined as a marker of embryo quality. In brief, embryos will be cultured as single embryos, and once the blastocyst has been reached 8 days after culture, PIF and HIV-RT concentrations in spent culture medium, blastocyst cell number and presence of apoptotic cells will be determined. The potential of PIF and HIV-RT to improve in vitro embryo production will be determined through the addition of the peptides during embryo culture. For both in vitro experiment, the sex of the embryo will be taken into account, either through the use sex-sorted semen or determination of the sex through PCR following culture.

• DFG Programme: Research Grants