SeQuaMol- Semen quality and fertility in bulls - Dvelopment of new molecular tools for diagnostic – SeQuaMol Consolidation

Reproductive efficiency is a key factor in effectiveness of the cattle breeding sector. Subfertile bulls are responsible for production losses and increase cows culling rates, resulting in significant economic losses and waste of resources. That’s why special attention is paid to quality control of semen used for animal insemination (6.5 million IA per year in France). Implementation of Genomics Selection has led to genetic evaluation of bulls without any progeny. The selection process does therefore not account for potential environmental effects, which can lead to epigenetic defects having an impact on embryo development or offspring’s phenotype. SeQuaMol aims thus to highlight biomarkers (DNA methylation, small RNAs, histone/protamine ratio and post-translational modifications of these proteins) associated with fertility. Development of tools for their routine analysis will make it possible to improve semen quality control processes and to integrate epigenetic factors in selection.

SeQuaMol is a public-private partnership, combining complementary skills to optimize bull fertility.
UMR 1198 biology of development and Reproduction (BDR) is an INRA-ENVA joint research unit in Jouy en Josas. Its main research topics are focused on the developmental mechanisms (during in utero life) that contribute to the adult phenotype, their regulation by the environment (in vitro and in vivo) and the long term effects of this early programming on growth, health and reproductive capacity of individuals. The team of H. Jammes (ER5) has expertise in epigenomics and the team of V. Duranthon (ER1) brings its expertise in embryo development.
ALLICE is a Union of Agricultural Cooperatives whose mission is to defend the Animal Insemination and the Bovine, Sheep and Goat Selection Cooperatives and to promote diffusion and adoption of innovations within its members. ALLICE develops R&D programs to help improving breeding programs and services, with the aim to increase cattle breeding techno-economic performance and sustainability. ALLICE provides access to biological resources, phenotypic databases and has expertise in genomics, reproductive biotechnology and semen quality control.

Biomarkers associated with fertility and breeds have been identified based on 3 types of epigenetic marks (methylation, microRNA, histone and protamine). These markers will now be used to develop innovative tools for semen quality control. Association between some of these markers and genes involved in embryonic development has been observed. Furthermore, our results highlight specificities of bovine sperm methylation (hypomethylation), stimulating new partnership to study the kinetics of development of these marks in cattle.