METTL7A improves bovine embryo competence by attenuating oxidative stress

In vitro fertilization (IVF) is currently one of the most used assisted reproductive technologies to achieve a successful pregnancy. However, the acquisition of oxidative stress in embryo in vitro culture impairs its competence. Here, we demonstrated that the S-adenosyl-L-methionine (SAMe)-dependent thiol methyltransferase, methyltransferase-like protein 7A (METTL7A) improves the developmental potential of bovine embryos. We found exogenous METTL7A modulates expression of genes involved in embryonic cell mitochondrial pathways and promotes trophectoderm development. Surprisingly, we discovered that METTL7A alleviates mitochondrial stress and DNA damage and promotes cell cycle progression during embryo cleavage. In summary, we have identified a novel mitochondria stress eliminate mechanism regulated by METTL7A that occurs during the acquisition of oxidative stress in embryo in vitro culture. This discovery lays the groundwork for the development of METTL7A as a promising therapeutic target for IVF embryo competence. To investigate the role of METTL7A in bovine pre-implantation development, we overexpressed METTL7A by zygotic injection of in vitro transcribed METTL7A mRNA and conducted RNA-seq at 2-cell, 8-cell and blastocyst stages to profile differentially expressed genes.