Abnormal gene methylation during embryonic development after preimplantation genetic testing increases risk of...

The operations involved in preimplantation genetic testing (PGT) occur during the key stages of gametogenesis and early embryonic development, and the health of progeny following PGT (PGT-born) is worthy of attention. In order to fully assess the potential risk of abnormal glucose metabolism in adult PGT-born offspring and to evaluate possible mechanisms, we compared a mouse model of PGT (in vitro cultured embryos with biopsy, hereafter "PTG-born mice"), an in vitro embryo manipulation mouse model (in vitro cultured embryos without biopsy), and normal mice. PGT-born mice displayed increased fasting glucose, and decreased glycogen synthesis and glucose oxidative utilization in the liver. Moreover, PGT-born mice also displayed reduced expression of insulin receptor, AKT, and insulin-stimulated Akt phosphorylation (pAkt) in the liver. These results suggest a potential risk of insulin resistance in adult PGT-born mice. By analyzing the DNA methylation profiles of 7.5 days postconception (dpc) embryos, we identified differentially methylated genes associated with liver development between PGT-born and control groups; some of these genes are associated with glucose homeostasis and insulin response. These results suggest that abnormal methylation in embryos that develop after PGT may be a potential mechanism occurring during embryonic development that can influence the risk of liver-derived insulin resistance in adulthood.