Buffalo SCNT embryos exhibit abnormal gene expression of ERK/MAPK pathway and DNA methylation

Abstract

Inhibition of ERK/MAPK pathway has been shown to decrease DNA methylation via down-regulation of DNA methyltransferases (DNMTs) in several studies suggesting that this pathway plays an important role in regulation of DNA methylation. We examined the relative expression level of seven important genes related to ERK/MAPK pathway and DNMTs (DNMT1, DNMT3a and DNMT3b) by quantitative real-time PCR in buffalo blastocysts produced by Hand-made cloning and compared it with that in blastocyst-stage embryos produced by in vitro fertilization (IVF). The expression level of six of seven genes related to ERK/MAPK pathway examined i.e., p21RAS, RAF1, AKT1, ERK2, PIK3R2 and c-Myc was significantly higher (p < 0.05) in cloned than in IVF embryos. However, the expression level of FOS was lower (p < 0.005) in cloned than in IVF embryos. The relative expression level of DNMT3a and DNMT3b but not that of DNMT1 was significantly higher (p < 0.05) in cloned than in IVF embryos. These results indicate that the cloned embryos exhibit an abnormal expression of several important genes related to ERK/MAPK pathway and DNMTs. Although a direct link between ERK/MAPK pathway and DNMTs was not examined in the present study, it can be speculated that ERK/MAPK pathway may have a role in regulating the expression of DNMTs in embryos, as also observed in other tissues.

Oviduct Epithelial Cell-Derived Extracellular Vesicles Improve Porcine Trophoblast Outgrowth

“…There are many differences in the extracellular environment between embryos grown in vitro and those grown in vivo [32]. On one hand, in the early stage of embryo development, cloned embryos grown in vitro have stable MAPK level loss compared to IVF embryos [33,34]. In contrast, the ovum grown in vivo can obtain more abundant cytokines and growth factors and can carry out rich biological information transmission with the epithelial cells of the fallopian tube [35].…”