methyl groups

Re: RNA-directed DNA methylation (1996) See: From Fertilization to Adult Sexual Behavior Molecular epigenetics. It is now understood that certain genes undergo a process called “genomic or parental imprinting.” Early in embryonic development attached methyl groups become removed from most genes. Several days later, methyl groups are reattached in appropriate sites. Fascinatingly, some such genes … Thanks again for asking about DNA methylation