Mechanisms of Transgenerational ‘Memory’ in Mice and Rats: A Review

Abstract

Researchers have discovered that parental experiences and environment can affect offspring behaviors and phenotypes through non-genetic mechanisms in one or more generations among various animals. This phenomenon is most commonly studied in mice and rats, where different mechanisms are believed to exist due to the diverse inheritance patterns discovered with different parental experiences in the experiments, including stress, liver damage, odor fear conditioning, environmental enrichment (EE), etc. Besides the commonly known factor, social transmission, epigenetic modifications are also suggested to be a major cause, with DNA methylation, histone modification, and microRNA level change observed in different studies. The epigenetic marks are lost after certain generations, and they are found to be reversible due to environmental change. This non-genetic phenotypic response to environmental stimuli could benefit or harm offspring.