Response to Kalchhauser et al.: Inherited Gene Regulation Is not Enough to Understand Nongenetic Inheritance

In their Opinion Adrian-Kalchhauser et al. [ 1. I. Understanding ‘Non-genetic’ inheritance: insights from molecular-evolutionary crosstalk. Trends Ecol. Evol. 2020; 35: 1078-1089 Abstract Full Text PDF PubMed Scopus (6) Google Scholar ] discussed the diverse molecular mechanisms underlying certain forms of nongenetic inheritance (see Box 1 for terminology). They proposed embracing these under unifying concept inherited gene regulation (IGR). We think article provides a valuable overview several nongenetically and interactions with genetic variation. However, we are concerned that this might lead readers to conclude all boil down IGR – conclusion regard as inconsistent known features many inheritance. following text, clarify our concerns, explain why believe variation cannot be understood solely in terms expression. 1Genetic Nongenetic Inheritance TerminologyWe use mean transmission something parent offspring, contributing parent–offspring resemblance. Genetic is DNA sequence during reproduction. then anything else offspring. This also occur reproduction (e.g., small RNAs present gametes), but other aspects like behaviour, microbiomes, physical structures can transmitted after without involvement gametes. Epigenetic has historically been used different ways. adhere predominating narrow-sense refers factors regulate explained above only subset kinds elements mediate Thus, framework encompasses those involve epigenetic factors, leaves out elements. broader than IGR.