Re-thinking Inheritance

In C.elegans small RNAs enable transmission of epigenetic responses across multiple generations. Many different environmental challenges generate heritable small RNA responses which change the physiology of the progeny and that in certain cases could be adaptive. Recently we have shown that neuronal activity can also produce small RNA-mediate heritable responses. The precise duration of small RNA-mediated transgenerational responses is governed by a number of feedback interactions, that together establish a “timer” mechanism. I will present new insights into the rules that dictate which small RNA responses would become heritable, and which wouldn’t. I will also discuss the underlying mechanisms, and the provocative possibility that small RNA inheritance could affect the process of evolution.