Eliezer,, Yifat, Itskovits,, Eyal, Hoch,, Lihi, Zaslaver*, Alon, Ben-Ezra, Shachaf, Deshe, Noa
[
International Worm Meeting,
2021]
Organisms often face changing environments; hence, the ability to predict future conditions is essential for survival. Associative memories play a central role in this regard, as memory reactivation generates fast physiological responses that aid in coping with impending developments. But could these valuable associative memories be transferred to subsequent generations? We show that parental associative memories of traumatic experiences are indeed inheritable. We trained worms to associate a naturally favorable odor with starvation. Subsequent odor-evoked memory reactivation induced stress. Surprisingly, the stressful associative memory was also transmitted to the F1 and F2 generations, even though these animals were never exposed to the odorant before. Moreover, the stress responses provided both the parents and the offspring with a fitness advantage. The sperm, but not the oocytes, transmitted the associative memory, and a candidate-gene screen revealed that H3K9 methylation and the RNAi machinery underlie these heritable responses. Furthermore, activation of a single chemosensory neuron (AWCOFF) sufficed to induce a systemic stress response in both the parents and their progeny, suggesting that this neuron is part of the memory engram. Our findings provide an important evidence, to the yet debatable idea, that associative memories can be inherited