Alanine tRNA Translate Environment into Behavior in Caenorhabditis Elegans

Caenorhabditis elegans nematodes produce and keep imprints of attractive chemosensory cues to which they are exposed early in life. These imprints enhance adult chemo-attraction to the same cues. Depending on the number of odor-exposed generations, imprinting is transiently or stably inherited. Strinkingly, we have found that early odor-exposed C. elegans produce odor-specific forms of the transfer RNAAla (UGC). Naive animals fed on these tRNAs acquire transient or stable odor-specific imprinting. The tRNAAla (UGC) controls C. elegans chemo-attractive responses through the multifunctional Elongator complex. Mutations that affect the functions of Elongator sub-units 1 or 3, either impaired chemo-attraction, or definitely abolish responses to the odors nematodes were exposed. We hypothesize that early olfactory experiences translate into tRNAAla (UGC) bearing odor-specific signatures. These diffusible odor memory, together with Elongator, can stably reprogram the C. elegans chemo-attractive behavior.