Faculty of Nuerobiology
Tel Aviv University
Oded Rechavi, Researcher, Faculty of Nuerobiology, Tel Aviv University, Israel.
The inheritance of acquired characteristics is a topic of long-standing interest and controversy. While some of the classic Lamarckian ideas have been dismissed (Weismann 1889), more recent studies suggest that certain traits acquired by an animal during its lifetime may be transmitted to next generations. Using the nematode C.elegans we established a robust model that unequivocally demonstrates “Lamarckian” inheritance and allows probing of the molecular mechanisms underlying such inheritance (for example see Rechavi al. Cell 2011 and Rechavi et al. Cell 2014). We found that the mechanism that allows such heretic phenomena to take place is transgenerational transmission of small RNAs, which mediate RNA interference (RNAi). Our study showed that antiviral RNAs (viRNAs), which protect the worm from viral propagation, can be transmitted from the soma to the germline and pass down to many ensuing generations in a non-Mendelian manner, in the absence of their DNA template, and thus protect RNAi-deficient progeny from viral propagation ("Inherited Vaccine"). Most genes are regulated by different endogenous regulatory small RNA species, and therefore small RNA inheritance might affect the inheritance of many complex traits. We found that inherited small RNAs maintain a memory of previous dietary states (specifically periods of severe starvation). We examine whether small RNAs are involved in the encoding of other “memories”, and if so, whether such regulation transmits transgenerationally. To fully understand how small RNAs regulate complex traits, we are developing sensitive functional assays and novel methods for transcriptome profiling. We have shown that small RNAs (Rechavi et al, Genes & Development 2009) and other macromolecules (Rechavi et al. Nature Methods 2010) serve as intercellular signaling molecules that shuttle between human cells when immunological synapses are transiently formed. Therefore, cellular and perhaps even transgenerational information transfer through RNAs or other molecules may be widely conserved.
Rechavi, O., Houri-Ze’evi, L., Anava, S., Goh, WS., Kerk, SY., Hannon, GJ., and Hobert, O.(2014). Starvation-Induced Transgenerational Inheritance of Small RNAs in C. elegans. Cell.
Leah Houri-Ze’evi, Yael Korem, Hila Sheftel, Lior Faigenbloom, Itai Antoine Toker, Yael Dagan, Lama Awad, Luba Degani, Uri Alon, *Oded Rechavi (2016) A Tunable Mechanism Determines the Duration of the Transgenerational Small RNA Inheritance in C. elegans. Cell.