Natural RNA interference directs a heritable response to the environment.

Area of Science:

• Epigenetics
• Molecular Biology
• Genetics

Background:

• RNA interference (RNAi) is known to cause heritable gene silencing.
• The role of RNAi in response to environmental cues in natural settings is largely unexplored.

Purpose of the Study:

• To investigate if RNA interference mechanisms play a general role in response to environmental cues in the wild.
• To determine if transient environmental stress can induce heritable changes in gene expression.

Main Methods:

• Utilized the nematode Caenorhabditis elegans as a model organism.
• Applied transient, mild heat stress to induce environmental changes.
• Analyzed messenger RNA (mRNA) levels across generations.
• Investigated the involvement of germline small interfering RNAs (siRNAs) and the piwi-interacting RNA (piRNA) pathway.
• Examined worms with defects in germline RNAi.

Main Results:

• Transient mild heat stress induced changes in mRNA levels that persisted for over one generation.
• Affected transcripts were predominantly genes targeted by germline siRNAs, downstream of the piRNA pathway.
• Worms deficient in germline RNAi exhibited defects in these heritable gene expression changes.

Conclusions:

• A specific siRNA pathway is involved in transmitting information about environmental conditions between generations in C. elegans.
• This mechanism allows for the inheritance of responses to environmental cues, such as heat stress.