Uptake and impact of natural diet-derived small RNA in invertebrates: Implications for ecology and agriculture

Abstract

The putative transfer and gene regulatory activities of diet-derived small RNAs (sRNAs) in ingesting animals are still debated. The existence of natural uptake of diet-derived sRNA by invertebrate species could have significant implication for our understanding of ecological relationships and could synergize with efforts to use RNA interference (RNAi) technology in agriculture. Here, we synthesize information gathered from studies in invertebrates using natural or artificial dietary delivery of sRNA and from studies of sRNA in vertebrate animals and plants to review our current understanding of uptake and impact of natural dietderived sRNA on invertebrates. Our understanding has been influenced and sometimes confounded by the diversity of invertebrates and ingested plants studied, our limited insights into how gene expression may be modulated by dietary sRNAs at the mechanistic level, and the paucity of studies focusing directly on natural uptake of sRNA. As such, we suggest 2 strategies to investigate this phenomenon more comprehensively and thus facilitate the realization of its potentially broad impact on ecology and agriculture in the future.

MicroRNAs from plants to animals, do they define a new messenger for communication?

“…These findings constitute the initial clues that miRNAs may act as new bioactive constituents of plants and have the potential travelling from plants to animals via GI tract to access their cellular targets, influencing the physio-pathological conditions of their recipients. If the above described miRNAs transmission from plants to human (the so called cross-kingdom transmission) is validated, it may revolutionize our current knowledge of the properties, effectiveness and biological actions of bioactive compounds in diets [ 30 , 31 ].…”

Risk Assessment Considerations for Genetically Modified RNAi Plants: EFSA’s Activities and Perspective

“…Once the dsRNA is ingested by the NTO, it must resist degradation in the gut, and be uptaken in sufficient quantities to activate the NTO's endogenous RNAi machinery. The latter can occur, either locally at the point of uptake (i.e., in cells lining the gut), or systemically if the NTO is able to trigger systemic RNAi (Ivashuta et al, 2015;Chan and Snow, 2017). A final condition is that the loss of the target transcript adversely affects the NTO (Bolognesi et al, 2012;Baum and Roberts, 2014).…”

Key factors determining variations in RNA interference efficacy mediated by different double‐stranded RNA lengths in Tribolium castaneum

“…Three possible processes determine the efficacy of intact RNAi machinery: cellular uptake of dsRNA, the intracellular RNAi machinery and extracellular factors (Saleh et al, 2006;Miller et al, 2012;Scott et al, 2013;Shukla et al, 2016;Chan and Snow, 2017). Thus, one or more factors associated with these three processes might contribute to the aforementioned phenomenon.…”