Email updates

Keep up to date with the latest news and content from BMC Genomics and BioMed Central.

Open Access Highly Accessed Research article

Analysis of plant-derived miRNAs in animal small RNA datasets

Yuanji Zhang1, B Elizabeth Wiggins1, Christina Lawrence2, Jay Petrick2, Sergey Ivashuta1* and Greg Heck2*

Author Affiliations

1 Chesterfield Village Research Center, Monsanto Company, 700 Chesterfield Parkway, North Chesterfield, MO, 63017, USA

2 St. Louis – World Headquarters, Monsanto Company, 800 North Lindbergh Blvd, St. Louis, MO, 63167, USA

For all author emails, please log on.

BMC Genomics 2012, 13:381  doi:10.1186/1471-2164-13-381

Published: 8 August 2012

Abstract

Background

Plants contain significant quantities of small RNAs (sRNAs) derived from various sRNA biogenesis pathways. Many of these sRNAs play regulatory roles in plants. Previous analysis revealed that numerous sRNAs in corn, rice and soybean seeds have high sequence similarity to animal genes. However, exogenous RNA is considered to be unstable within the gastrointestinal tract of many animals, thus limiting potential for any adverse effects from consumption of dietary RNA. A recent paper reported that putative plant miRNAs were detected in animal plasma and serum, presumably acquired through ingestion, and may have a functional impact in the consuming organisms.

Results

To address the question of how common this phenomenon could be, we searched for plant miRNAs sequences in public sRNA datasets from various tissues of mammals, chicken and insects. Our analyses revealed that plant miRNAs were present in the animal sRNA datasets, and significantly miR168 was extremely over-represented. Furthermore, all or nearly all (>96%) miR168 sequences were monocot derived for most datasets, including datasets for two insects reared on dicot plants in their respective experiments. To investigate if plant-derived miRNAs, including miR168, could accumulate and move systemically in insects, we conducted insect feeding studies for three insects including corn rootworm, which has been shown to be responsive to plant-produced long double-stranded RNAs.

Conclusions

Our analyses suggest that the observed plant miRNAs in animal sRNA datasets can originate in the process of sequencing, and that accumulation of plant miRNAs via dietary exposure is not universal in animals.

Keywords:
Plant miRNA; Animal small RNA datasets; RNAi; miR168; Aphid; Corn ear worm; Corn rootworm; Fall army worm; Silkworm