Meeting Abstract

45.3  Thursday, Jan. 5  siRNA-mediated down-regulation of hexamerins suppresses reproduction and feeding in the lubber grasshopper Romalea microptera KUMAR, Sandeep*; GANJI, Purna Chandra Nagaraju ; SONG, Hojun; VON KALM, Laurence; BORST, David W.; University of Central Florida; University of Central Florida; University of Central Florida; University of Central Florida; University of Central Florida skumar@knights.ucf.edu

Juvenile hormone binding proteins (Hexamerins) are the major insect storage proteins. They are important for many regulatory processes, including stress management. In the lubber grasshopper Romalea microptera there are 3 major hexamerin proteins of molecular weight 90 kd, 270 kd and 500 kd. Simultaneous siRNA knockdown of all three hexamerins leads to decreased reproduction (both male and female animals) and feeding capacity (female animals only). We demonstrate a significant decrease in mean ovarian index, mean oocyte diameter and mean oocyte length in female animals treated with siRNA against all three hexamerins. In treated males, testicular indices and testicular follicular diameters were significantly lower than control animals. siRNA against all hexamerins also significantly decreased the feeding capacity, body weight, and rolling time. Taken together, our observations suggest that the hexamerin proteins are essential for grasshopper development and reproduction. To the best of our knowledge, this is the first report of simultaneous multicistronic gene silencing in invertebrates.