Non-gonadal somatic piRNA pathway regulates sexual differentiation, larval growth and wing development in silkworms

PIWI-interacting RNAs (piRNAs) guide PIWI proteins to target transposons in germline cells, thereby suppressing transposon activity to preserve genome integrity in gonadal tissues of metazoans. Here we generated Siwi (aub orthologue) and BmAgo3 (ago3 orthologue) knockout strains in Bombyx mori and observed that both of them showed delayed larval growth and failed to become adult moths. They also exhibited defects in wing development and sexual differentiation. Then we performed small RNA-seq and mRNA-seq of ovaries, fat bodies and wing discs and RNA-seq of male and female whole body of mutant silkworms.