Dicer-1 is a key enzyme in the regulation of oogenesis in panoistic ovaries

Abstract

Background information: In insects, the action of microRNAs (miRNAs) on oogenesis has been explored only in dipterans, which possess meroistic ovaries, a highly modified ovarian type. Here we study miRNA function in the most primitive, panoistic type of ovaries using the phylogenetically basal insect Blattella germanica (Dictyoptera, Blattellidae) as model.

Results: Dicer-1 (Dcr1), a key enzyme in miRNA biogenesis, was depleted using RNAi. Females treated with double-stranded RNA targeting Dicer-1, exhibited deep alterations in oocyte development; among them, the follicular epithelia of the basal oocytes did not develop, thus resulting in sterile females.

Conclusions: These effects derived from the absence of Dicer-1 suggest that miRNAs are crucial for the regulation of oogenesis in panoistic ovaries, the most primitive insect ovarian type.