Knockdown of the Genes , and Influences Oocyte Development, Egg Shape, Oviposition and Hatching in the Desert Locust.

Ecdysteroids are widely investigated for their role during the molting cascade in insects; however, they are also involved in the development of the female reproductive system. Ecdysteroids are synthesized from cholesterol, which is further converted via a series of enzymatic steps into the main molting hormone, 20-hydoxyecdysone. Most of these biosynthetic conversion steps involve the activity of cytochrome P450 (CYP) hydroxylases, which are encoded by the genes. Three of these genes, (), () and (), were previously characterized in the desert locust, . Based on recent sequencing data, we have now identified the sequences of () and (), for which we also analyzed spatiotemporal expression profiles using qRT-PCR. Furthermore, we investigated the possible role(s) of five different genes in the oogenesis process by means of RNA interference mediated knockdown experiments. Our results showed that depleting the expression of , and had a significant impact on oocyte development, oviposition and hatching of the eggs. Moreover, the shape of the growing oocytes, as well as the deposited eggs, was very drastically altered by the experimental treatments. Consequently, it can be proposed that these three enzymes play an important role in oogenesis.