Genes expressed in the pleuropodia from embryos of the locust Schistocerca gregaria (Insecta, Orthoptera).

RNA-seq was used to study the genes expressed in peculiar glandular organs that transiently appear in insect embryos and are called the pleuropodia. The locust Schistocerca gregaria (Orthoptera) was used as a model. The purpose of the study is to identify the function of these organs. Our results suport the hypothesis (Slifer, 1937) that the pleuropodia secrete enzymes that digest the serosal cuticle before hatching. Additionally, we found that the pleuropodia may also have other functions, such as in embryonic immunity. The pleuropodia are peculiarly modified limbs. We show that in their early stages both legs and pleuropodia share a similar genetic landscape, but as the appendages become more morphologically diverse they became also more diverse genetically. Pleuropodia and legs of the third pair ("T3") at an equal age were compared. To identify DEGs upregulated in the mature pleuropodia that have morphological markers of active (secreting) organs samples from stages 10, 11 and 12 days were merged (legs and pleuropodia separately).