The odd‐skipped related gene drumstick is required for leg development in the beetle Tribolium castaneum

Abstract

Background: The evolutionarily conserved odd-skipped related genes oddskipped (odd), drumstick (drm), sister of odd and bowel (sob), and brother-ofodd-with-entrails-limited (bwl) act downstream of the Notch pathway in various insect tissues including the appendages and the gut. While the function of some of these genes have been analyzed in the adult Tribolium beetle, the expression during and their requirement for embryonic development is not known. Results: We describe here the embryonic expression patterns of drm, sob, and bwl and analyze the RNAi knockdown phenotypes with emphasize on the appendages and the hindgut. We show that in Tribolium, drm acts independently of other odd-family members in the formation of legs, hindgut, and the dorsal epidermis. Moreover, we establish drm and sob as further markers for segment borders in the appendages that include the gnathobasic mandibles. Conclusions:We conclude that the regulatory interrelationship among the odd genes differs between Tribolium and Drosophila, where odd and drm seem to act redundantly. In Tribolium, the genes drm and sob uncover the relict of a precoxal joint incorporated in the lateral body wall.

Lepidopteran prolegs are novel traits, not leg homologs

“…To further confirm that prolegs are not homologous to the protopod, as proposed by Snodgrass ( 5 ), we examined, ara , a marker gene for protopod segments, including those now incorporated into the body wall in Tribolium and a crustacean ( 19 ); pannier ( pnr ), a body wall marker gene ( 19 ); drumstick ( drm ), a leg joint marker ( 43 , 44 ); and hth , a protopod marker in embryos ( 45 , 46 ). drm was expressed in all body segments and in six armbands and two smudge patterns in thoracic legs ( Fig.…”