Beetle a-head Investigating embryonic head formation using a novel model organism

Studies in the vinegar 1 fly Drosophila melanogaster indicate that head development differs significantly from trunk formation, since anterior head segments lack pair rule and Hox gene activity. However, despite the belief that head segmentation mechanisms have been conserved during evolution, they have not been identified in any organism so far. Due to the headless appearance of a fly maggot, Drosophila does not easily lend itself to the study of embryonic head development. To identify genes crucial to head segmentation, we are therefore currently isolating and functionally characterizing homologous candidate genes in two different arthropod species, the red flour beetle Tribolium castaneum and the amphipod crustacean Parhyale hawaiensis. Moreover, we aim to identify head-specific genes in an unbiased manner by a transposon mutagenesis screen in Tribolium. Since head structures of insects and crustaceans can be easily compared to each other, these analyses will enable us to draw conclusions on the evolution of head development over a period of about 450 million years