Patterning of the head epidermis

In contrast to Drosophila, Tribolium develops a head with all structures that are typical for insects. With all the techniques available now, Tribolium is becoming the primary arthropod model system for head development.

The Drosophila head is extremely derived - the Tribolium head not © Klingler

How many segments build up the insect head? Despite over hundred years of investigation, this issue is not solved, and has consequently been called the "endless dispute". But this is not the only puzzle of head development: Still nobody knows, how the insect head is patterned.

One reason for our lack of understanding is the extremely derived head development of Drosophila: its involuted head comes to lie right within the thorax and the assignment of its derived structures to single segments is extremely difficult. This has hampered the recovery and interpretation of head phenotypes.

It is clear, however, that the genetic cascade known from trunk segmentation does not account for more anterior pattern formation as pair-rule genes are only expressed posterior to the intercalary segment. Some head-gap genes have been described in Drosophila but recent data shows that their mode of action is not equivalent to their namesakes in the trunk.

As a basis for our understanding of head development, we are using several complementary approaches. First, we will exploit the genomic sequence and RNAi to investigate the functions of candidate genes. This approach will provide a rapid overview on the function of conserved genes. The second approach is the insertional mutagenesis. Together with our collaborators we hope to recover a complete set of mutants affecting head development independent from preassumptions. Third, we have developed in vivo imaging techniques that allow the observation of cell and tissue movements during ontogenesis of the head.

More information on head development..

© Gregor Bucher, last update: july 07