The molecular mechanisms underlying early embryonic development have been studied in detail in a few model organisms thusfar. The best studied model system is the fruit fly Drosopilila melanogaster (Arthropoda). Homologues for genes involved in early development of Drosopllila wrere found in a great variety of other metazoan organisms.
Studying the processes underlying early development in other organisms will indicate in how far these developmental processes are conserved in evolution, or are changed to create modifications in the body plans. In the proposed project, the expression patterns of a number of developmental genes will be studied in another arthropod system, the spider Cupiennius salei. These expression patterns will be compared with expression patterns of homologous genes in other species, such as in Drosophila. These comparisons may allow the identification of conserved developmental pathways and may give cues about the modification of body plans.