HEART DEVELOPMENT IN DROSOPHILA AND VERTEBRATES - CONSERVATION OF MOLECULAR MECHANISMS

Vertebrate and insect (Drosophila) hearts look and function quite diff erently from each other. Nevertheless, during embryogenesis their meso dermal origin and initial assembly into a linear heart tube are compar able in many respects. In the past few years, numerous gene functions have been identified that are utilized by both vertebrates and Drosoph ila for the specification and differentiation of the heart progenitor cells. These studies have begun with the discovery of the homeobox gen e tinman in Drosophila and its vertebrate counterparts. By now, there is also evidence that MEF2 transcription Factors and TGF-beta signalin g have cardiogenic functions in both these systems. Perhaps in a few y ears, the GATA and HAND transcription factors and Wnt signaling, which currently only have a demonstrated cardiogenic function in one of the systems, may also be part of this group. One of the pressing but stil l wide open questions is if the spectrum of targets for these transcri ption factors and signaling pathways is also conserved. (C) 1998 Wiley -Liss, Inc.