Mesoderm induction: from caps to chips

Publisher Website
Google Scholar
Abstract
Studies of mesoderm induction in Xenopus and zebrafish trace their origins back to Pieter Nieuwkoop's experiments nearly 40 years ago, and have been a subject of intensive investigation ever since. Four major signalling pathways are involved in this process: Nodal (including Activin and Vg1), FGF (Fibroblast growth factor), canonical Wnt, and BMP (Bone morphogenetic protein), which have both distinct and overlapping roles in the process of mesoderm induction. There are important controversies in the field regarding the existence and function of Nodal gradients in regulating mesoderm formation. The four main signalling pathways interact in different ways to regulate the formation of the head, trunk and tail. The roles of signalling factors in mesoderm induction are seen to change over time, although this is still a relatively new area and further studies will be important. Evidence is emerging for the importance of combinatorial signalling in regulating mesoderm formation. Mesoderm induction is generally conserved among vertebrates, albeit with interesting species-specific differences. New avenues of research will involve defining key mesodermal genes using microarrays and expression screens.