THE ROLE OF POSITIVE AND NEGATIVE SIGNALS IN SOMITE PATTERNING

Signals from the axial tissues, neural tube and notochord play a cruci al role in patterning cell fates in adjacent semitic tissue. Work over the past four decades has indicated how signals from the axial tissue s, as well as the surface ectoderm and lateral plate mesoderm, togethe r act to pattern semitic cell fate. Furthermore, recent results have s hed light on how some of these molecules control the specification and migratory behaviour of semitic cells.