Chris Lowe (Hopkins Marine Station) is coming next week from thursday 7th to friday 8th. He will give a seminar friday at 10 am : Patterning contrasting body plans with deeply conserved developmental programs.
The origin of the vertebrate head has been a topic of debate for over a century. Much of what we understand about the origins of our own complex body plan has been based on comparative studies between the body plan of vertebrates and the simpler basal chordate lineages. Our work adds a new perspective to the origins of vertebrates: Hemichordates are a phylum closely related to chordates, but with a contrasting body plan. Despite this organizational and morphological disparity, our detailed studies using both descriptive and functional approaches reveal that hemichordate and vertebrate anterior developmental programs share some exquisite similarities. Surprisingly, recent transgenic approaches have revealed some of this conservation is a result of deep conservation of the underlying regulatory logic, not shared with basal chordates, despite their much closer morphological affinities with vertebrates. I will discuss the implications of our findings for early vertebrate origins, but also what our data suggests about the rather loose connection between gene regulatory network and morphological evolution.