Multipotency and Gene Regulatory Networks (GRNs) in Marine Invertebrates

We are interested in the function and evolution of developmental gene regulatory networks and transcriptional multipotency. We work with indirectly developing sea urchin and polychaete embryos because they are excellent experimental systems for global developmental gene regulatory studies and ideal to resolve major enigmas in metazoan evolution. For example, it is unknown if the last common ancestor of all bilaterians was a direct or an indirect developer, and, therefore, some complex organs of macroscopic bilaterians such as the eyes, kidney, olfactory epithelia, etc. may represent evolutionary derivatives of very simple larval organs.

I have contributed to the characterization of the sea urchin endomesoderm GRN, and, in my current laboratory we are deciphering the GRN that controls gut formation in the indirectly developing annelid Hydroides elegans. This lophotrochozoan representative gastrulates by invagination, has a feeding-trochophore larva and its phylogenetic position provides fundamental information about the macroevolutionary dynamics of endoderm-gastrulation GRNs, indirect development origins and the bilaterian body plan.

Embryogenesis in indirectly developing marine invertebrates promptly generates a minute feeding larva that gradually grows and transforms into a complex adult during postembryonic development. The simultaneous occurrence of differentiated larval cells and undifferentiated adult precursor provides the ideal high-contrast between mechanisms that set the transcriptional stability of differentiation and mechanisms that set the transcriptional flexibility of multipotency. This contrast helped to identify the association of the particular histone variant H2A.Z with multipotency. Our results and previous functional studies make this histone an excellent candidate for having generalized multipotency transcriptional roles during development.

 

Research in our laboratory is funded by NIH