Most marine invertebrates have a distinct larval body plan that only develops features of the adult body plan late in larval development, often months following embryogenesis. Enteropneust hemichordate worms have both direct and indirect-developing species and we work on both types of development in the lab. We compare and contrast the developmental modes in their strategies for forming adults.
Despite fundamental differences in neural organization, hemichordates and vertebrates share exquisite conservation of the gene regulatory networks involved in neural A/P patterning. Does this conservation reflect some cryptic neural patterning similarities in cell types along the A/P axis? We are investigating the basic organization of the nervous system using in situ hybridization, immunohistochemistry, transgenics and single cell sequencing to investigate the basic neural organization of hemichordates.
The general consensus from broad genomic comparisons is that developmental enhancers are reasonably well conserved between species within phyla with the same body plan, but not conserved between individuals from different phyla with distinct body plans. Our work challenges this hypothesis.
Echinoderms are one of the most intriguing of the metazoan phyla. As one of the four deuterostome phyla, they are the sister group to hemichordates and closely related to chordates. We try to understand how the evolution of the radial body plan came about.