Stanford University

Regulating two distinct body plans from a single genome

Marine invertebrates are characterized by a rich array of life history strategies; some species are direct-developers, like most developmental model species, where the adult body plan emerges straight from the embryo. However, 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. Schizocardium californicum is a local CA species that has distinct larval and adult body plans. The larvae develop for several months in the plankton transforming into an adult in a rapid and radical transition that last 24- 48hrs. We are investigating the transition of metamorphosis between the larval and adult body plan at the cellular level to investigate how such rapid reorganization occurs. 

We are taking a genomic approach to investigate how this dramatic transformation takes place and how cellular composition changes through metamorphosis. A collaboration with Pacific Biosciences and Dan Rohksar's lab at UC Berkeley has delivered a very high-quality genome assembly. This high-quality resource then made it possible to partner with the CZ Biohub through their intercampus award program to use a single cell RNAseq approach to determine how the cellular composition of the larval body plan changes through the process of metamorphosis. This has provided a unique perspective how a single genome regulates the formation of two distinct body plans. This work has been a highly collaborative effort and we are grateful to have partnered to do the analysis with Blair Benham-Pyle and Carolyn Brewster in Alejandro Sánchez Alvarado’s lab.

 

Relevant Publications:

Gonzalez, P., Jiang, J. Z., & Lowe, C. J. (2018) The development and metamorphosis of the indirect developing acorn worm Schizocardium californicum (Enteropneusta: Spengelidae). Frontiers in zoology, 15(1), 1-24. DOI:10.1186/s12983-018-0270-0

Gonzalez P, Uhlinger KR, Lowe CJ. (2017) The adult body plan of indirect developing hemichordates develops by adding a hox-patterned trunk to an anterior larval territory. Current biology, 27(1), 87-95. DOI:10.1016/j.cub.2016.10.047