It is not yet known why some animals have remarkable abilities to regenerate (some can replace their whole body from just a small part that has been cut off), while others have very little regenerative capacity. Surprisingly, the ability to regenerate has been lost and gained many times independently across animals. This research uses two closely related invertebrate animals, ctenophores (known as comb jellies), one that can regenerate its whole body and one that cannot, to test the hypothesis that evolutionary changes in epigenomic regulation (differences in how the DNA of the genome is physically packaged) plays a major role in the gain and loss of regenerative abilities. The results of this project will contribute to understanding whether ctenophores have specialized stem cells, or if all body cells have the ability to regenerate. The results may help to identify ways to increase regeneration in other animals and ultimately to repair or replace damaged or diseased human tissues. This project includes a plan to help teachers and scientists work together to develop class activities that anyone can use so that a scientist does not need to live nearby to bring their knowledge to any classroom that wants it.
The ctenophore Mnemiopsis has biological features that make it an ideal laboratory model to study the intersection of normal development and regeneration: it has stereotyped development with known cell lineages, optically clear embryos and juveniles, and can undergo whole-body regeneration. This research uses ctenophoresâ€™ highly stereotyped development to lineage trace the source of replacement cells in a regenerating ctenophore, focusing on both whole-body as well as organ-specific regeneration. Moreover, since competence to regenerate appears at a stereotyped developmental stage in Mnemiopsis, profiling chromatin accessibility with ATAC-seq in pre-competent and competent Mnemiopsis as well in as a non-regenerative ctenophore (Beroe) will identify open chromatin regions specifically associated with regenerative competence in ctenophores. These open chromatin regions can then be assessed for actual function in regeneration. The research is integrated with an outreach program to share both the results and underlying scientific concepts with students and interested members of the public. Conducting the research and outreach activities will prepare the fellow for an independent research career, contribute to the ongoing efforts to establish ctenophores a powerful model system, and directly benefit students and educators by creating and disseminating lesson plans.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.