The ability to regenerate lost tissues or organs is widespread in the animal kingdom, but the mechanistic basis underpinning this process is incompletely understood. The planarian flatworm Schmidtea mediterranea has an incredibly robust and flexible capacity for regeneration, able to regenerate an entire organism from arbitrary starting points. This makes it an ideal model for the study of how regenerating fragments retain body-axis polarity and use this information to correctly pattern their regeneration. The findings presented here identify a role for Wnt11 and Dvl signaling in encoding AP axis information within the planaria, enabling a proper head/tail regeneration decision. Importantly, these factors are shown to act prior to injury to establish latent polarity mechanisms that are read out after injury through asymmetric expression of the Wnt signaling antagonist notum. This process differentiates the anterior and posterior ends of the regenerating fragment, allowing restoration of posterior Wnt11 expression to reinscribe AP polarity and enable future regeneration. Additionally, findings are presented establishing a function for the kinase src-1 as a global patterning regulator and suppressor of anterior identity. Together, these findings provide new insights into the mechanisms body-axis patterning during planarian regeneration.

Creator

• Gittin, David I

DOI

• https://doi.org/10.21985/n2-6ehs-7j98

Subject

• Molecular biology

Language

• en

Alternate Identifier

• http://dissertations.umi.com/northwestern:16379
• etdadmin_upload_947402

Date created

• 2022-01-01

Resource type

• Dissertation

Rights statement

• In Copyright