Date of Award

Spring 5-15-2023

Degree Type

Honors Thesis



Degree Name

Bachelor of Science



First Advisor

James Sikes

Second Advisor

Louise Goupil

Third Advisor

Sangman Kim


Whole-body regeneration and asexual reproduction are widespread in the Metazoa, yet little is known about the genetic systems that drive the regeneration process outside of a few model organisms. While many animals utilize fission followed by regeneration to accomplish asexual reproduction, Convolutriloba longifissura is unusual in performing a double fission, requiring significant anterior-posterior and medial-lateral regeneration that alters the orthogonal body axes in adult tissues. To better understand the process of axial re-specification during postembryonic development, we studied the genetic mechanisms used by C. longifissura to modify and respecify axial polarity during asexual reproduction and subsequent regeneration. Because conserved signaling pathways play integral roles in establishing the body axes during embryonic development and regeneration, we investigated potential roles of BMP (Bone Morphogenic Protein) signals during axial re-establishment and repatterning in C. longifissura asexual fission. Perturbation of the BMP signaling pathway resulted in a reduction in fission ability, disruption of posterior regeneration along the left-right axis after transverse fission, and altered mediolateral axis development during longitudinal fission. The ability to initiate changes in midline tissue identity and to re-establish mediolateral axis polarity during double fission seems to be mediated through crosstalk communication between BMP signals and BMP signaling antagonists.