Poster #008, Charles R. Drew University of Medicine and Science
The Imperfect Replicate: Lizard Tail Regeneration
Mentor: Thomas Lozito, PhD
Blastemas are regenerative structures made up of proliferating cells that reform lost tissues. While lizards represent the closest mammalian relatives capable of multilineage, blastema-based regeneration, they can regrow amputated tails but are unable to regenerate amputated limbs. However, when they regenerate their tails, they create an “imperfect replicate” with an unsegmented cartilage tube instead of a vertebral column. The mechanisms preventing limb blastema formation remain unknown, but our research can identify specific cellular roadblocks to regeneration, which is critical for advancing mammalian tissue engineering. We hypothesize that amputated lizard limbs fail to form functional blastemas due to a lack of sustained local cell proliferation creating an imperfect tail. The purpose of this study is to characterize post-amputation cellular responses and blastema formation in green anoles (Anolis carolinensis) to understand why their regenerative capabilities differ between appendages and why they are unable to form a vertebral column, causing the imperfect replicate. We aim to identify the cellular roadblocks that prevent the formation of functional blastemas, and by identifying these blocks, we can better understand why limbs don’t achieve sustained cell proliferation seen in tail regeneration. This ongoing laboratory study evaluates green anoles to assess their tissue responses following amputation. Using samples collected via random sampling after their tails had regenerated, we analyzed tail regeneration to locate the blastema and visualize the imperfect cartilage tube produced instead of a full vertebral column. To analyze cell proliferation, we utilized evidence-based immunohistochemical measures, specifically immunostaining for the established cell cycle markers Ki67 and PCNA, then used fluorescent microscopy to localize the individual positive cells using DAPI and TRITC. Data collection and tissue analysis for this research are currently ongoing. Preliminary results show validation of the antibodies, which will be used to measure cell proliferation levels in future experiments.