Affiliation: University of Illinois at Urbana-Champaign
Keywords: k. regeneration; t. regeneration
Regeneration is a complicated process through which some animals restore missing tissue upon damage. While many signaling pathways crucial for regeneration are critical in normal development, regeneration is not as simple as recapitulating normal development. We study regeneration using our genetic ablation system in Drosophila wing imaginal discs. One of the genes that are important in regeneration is Myc, whose expression levels and transcription levels are upregulated in the regenerating region of wing imaginal discs. Overexpression of Myc improves wing imaginal disc regeneration, while reduction of Myc expression worsens wing disc regeneration. During normal development, one primary role of Myc is ribosomal biogenesis. However, the exact function of Myc in regeneration is unknown. Our recent findings suggest that the nucleoli sizes, indicating ribosomal biogenesis activity, in the regenerating wing pouch are similar to those in the undamaged pouch. Interestingly, smaller nucleoli were found in the undamaged hinge tissue of the damaged wing discs. This finding suggests that one possible role of Myc might be maintaining ribosomal biogenesis activity in the regeneratiion blastema while the activity is reduced in other parts of the damaged disc. Thus, we aim to identify the exact role of upregulated Myc in wing disc regeneration. In addition to ribosomal biogenesis, Myc is also involved in cell competition. After tissue damage, the difference in Myc expression levels between the regeneration blastema and the rest of the disc is increased, as Myc is only upregulated in the regenerating tissue. During normal development, Myc expression level differences in the wing imaginal disc lead to cell competition, where cells with lower Myc are eliminated. However, we observed no extreme cell death at the boundary between high and low Myc expression levels in regenerating wing discs. Therefore, we aim to study whether cell competition takes place in regenerating wing discs.