# Comparative multi-omic analysis reveals conserved and derived mechanisms of fin and limb regeneration

## TL;DR

This study compares how different animals regenerate limbs and fins, finding both shared and unique mechanisms involved in the process.

## Contribution

The study identifies conserved and species-specific molecular and genomic mechanisms underlying fin and limb regeneration in vertebrates.

## Key findings

- Conserved markers of blastema territories and DNA damage repair are shared across species.
- Hif1a-mediated hypoxia response and inflammatory programs are sequentially activated during regeneration.
- Genome-wide chromatin profiling reveals conserved AP-1 binding and candidate regulatory elements.

## Abstract

Comparative studies of vertebrate appendages offer a powerful framework for uncovering shared components of an ancestral regeneration toolkit. Here, we employed a multi-omics comparative approach leveraging the regenerative capacity of the axolotl, zebrafish, and Polypterus senegalus, a fish capable of full fin regeneration. We identified conserved markers of proximal and distal blastema territories, shared activation of DNA damage repair, hif1a-mediated hypoxia response, and sequential activation of pro- and anti-inflammatory program. Apical epithelial ridge markers were expressed in both the wound epidermis and distal mesenchyme during limb and fin regeneration. Notably, hif4a-expressing erythrocytes were uniquely associated with proximal limb and fin amputations but not fin rays, while epidermal myoglobin expression was upregulated only in Polypterus and zebrafish fins. Genome-wide chromatin profiling identified candidate regeneration-responsive elements and a conserved enrichment for AP-1 transcription factor binding. Together, these findings identify shared and derived mechanisms of limb and fin regeneration.

Here they compare fin and limb regeneration at the single-cell and genomic level, revealing conserved mechanisms and unique adaptations that shaped the evolution of vertebrate appendage regeneration.