Unraveling Genomic Signatures of lncRNA Expression in Zebrafish Caudal Fin Regeneration: Bridging Regenerative Potential and Positional Memory.

Zebrafish (Danio rerio) is an essential model organism for tissue regeneration, but the function of long non-coding RNAs (lncRNAs) in tissue regeneration is not well understood. Identifying important regeneration-associated lncRNAs may allow for cross-species applications, improving tissue repair in other organisms. However, few studies and a lack of functional validation complicate our understanding of their mechanistic functions. This research explores novel lncRNAs associated with caudal fin regeneration and positional memory, aiming to identify those that are evolutionarily important across species and may hold universal significance. RNA-seq data deposited in the NCBI database were compared at various important time points (0h post-amputation (hpa), 12 hpa, 1 day post-amputation (dpa), two dpa, three dpa, and seven dpa) and fin parts (proximal, middle, and distal) to uncover major regulatory lncRNAs. Using HISAT2, StringTie, FEELnc, Conservation Analysis and WGCNA (Weighted Gene Co-expression Network Analysis), we found 107 lncRNAs related to regeneration time points and 229 about positional memory during regeneration. Overlapping analysis identified 13 common genomic regions that are complete or partial lncRNAs, indicating a functional connection between regeneration and positional identity and expressed differently in each time point and each position. Additionally, a comparison with regeneration-associated mRNAs revealed that these 13 regions play critical roles in both processes, providing insights into the molecular mechanisms of regenerative precision. Following validation by RT-PCR, the results further suggest that these overlapping regions are differentially expressed across distinct positions within the same tissue, despite a consistent injury pattern. This positional variation in expression may indicate potential roles in both evolutionary adaptation and the regulation of regenerative processes across multiple tissues.