Genome-Wide Identification and Expression Analysis of TTC39 Genes Associated with Red Skin Coloration in Plectropomus leopardus

Despite the recognized involvement of TTC39 family genes in metabolism related to pigment deposition, their evolutionary features and potential roles in body coloration in teleost fish remain largely unexplored. We identified three TTC39 genes in Plectropomus leopardus, conserved domains, and evolutionary relationships. The three genes (TTC39A, TTC39B, and TTC39C) were mapped to different chromosomes, yet they shared similar conserved protein domains. Phylogenetic and collinearity analyses indicated that TTC39 genes are evolutionarily conserved among Danio rerio. Gene structure and motif analyses further highlighted the homology and distributional diversity within the TTC39 family. Quantitative expression assays comparing red and black skin revealed significant upregulation of TTC39A and TTC39B in red skin, suggesting that these genes play a role in regulating skin color. These findings provide a foundation for future studies examining how TTC39 genes regulate red skin coloration in P. leopardus.