Transcriptome analyses of betta fish (Betta splendens) provide novel insights into fin regeneration and color-related genes.

• The first fin regeneration transcriptome analysis of betta fish was performed. • Many pathways and genes related to fin regeneration were identified here. • Pigment gene expression levels of the red and white fins were significantly different. • It provides data source for understanding fin regeneration and color formation of betta fish. The betta fish (Betta splendens), an important ornamental fish, has well-developed and colorful fins. After fin amputation, betta fish can easily regenerate fins similar to the originals in terms of structure and color. The powerful fin regeneration ability and a variety of colors in the betta fish are fascinating. However, the underlying molecular mechanisms are still not fully understood. In this study, tail fin amputation and regeneration experiments were performed on two kinds of betta fish: red and white color betta fish. Then, transcriptome analyses were conducted to screen out fin regeneration and color-related genes in betta fish. Through enrichment analyses of differentially expressed genes (DEGs), we found a series of enrichment pathways and genes related to fin regeneration, including cell cycle (i.e. plcg2), TGF-beta signaling pathway (i.e. bmp6), PI3K-Akt signaling pathway (i.e. loxl2a and loxl2b), Wnt signaling pathway (i.e. lef1), gap junctions (i.e. cx43), angiogenesis (i.e. foxp1), and interferon regulatory factor (i.e. irf8). Meanwhile, some fin color-related pathways and genes were identified in betta fish, especially melanogenesis (i.e. tyr , tyrp1a , tyrp1b, and mc1r) and carotenoid color genes (i.e. pax3 , pax7 , sox10 , and ednrba). In conclusion, this study can not only enrich the research on fish tissue regeneration, but also has a potential significance for the aquaculture and breeding of the betta fish. [ABSTRACT FROM AUTHOR]