Transcriptomic Signatures in Common Carp Skin during Scale Regeneration

Scales form a crucial physical barrier to protect fish from foreign invasion. Scales can be regenerated in some teleost fish including common carp (Cyprinus carpio). Common carp possesses cycloid-type scales which can be completely regenerated after being removed. In this study, we conducted RNA-Seq analysis to characterize genes and their pathways involved in scale regeneration in common carp. Skin samples were collected at time-points of 12 hour, 24 hour, 3 day, 5 day, 7 day, 14 day and 21 day after removal of the scales. RNA-Seq analysis was conducted using Illumina HiSeq 1500. Over 467 million 100 bp paired-end reads were generated, and assembled into 395,135 contigs with an average length of 878 bp and N50 of 1700 bp. Through BLAST search, 24,104 known genes and 3,822 hypothetical genes were annotated from the assembly of common carp skin transcriptome.The differentially expressed genes during the process of scale regeneration were extensively involved in collagen, energy metabolism, regeneration, phospholipase activity, immune response, and calcium ion binding. Pathway analysis is being conducted to infer the important gene pathways that are responsible for the scale regeneration. This study lays a foundation for understanding the molecular mechanisms underlying scale development in teleost fish, and present an example to monitor the transcriptome profiles involved in organ regeneration process using the RNA-Seq approach.