COMPARATIVE TRANSCRIPTOME ANALYSIS OF PAPILLA AND SKIN IN THE SEA CUCUMBER, APOSITICHOPUS JAPONICAS

Xiuli Wang*, Xiaoxu Zhou, Jun Cui, Shikai Liu, Derong Kong, He Sun, Chenlei Gu, Hongdi Wang, Xuemei Qiu,Yaqing Chang, Zhanjiang Liu
 
Key Laboratory of Mariculture&Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian, 116023, China.
xlwang@dlou.edu.cn

 

 

Papilla and skin are two important organs of the sea cucumber. Both tissues have ectodermic origin, but are morphologically and functionally very different. In the present study, we performed comparative transcriptome analysis of the papilla and skin from the sea cucumber (Apostichopus japonicus) in order to identify and characterize their gene expression profiles by RNA-Seq. Around 30.6 and 36.4 million clean reads were obtained from the papilla and skin and de novo assembled in 156,501 transcripts. The gene ontology (GO) analysis indicated that cell part, metabolic process and catalytic activity were the most abundant GO category in cell component, biological process and molecular funcation, respectively. Comparative analysis between the papilla and skin allowed the identification of 1,059 differentially expressed genes, of which 739 and 320 were higher expressed in papilla or skin respectively. Among 1,059 differentially expressed genes, 739 were significantly higher in papilla, while 320 genes were higher in skin. There are 236 differentially expressed genes were not annotated with any database, 160 of which were apparently higher in papilla, 76 were higher in skin. We also obtained 288 papilla-specific genes, 171 skin-specific genes and 600 co-expressed genes. And 40 genes in papilla-specific were not annotated with any database, 2 in skin-specific. Development-related genes such as fibroblast growth factor, transforming growth factor-β, collagen-α2 and Integrin-α2, which may be related to the formation of the papilla and skin in sea cucumber, were also identified. Further analysis identified ten KEGG pathways that were differently enriched in papilla and skin. The present works has identified genes with distinct expression profiles between two key organs of the sea cucumber providing new insights into the development of organs that are related but with morphological differences in the sea cucumber.