Iso-Seq combined with RNA-Seq analysis provided insight into the molecular response to dietary oxidized fish oil in juvenile Amur sturgeon, Acipenser schrenckii

Abstract

Despite the economic and biological importance of Amur sturgeon in the world, limited full-length transcripts are available. Oxidized fish oil (OFO) might induce injury stress, but few related studies were conducted in Amur sturgeon. In this study, an 8-week experiment with diets containing 6% fresh fish oil (FFO) or 6% OFO was conducted, and Iso-Seq combined with RNA-Seq analysis were used to explore the molecular response to dietary OFO in juvenile Amur sturgeon. A total of 18,408 high quality, unique full-length isoforms were generated by Iso-Seq, with an average length of 2180 bp and an N50 of 2793 bp. ~382 million clean reads were obtained from RNA-Seq, and the mapping ratio of the clean reads to the unigenes was 84.25% ~ 88.25%. There were 839 differently expressed genes (DEGs) in FFO vs OFO, of which 360 were up-regulated, and 479 were down-regulated. DEGs were mapped into 276 KEGG pathways, of which 45 pathways were significantly influenced. The proportion analysis of 45 significantly changed pathways revealed that human disease was the most enriched category, and cancers, endocrine system, signal transduction, cell growth and death and carbohydrate metabolism was the most affected subcategory in each category, indicating that OFO might induce cancers, endocrine disorder, and carbohydrate metabolism disruption. Further analysis discovered that transcriptional misregulation in cancer and FOXO signaling pathway were the top2 regulated pathways. PPI network analysis showed that foxo1 and pik3cα were identified as hub genes in response to dietary OFO in Amur sturgeon. The present study provided the first systematic full-length transcriptome dataset of Amur sturgeon and laid a solid foundation for further research on the molecular mechanism in response to dietary OFO.