Next-Generation Sequencing Reveals that Oxidative Phosphoryla-tion Might Be a Key Pathway Differently Expressed in the Third and Fourth Stages Larvae of Angiostrongylus cantonensis

Background When Angiostrongylus cantonensis develops from the third and fourth stage, it needs to change its host from the middle host, snail to the final host, rat. However, the mechanism involved in this change remains unclear. Methods The transcriptome differences of the third and fourth stages of A. cantonensis were explored by next-generation Illumina Hiseq/Miseq sequencing in China, in 2018. Results Overall, 137 956 488 clean reads and 20 406 213 373 clean bases of the two stages larvae were produced. Based on the queries against the Gene Ontology (GO), NCBI non-redundant protein sequences (Nr), Swissprot, and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, 14 204 differentially expressed genes (DEGs) were predicted. GO enrichment analysis revealed 5660 DEGs with the top s categories as followings: biological process (GO:0008150, related to 5345 DEGs), cellular component (GO:0005575, related to 5297 DEGs), molecular function (GO:0003674, related to 5290 DEGs). In KEGG enrichment analysis, 116 genes were related to oxidative phosphorylation and 49 genes involved in the glycolytic process. Conclusion Metabolism changes, especially oxidative phosphorylation and glycolysis, might play a key role in A. cantonensis infection of its final rat host. Many other pathways might also contribute to the transcriptome changes between these two life stages. Overall, additional studies are needed for further details.