Dual RNA-seq reveals a host-pathogen interaction transcriptional regulation pattern between Cryptocaryon irritans and large yellow croaker (Larimichthys crocea)

Cryptocaryon irritans is an obligate ectoparasite of marine fish that causes severe damage to wild and farmed marine fish populations due to its wide parasitic range. Recently, the publication of the draft genome of C. irritans provides the necessary genetic basis for studying virulence mechanisms. In this study, the marine economic fish large yellow croaker and C. irritans were used as models to identify 5520 and 700 differentially expressed genes (DEGs) by dual RNA-seq technology with high sequencing depth (12x), revealing the dynamic expression pat-terns of host-pathogen interaction after infection. The results of functional enrichment showed that during C. irritans infection, the enhancement of metabolism and activation of immune regulatory pathways were enriched in large yellow croaker, while the increased proliferation and synthesis of surface antigens was enriched in C. irritans. Protein-protein interaction (PPI) network analysis identified 10 hub genes in large yellow croaker (myc, becn1, tbk1, stat1, stat3, irf3, hif1 alpha, myd88, cdc42, and syk) and 2 hub genes in C. irritans (mcm7 and cak76459). In addition, further correlation studies showed that hif1 alpha and mcm7 were interacting gene pairs significantly related to the infection process. This study is helpful in exploring the molecular regulation mech-anism of large yellow croaker after C. irritans infection and provides a necessary theoretical basis for the up-coming host-pathogen interaction research.