GEOapplication/xmlftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE334nnn/GSE334037/primary200OKTranscriptomicsDanio rerioExpression profiling by high throughput sequencinghttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE334037GEOGSEfalseSingle-cell RNA sequencing reveals the transcriptional landscape of intestinal lymphoid cells in zebrafish challenged with SVCVHow diffuse gut-associated lymphoid tissues (GALT) in bony fish coordinate efficient local antiviral defense without encapsulated lymph nodes and germinal centers remains an evolutionary mystery. Here, utilizing a zebrafish model of intestinal spring viremia of carp virus (SVCV) infection, we profiled 46,606 single mucosal immune cells at 14 days post-infection. By comprehensively defining the T and B cell compartments, we demonstrated a high evolutionary similarity in immune cell composition between teleosts and mammals. Single-cell transcriptomics further revealed a specialized antiviral functional division paradigm: cd8+ T cells mediate frontline cytotoxic killing via isg15+ clusters, while cd4+ Th17 cells (rorc+/il17a/f3+) repair the epithelial barrier. Moreover, intercellular communication and functional assays showed that macrophages and T cells deliver MIF signals via CD74/CXCR4 to compensate for anatomical defects, driving the local survival and clonal expansion of IgM+ B cells outside germinal centers. Together, these findings reveal how decentralized mucosal immunity provides robust local protection in jawed vertebrates.2026/08/31GSE334037GSM9779537GSM9779538GSM9779539GSM9779540GSM9779541GSM977953630277334037Danio rerio