The immune system of sturgeons and paddlefish (Acipenseriformes): a review with new data from a chromosome‐scale sturgeon genome

Sturgeon immunity is relevant for basic evolutionary and applied research, including caviar- meat-producing aquaculture, protection of wild sturgeons their re-introduction through conservation aquaculture. Starting from a comprehensive overview immune organs, we discuss pathways innate adaptive systems in vertebrate phylogenetic genomic context. The thymus as key organ requires future molecular studies. Likewise, data on functions sturgeon-specific pericardial meningeal tissues are largely missing. Integrating immunological endocrine functions, the sturgeon head kidney resembles that teleosts. Recently identified pattern recognition receptors require research downstream regulation. We review first acipenseriform Toll-like (TLRs), type I transmembrane glycoproteins expressed membranes endosomes, initiating inflammation host defence by pattern-induced activation. Retinoic acid-inducible gene-I-like (RIG-like) present RNA sensors virus infections most cell types. Sturgeons teleosts share major components system, B cells, immunoglobulins, histocompatibility complex cellular response T cells. ontogeny onset genes different organs remain understudied. In genomics perspective, our new 100 exemplify multitude trajectories after genome duplication, where some single-copy contrast with many duplications, allowing tissue specialization, sub-functionalization or both. Our preliminary conclusion should be tested bioinformatics, involving all >1000 genes. This knowledge update about system identifies several important gaps presents basis applications.