Gene expression profiling at the single nuclei level of channel catfish spleen

Channel catfish, Ictalurus punctatus, is an important model U.S. aquaculutre species. Given its role in food production, the catfish immune response to industry-relevant pathogens has been extensively studied and has provided crucial information on innate and adaptive immune function during disease progression. To further examine the channel catfish immune system, single-nuclei RNA sequencing on whole spleens from three adult individuals was performed. Spleen cell suspensions were prepared by passing tissues through cell sieves. Single-cell RNAseq libraries were then prepared using the 10X Genomics Chromium X with the Next GEM Single Cell 3’ Reagents and sequenced 2x150bp on an Illumina sequencer. Each demultiplexed library was aligned to the CoCo_2.0 channel catfish reference assembly, filtered, and counted to generate feature-barcode matrices. Cluster analysis allowed for the identification of multiple cell types including erythrocytes, hematopoietic stem cells, B cells, T/NK cells, myeloid lineage derivatives, plasma cells and endothelial cells. The majority of cells detected were erythrocytes, which are nucleated in teleost fish. Whole spleen samples from three adult catfish were collected to generate a channel catfish spleen cell atlas.