Dual RNA-seq of spleens extracted from channel catfish infected with Aeromonas veronii reveals novel insights into host-pathogen interactions.

Interactions between host and pathogen are involving various dynamic changes in transcript expression and critical for understanding host immunity against infections and its associated pathogenesis. Herein, we established a model of channel catfish infected with Aeromonas veronii. The infected fish had prominent body surface bleeding, and the spleen showed hyperemia and swelling. Then, the spleen of channel catfish infected with A. veronii was analyzed by dual RNA sequencing (RNA-seq), and the transcriptome data were compared with uninfected channel catfish spleen or bacteria cultured in vitro. The transcript expression profile of pathogen-host interaction between A. veronii and channel catfish was successfully studied. During infection, the host was enriched for multiple immune-related signaling pathways, such as the Toll-like receptor signaling pathway, Cytokine-cytokine receptor interaction, and T cell receptor signaling pathway; and significantly upregulated for many innate immune-related genes, including IL-8. At the same time, we found that A. veronii mainly harmed the host spleen through hemolysin. Our current findings are of great significance in clarifying the pathogenesis of channel catfish induced by A. veronii and provide gene targets for developing preventive measures.

Complete mitochondrial genome of Rhynchocinetes durbanensis (Rhynchocinetidae: Rhynchocinetes).

The complete mitochondrial genome of Rhynchocinetes durbanensis (Rhynchocinetidae: Rhynchocinetes) was sequenced in this study. The genome sequence was 17,695 bp in size, with the base composition of 35.14% A, 32.98% T, 20.34% G and 11.55% C of the light strand. The gene order and genes were the same as that found in other previously reported shrimps, including 13 protein-coding genes, 24 transfer RNA genes and two ribosomal RNA genes. Except for ND5, ND4, ND4L, ND1 genes and eight tRNA genes and two ribosomal RNA genes, all other mitochondrial genes were encoded on the heavy strand. The start codon of COX1 gene was not determined. These complete mitogenome data provide the basis for taxonomic and conservation research of Rhynchocinetes durbanensis, and closely related species.