Comparative analysis of the expression patterns of eight suppressors of cytokine signaling in tongue sole, Cynoglossus semilaevis.

Suppressor of cytokine signaling (SOCS) family members are inhibitors of cytokine signaling pathways and key regulators of immunological homeostasis. They have been extensively studied in mammalian models, but systematic analyses of SOCS in fish are limited. In the current study, a total of eight SOCS genes from tongue sole (Cynoglossus semilaevis) were characterized. All eight CsSOCS exhibit conserved structures of SOCS and were phylogenetically grouped together with the respective SCOS members known in mammalian and teleost species. Under normal physiological conditions, the expressions of the eight CsSOCS genes were detected at varied levels in nine major tissues, with most CsSOCS highly expressed in kidney. Following challenge with intracellular and extracellular bacterial pathogens, the majority of CsSOCS genes exhibited distinctly different expression profiles in a time-, tissue-, and pathogen-dependent manner. In general, intracellular pathogen caused wider and higher levels of CsSOCS expressions than extracellular pathogen. These results suggest that different members of SOCSs in teleost may play different roles in the infection processes of different bacterial pathogens.