Research advances in the structure,function,and regulation of the gill barrier in

The gill is an important organ in fish that is involved in various physiological functions,including respiration,filter-feeding,ammonia nitrogen excretion,and osmoregulation.The physiological functions of gills are closely related to their structure,external feeding conditions,and environmental factors.Herein,we first briefly summarize the basic structure and functions of the gills of teleosts,then explain the structure and function of the gill barrier(as a microbial barrier,a chemical barrier,a physical barrier,and an immune barrier)in detail.Finally,we introduce the regulation of fish gill barrier health by ubiquitous feeding factors and environmental factors,and provide an outlook on the prospects of gill barrier health.We found that improving health through modulating feed factors is more convenient than improving environmental factors.This review increases our understanding of how nutrient composition and level in fish diet influences gill health and overall growth performance of fish.

Interactions between commensal bacteria and viral infection:insights for viral disease control in farmed animals

Viral diseases cause serious economic loss in farmed animals industry.However,the efficacy of remedies for viral infection in farmed animals is limited,and treatment strategies are generally lacking for aquatic animals.Interactions of commensal microbiota and viral infection have been studied in recent years,demonstrating a third player in the interaction between hosts and viruses.Here,we discuss recent developments in the research of interactions between commensal bacteria and viral infection,including both promotion and inhibition effect of commensal bacteria on viral pathogenesis,as well as the impact of viral infection on commensal microbiota.The antiviral effect of commensal bacteria is mostly achieved through priming or regulation of the host immune responses,involving differential microbial components and host signaling pathways,and gives rise to various antiviral probiotics.Moreover,we summarize studies related to the interaction between commensal bacteria and viral infection in farmed animals,including pigs,chickens,fish and invertebrate species.Further studies in this area will deepen our understanding of antiviral immunity of farmed animals in the context of commensal microbiota,and promote the development of novel strategies for treatment of viral diseases in farmed animals.