Characterization,expression,and Evolution Analysis Of Miiuy Croaker IL-1 And IL-17 Family Genes

Inflammation is an important process that reduces the risk of damage caused by various stimuli to organisms.In inflammation and immunity processes,cytokines play a very important role.Interleukins(IL)are a group of cytokines that play important roles in the inflammation.Several subfamilies of ILs have been characterized in mammals,but studies of ILs in teleost species have been still lacking.In this study,we conducted the bioinformatics analysis,synteny analysis,comparative analysis,expression analysis,and evolution analysis about the two IL families : IL-1 and IL-17 family genes in miiuy croaker.IL-1? is a prototypical proinflammatory cytokine that belongs to the IL-1 family.This cytokine possesses two receptor types,namely,IL-1 receptor type I(IL-1RI)and IL-1 receptor type II(IL-1RII).IL-1RI,is an IL-1 receptor that plays a crucial role in immune responses and IL-1RII is a decoy receptor for IL-1? signaling inhibitors in mammals.IL-1?,together with its two types of receptors,has been characterized in mammals and implicated in immunity.However,IL-1? and IL-1 receptors in teleost species have been rarely investigated.In this study three genes,namely,IL-1?,IL-1RI,and IL-1RII,were identified and characterized from miiuy croaker.Structural and comparative analysis revealed that miiuy croaker IL-1?,IL-1RI and IL-1RII,particularly their functional domains,were conservative in most of the species.Simultaneously,synteny phylogenetic analysis indicated that IL-1? and IL-18 were widely distributed in vertebrates and hence might be the ancestors of the IL-1 family.Challenge experiment demonstrated that IL-1?,IL-1RI and IL-1RII expression in miiuy croaker was induced by LPS and Poly(I:C).IL-1RI expression was also induced by the overexpressed miiuy croaker IL-1? protein which in cell supernatant,whereas IL-1RII was not induced.IL-17 family is a cytokine family which is one of the major signaling molecules family involved in immunity.Six member of IL-17 family cytokines(IL-17A-F)were found in mammals.In fish,all IL-17 family genes except IL-17 B and IL-17 E have been isolated and identified.Besides,IL-17 N is uniquely found from teleosts.IL-17 family genes are widely studied in mammals,but have not been widely reported in lower vertebrates.In this study,we identify six IL-17 family genes(IL-17A/F1-3,IL-17 C,IL-17 D,IL-17N)from miiuy croaker.We found every IL-17 family genes in miiuy croaker had four cysteine molecules which were important for a classical cysteine knot formation.The miiuy croaker IL-17A/F1 and IL-17A/F2 were found has synteny relationship and the linear relationship of IL-17 D was conservative.We explored the expression of these six genes in miiuy croaker.The expression of IL-17 in tissues showed that different gene has expressed in different tissues.Through the analysis of IL-17 family members exist in various representative species to study the evolution of the IL-17 family,and the result showed IL-17 C and IL-17 D should be present in early gnathostomes species and IL-17 D may be the ancestor gene in this family.