Abstract: In nature,invertebrates develop and form a complete set of innate immune systems in order to resist the invasion of external pathogens. As a key enzyme in the innate immune system of invertebrates,dopa decarbox（DDC）not only participates in the regulation of the immune system,but also it-catalyzed neurotransmitters such as dopamine play an important role in the neuroendocrine system;thus it is an ideal material to study the neuroendocrine immune system of invertebrates. This paper first summarized the research status,protein molecular structure and catalytic mechanism of dopa decarboxylase in invertebrates,and then illustrated the important physiological function in the innate immune system of invertebrates. In addition,the paper outlined the neuroendocrine system in which dopamine is involved,further introduced The role of catecholamine system,dopamine,the role of dopamine and its receptors in neuroendocrine system is introduced. Dopamine decarboxylase exists widely in nature,and the research on it is also very rich. However,the domestic and foreign literature reports on dopamine decarboxylase in crayfish are very rare. P. clarkii is an invertebrate crustacean and it is an important aquatic product in China. In recent years,the yield of P. clarkii’s aquaculture is reduced due to infection from pathogenic bacteria. Bacterial diseases are the main cause of P. clarkii’s diseases. Therefore,to explore the defense mechanism of P. clarkii against bacteria is an important scientific issue that urgently needs to be solved;moreover,the study of dopamine decarboxylase in crayfish may provide scientific basis for the exploration of its neuroendocrine immune system.

Key words: neuroendocrine immune regulatory system, dopa decarboxylase, invertebrates, dopamine