免疫是生物机体识别和排除抗原物质的一种保护性反应，是生物赖以生存和繁衍的基础。伴随长期的进化过程，生物界适应产生了两套免疫系统，即固有免疫（Innate immunity）和适应性免疫（Adaptive immunity）。长期以来，人们普遍认为无脊椎动物缺乏适应性免疫而仅依赖固有免疫维持机体健康和正常的生命活动。近年来，越来越多的实验证据表明无脊椎动物的免疫具有适应性特征，但对其免疫适应的机制尚缺乏深入的了解。本研究拟以长牡蛎等重要海水养殖无脊椎动物为研究对象，利用免疫学、细胞生物学、分子生物学及生物信息学等手段，研究造血组织、新生血细胞及记忆细胞类型，确定记忆细胞产生、维持的过程及调节机制，分离鉴定与免疫适应相关的特异性识别分子，明确其功能及表达模式，初步揭示长牡蛎免疫适应性防御策略，进而增进对海洋无脊椎动物免疫适应机制的了解，也为水产养殖业病害防治提供重要理论依据。

Immunity is a protective response of organisms to recognize and eliminate antigen, and it is also essential for their survival and reproduction. In the long-term of evolution, there are two sets of the immune system built in animals, namely the innate immunity and adaptive immunity. For a long time, it has been generally accepted that invertebrates lack adaptive immunity and they only rely on innate immune to maintain the homeostasis and normal life activities. In recent years, the accumulating experimental evidences suggest that the invertebrate immunity exhibits adaptive features, but the underlying mechanism of their immune adaptation is still not well understood. In the present project, the mechanism of immune adaptive defense strategy in pacific oyster will be investigated by using the techniques of immunology, cell biology, molecular biology and bioinformatics to identify the hematopoietic tissue, the newborn blood cells and memory cells. The processes of hematopoiesis, generation and maintainence of memory cells will be recorded, and the specific recognition molecules involved in immune adaptation will be characterized. The results will promote the understanding of the immune adaptive mechanism in marine invertebrate, also provide important theoretical basis for aquaculture disease prevention and control.