中文摘要：

主要组织相容性复合体（MHC）与免疫应答和疾病抗性密切相关，对其免疫遗传机制的深入探讨是多年来的研究热点。随着分子生物学的发展，从遗传选育角度提高鱼类对病原的抗性，开展抗病育种具有治本的功效。就鱼类MHCⅡ类基因的表达调控和多态性研究与细菌性疾病、病毒性疾病和寄生虫的关联分析加以阐述，为今后进一步探讨MHC基因与鱼类抗病育种等提供了参考。

英文摘要：

The major histocompatihility complex are closely associated with the immune response and disease resistance, and a series of study had been focused on revealing the immunogenetic mechanisms in fish for many years. Accompanying the development of molecular biology, disease - resistant breeding will be a permanent effect to improve fish＇s resistance to pathogens by means of animal genetics and breeding. The association of MHC class Ⅱ expression, regulation and polymorphism with bacterial, virus and parasite were particularly reviewed in this paper, which could provide insight for the further research on the breeding for disease resistance.