生物体对环境刺激的适应依赖于基因表达的精细调控，因此研究调控低温反应的关键转录因子对于认识鱼类的低温适应具有重要的意义。我们在前期研究中发现斑马鱼fos家族转录因子fosaa、fosab和fosb是响应低温刺激的即刻早期基因，过表达Fosaa和Fosab能显著增强斑马鱼幼体的低温耐受能力，而抑制Fos家族蛋白功能复合体AP-1的活性可消除斑马鱼幼体的低温适应能力。本项目在前期研究基础上进一步验证这些基因在斑马鱼低温适应中的功能并研究其作用机制，主要内容包括：1）研制各基因的基因敲除斑马鱼品系；2）研究缺失fos家族基因对斑马鱼低温适应的影响；3）研究调控这些基因响应低温刺激的上游信号通路，鉴定其启动子中的低温反应元件；4）鉴定各基因编码蛋白的相互作用蛋白及其调控的下游基因。本项目的顺利实施，对于深入揭示鱼类低温信号传导和低温适应的分子机理，指导鱼类的抗寒育种具有重要的理论意义。

Acclimation of organisms to environmental stresses is dependent on fine-tune regulation of gene expression. Transcription factors are known to play critical roles in the regulation of gene expression, so the characterization of cold-responsive transcription factors is important for exploring mechanisms of cold acclimation in fish. We previously found that zebrafish fos family transcription factors fosaa, fosab and fosb are cold-inducible immediate early genes and overexpression of Fosaa and Fosab in zebrafish larvae significantly increased their resistance to lethal cold stress. In addition, inhibiting the activity of Fos family protein complex AP-1 eliminated the cold acclimation response in zebrafish larvae. This project is aimed to verify the roles of these immediate early genes in the cold acclimation of zebrafish and investigate the underlying mechanisms. The main contents include: 1) develop gene-knockout zebrafish lines for these genes; 2) characterize the effect of lacking fos family genes on the cold acclimation of zebrafish; 3) investigate the upstream signaling pathways that mediate cold-inducible responses of these immediate early genes and identify cold-responsive cis-elements; 4) identify proteins that can interact with these immediate early factors and downstream genes regulated by these immediate early genes. The approval and successful implementation of this project is of theoretical significance for revealing mechanisms underlying intracellular cold-stress signaling and acclimation in fish and for breeding fish strains with cold tolerance.