本项目在课题组海蚯蚓肽衍生物等抗菌肽研究前期工作基础上，应用细胞和分子学技术从细胞、基因和蛋白水平研究抗菌肽杀灭畜禽细菌性腹泻致病菌时空关系及其机制，研究内容：1）利用细胞学技术（流式细胞仪、分子荧光和电镜等）分析膜完整性/渗透性、孔隙大小和细胞形态变化等，确定类凋亡前胞膜是抗菌肽作用靶位点；2）借助共聚焦显微镜、圆二色谱和凝胶阻滞等技术分析抗菌肽对早期（ROS/•OH累积、质膜电位下降、Caspases激活、PS易位）、晚期类凋亡（染色质浓缩、DNA片段化、细胞周期停滞）影响，揭示类凋亡过程中DNA是抗菌肽在细胞内的作用靶位点；3）通过RNA-Seq、iTRAQ技术从mRNA、蛋白水平分析抗菌肽诱导类凋亡的关键功能基因/蛋白，揭示抗菌肽诱导致病菌类凋亡基因/蛋白表达变化及其分子机制。这将为设计新型、能激活致病菌细菌类细胞凋亡的抗菌肽提供重要的理论依据，为畜禽细菌性腹泻疾病的防控另辟途径。

The bactericidal mechanisms of arenicin derivatives against enteropathogenic bacteria in livestock and poultry will be focused on the following three aspects: 1) interaction with cell membrane: flow cytometry, fluorescence spectrophotometer and electron microscope will be used to analyze integrity, permeabilization, pore size of membrane and cell morphological changes to determine whether cell membrane is one of target sites; 2) interaction with the genomic DNA: laser scanning confocal microscope, CD spectra and gel retardation assays will be used to detect nuclear fragmentation, chromatin condensation and cell cycle to determine whether DNA is another target site; 3) molecular mechanism of apoptosis-like death of bacteria treated with arenicin derivatives: high-throughput transcriptomics and proteomics methods will be used to explore the effect of arenicin derivatives on bacteria at the mRNA and protein levels. The aim of this work is to reveal molecular mechanisms of apoptosis-like death of pathogenic bacteria induced by arenicin derivatives. It provides an important theoretical basis for design new antibacterial peptides that can activate apoptosis-like death of bacteria and a new way to prevent bacterial diseases in livestock and poultry.