碱性鞘磷脂酶基因剔除鼠的基因型和表型特征

目的：阐明碱性鞘磷脂酶(Alkaline sphingomyelinase, alk-SMase) 基因剔除小鼠的背景特征，为研究alk-SMase在结肠癌发生发展中的作用提供动物模型的实验数据。方法: 将野生型（WT， / ）、杂合子( /-)、纯合子（KO,-/-）alk-SMase基因剔除小鼠剪尾提取DNA，PCR法作基因型鉴定；取其肝肠组织进行HE染色、激光共聚焦分析以及质谱仪检测，观察和分析不同基因型鼠的表型特征。结果: 与WT和杂合子比较，KO鼠显示：外观和体重无明显区别；基因型鉴定出现一个条带，其分子量为247bp; 小肠粘膜明显增厚，但alk-SMase表达减弱；质谱分析显示在肠道和肝脏中的鞘磷脂含量增高，1-磷酸鞘氨醇含量增加，而神经酰胺含量降低。结论: alk-SMase KO鼠有明显特征，但其外观和体重与其他基因型比较没有明显区别,这为研究alk-SMase的生物功能提供了一个理想的动物模型。【关键词】碱性鞘磷脂酶；基因剔除小鼠；基因型；表型

Genotypic and phenotypic characteristics of alkaline sphingomyelinase knockout mice

Objective To determine the genotypic and phenotypic characteristics of alkaline sphingomyelinase (alk-SMase) knockout (KO) mice and to provide the foundation data of this animal model for further study of the role of alk-SMase in colon cancer. Methods DNA was extracted from the tail tissue of wild type, heterozygous, homozygous KO mice, respectively. PCR analysis was used for genotyping. HE staining, confocal microscopy, and mass spectrometry were used for the detection of morphology, alk-SMase expression and sphingolipid metabolites in liver and intestine of the mice. Results Compared with the wild type and heterozygous mice, the homozygous KO mice showed that no changes occurred in the appearance and body weight, there was only one band (247bp) appeared on the genotyping, the thickness in small intestinal mucosa was significantly increased with a lower expression level of alk-SMase, and the amount of sphingolipid metabolites in the intestine and liver was changed, i.e. increase of SM and S1P, and reduction of ceramide. Conclusions Our findings demonstrate that the homozygous KO mice have specific genotype and phenotype that do not affect their growth. These mice will provide an ideal animal model for further study of alk-SMase functions.