A comparative study of the characterization of miR-155 in knockout mice

miR-155 is one of the most important miRNAs and plays a very important role in numerous biological processes. However, few studies have characterized this miRNA in mice under normal physiological conditions. We aimed to characterize miR-155 in vivo by using a comparative analysis. In our study, we compared miR-155 knockout (KO) mice with C57BL/6 wild type (WT) mice in order to characterize miR-155 in mice under normal physiological conditions using many evaluation methods, including a reproductive performance analysis, growth curve, ultrasonic estimation, haematological examination, and histopathological analysis. These analyses showed no significant differences between groups in the main evaluation indices. The growth and development were nearly normal for all mice and did not differ between the control and model groups. Using a comparative analysis and a summary of related studies published in recent years, we found that miR-155 was not essential for normal physiological processes in 8-week-old mice. miR-155 deficiency did not affect the development and growth of naturally ageing mice during the 42 days after birth. Thus, studying the complex biological functions of miR-155 requires the further use of KO mouse models.

miR-155是目前最重要的微小RNA（microRNA，miRNA）之一，广泛参与诸多生物学进程。然而，目前鲜有研究在正常生理状态下对小鼠体内的该miRNA进行系统性表征。本研究旨在通过对比分析策略，实现小鼠体内miR-155的体内表征。在本研究中，我们以miR-155基因敲除（knockout, KO）小鼠与C57BL/6野生型（wild type, WT）小鼠为研究对象，采用生殖性能分析、生长曲线测定、超声评估、血液学检查及组织病理学分析等多种评价手段，在正常生理状态下对小鼠体内的miR-155开展表征研究。上述分析结果显示，两组小鼠的核心评价指标均无显著性差异。所有受试小鼠的生长发育状态均基本正常，对照组与模型组间无显著差异。结合本次对比分析结果与近年发表的相关研究综述，本研究发现miR-155对于8周龄小鼠的正常生理进程并非必需。miR-155基因缺失不会影响出生后42天内自然衰老小鼠的发育与生长。因此，若要深入解析miR-155复杂的生物学功能，仍需进一步依托基因敲除小鼠模型开展相关研究。