中文摘要：

目的：寻找唐氏综合征模型鼠Ts65Dn和对照二倍体组小鼠海马组织中差异表达的microRNAs。方法：从小鼠的海马组织中提取小分子RNA,采用RNA加尾和引物延伸RT-PCR法检测microRNAs。通过geNorm软件和Normfinder软件分析选择最佳的内参照基因,将每种microRNAs按其引物Tm值排成阵列,用梯度实时PCR仪在不同的退火温度扩增,并计算每种相对于microRNAs内参照基因的表达量。结果：geNorm和Normfinder两种方法均选定miR-27a为最稳定的内参照基因,共检测了52种microRNAs,其中miR-33和miR-19a在Ts65Dn小鼠海马组织中表达显著下调,miR-130在Ts65Dn小鼠海马组织中表达显著上调,小鼠16号染色体三体区段包含的miR-802在Ts65Dn小鼠和对照二倍体小鼠海马组织中表达量均低,差异没有统计学意义。结论：MicroRNAs在Ts65Dn小鼠海马组织中的异常表达可能与唐氏综合征脑发育不良有关。

英文摘要：

Objective：To identify the differentially expressed microRNAs in the hippocampus of Down Syndrome model mouse Ts65Dn.Methods： Low molecular weight RNA from hippocampus were tailed and reverse transcribed by extended RT-primer.MicroRNAs primers were arrayed on plates according to the Tm of each primer.PCR were carried out at different annealing temperatures using a gradient real-time PCR instrument.The relative expression level of each microRNAs was calculated using the most stable reference gene as normalizer which was selected by geNorm and Normfinder software.Results： miR-27a was identified as the most stable reference gene by geNorm and Normfinder software.Among the 52 microRNAs detected by real time PCR array,miR-33 and miR-19a were significantly down-regulated,whereas miR-130 were significantly up-regulated in the hippocampus of Ts65Dn mice as compared with the euploid control mice.The expression of miR-802,which was the trisomy chromosome 16 derived microRNAs,was very low in hippocampus with no difference between the two groups.Conclusion： MicroRNAs are dysregulated in the hippocampus of Ts65Dn mice,which may contribute to the reduced neurogenesis of Down syndrome.