Arc基因表达及甲基化与幼龄鼠和成年鼠空间记忆形成的相关性  

Relationship of expression and methylation of Arc gene to spatial memory formation of young and adult rats

作　　者：叶保国[1] 滕士勇[1] 李新白[1] 宋雪松[1] 麻海春[1] 朱庆三[1] 

机构地区：[1]吉林大学第一医院,吉林长春130021

出　　处：《中国生物制品学杂志》2013年第3期363-367,共5页Chinese Journal of Biologicals

摘　　要：目的探讨Arc基因表达及甲基化与幼龄鼠和成年鼠空间记忆形成的相关性。方法应用Morris水迷宫对2月龄幼龄鼠和6月龄成年鼠进行定位航行训练,以判断其空间记忆形成情况。采用RT-PCR检测定位航行训练后大鼠海马组织Arc基因mRNA的转录水平,并对海马基因组DNA进行亚硫酸盐处理,采用甲基化特异性聚合酶链反应(Methylation specific polymerase chain reaction,MS-PCR)检测Arc基因的甲基化情况,并进行DNA甲基化序列分析。结果随着定位航行训练入水次序及训练天数的增加,幼龄鼠逃避潜伏期缩短(P<0.05);而成年鼠在训练当天随着入水次序的增加,逃避潜伏期缩短,但第2天逃避潜伏期不仅与入水次序有关,也随着放入点距离的增大,逃避潜伏期相对延长(P<0.05),至第3天逃避潜伏期与入水次序及距离均无关,形成稳定的记忆能力。成年鼠定位航行训练组海马组织Arc基因mRNA的转录水平显著高于正常对照组(P<0.01),且高于幼龄鼠(P<0.05)。与幼龄鼠正常对照组相比,幼龄鼠和成年鼠定位航行训练组第8和24位点均无甲基化,成年鼠定位航行训练组与正常对照组相比,甲基化位点无变化。结论幼龄鼠瞬时记忆能力接近成年鼠,但形成稳定记忆的能力弱于成年鼠。Arc启动子甲基化影响其mRNA的表达,而Arc基因mRNA的转录水平与大鼠空间记忆能力及年龄相关,进一步证实了甲基化参与调解学习和记忆。Objective To investigate the relationship of expression and mechanism of Arc gene to the spatial memory formation of young and adult rats. Methods Morris maze was applied to detect place navigation and space exploration abilities of young rats at age of 2 months and adult rats at age of 6 months. At the test, the transcription levels of Arc mRNA in hippocampus of rats were determined by RT-PCR, while genomic DNA in hippocampus was treated with sulfite and determined for the methylation of Arc gene by methylation specific polymerase chain reaction （MS-PCR）, and the methylated DNA sequences were analyzed. Results As the increasing orders and days of entering into the water in place navigation test, the escape latency of young rats was shortened （P 〈 0. 05 ）. On the same day of place navigation test, as the increasing orders of entering into the water in place navigation test, the escape latency of adult rats was shortened. Howev- er, on the second day, the escape latency was not only related to the order of entering into the water, but also was prolonged with the increased distance from the entrance to the platform area （P 〈 0. 05 ）. On the third day, the escape latency was unrelated to the order of entering into the water or the distance from the entrance to the platform, indicating the formation of stable memory of adult rats. The Arc mRNA transcription levels in hippocampal tissue of adult rats after place navigation test were significantly higher in those in normal control （P 〈 0. 01） and those in young rats （P 〈 0. 05）. No methylations were observed in sites 8 and 24 of young and adult rats after place navigation test as compared with those in normal young rats. However, the methylation site of adult rats after the test showed no significant change as compared with that in normal adult rats. Conclusion The immediate memory ability of young rats was closed to, while the ability in formation of stable memory was weaker than that of adult rats. Arc promoter methylation affected the mRN

关 键 词：Arc基因 DNA甲基化 定位航行训练 记忆 

分 类 号：R776.1[医药卫生—眼科] Q78[医药卫生—临床医学]