摘要
为了探讨自然环境下生物体内DNA的降解 残存规律,设计了模拟特殊自然沉积环境的实验装置以控制温度、湿度和含氧水平,采用Brassicachinensis叶片作为实验材料,从实验装置中定期采集叶片组织进行总DNA的提取与检测,然后采用定量PCR方法,对目标DNA片段(28SrDNA,630bp)进行特异扩增,依据PCR反应的强弱,描绘目标DNA的变化曲线.共报道了8种不同模拟条件下的DNA降解(残存)趋势.实验结果如下:1)环境温度升高,DNA的降解速率增加,如温度从10℃上升到30℃,DNA的降解速率最大可增加近300倍.环境含水量增加可明显促进DNA的降解,在本实验中潮湿状态(浸没在水中)与干燥状态的叶片相比,其DNA的残存量在相同的实验时间内可相差近700倍.初步的实验结果表明,环境温度和湿度均是影响DNA降解的重要因素.
Experimental devices simulating natural sedimentary environment were designed to study DNA degradation/survival through time. The leaves of Brassica chinensis were used as experimental materials, preserved under different environmental conditions, i.e., different environmental temperature, humidity, and oxygen content. Samples were collected from the preservational devices in fixed intervals and then the total nucleic acids were extracted. The detection of survival DNA in the timeseries samples was conducted using quantitative PCR method with plantspecific primers, and the DNA survival curves under the simulating conditions were obtained according to the concentrations of PCR products. From the experiment data, the following conclusions can be drawn: the survival amount of specified DNA fragment (28S rDNA, 630 bp) under simulating conditions decreases gradually as the preservation time increases, and the change of environmental temperature and humidity greatly influenced the rate of DNA degradation, which increases as the environmental temperature and water content rise. The relative template DNA concentration data show that the survival amount of template DNA at 10℃is about 300 times than that at 30 ℃ after 42 days. Leaves submerged in water rot more quickly than those preserved with dry agent. The amount of surviving DNA of Brassica chinensis leaves submerged in water is only about 1/700 that under dry environment after 12 days.
出处
《生命科学研究》
CAS
CSCD
2003年第3期249-254,共6页
Life Science Research
基金
中国科学院现代古生物学和地层学开放实验室基金(990913)
科技部重大基础研究前期专项基金(2002CCA03300)
国家杰出青年基金(49725204)
关键词
沉积环境
温度
湿度
叶片
DNA降解
古DNA
temperature
humidity
Brassica chinensis
leaf DNA degradation
quantitative PCR
