【摘要】 本文从河南省西峡晚白垩世的一枚保存方式特殊的恐龙蛋化石中提取ＤＮＡ，经过￣３２Ｐ同位素标记和电泳分析，发现在蛋内腔的絮状物样品中确有ＤＮＡ片段存在。它们的大小约在１０００ｂｐ至几十ｂｐ之间，大多数片段在４００ｂｐ以下。用１８ＳｒＤＮＡ特异引物，以上述ＤＮＡ为模板进行了ＰＣＲ扩增，经电泳分析得到约２００ｂｐ的ＰＣＲ产物。经过连接、转化到大肠杆菌，最终筛选出６个阳性克隆。测序分析和同源性比较发现这６个克隆的序列与两栖类、爬行类、鸟类及人类等的１８ＳｒＤＮＡ具有很高的同源性，但是与原核生物没有发现同源性，而且没有检索出与该基因完全相同的已知序列。更多还原

【Abstract】 We have extracted DNA from the inclusion of a dinosaur egg fossil from the Late Cretaceous in Xixia Henan,China, DNA fragments are isolated from the floccus in the cavity of the egg fossil,and confirmed by the method of random primer isotope labelling. Their size ranges from tens base pairs to one thousand base pairs,and most of them are less than four hundred base pairs。 Polymerase chain re action(PCR ) is performed with the specific l8S rDNA primers and the extracted DVA as template,and DNA fragments about 200 base pairs are obtained. After liga-tion,transformation and screening,we get six positive clones, Sequence analysis and homology comparison reveal that these fragments have high homology with the l8S rDNA of Amphlbia,Reptile,Aves and Human in order,but no significant homology with prokaryotes。 The same sequences have not been found in the EMBL data ban.更多还原