摘要
利用ＩＮＴＥＲＮＥＴ网络上ＢＬＡＳＴ服务器和ＦＡＳＴＡ服务器程序对文献中发表的西峡县恐龙蛋化石的ＤＮＡ序列数据进行了序列数据库的类似性检索和分子系统学分析，证实克隆ＤＡ１８Ｓｌ和ＤＡ１８Ｓ７分别属于真菌和植物１８ＳｒＤＮＡ。文中还就在分子序列水平上对古ＤＮＡ的甄别与鉴定进行了讨论。
To identify the real source of two putative dinosaur 18S rDNA sequences of DA 18Sl and DA 18S7 cloned from a dinosaur egg fossil unearthed in Xixia of Henan Province,China,sequence homology searching was performed on the INTERNET by programs of the BLAST server and FASTA server.Neither of the two sequences was found to be similar with prokaryotic sequences.The base identity between DA18S7 with several plant 18S rDNA sequences is among 89.0-92.4%,much higher than that with 18S rDNAs of other organisms.DA18Sl has larger similarities with funga1,invertebrate and plant 18S rDNAs than with the vertebrate sequences.Molecular phylogeny analysis of DA18Sl indicated that DA18Sl clusters with fungal 18S rDNAs.These results show that DA18Sl and DA18S7 are of fungal and plant origin,respectively.
关键词
恐龙
恐龙蛋
化石蛋
古DNA
序列分析
Dinosaur egg,Ancient DNA,18S rRNA,Sequence analysis,Molecular phylogeny
