摘要
采用 14种限制性内切酶 (ApaⅠ、BamHⅠ、BglⅡ、EcoRI、EcoRⅤ、HindⅢ、HpaⅠ、KpnⅠ、PstⅠ、PvuⅡ、SalⅠ、ScaⅠ、XbaⅠ和XhoⅠ )对雀形目 3科 10种鸟类 (蒙古百灵、喜鹊、小嘴乌鸦、白腰朱顶雀、锡嘴雀、朱雀、红腹灰雀、灰腹灰雀、红交嘴雀和黄喉 )进行限制性片段长度多态分析 (RFLP分析 )。结果表明 :雀形目鸟类基因组大小存在遗传多态性 ,不同类群在酶切类型上表现出各自的特点 ,雀形目鸟类与非雀形目鸟类在线粒体DNA的进化速率有着相同的特点 ,化石记录的地质年代与线粒体DNA分子时钟记录的年代有着惊人的吻合 ,这两个互为独立事件的统一 ,提示线粒体DNA作为分子进化的良好工具。
The mitochondrial RFLP analyzing method was used to study the phylogenetic relationships of ten species from three families of passeriformes,including Melanocorypha mongolica, Corvus corone, Pica pica, Carpodacus erythrinus, Caduelis flame, Coccothraustes coccohraustes, Loxia curvirostra, Pyrrhula griseiventris, Pyrrhula pyrrhula, and Emberiza elegans. Fourteen restriction enzymes were used in this study. Based on the electrophoretic patterns of mtDNA in ten species, phylogenetic trees were constructed using the computer program MEGA 2 1. Mitochondrial genome polymorphism. mtDNA fragments from different species showed different restriction endonuclease maps. The length of the mitochondrial genome of Carduelis flamme, Melano corypha mongolica and other eight species was 23 13 kb, 20 3 kb and 16～17 kb, respectively. The mtDNA genome enlargement observed in this study has never been previously reported.It was initially thought that this result was due to the opposite replication of the non coding region,but this requires more detailed sequence analysis. Interspecific heredity and mutation. Though the Alaudidae were represented by only one species ( Melanocorypha mongolica ) in our study, Alaudidae Ⅰ was obviously different from the other two families in restriction endonuclease type: all species had 1～2 Kpn Ⅰ sites except Melanocorypha mongolica which had no Kpn Ⅰ sites; Melanocorypha mongolica had 1 Xba Ⅰ site while other species had 2～3 Xba Ⅰ sites. From a morphological perspective, the scale of the tarsometatarsus in the Alaudidae was significantly different from other families. Furthermore, the karyotype of the Alaudidae also displayed some unique features. As far as Carduelis falmme was concerned, there were two apparent characters of restriction endonuclease type: one was that 57% of restriction sites belonged to a single site; the other was that genome length was longer (6～7 kb)than the other species in the Fringgillidae family. Consistent to a study of the karyotypes of 120 passeriforms species by other researchers, we found that the species demonstrating unique karyotypes showed the the same uniqueness in mtDNA RFLP. Phylogenetic analysis. The mitochondrial gene tree constructed in this study suggests that the Alaudidae are a single branch separate from the other two families, and the Fringgillidae are more related to the Corvidae than the Alaudidae. It has been reported that mitochondrial DNA evolves at a rate of 2% per million years. Using this evolutionary rate, our results indicate that these taxa diverged 4 million years ago, which is identical to what is suggested by the fossil record. This suggests that mitochondrial DNA may provide an appropriate molecular clock for research on the evolutionary history of birds.
出处
《动物学报》
SCIE
CAS
CSCD
北大核心
2002年第5期625-632,共8页
ACTA ZOOLOGICA SINICA
基金
国家自然科学基金资助项目 (No .3 9670 3 94)~~
