宁夏束颈蝗Cytb基因的Numt分析

核线粒体假基因Numt（Nuclear Mitochondrial pseudogene）的存在具有重大的进化意义,它为基因组进化和基因组间相互作用的动态研究打开了一个窗口。假基因是基因组上与编码基因序列非常相似的非功能性基因组DNA拷贝,一般情况都不被转录,且没有明确生理意义。Numts由于处于不同的突变压力下,与真正的线粒体序列相比具不同的进化模式,其进化速率比线粒体同源基因要慢的多,类似分子化石,在核苷酸序列上更接近现存mtDNA的祖先状态。本研究在前几年研究的基础上,通过PCR技术,旨在发现宁夏束颈蝗核基因组中所存在的线粒体Cytb基因的假基因（Numt）。通过对PCR产物的检测,推断宁夏束颈蝗存在Numt,在对目标片断进行测序并利用GeneBank的BLASTn序列比对后确定序列特征,进一步确定Numt的实验正在规化进行中。预期本研究的结果将为Numts来源和机制,基因组进化和基因组间相互作用、系统进化、横向基因转移和核序列突变等研究提供实验基础。     

Analysis of the genetic structure of red-legged partridge (Alectoris rufa, Galliformes) populations by means of mitochondrial DNA and RAPD markers: a study from central Italy

The strong hunting pressure on the red-legged partridge, Alectoris rufa, warranted its inclusion into the list of species of European conservation concern. During the last decades, restocking plans with farmed specimens have counterbalanced the hunting drawings from wild populations. Our concern was the study of A. rufa in the easternmost part of its range, the central Italy, to gain insights into the effects of this compensation practice on the genetic structure of its populations. Partridges from both a geographically isolated, long-time protected, wild population (Pianosa island, Tuscan Archipelago National Park) and two Tuscan farms (Bieri and Scarlino) were investigated. All the specimens were very similar in outward appearance, looking much like to A. rufa. Ninety-six sequences of both Cytochrome b and D-loop Control Region of mitochondrial DNA (mtDNA) were analysed to get evidence of ancestry at the population level, whereas, the Random Amplified Polymorphic DNA (RAPD) technique was employed to get fingerprinting at the individual level. Pianosa and Bieri populations showed both the A. rufa and Alectoris chukar mtDNA lineages, whereas the Scarlino one only the A. rufa-mtDNA line. However, a spread overall pattern of A. rufa × A. chukar hybridisation among specimens, whatever their mtDNA lineage could result to be, was disclosed by means of RAPD species-specific markers. This is the first genetically documented record of the A. rufa × A. chukar hybrids. The occurrence of the pure, native A. rufa genome in the easternmost part of the species’ geographical range may be guessed to be virtual.