Ke Xiayi, Thomas N Simon, Robinson David O, Collins Andrew
Human Genetics, Duthie Building (808), University of Southampton, Tremona Road, Southampton SO16 6YD, UK.
Mamm Genome. 2002 Nov;13(11):639-45. doi: 10.1007/s00335-002-3038-x.
Sequence comparison analysis has been carried out for 31 imprinted mouse genes and a set of 150 control genes. The imprinted genes were found to be associated with significantly reduced numbers of short interspersed transposable elements (SINEs), in particular SINE Alu repeats. This is similar to recent analyses of human imprinted genes and supports the suggestion that there is either active selection against SINE elements in imprinted regions or a reduced rate of insertion of these elements. The reduction in numbers of SINEs was more consistent in paternally expressed genes, whereas for maternally expressed genes significantly reduced numbers of SINE-B2 elements were coupled with increased numbers of SINE-B4 and SINE-ID elements. Paternally expressed genes were also found to be associated with a lower GC content. Discriminant analysis revealed that the two sub-groups of imprinted genes can be cleanly separated from each other on the basis of their genomic sequence characteristics and that they tend to localize to different genomic compartments. The differences between the sequence characteristics of imprinted and control genes have also enabled us to develop a discriminant function that can be used in a genome-wide screen to identify candidate imprinted genes.
已对31个印记小鼠基因和一组150个对照基因进行了序列比较分析。发现印记基因与短散在转座元件(SINEs)数量显著减少有关,尤其是SINE Alu重复序列。这与最近对人类印记基因的分析相似,并支持以下观点:要么在印记区域对SINE元件进行了积极选择,要么这些元件的插入率降低。SINEs数量的减少在父系表达基因中更为一致,而对于母系表达基因,SINE-B2元件数量显著减少的同时,SINE-B4和SINE-ID元件数量增加。还发现父系表达基因与较低的GC含量相关。判别分析表明,根据其基因组序列特征,印记基因的两个亚组可以清晰地相互分离,并且它们倾向于定位于不同的基因组区域。印记基因和对照基因序列特征的差异也使我们能够开发一种判别函数,可用于全基因组筛选以识别候选印记基因。