摘要
分析了人类加工假基因在染色体上的分布,发现加工假基因密度与重组率负相关,而与基因密度正相关。加工假基因在低重组区的积累与插入有害模型和异位重组模型相吻合:在插入有害模型下,低重组区的选择强度由于Hill-Robertson干涉而变弱,所以加工假基因较多地插入到低重组区;在异位重组模型下,同源加工假基因家族(包括同源祖先基因)之内可能发生异位重组而对机体造成危害,所以加工假基因在高重组区的插入受到较强的负选择,导致加工假基因较多地分布在低重组区。除以上两种模型以外,加工假基因还可能通过降低重组率的方式对加工假基因密度与重组率的负相关有所贡献。加工假基因偏好分布在基因密区,这可能与异位重组在该区较少发生有关。
The distribution of processed pseudogenes along chromosomes of human was analyzed, and it was found that the density of the processed pseudogenes was negatively correlated with recombination rate and positively correlated with gene density. The negative correlation between processed pseudogene density and recombination rate is compatible with a model of selection against processed pseudogene insertions which expects an accumulation of processed pseudogenes in regions of reduced recombination where selection is weaker due to Hill-Robertson interference. It is also compatible with a model of selection against ectopic recombination which also expects processed pseudogenes accumulate in regions of reduced recombination. Besides, processed pseudogenes may contribute to the negative correlation by reducing meiotic recombination. Processed pseudogenes tend to accumulate in gene-dense regions probably because the ectopic recombination less occurs in these regions.
出处
《生物物理学报》
CAS
CSCD
北大核心
2008年第5期371-378,共8页
Acta Biophysica Sinica
基金
国家自然科学基金(30660044)
高等学校博士点基金(20050126003)资助项目~~
