人类核糖体蛋白加工假基因在进化中的熵变

Entropy Variation of the Human Ribosomal Protein Processed Pseudogenes During Evolution

用生物信息学方法计算出人类核糖体蛋白加工假基因(RP加工假基因)的进化距离.假定在统计意义上,不同进化距离的假基因可粗略代表假基因的进化历程.在此假定基础上从信息论的角度去研究假基因在进化中的熵变.结果发现,1)假基因序列的紧邻碱基关联随进化逐步增强;2)k-mer信息熵中,小k-mer(k=1,2,…,5)信息熵随进化减少,大k-mer(k=7,8)信息熵随进化先迅速减少,随后增加;3)关联信息熵随进化减少,其中紧邻碱基关联信息熵的减少幅度最明显.这些可能与背景突变压力作用有关.

The evolutionary distances of the human ribosomal protein （ RP ） processed pseudogenes are calculated by the methods of bioinformatics. It is assumed that the list of the pseudogenes sorted by their evolutionary distances can statistically represent the evolution course of pseudogenes. Based on this assumption, the entropy variation of pseudogenes is studied from the perspective of information theory. It is found that. 1） the adjacent base correlation gradually strengthens during evolution;2） small k-mer（k=1,2,…, 5） information entropy gradually decreases during evolution, however, large k-mer （k =7, 8） information entropy rapidly decreases to its minimum and then gradually increases during evolution ;3） the correlation entropies decrease during evolution and this trend is the most dominant in the case of adjacent base correlation entropy. All above may be due to the background mutational pressure in the genome.