Department of Statistics and Operations Research, Universidad de Valladolid, Prado de Magdalena s.n., 47005 Valladolid, Spain.
Nucleic Acids Res. 2012 Apr;40(7):2823-32. doi: 10.1093/nar/gkr1077. Epub 2011 Dec 1.
A cell division cycle is a well-coordinated process in eukaryotes with cell cycle genes exhibiting a periodic expression over time. There is considerable interest among cell biologists to determine genes that are periodic in multiple organisms and whether such genes are also evolutionarily conserved in their relative order of time to peak expression. Interestingly, periodicity is not well-conserved evolutionarily. A conservative estimate of a number of periodic genes common to fission yeast (Schizosaccharomyces pombe) and budding yeast (Saccharomyces cerevisiae) ('core set FB') is 35, while those common to fission yeast and humans (Homo sapiens) ('core set FH') is 24. Using a novel statistical methodology, we discover that the relative order of peak expression is conserved in ∼80% of FB genes and in ∼40% of FH genes. We also discover that the order is evolutionarily conserved in six genes which are potentially the core set of signature cell cycle genes. These include ace2 (a transcription factor) and polo-kinase plo1, which are well-known hubs of early M-phase clusters, cdc18 a key component of pre-replication complexes, mik1 which is critical for the establishment and maintenance of DNA damage check point, and histones hhf1 and hta2.
细胞分裂周期是真核生物中一个高度协调的过程，细胞周期基因随时间表现出周期性表达。细胞生物学家非常感兴趣的是确定在多种生物体中具有周期性的基因，以及这些基因在其表达峰值的相对时间顺序上是否在进化上保守。有趣的是，周期性在进化上并没有很好地保守。裂殖酵母（Schizosaccharomyces pombe）和芽殖酵母（Saccharomyces cerevisiae）（“核心 FB 集”）中共有约 35 个周期性基因，而裂殖酵母和人类（Homo sapiens）（“核心 FH 集”）中共有约 24 个周期性基因。使用一种新颖的统计方法，我们发现约 80%的 FB 基因和约 40%的 FH 基因的表达峰值相对顺序是保守的。我们还发现，在六个潜在的核心细胞周期基因中，这种顺序在进化上是保守的。其中包括转录因子 ace2 和 polo 激酶 plo1，它们是早期 M 期簇的众所周知的中心，cdc18 是前复制复合物的关键组成部分，mik1 对于建立和维持 DNA 损伤检查点至关重要，以及组蛋白 hhf1 和 hta2。
