中國(guó)科學(xué)院北京基因組研究所于軍研究員指導(dǎo)的,,碩博生朱江,、和夫紅等所在小組利用基于EST數(shù)據(jù)對(duì)基因表達(dá)組織特異性的重新評(píng)估,在基因結(jié)構(gòu),、進(jìn)化選擇、起源時(shí)間和啟動(dòng)子結(jié)構(gòu)等方面對(duì)housekeeping (HK)和tissue-specific (TS)基因進(jìn)行了系統(tǒng)的分析,,研究工作取得進(jìn)一步成果,。研究進(jìn)展發(fā)表在近期出版的愛(ài)思唯爾期刊《遺傳學(xué)趨勢(shì)》(Trends in Genetics)雜志上。
研究結(jié)果表明:HK基因的基因組長(zhǎng)度,、轉(zhuǎn)錄本長(zhǎng)度和外顯子個(gè)數(shù)都顯著大于TS基因,,具有相對(duì)松散的基因結(jié)構(gòu)。在進(jìn)化上,,HK基因的編碼區(qū)和核心啟動(dòng)子均受到負(fù)選擇,,相比TS基因具有較強(qiáng)的序列保守性。HK基因具有較為古老的進(jìn)化起源,,超過(guò)50%的HK基因起源于脊椎動(dòng)物分化前而僅有5%的TS基因如此,。在啟動(dòng)子結(jié)構(gòu)上,超過(guò)80%的HK基因的核心啟動(dòng)子位于CpG島內(nèi)而僅有20%的TS基因如此,。大多數(shù)(60%)TS基因核心啟動(dòng)子內(nèi)既沒(méi)有CpG島也沒(méi)有TATA元件,,這部分基因的轉(zhuǎn)錄起始機(jī)制仍有待進(jìn)一步研究。上述結(jié)果揭示了HK基因在構(gòu)成基本轉(zhuǎn)錄組時(shí)具有的特殊角色,,同時(shí)是理解多細(xì)胞生物中細(xì)胞特異轉(zhuǎn)錄組的重要基礎(chǔ),。
細(xì)胞特異表達(dá)模式的建立決定了細(xì)胞分化的過(guò)程,胚胎干細(xì)胞轉(zhuǎn)錄組和分化細(xì)胞特異的轉(zhuǎn)錄組分別是這一過(guò)程的起點(diǎn)和終點(diǎn),。該小組目前正在開(kāi)展關(guān)于胚胎干細(xì)胞轉(zhuǎn)錄組的研究,,分析HK基因和TS基因在細(xì)胞分化過(guò)程中的動(dòng)態(tài)表達(dá)模式和表觀修飾模式。該研究對(duì)于系統(tǒng)理解細(xì)胞分化過(guò)程中的轉(zhuǎn)錄因子調(diào)控,、基因組表觀修飾調(diào)控等基因表達(dá)調(diào)控機(jī)制具有重要意義,。(生物谷Bioon.com)
生物谷推薦原始出處:
Trends in Genetics,doi:10.1016/j.tig.2008.08.004,,Jiang Zhu, Fuhong He, Songnian Hu and Jun Yu
On the nature of human housekeeping genes
Jiang Zhu1, 2,, Fuhong He1, 2, Songnian Hu1 and Jun Yu1
1 Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
2 Graduate University of Chinese Academy of Sciences, Beijing, China
Using a collection of expressed sequence tag (EST) data, we re-evaluated the correlation of tissue specificity with genomic structure, phyletic age, evolutionary rate and promoter architecture of human genes. We found that housekeeping genes are less compact and older than tissue-specific genes, and they evolve more slowly in terms of both coding and core promoter sequences. Housekeeping genes primarily use CpG-dependent core promoters, whereas the majority of tissue-specific genes possess neither CpG-islands nor TATA-boxes in their core promoters.
相關(guān)鏈接:合作是現(xiàn)代科學(xué)研究的基本前提——生物谷專(zhuān)訪中科院北京基因組研究所副所長(zhǎng)于軍研究員