School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, People's Republic of China.
Yeast. 2011 Sep;28(9):683-91. doi: 10.1002/yea.1896. Epub 2011 Aug 3.
Histone modification is an important subject of epigenetics that plays an intrinsic role in transcriptional regulation. It has been suggested that multiple histone modifications act in a combinatorial fashion to form a 'histone code'. In this study, the combinatorial patterns of histone modifications were studied by using a Bayesian network at the level of individual nucleosomes in S. cerevisiae. Our results indicated that there were 23 combinatorial patterns for 12 histone modifications investigated when a general Bayesian network was constructed. Meanwhile, different networks were also constructed for the genes with high transcript levels (H-network) and low transcript levels (L-network), respectively. Comparison among the general network, H-network and L-network illustrated four conserved combinations: H2BK16Ac → H3K4me3; H3K14Ac → H3K4me3; H2AK7Ac → H3K14Ac; and H4K12Ac → H3K18Ac. The detailed analysis for some combinations demonstrated that the combinations were ascribed to some histone-modifying enzymes.
组蛋白修饰是表观遗传学的一个重要课题，它在转录调控中起着内在的作用。有人提出，多种组蛋白修饰以组合的方式作用，形成“组蛋白密码”。在这项研究中，通过使用贝叶斯网络在单个核小体水平上研究了酿酒酵母中组蛋白修饰的组合模式。我们的结果表明，当构建一个通用贝叶斯网络时，对于研究的 12 种组蛋白修饰，存在 23 种组合模式。同时，还分别为转录水平较高的基因（H 网络）和转录水平较低的基因（L 网络）构建了不同的网络。通用网络、H 网络和 L 网络之间的比较表明存在四个保守组合：H2BK16Ac→H3K4me3；H3K14Ac→H3K4me3；H2AK7Ac→H3K14Ac；和 H4K12Ac→H3K18Ac。对一些组合的详细分析表明，这些组合归因于一些组蛋白修饰酶。
