The sequence of H 1 varies greatly in different organisms. In some tissues, H 1 is replaced by a special histone. For example, in red blood cells of mature fish and birds, H 1 is replaced by h5, and in sperm cells, histone is replaced by protamine. The ratio of histone content to DNA content in chromatin is 1: 1.
Significance of histone: The target of histone methyltransferase is not limited to histone, but some non-histone can also be methylated by histone, which will provide a broader space for exploring the mechanism of gene transcription, signal transduction and even individual development and differentiation.
Considering the diversity of histone modification patterns, the information of other histone modification sites will help us to further classify patients, including patients with high scores. The application of immunohistochemistry and more and more antibodies to detect histone modification will help the application of this detection index in other tumors.
Extended data:
Discovery of histone:
1884, Abridgy Causel first discovered histone. It was not until the early 1990s that histone was considered as an inert filler of pure nucleus. Based on the model of Mark Ptashne and others, it is believed that transcription is largely activated by the interaction between protein DNA and protein, such as bacteria, activated by naked DNA template. So as to find its regulating function.
In the1980s, Yahli Lorch and Roger Kornberg proved in vitro that nucleosomes on the core promoter blocked the initiation of transcription, and Michael Grennstam proved in vivo that histones inhibited transcription, leading to nucleosomes becoming general gene inhibitors.
Baidu Encyclopedia-Histone
Baidu Encyclopedia-Histone Modification