Elgin S C
Washington University, Department of Biology, St. Louis, Missouri 63130, USA.
Curr Opin Genet Dev. 1996 Apr;6(2):193-202. doi: 10.1016/s0959-437x(96)80050-5.
We have recently learned more about the biochemistry of heterochromatin and about how heterochromatic environments affect gene function. New findings have emphasized the distinctions between telomeric and pericentric heterochromatin in Drosophila and have suggested a mosaic structure within pericentric heterochromatin. Theories concerning the mechanism of inactivation of euchromatic genes in heterochromatic environments have been tested using transgenes inserted into heterochromatin. The current data support a competition/chromatin structure model, in which multiprotein repressor complexes compete with transcriptional activators to assemble an active or inactive chromatin structure.
我们最近对异染色质的生物化学以及异染色质环境如何影响基因功能有了更多了解。新的研究结果强调了果蝇端粒异染色质和着丝粒周围异染色质之间的区别，并提出了着丝粒周围异染色质内的镶嵌结构。利用插入异染色质的转基因，对异染色质环境中常染色质基因失活机制的理论进行了验证。目前的数据支持一种竞争/染色质结构模型，即多蛋白阻遏复合物与转录激活因子竞争，以组装活性或非活性染色质结构。
