Hancock R L
Canadian Institute of Theoretical Biology, Nova Scotia.
Med Hypotheses. 1992 Apr;37(4):245-9. doi: 10.1016/0306-9877(92)90195-i.
Embryonic genes are considered as a separate subset of genes with unique chromatin properties. There is a problem of defining the duration of perturbations of embryonic gene activity that has been chemically induced and the normal relatively longer lasting changes that occur during differentiation. This problem may be related to unique properties of the chromatin of embryonic genes. Methylation of DNA is thought to be only one level of control and the superstructure of chromatin involving heterochromatin is of equal importance to embryonic gene expression. Proto-oncogenes are considered to be embryonic type genes whose activities are regulated under the same mechanisms by which other embryonic genes are regulated. Control aspects are discussed in the light of i) repressor-derepressor and blocking-deblocking mechanisms, ii) activator genes, pseudogenes, LINES, SINES, v-type position effects, iii) effects of ethionine, and iv) steroid hormone effects especially with respect to a subset of repeated rRNA genes which are considered to be structured in embryonic type chromatin.
胚胎基因被视为具有独特染色质特性的一个单独的基因子集。存在一个问题，即确定化学诱导的胚胎基因活性扰动的持续时间以及分化过程中发生的正常相对持久的变化。这个问题可能与胚胎基因染色质的独特特性有关。DNA甲基化被认为只是控制的一个层面，涉及异染色质的染色质超结构对胚胎基因表达同样重要。原癌基因被认为是胚胎型基因，其活性受与其他胚胎基因相同的调控机制调控。根据以下方面讨论控制问题：i）阻遏物-去阻遏物和阻断-解除阻断机制；ii）激活基因、假基因、长散在重复序列（LINES）、短散在重复序列（SINES）、v型位置效应；iii）乙硫氨酸的影响；iv）类固醇激素的影响，特别是关于被认为以胚胎型染色质结构存在的重复rRNA基因子集的影响。
