TRANSITION IN SPECIFICATION OF EMBRYONIC METAZOAN DNA-REPLICATION ORIGINS
TRANSITION IN SPECIFICATION OF EMBRYONIC METAZOAN DNA-REPLICATION ORIGINS
复制标题
DOI：
10.1126/science.270.5238.994
复制
发表时间：
1995-11-10
期刊：
影响因子：
56.9
通讯作者：
MECHALI, M
中科院分区：
文献类型：
--
作者：
HYRIEN, O;MARIC, C;MECHALI, M
在早期非洲爪蟾胚胎中，核糖体RNA基因（rDNA）不被转录，rDNA复制以9- 12个酶对的间隔开始和终止，对特定的DNA序列没有可检测的依赖性。在囊胚晚期和原肠胚早期核糖体RNA（rRNA）合成的恢复伴随着转录单位内复制起始的特异性抑制;基因间间隔区内的起始频率保持与早期囊胚中一样高，这些结果表明对于rRNA基因，在后生动物发育过程中，当染色质被重塑以允许基因转录
In early Xenopus embryos, in which ribosomal RNA genes (rDNA) are not transcribed, rDNA replication initiates and terminates at 9- to 12-kilobase pair intervals, with no detectable dependence on specific DNA sequences. Resumption of ribosomal RNA (rRNA) synthesis at late blastula and early gastrula is accompanied by a specific repression of replication initiation within transcription units; the frequency of initiation within intergenic spacers remains as high as in early blastula, These results demonstrate that for rRNA genes, circumscribed zones of replication initiation emerge in intergenic DNA during the time in metazoan development when the chromatin is remodeled to allow gene transcription.