Vasetskiĭ E S
Institut de Genetique Humaine, Montpellier, France.
Ontogenez. 2003 Jul-Aug;34(4):262-6.
Replication initiation proceeds in a random fashion in early development of Xenopus laevis. The replication origins become fixed only at later stages of development after the mid-blastula transition. Specification of replication origins occurs at the same time with the specification of the DNA attachment to the nuclear matrix. Replication origins of many species coincide or are located in the vicinity of sites of DNA attachment to the nuclear matrix. The present work was dedicated to development of an experimental system where DNA loops were specifically attached to an artificial matrix and a study of an effect of this attachment on specificity of DNA replication initiation in extracts of Xenopus laevis oocytes. We have found that DNA attachment to the artificial matrix increases the efficacy of DNA replication as compared to the control, but does not affect the replication specificity. It is likely that the transition from non-specific to specific replication is determined by a combination of several factors, and specificity of DNA attachment to a matrix alone is not sufficient for specification of a replication origin.
在非洲爪蟾早期发育过程中，复制起始以随机方式进行。复制起点仅在囊胚中期转变后的发育后期才固定下来。复制起点的确定与DNA附着于核基质的确定同时发生。许多物种的复制起点与DNA附着于核基质的位点重合或位于其附近。本研究致力于开发一种实验系统，其中DNA环被特异性附着于人工基质，并研究这种附着对非洲爪蟾卵母细胞提取物中DNA复制起始特异性的影响。我们发现，与对照相比，DNA附着于人工基质可提高DNA复制效率，但不影响复制特异性。从非特异性复制到特异性复制的转变可能由多种因素共同决定，仅DNA附着于基质的特异性不足以确定复制起点。
