Phi-van L, Sellke C, von Bodenhausen A, Strätling W H
Institut für Tierzucht und Tierverhalten, Bundesforschungsanstalt für Landwirtschaft, Dörnbergstrasse 25-27, 29223 Celle, Germany.
J Biol Chem. 1998 Jul 17;273(29):18300-7. doi: 10.1074/jbc.273.29.18300.
The chicken lysozyme gene domain is distinguished by a broad knowledge of how its expression is regulated. Here, we examined the in vivo replication of the lysozyme gene locus using polymerase chain reaction amplification and competitive polymerase chain reaction of size-fractionated, nascent DNA strands. We found that DNA replication initiates at multiple sites within a broad initiation zone spanning at least 20 kilobases, which includes most of the lysozyme gene domain. The 5' border of this zone is probably located downstream of the lysozyme 5' nuclear matrix attachment region. Preferred initiation occurs in a 3'-located subzone. The initiation zone at the lysozyme gene locus is also active in nonexpressing liver DU249 cells. Furthermore, examining the timing of DNA replication at the lysozyme gene locus revealed that the gene locus replicates early during S phase in both HD11 and DU249 cells, irrespective of its transcriptional activity.
鸡溶菌酶基因结构域因其表达调控的广泛知识而独具特色。在此，我们利用聚合酶链反应扩增以及对大小分级的新生DNA链进行竞争性聚合酶链反应，研究了溶菌酶基因位点的体内复制情况。我们发现，DNA复制起始于一个至少跨越20千碱基的广泛起始区内的多个位点，该区域包括了大部分溶菌酶基因结构域。这个区域的5'边界可能位于溶菌酶5'核基质附着区域的下游。优先起始发生在一个位于3'的子区域。溶菌酶基因位点的起始区在不表达的肝脏DU249细胞中也具有活性。此外，对溶菌酶基因位点DNA复制时间的研究表明，无论其转录活性如何，该基因位点在HD11和DU249细胞的S期早期都会进行复制。
