Linzmeier Rose M, Ganz Tomas
Department of Medicine and Department of Pathology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1690, USA.
Genomics. 2005 Oct;86(4):423-30. doi: 10.1016/j.ygeno.2005.06.003.
To investigate defensin gene copy number polymorphisms, a quantitative real-time PCR assay was developed and used to study DNA from 27 unrelated individuals of diverse ethnic and racial backgrounds. The DEFB4 and DEFB103A genes varied in tandem, with copy numbers 2 to 8, with a mode of 6 per diploid genome (PDG). The combined copy numbers of the DEFA1 and DEFA3 genes ranged from 5 to 14, with a mode of 10 copies PDG. The copy numbers of the DEFA1/3 genes varied independently of those of the DEFB4 and DEFB103A genes. The amount of HNP-1 and HNP-3 peptides expressed in neutrophils was found to be proportional to the combined copy number of DEFA1 and DEFA3. The DEFA3 allele was absent in 7/27 subjects. The highly copy-number-variable DEFA1 and DEFA3 genes are flanked by other defensin genes present uniformly at 2 copies PDG. The remarkable variability in defensin gene copy numbers could contribute to differences in individual resistance to infections.
为了研究防御素基因拷贝数多态性，开发了一种定量实时聚合酶链反应（PCR）检测方法，并用于研究来自27名不同种族和民族背景的无亲缘关系个体的DNA。DEFB4和DEFB103A基因串联变化，拷贝数为2至8，每个二倍体基因组（PDG）的模式数为6。DEFA1和DEFA3基因的联合拷贝数范围为5至14，每个PDG的模式数为10个拷贝。DEFA1/3基因的拷贝数与DEFB4和DEFB103A基因的拷贝数独立变化。发现中性粒细胞中表达的HNP-1和HNP-3肽的量与DEFA1和DEFA3的联合拷贝数成正比。27名受试者中有7名不存在DEFA3等位基因。高度拷贝数可变的DEFA1和DEFA3基因两侧是其他防御素基因，这些基因在每个PDG中均以2个拷贝的形式均匀存在。防御素基因拷贝数的显著变异性可能导致个体对感染抵抗力的差异。
