Coto E, Martínez-Naves E, Domínguez O, DiScipio R G, Urra J M, López-Larrea C
Servicio de Immunología, Hospital Covadonga, Oviedo, Spain.
Immunogenetics. 1991;33(3):184-7. doi: 10.1007/BF01719238.
In this report we describe the linkage between genes encoding human complement components C6, C7, and C9. Polymorphisms have been described at the DNA level for the C7 and C9 genes. We have studied 20 individuals by Southern blot analysis with four C6 cDNA subclones to detect restriction fragment length polymorphisms (RFLPs). We have found a Taq I polymorphism defined by two alleles of 8.0 (C6 H) and 6.0 (C6 L) kilobases (kb). RFLP segregation for the C6, C7, and C9 loci in informative families allowed us to estimate the maximum Lod scores at a recombination fraction of theta = 0.0 (C6-C7), theta = 0.0 (C7-C9), and theta = 0.0 (C6-C9). Significant linkage disequilibrium was found between C6 and C7 and between C7 and C9 loci in directly determined haplotypes of unrelated parents. Data from this study show that the genes encoding the human terminal complement components C6, C7, and C9 define a cluster in the short arm of chromosome 5. We propose that the clusters involving the C8A and C8B and the C6, C7, and C9 genes be referred to as MACI and MACII, respectively.
在本报告中，我们描述了编码人类补体成分C6、C7和C9的基因之间的连锁关系。已在DNA水平上描述了C7和C9基因的多态性。我们用四个C6 cDNA亚克隆通过Southern印迹分析研究了20个个体，以检测限制性片段长度多态性（RFLP）。我们发现了一种由8.0（C6 H）和6.0（C6 L）千碱基（kb）的两个等位基因定义的Taq I多态性。在信息丰富的家系中，C6、C7和C9位点的RFLP分离使我们能够在重组率θ = 0.0（C6 - C7）、θ = 0.0（C7 - C9）和θ = 0.0（C6 - C9）时估计最大Lod分数。在无关父母的直接确定的单倍型中，发现C6与C7之间以及C7与C9位点之间存在显著的连锁不平衡。本研究的数据表明，编码人类末端补体成分C6、C7和C9的基因在5号染色体短臂上形成一个簇。我们建议将涉及C8A和C8B以及C6、C7和C9基因的簇分别称为MACI和MACII。
