Determining the one, two, three, or four long and short loci of human complement C4 in a major histocompatibility complex haplotype encoding C4A or C4B proteins
Determining the one, two, three, or four long and short loci of human complement C4 in a major histocompatibility complex haplotype encoding C4A or C4B proteins
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DOI：
10.1086/342778
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发表时间：
2002-10-01
影响因子：
9.8
通讯作者：
Yu, CY
中科院分区：
文献类型：
--
作者：
Chung, EK;Yang, Y;Yu, CY
人类补体C4的复杂遗传学，以及主要组织相容性复合体中C4a和C4b及其邻近基因的大小和数量异常频繁的变化，一直是准确进行C4相关疾病流行病学研究的障碍。已开发出一系列新的或改进的技术来确定二倍体基因组中C4的总基因数量以及C4a和C4b的相对剂量。这些技术包括(1)基于RCCX(RP-C4-CyP21-TnX)模块的离散复制模式以及C4a和C4b亚型的特定核苷酸变化的决定性基因组限制性片段长度多态(RFLP)；(2)模块特异性PCR，通过比较RP1或TNXB特异片段与TNXA-RP2片段的相对数量，提供C4基因总数的信息；(3)标记引物单环DNA聚合程序，扩增C4D基因组DNA，用于诊断C4a和C4b的RFLP分析；以及(4)一种重复性高的远程作图方法，该方法使用PMEL消化的基因组DNA进行脉冲场凝胶电泳，以获得关于单倍型中长和短C4基因数量的准确信息。这些经过严格测试的技术的应用可能会阐明人类C4a和C4b基因剂量变异在传染病和自身免疫性疾病中所起的作用。
The complex genetics of human complement C4 with unusually frequent variations in the size and number of C4A and C4B, as well as their neighboring genes, in the major histocompatibility complex has been a hurdle for accurate epidemiological studies of diseases associated with C4. A comprehensive series of novel or improved techniques has been developed to determine the total gene number of C4 and the relative dosages of C4A and C4B in a diploid genome. These techniques include (1) definitive genomic restriction-fragment-length polymorphisms (RFLPs) based on the discrete duplication patterns of the RCCX (RP-C4-CYP21-TNX) modules and on the specific nucleotide changes for C4A and C4B isotypes; (2) module-specific PCR to give information on the total number of C4 genes by comparing the relative quantities of RP1- or TNXB-specific fragments with TNXA-RP2 fragments; (3) labeled-primer single-cycle DNA polymerization procedure of amplified C4d genomic DNA for diagnostic RFLP analysis of C4A and C4B; and (4) a highly reproducible long-range-mapping method that employs Pmel-digested genomic DNA for pulsed-field gel electrophoresis, to yield precise information on the number of long and short C4 genes in a haplotype. Applications of these vigorously tested techniques may clarify the roles that human C4A and C4B gene-dosage variations play in infectious and autoimmune diseases.