Krajci P, Gedde-Dahl T, Høyheim B, Rogde S, Olaisen B, Brandtzaeg P
Laboratory for Immunohistochemistry and Immunopathology (LIIPAT), University of Oslo, National Hospital, Norway.
Hum Genet. 1992 Nov;90(3):215-9. doi: 10.1007/BF00220065.
The human transmembrane secretory component (SC or poly-Ig receptor, PIGR) is expressed basolaterally on glandular epithelial cells and is responsible for the external translocation of polymeric IgA and IgM. SC is hence a key molecule in antibody protection of mucosal surfaces. The human SC gene (locus PIGR) is located on chromosome 1 (1q31-q41). Here we present the first genetic linkage study of PIGR versus syntenic markers, including D1S58 and F13B, which have been previously regionalized to 1q31-q32 and 1q31-q32.1, respectively. We found that PIGR is closely linked to D1S58 (lods + 5.06 at theta max = 0.06, without sex difference). PIGR versus F13B showed + 1.46 at theta max = 0.25 for both sexes combined. A recombination of 0.06 between F13B and D1S58 (lods + 2.24) was in contrast to a previously published study giving theta max = 0.22 (lods + 3.9), the combined lods being 5.6 at theta max = 0.20. The progeny of a triply heterozygotic female indicated that PIGR is the flanking locus, therefore suggesting a cen-F13B-D1S58-PIGR-qter gene sequence on human chromosome 1. Only negative lod scores to RH, C8@, and PGM1 on 1p, and FY on proximal 1q, were found. Current combined Norwegian allele frequencies were estimated for PIGR to be A1 = 0.63, A2 = 0.37 (370 chromosomes), and for D1S58 to be A1 = 0.44, A2 = 0.56 (218 chromosomes).
人类跨膜分泌成分（SC或多聚免疫球蛋白受体，PIGR）在腺上皮细胞的基底外侧表达，负责聚合型IgA和IgM的外向转运。因此，SC是黏膜表面抗体保护中的关键分子。人类SC基因（基因座PIGR）位于1号染色体（1q31-q41）上。在此，我们展示了PIGR与同线标记（包括D1S58和F13B）的首次遗传连锁研究，此前它们分别被定位到1q31-q32和1q31-q32.1区域。我们发现PIGR与D1S58紧密连锁（在θ最大值 = 0.06时，连锁值 + 5.06，无性别差异）。PIGR与F13B在两性合并时，在θ最大值 = 0.25时显示为 + 1.46。F13B与D1S58之间0.06的重组率（连锁值 + 2.24）与之前发表的研究结果形成对比，之前的研究给出的θ最大值 = 0.22（连锁值 + 3.9），在θ最大值 = 0.20时合并连锁值为5.6。一位三重杂合女性的后代表明PIGR是侧翼基因座，因此提示人类1号染色体上存在着cen-F13B-D1S58-PIGR-qter基因序列。仅在1p上的RH、C8@和PGM1以及近端1q上的FY发现了负连锁值。目前估计挪威人群中PIGR的合并等位基因频率为A1 = 0.63，A2 = 0.37（370条染色体），D1S58的合并等位基因频率为A1 = 0.44，A2 = 0.56（218条染色体）。
