Skovby F, Krassikoff N, Francke U
Hum Genet. 1984;65(3):291-4. doi: 10.1007/BF00286520.
Among several established mouse, rat, and Chinese hamster cell lines that were screened for cystathionine beta-synthase (CBS) activity, mouse 3T3 and Chinese hamster Don fibroblasts were found to contain no detectable activity. Somatic cell hybrids between human fibroblasts KG-7 with normal CBS activity and Don/a23TK- cells (series XXI) were examined for CBS activity and for human chromosome content. Only chromosome 21 cosegregated with CBS activity. Because the activities measured could represent either Chinese hamster or human gene products, we have prepared a new series of hybrids between Don/a23TK- cells and mutant human fibroblasts from a patient with homocystinuria due to deficiency of functional CBS mRNA. None of these (series XXV) hybrids contained detectable CBS activity, although collectively all human chromosomes were represented. Our results suggest that the human gene for CBS, called CBS, and thus for the most common form of homocystinuria, is located on chromosome 21.
在对几种已建立的小鼠、大鼠和中国仓鼠细胞系进行胱硫醚β-合酶（CBS）活性筛选时，发现小鼠3T3细胞和中国仓鼠Don成纤维细胞没有可检测到的活性。对具有正常CBS活性的人成纤维细胞KG-7与Don/a23TK-细胞（XXI系列）之间的体细胞杂种进行了CBS活性和人类染色体含量检测。只有21号染色体与CBS活性共分离。由于所测活性可能代表中国仓鼠或人类基因产物，我们制备了一系列新的杂种细胞，这些杂种细胞来自Don/a23TK-细胞与一名因功能性CBS mRNA缺乏而患同型胱氨酸尿症患者的突变人成纤维细胞。这些杂种细胞（XXV系列）均未检测到CBS活性，尽管所有人类染色体均有出现。我们的结果表明，人类CBS基因（称为CBS），也就是导致最常见形式同型胱氨酸尿症的基因，位于21号染色体上。
