CHROMOSOMAL LOCALIZATION OF THE CHEDIAK-HIGASHI GENE

由于小鼠细胞可以很容易地建立为 在体外连续细胞系中，可以使用小鼠突变体 这些基因被认为是人类突变的同源基因， 人类基因的染色体定位。 在这样做时， 小鼠突变细胞系及其与正常人细胞的杂交 这可能是有用的进一步研究， 亚染色体定位和基因产物的性质， 如果这是未知。 米色小鼠突变体（bgJ/bgJ）被认为是 人类的Chediak-Higashi综合征 两者都是继承的， 常染色体隐性遗传性状，并涉及畸形的存在， 细胞内的细胞器，包括溶酶体和黑素体， 血小板贮库缺乏和免疫功能低下 响应能力。 将在培养物中建立的米色小鼠细胞 使HAT中等敏感，并与正常人类细胞杂交， 提供一组杂交系，其分离用于校正的（损失）杂交系。 畸形颗粒）和未校正的表型。 混合线路将 也可以通过将建立的米色小鼠细胞与 携带neoR基因的正常人成纤维细胞， 杂种在G418培养基上生长。 这两种杂交的后代 使用同工酶标记物测定人类染色体含量， 其中预期经校正的线将共享共同的 人类染色体携带的基因编码的纠正 因子 HAT中等敏感的米色细胞与Chediak- Higashi人类细胞将用于确定假定的同源性 这两种基因之间的联系 作为第一个结果，将有可能确定染色体 Chediak-Higashi基因在人类中的定位。 这些研究 也将提供一个直接测试的假定同源性的 有这种人类遗传疾病的米色突变小鼠 他们将 也揭示了溶酶体的病理生理学和遗传 负责这些细胞正常结构和功能的元素 胞内细胞器

Due to the ease with which mouse cells can be established as continuous cell lines in vitro, it is possible to use mouse mutants that are presumed homologs of mutations in humans to determine the chromosomal localization of the human gene. In so doing, permanent mouse mutant cell lines and their hybrids with normal human cells are produced which can be useful for further studies concerning sub-chromosomal localization and the nature of the gene product, if this is not known. The beige mouse mutant (bgJ/bgJ) is considered a homolog of the Chediak-Higashi syndrome in humans. Both are inherited as autosomal recessive traits and involve the presence of dysmorphic intracellular organelles, including lysosomes and melanosomes, platelet storage pool deficiency and diminished immunological responsiveness. Beige mouse cells established in culture will be made HAT medium-sensitive and crossed with normal human cells to provide a panel of hybrid lines segregating for corrected (loss of dysmorphic granules) and uncorrected phenotypes. Hybrid lines will also be made by crossing the established beige mouse cells with normal human fibroblasts carrying the neoR gene and selecting for hybrids in G418 medium. Hybrids from both of these crosses will be assayed for human chromosome contents using isozyme markers, where it is anticipated that corrected lines will share a common human chromosome carrying the gene encoding for the correcting factor. Crosses of HAT medium-sensitive beige cells with Chediak- Higashi human cells will be used to determine the presumed homology between these two genes in these two species. As a first result, it will be possible to determine the chromosomal localization of the Chediak-Higashi gene in humans. These studies will also provide a direct test of the presumed homology of the beige mouse mutant with this human genetic disorder. They will also shed light on lysosomal pathophysiology and the genetic elements responsible for normal structure and function of these intracellular organelles.