Clark D V, Baillie D L
Department of Biological Sciences, Simon Fraser University, Burnaby, B.C., Canada.
Mol Gen Genet. 1992 Mar;232(1):97-105. doi: 10.1007/BF00299142.
The subject of this study is the organization of essential genes in the 2 map-unit unc-22 IV region of the Caenorhabditis elegans genome. With the goal of achieving mutational saturation of essential genes in this region, 6491 chromosomes mutagenized with ethyl methanesulfonate (EMS) were screened for the presence of lethal mutations in the unc-22 region. The genetic analysis of 21 lethal mutations in the unc-22 region resulted in the identification of 6 new essential genes, making a total of 36 characterized to date. A minimum of 49 essential genes are estimated to lie in this region. A set of seven formaldehyde-induced deficiencies of unc-22 and surrounding loci were isolated to facilitate the positioning of essential genes on the genetic and physical maps. In order to study essential genes at the molecular level, our approach was to rescue lethal mutations by the injection of genomic DNA in the form of cosmid clones into the germ-line of balanced heterozygotes carrying a lethal mutation. The cosmid clones containing let-56 and let-653 were identified by this method.
本研究的主题是秀丽隐杆线虫基因组中2个图距单位的unc-22 IV区域内必需基因的组织。为了实现该区域必需基因的突变饱和，对6491条经甲磺酸乙酯（EMS）诱变的染色体进行了筛选，以检测unc-22区域内致死突变的存在。对unc-22区域内21个致死突变的遗传分析鉴定出6个新的必需基因，使迄今为止已鉴定的必需基因总数达到36个。据估计，该区域至少有49个必需基因。分离出一组由甲醛诱导的unc-22及周围位点的缺失，以促进必需基因在遗传图谱和物理图谱上的定位。为了在分子水平上研究必需基因，我们的方法是将黏粒克隆形式的基因组DNA注射到携带致死突变的平衡杂合子的生殖系中，以挽救致死突变。通过这种方法鉴定出了包含let-56和let-653的黏粒克隆。
