Koundakjian Edmund J, Cowan David M, Hardy Robert W, Becker Ann H
Howard Hughes Medical Institute and Departments of Biology and Neurosciences, University of California, San Diego, California 92093, USA.
Genetics. 2004 May;167(1):203-6. doi: 10.1534/genetics.167.1.203.
The majority of genes of multicellular organisms encode proteins with functions that are not required for viability but contribute to important physiological functions such as behavior and reproduction. It is estimated that 75% of the genes of Drosophila melanogaster are nonessential. Here we report on a strategy used to establish a large collection of stocks that is suitable for the recovery of mutations in such genes. From approximately 72,000 F(3) cultures segregating for autosomes heavily treated with ethyl methanesulfonate (EMS), approximately 12,000 lines in which the treated second or third chromosome survived in homozygous condition were selected. The dose of EMS induced an estimated rate of 1.2-1.5 x 10(-3) mutations/gene and predicts five to six nonessential gene mutations per chromosome and seven to nine alleles per locus in the samples of 6000 second chromosomes and 6000 third chromosomes. Due to mosaic mutations induced in the initial exposure to the mutagen, many of the lines are segregating or are now fixed for lethal mutations on the mutagenized chromosome. The features of this collection, known as the Zuker collection, make it a valuable resource for forward and reverse genetic screens for mutations affecting a wide array of biological functions.
多细胞生物的大多数基因编码的蛋白质，其功能并非生存所必需，但对诸如行为和繁殖等重要生理功能有贡献。据估计，黑腹果蝇75%的基因是非必需的。在此，我们报告一种用于建立大量品系库的策略，该品系库适用于恢复此类基因中的突变。从大约72,000个经甲磺酸乙酯（EMS）重度处理的常染色体分离的F(3)培养物中，挑选出约12,000个品系，其中经处理的第二条或第三条染色体以纯合状态存活。EMS剂量诱导的突变率估计为1.2 - 1.5×10(-3)个突变/基因，并预测在6000条第二条染色体和6000条第三条染色体的样本中，每条染色体有五到六个非必需基因突变，每个基因座有七到九个等位基因。由于在最初接触诱变剂时诱导产生了嵌合突变，许多品系在诱变染色体上正在分离或现已固定为致死突变。这个被称为祖克品系库的集合的特点，使其成为用于正向和反向遗传筛选影响广泛生物学功能突变的宝贵资源。
