Hentges Kathryn E, Nakamura Hisashi, Furuta Yasuhide, Yu Yuejin, Thompson Debrah M, O'Brien William, Bradley Allan, Justice Monica J
Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
Gene Expr Patterns. 2006 Aug;6(6):653-65. doi: 10.1016/j.modgep.2005.11.015. Epub 2006 Feb 8.
Mutagenesis screens are a valuable method to identify genes that are required for normal development. Previous mouse mutagenesis screens for lethal mutations were targeted at specific time points or for developmental processes. Here we present the results of lethal mutant isolation from two mutagenesis screens that use balancer chromosomes. One screen was localized to mouse chromosome 4, between the STS markers D4Mit281 and D4Mit51. The second screen covered the region between Trp53 and Wnt3 on mouse chromosome 11. These screens identified all lethal mutations in the balancer regions, without bias towards any phenotype or stage of death. We have isolated 19 lethal lines on mouse chromosome 4, and 59 lethal lines on chromosome 11, many of which are distinct from previous mutants that map to these regions of the genome. We have characterized the mutant lines to determine the time of death, and performed a pair-wise complementation cross to determine if the mutations are allelic. Our data suggest that the majority of mouse lethal mutations die during mid-gestation, after uterine implantation, with a variety of defects in gastrulation, heart, neural tube, vascular, or placental development. This initial group of mutants provides a functional annotation of mouse chromosomes 4 and 11, and indicates that many novel developmental phenotypes can be quickly isolated in defined genomic intervals through balancer chromosome mutagenesis screens.
诱变筛选是鉴定正常发育所需基因的一种有价值的方法。先前针对致死突变的小鼠诱变筛选针对特定时间点或发育过程。在此，我们展示了从两个使用平衡染色体的诱变筛选中分离致死突变体的结果。一个筛选定位于小鼠4号染色体，在STS标记D4Mit281和D4Mit51之间。第二个筛选覆盖了小鼠11号染色体上Trp53和Wnt3之间的区域。这些筛选鉴定了平衡区域内的所有致死突变，而不偏向任何表型或死亡阶段。我们在小鼠4号染色体上分离出19个致死品系，在11号染色体上分离出59个致死品系，其中许多与先前定位到基因组这些区域的突变体不同。我们对突变品系进行了表征以确定死亡时间，并进行了两两互补杂交以确定突变是否等位。我们的数据表明，大多数小鼠致死突变在子宫着床后的妊娠中期死亡，在原肠胚形成、心脏、神经管、血管或胎盘发育方面存在各种缺陷。这组初始突变体为小鼠4号和11号染色体提供了功能注释，并表明通过平衡染色体诱变筛选可以在定义的基因组区间快速分离出许多新的发育表型。
