Large scale mutagenesis screens are being used to create dominant mutations in mice that can provide new insights into gene function and enable identification of novel genes involved in particular developmental processes. The purpose of this study was to describe the craniofacial skeletal phenotypes of several mutated mouse lines generated from ethyl nitrosourea (ENU) and a combined X-ray/chemical mutagenesis in order to determine the usefulness of this approach to studying craniofacial development.
Materials and Methods:
Adult mouse heads from five mutant lines were fixed and stained to reveal cartilage and bone. The skeletons were analysed in detail and compared to littermate controls.
The craniofacial skeletal phenotypes of two mutant mice induced by combined chemical and X-ray treatment and three mutants from ENU treatment have been analysed. All mutations were dominant: heterozygous mice were born smaller and homozygotes were embryonic lethal. A range of phenotypes were observed, including frontonasal defects, midline asymmetries, robust ossifications and unusual suture formations.
The use of mutagenesis screens to produce craniofacial phenotypes from dominant gene mutations can reveal novel and unusual phenotypes not previously observed from gene knock-outs.
mutagenesis, ENU, craniofacial