Gene-Specific Mutagenesis

Publisher Summary Mouse mutagenesis refers to any genetic abnormality in the mouse genome. Genetic mutations can either occur spontaneously or be induced. Spontaneous events cause unpredictable and variable mutations at a very low frequency of occurrence at any one locus. On the other hand, induced mutations can be accomplished either by random changes in DNA or by directed mechanisms that have a significantly higher frequency of occurrence at any one locus. Because available methods enable their relative expediency and efficiency, induced mutations more rapidly lead to models of human and animal disease and development in a shorter period of time than spontaneous mutations. Induced mutations can further be categorized into those resulting from either indirect or direct manipulation of the genome. This chapter focuses on strategies for directly induced gene-specific mutagenesis that refers to the induction of specific genetic alterations in a gene by either inserting a mutagenized allele into an endogenous gene or replacing an endogenous gene with a mutagenized allele. In these approaches, the nature of the mutation is already known as a result of using a genotypic screening method for which one must apply only a reverse genetics approach to define the mutant phenotype. The chapter describes DNA transgenesis, gene targeting, gene trapping as well as the modifying techniques of conditional (spatial) and inducible (temporal) mutagenesis. For completeness, the application of RNA-interference mutagenesis is presented in the chapter. The principles and applications of each of the strategies are also discussed, although exhaustive technical details are not provided.