Describes an experimental cross in mice that can be used to define and map induced germ-line mutations that map to a single chromosome. The cross is a modification and extension of a conventional three-generation recessive mutagenesis screen. Includes: The Mutagenesis Breeding Plan; Consomic Strains; Generating Mutations; Generating and Genotyping G2 Females; Genotyping G3 Progeny; Phenotyping G4 Progeny; etc.. - [Read A Targeted Screen to Detect Recessive Mutations that have Quantitative Effects Protocol]
The goal of this method is to identify transcriptionally active genes in cloned segments of genomic DNA. The protocol uses hybridization and affinity purification to recover biotin-labeled cDNAs that bind to a 500-kb segment of human DNA cloned in a BAC vector. However, the method can be easily adapted to other clones of genomic DNAs cloned in high-capacity vectors. - [Read Direct Selection of cDNAs with Large Genomic DNA Clones Protocol]
In this method, the nuclease BAL 31 is used to make uni- or bidirectional deletions in a segment of cloned DNA. BAL 31 is a complex enzyme and tends to digest a population of double-stranded DNA targets in an asynchronous fashion, Deletions created by BAL 31 are therefore far more heterogeneous in size than those created by processive enzymes such as exonuclease III. - [Read Generation of Bidirectional Sets of Deletion Mutants by Digestion with BAL 31 Nuclease Protocol]
The double-stranded DNA of recombinant plasmid, phagemid, or bacteriophage M13 replicative form DNA is digested with two restriction enzymes whose sites of cleavage both lie between one end of the target DNA and the binding site for universal primer. The enzyme that cleaves nearer the target sequence must generate either a blunt end or a recessed 3' terminus; the other enzyme must generate a four-nucleotide protruding 3' terminus. - [Read Generation of Sets of Nested Deletion Mutants with Exonuclease III Protocol]