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]
EMS is used at concentrations that induce multiple point mutations in each plant, such that mutant alleles of a specific locus are found at a rate of ~1 in 2000-5000 M2 plants. This high rate of mutagenesis makes possible the screening of relatively few plants to find those with the phenotype of interest, a particular advantage if the screen is laborious or if only a small number of genes mutate to the required phenotype. - [Read EMS Mutagenesis of Arabidopsis Seed Protocol]
CHO Lec3.2.8.1 cells have 4 independent mutations in the N and O glycosylation pathways. When cultured with alpha-glucosidase I inhibitor N-butyl-deoxynojirimycin, glycoproteins produced in CHO Lec3.2.8.1 cells are completely susceptible to Endo H digestion. Endo H cleaves chitobiose, leaving a single N-linked N-acetylglucosamine per site which is ideal for maintenance of protein solubility and special carb-protein interactions, such as between the first N-acetyl glucosamine residue and tryp. - [Read Establishment of Stable Transfectant of CHO Lec Cells Protocol]
Forward genetics is used to identify genes that are involved in particular biological processes. For example, genes required for disease resistance can be found by identifying mutants with reduced or increased disease resistance, genes that control flower development can be identified by searching for mutants with altered flower morphology, and genes encoding enzymes for tryptophan biosynthesis can be identified by searching for mutants that require exogenous tryptophan for growth. - [Read Forward Genetics in Arabidopsis: Finding Mutations that Cause Particular Phenotypes Protocol]
A guide to genetic mapping in C. elegans. Includes: Introduction and basics; Two-point mapping; Three-point mapping; Deficiency and duplication mapping; Basics of SNP mapping; Mapping dominant mutations; Mapping suppressor/enhance mutations; Mapping of synthetic mutations. - [Read Guide to Genetic Mapping in C. elegans]
High-resolution SNP mapping by denaturing HPLC. A SNP mapping procedure that relies on resolving polymorphisms by denaturing HPLC without the necessity of determining the nature of the SNPs. They demonstrate the use of denaturing high-performance liquid chromatography to identify mutations in the candidate genes and to fine-map chromosomal breakpoints. - [Read High-resolution SNP mapping by denaturing HPLC]
Isolation of postimplantation-stage embryos allows one to study normal development as well as genetic mutations which cause postimplantation defects. This protocol describes a method for isolation of early neural-fold-stage embryos. - [Read Isolating Postimplantation Embryos: Early Neural-Fold-Stage Protocol]
Isolation of postimplantation-stage embryos allows one to study normal development as well as genetic mutations which cause post-implantation defects. This protocol describes a method for isolating early primitive-streak-stage embryos. - [Read Isolating Postimplantation Embryos: Early Primitive-Streak-Stage Protocol]
Isolation of postimplantation-stage embryos allows one to study normal development as well as genetic mutations which cause postimplantation defects. This protocol describes a method for isolating early somite-stage embryos (~8.5 days post coitum [dpc]). - [Read Isolating Postimplantation Embryos: Early Somite-Stage Protocol]
Isolation of postimplantation-stage embryos allows one to study normal development as well as genetic mutations which cause postimplantation defects. This protocol describes a method for isolating late primitive-streak-stage embryos (~7.5 days post coitum [dpc]). - [Read Isolating Postimplantation Embryos: Late Primitive-Streak-Stage Protocol]
Isolation of postimplantation-stage embryos allows one to study normal development as well as genetic mutations that cause post-implantation defects. This protocol describes a method for isolating prestreak-stage embryos (~5.5 days post coitum [dpc]). - [Read Isolating Postimplantation Embryos: Prestreak-Stage Protocol]
Single-stranded templates of bacteriophage M13 DNA containing 20-30 residues of uracil in place of thymine are generated during growth of the bacteriophage in an F' strain of E. coli carrying mutations in the ung and dut genes. This DNA is used as a template in the Kunkel method of oligonucleotide-directed mutagenesis (Oligonucleotide-directed Mutagenesis of Single-stranded DNA). - [Read Preparation of Uracil-containing Single-stranded Bacteriophage M13 DNA Protocol]
Plaques formed by M13 bacteriophages or bacterial colonies transformed by plasmids carrying specific mutations can be detected by hybridization, using a radiolabeled oligonucleotide that forms a perfect duplex with the mutant sequence. Hybridization is carried out under conditions of low stringency that allow the radiolabeled oligonucleotide to anneal to both mutant and wild-type DNAs. - [Read Screening Recombinant Clones for Site-directed Mutagenesis by Hybridization to Radiolabeled Oligos]
Phage are streaked onto a medium to obtain an independent isolate prior to preparing a new lysate. This is done to reduce the likelihood of working with lysates which have become contaminated, and/or have accumulated mutations. - [Read Streaking Lambda Phages Protocol]
Protocol describes the general procedure for creating mutations in the DNA of Drosophila by exposure to X-rays. Irradiation of cells with X-rays creates double strand breaks (DSBs) in DNA. Mutations introduced in the DNA of germ line cells (sperm) are propagated by mating the exposed males to virgin females. The progeny of this cross can be mated to each other so that a percentage of the subsequent offspring will have two copies of the same mutant allele. - [Read X-Ray Mutagenesis of Drosophila Protocol]
This protocol describes the electroporation of the BMH 81-17 mut S strain that is recommended for tranformation of the site directed mutagenesis of dsDNA (See Protocol on Site-Directed Mutagenesis on Double Stranded DNA). BMH 81-17 mut S are a mismatch repair defective (mut S) Escherichia coli strain. The probability that the two mutations will cosegregate during the first round of DNA replication is increased in this strain.
The protocol gives general considerations for the design of targeting vectors for transgenic mice. The protocol shares tips in the design of knock-out and knock-in vectors and some of their strategies for producing homologously recombined embryonic stem cells.