Mutant generation in vertebrate model organisms by TILLING

Area of Science:

• Genetics
• Molecular Biology
• Genomics

Background:

• TILLING (Targeting Induced Local Lesions IN Genomes) is a widely used reverse genetics technique.
• Unlike direct knockout methods, TILLING employs an indirect strategy involving mutagenized libraries.
• It is applicable to various model organisms like zebrafish, Drosophila, and Arabidopsis.

Purpose of the Study:

• To describe the design and pipeline of a TILLING facility for zebrafish.
• To detail protocols for mutation detection using direct re-sequencing.
• To highlight the utility of TILLING for comprehensive gene functional analysis.

Main Methods:

• Generation of a TILLING library with numerous mutagenized individuals.
• Screening the library for mutations in target genes via PCR amplification of exons.
• Mutation detection using direct re-sequencing or CEL1 endonuclease assays.
• Isolation of individuals with deleterious mutations and establishment of mutant lines.

Main Results:

• TILLING identifies a spectrum of point mutations, including nonsense, splice site, and missense mutations.
• The method is unbiased in mutation generation and screening.
• It allows for the isolation of allelic series, from null to hypomorphic or dominant-negative alleles.

Conclusions:

• TILLING provides a powerful approach for identifying point mutations and analyzing gene function.
• The described pipeline facilitates efficient mutant line generation in zebrafish.
• The technique is versatile and applicable to any genetically tractable organism with available genomic data and amenability to mutagenesis.