Methods for reverse genetic screening in zebrafish by resequencing and TILLING

Area of Science:

• * Genetics and Genomics
• * Developmental Biology
• * Zebrafish as a Model Organism

Background:

• * Traditional knockout approaches for gene function studies are limited in zebrafish due to the absence of embryonic stem cells.
• * Reverse genetics, specifically TILLING (Targeting Induced Local Lesions INGenomes) and resequencing, offers an alternative for zebrafish research.
• * Efficiently identifying mutations is crucial for advancing zebrafish functional genomics.

Purpose of the Study:

• * To provide optimized protocols for resequencing and TILLING in zebrafish.
• * To establish cost-effective, high-throughput methods for screening ENU-induced mutations.
• * To facilitate the identification and study of novel gene mutations in zebrafish.

Main Methods:

• * Spermatogonia mutagenesis using N-ethyl-N-nitrosourea (ENU) in male zebrafish.
• * Generation of sperm and DNA banks from F1 progeny.
• * Screening for mutations using DNA resequencing and TILLING (Targeting Induced Local Lesions INGenomes) via capillary electrophoresis.
• * Analysis of sequencing data and capillary electrophoresis fragments using specialized software.

Main Results:

• * A pilot screen of 1235 F1 males successfully identified ENU-induced mutations.
• * Optimized protocols for resequencing and TILLING were developed and validated.
• * A combination of TILLING and sequencing proved optimal for cost-effective, high-throughput mutation detection.
• * Specific amplicon characteristics were identified as ideal for either TILLING or sequencing.

Conclusions:

• * Optimized resequencing and TILLING protocols enable efficient reverse genetics in zebrafish.
• * Combining TILLING and sequencing offers a powerful strategy for large-scale zebrafish mutagenesis screens.
• * These methods facilitate the study of gene function and the recovery of mutant zebrafish lines.