Efficient genome-wide first-generation phenotypic screening system in mice using the piggyBac transposon

Area of Science:

• Genetics
• Developmental Biology
• Mammalian Genetics

Background:

• Genome-wide phenotypic screens are crucial for identifying genes related to biological traits.
• High costs and time requirements have historically limited mammalian genetic screens.
• A need exists for efficient, accessible tools for large-scale genetic analysis in mammals.

Purpose of the Study:

• To develop and validate a novel, efficient piggyBac transposon-based screening system for first-generation (F1) dominant screens in mice.
• To enable individual investigators to conduct genome-wide phenotypic screens affordably and within a practical timeframe.
• To identify novel mutations affecting mammalian traits using this new screening platform.

Main Methods:

• Development of a piggyBac (PB) transposon system for inducing gain- and loss-of-function mutations in mice.
• Utilizing visually trackable transposons for efficient genetic manipulation and insertion tracking.
• Conducting a pilot genome-wide F1 screen with fewer than 300 cages to assess system efficiency and identify mutations.

Main Results:

• The PB F1 screening system achieved genome-wide distributed insertions in over 55% of F1 progeny.
• A pilot screen successfully identified five mutations associated with growth retardation.
• One identified mutant (Six1/4) exhibited impaired milk intake behavior and cranial nerve developmental defects.

Conclusions:

• The PB F1 screening system provides an efficient and cost-effective method for genome-wide phenotypic screens in mice.
• This system significantly enhances the capacity for individual laboratories to investigate mammalian genetics and disease.
• The identified Six1/4 mutation highlights the system's potential for uncovering genes involved in complex behaviors and developmental processes.