Ends-out, or replacement, gene targeting in Drosophila

Area of Science:

• Genetics
• Molecular Biology
• Drosophila Research

Background:

• Gene targeting enables precise genetic modifications.
• Ends-in and ends-out are two donor DNA configurations for gene targeting.
• Ends-out targeting is common in mice and yeast but has faced challenges in Drosophila.

Purpose of the Study:

• To investigate the efficacy of ends-out gene targeting in Drosophila.
• To establish reliable methods for ends-out gene replacement and disruption in Drosophila.

Main Methods:

• Applied two ends-out strategies for gene replacement at the endogenous yellow (y) locus.
• Utilized I-SceI endonuclease and FLP recombinase to generate extrachromosomal donors.
• Assessed targeting rates for rescuing a mutant allele and disrupting a wild-type gene.

Main Results:

• Successfully rescued a mutant allele via replacement with an 8-kb y(+) DNA fragment at approximately 1/800 gametes.
• Disrupted a wild-type gene by inserting a marker into exon 1 at approximately 1/380 gametes.
• Demonstrated that ends-out targeting efficiency is comparable to ends-in targeting when both I-SceI and FLP recombinase are used.

Conclusions:

• Ends-out gene targeting is a viable and efficient strategy in Drosophila.
• This method provides a versatile tool for targeted mutagenesis in Drosophila.
• The findings suggest broad applicability for ends-out gene targeting in Drosophila research.