Large-scale identification of chemically induced mutations in Drosophila melanogaster

  1. Hugo J. Bellen1,2,4,5,6,8,9
  1. 1Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030, USA;
  2. 2Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA;
  3. 3Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA;
  4. 4Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas 77030, USA;
  5. 5Program in Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, Houston, Texas 77030, USA;
  6. 6Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030, USA;
  7. 7Verna and Mars Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA;
  8. 8Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas 77030, USA;
  9. 9Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA
  1. Corresponding authors: hbellen{at}bcm.edu, ruichen{at}bcm.edu

Abstract

Forward genetic screens using chemical mutagens have been successful in defining the function of thousands of genes in eukaryotic model organisms. The main drawback of this strategy is the time-consuming identification of the molecular lesions causative of the phenotypes of interest. With whole-genome sequencing (WGS), it is now possible to sequence hundreds of strains, but determining which mutations are causative among thousands of polymorphisms remains challenging. We have sequenced 394 mutant strains, generated in a chemical mutagenesis screen, for essential genes on the Drosophila X chromosome and describe strategies to reduce the number of candidate mutations from an average of ∼3500 to 35 single-nucleotide variants per chromosome. By combining WGS with a rough mapping method based on large duplications, we were able to map 274 (∼70%) mutations. We show that these mutations are causative, using small 80-kb duplications that rescue lethality. Hence, our findings demonstrate that combining rough mapping with WGS dramatically expands the toolkit necessary for assigning function to genes.

Footnotes

  • Received February 28, 2014.
  • Accepted July 8, 2014.

This article is distributed exclusively by Cold Spring Harbor Laboratory Press for the first six months after the full-issue publication date (see http://genome.cshlp.org/site/misc/terms.xhtml). After six months, it is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/.

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