CRISPR In Drosophila

Comparison of CRISPR genome engineering studies in Drosophila

from Bassett and Liu (2014) CRISPR/Cas9 and Genome Editing in Drosophila. J. Genetics and Genomics 41, 7-19 doi.10.1016/j.gg.2013.12.004

Reference Gratz et al., 2013 Bassett et al., 2013 Yu et al., 2013 Kondo and Ueda, 2013 Sebo et al., 2013 Ren et al., 2013
Cas9 promoter hsp70 T7 Sp6 nos vasa nos
Delivery DNA injection mRNA injection mRNA injection Transgenic Transgenic Transgenic
sgRNA promoter U6 T7 T7 U6 U6 U6a, U6b, nos-mini
Delivery DNA injection sgRNA injection sgRNA injection Transgenic DNA injection DNA injection
Gene targeted yellow yellow, white yellow, K81, CG3708, CG9652, kl-3, light, RpL15 white, neuropeptide genes (Ast, capa, Ccap, Crz, Eh, Mip, npf), mir-219, mir-315 EGFP, mRFP white
Mutant detection Body colour, surveyor assay, DNA sequencing Body colour, eye colour, DNA sequencing, HRMA Body colour, DNA sequencing Eye colour, T7 endonuclease, DNA sequencing Fluorescence in the eye Eye colour, HRMA, DNA sequencing
G0 adult fertility (%)a nd 37.5–73.1 21.6–94.4 N/A 32–55 29.4–92.9
Mosaic G0 (%)b 6–66 4–88 35.7–80 N/A 0g 0g
Germline mutants (among fertile flies) (%)c 5.9–20.7 0–79 35.7–100 0–100 35–71 0–100
Germline mutants (of injected flies) (%)d nd 0–58 nd N/A N/A 0–81.2
G1 mutant rate per fly (%)e nd 0–88.5 N/A N/A 0–100 0–100
G1 mutant overall (%)f 0.25–1.37 0–34.5 2.1–98.9 0–99.4 7.7–24.7 0–74.2
Off-target detection method nd HRMA nd nd nd HRMA, DNA sequencing
Off-target detected nd No nd nd nd No
Homologous recombination Oligonucleotide nd nd nd nd nd
Long deletions Yes No No Yes No Yes
a Number of fertile flies as a proportion of the surviving injected flies.
b Percentage of flies that exhibit mosaic expression in the injected generation, either visibly in males or detected using HRMA (high resolution melt analysis).
c Proportion of fertile flies giving rise to at least one mutant offspring.
d Proportion of injected flies giving rise to at least one mutant offspring.
e For individual flies, the range of the percentage of mutant offspring.
f Total number of mutant G1 offspring as a percentage of the total offspring.
g No mosaic expression would be expected, due to germline expression of Cas9; N/A, not applicable to this technique; nd, not determined in this study