Genetic annotation of gain-of-function screens using RNA interference and in situ hybridization of candidate genes in the Drosophila wing.
Gain-of-function screens in Drosophila are an effective method with which to identify genes that affect the development of particular structures or cell types. It has been found that a fraction of 2-10% of the genes tested, depending on the particularities of the screen, results in a discernible phenotype when overexpressed. However, it is not clear to what extent a gain-of-function phenotype generated by overexpression is informative about the normal function of the gene. Thus, very few reports attempt to correlate the loss- and overexpression phenotype for collections of genes identified in gain-of-function screens. In this work we use RNA interference and in situ hybridization to annotate a collection of 123 P-GS insertions that in combination with different Gal4 drivers affect the size and/or patterning of the wing. We identify the gene causing the overexpression phenotype by expressing, in a background of overexpression, RNA interference for the genes affected by each P-GS insertion. Then, we compare the loss and gain-of-function phenotypes obtained for each gene and relate them to its expression pattern in the wing disc. We find that 52% of genes identified by their overexpression phenotype are required during normal development. However, only in 9% of the cases analyzed was there some complementarity between the gain- and loss-of-function phenotype, suggesting that, in general, the overexpression phenotypes would not be indicative of the normal requirements of the gene.
Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid and CSIC, Madrid 28049, Spain.
Cristina
C
Molnar
Mar
M
Casado
Ana
A
López-Varea
Cristina
C
Cruz
Jose F
JF
de Celis
D000818:Animals; D004251:DNA Transposable Elements / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D056726:Genetic Association Studies; D017403:In Situ Hybridization; D016254:Mutagenesis, Insertional / Q000235:genetics; D009154:Mutation; D010641:Phenotype; D034622:RNA Interference; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics*; D014921:Wings, Animal / Q000166:cytology / Q000378:metabolism
D004251:DNA Transposable Elements; D029721:Drosophila Proteins; C557617:GAL4 protein, Drosophila; D051880:Receptors, Notch; D014157:Transcription Factors