Table 13.

Questions that motivate common experiments and corresponding fly stock reagents.

Question	Relevant in vivo reagents
What is the whole-animal loss-of-function phenotype?	Loss-of-function mutant allele (e.g. null allele) UAS-RNAi + ubiquitous-GAL4 UAS-CRISPR system + ubiquitous-GAL4
What is the stage- and/or tissue-specific loss-of-function phenotype?	UAS-RNAi + stage- and/or tissue-specific GAL4 (± GAL80ts) UAS-CRISPR system + stage- and/or tissue-specific GAL4 (± GAL80ts)
In what stages, tissues, or cell types is the gene expressed?	“Gold” type MiMIC insertion with T2AGAL4 + UAS-fluorescent reporter CRISPR knock-in T2AGAL4 allele + UAS-fluorescent reporter
In what stages, tissues, or cell types is the protein expressed?	CRISPR knock-in NanoTag allele + NanoTag Chromobody CRISPR knock-in NanoTag or other epitope tag allele + Antibody Protein-specific antibody
Is function cell autonomous or noncell autonomous?	Mutant allele on an FRT chromosome + heat shock-FLP