Table 4. Variable regions outside of the RNA-binding domain regulate FBF function.

Transgene	Mutated variable region (VR) sequence	Rescues fbf-1(lf)?	Rescues fbf-2(lf)?	Dependent on CCR4-NOT
GFP::FBF-2wt	N/A	No	Yes	No*
GFP::FBF-1wt	N/A	Yes	No	Yes*
GFP::FBF-2(vrm)	mutated VR1, 2; VR4 deleted	Yes	No	Yes†
GFP::FBF-1(FBF-2vr4)	VR4 swapped with FBF-2	No	Yes	No†
GFP::FBF-1(FBF-2vr3)	VR3 swapped with FBF-2	Yes	No	Yes†

Rescue assays were performed by crossing transgenic GFP::FBFs into loss of function mutant of each fbf, followed by SPC zone length measurement (Figure 6, Figure 6—figure supplement 1, and Figure 7—figure supplement 1). Dependence on CCR4-NOT was defined as a decrease in the length of SPC zone after knocking down CCR4-NOT subunits.

^* – analyzed in single fbf loss-of-function mutants, Figure 3B.

^† – analyzed in the strains containing GFP::FBF transgenes in fbf-1 fbf-2 double-mutant background, Figures 6E and 7D.