Table 1.

Yeast strains used in this study

Strain	Genotype	Source
SEY6210	MATα leu2-3,112 ura3-52 his3-Δ200 trpl-Δ900 lys2-810 suc2-Δ9 Gal+	S. D. Emr
SEY6211	MATa leu2-3,112 ura3-52 his3-Δ200 trp1-Δ900 ade2-101 suc2-Δ9 Gal+	S. D. Emr
ABY02	MATa leu2-3,112 ura3-52 his3-Δ200 trp1-Δ900 ade2-101 lys2-810 suc2-Δ9 Gal+	This work
JE104	MATα mfα1Δ∷LEU2 mfα2Δ∷LYS2 ura3-52 his4 lys2 suc2-Δ9 Gal+	J. Thorner
DC14	MATa his1	J. Thorner
DC17	MATα his1	J. Thorner
CRY2	MATα his3-11,15 leu2-3,112 ura3-1 trp1-1 ade2-1 can1-100	Fuller lab
ABY06	MATα mfa1Δ∷LEU2 mfa2Δ∷LYS2 kex2Δ∷hisg ura3-52 his3-Δ200 trp1-Δ900 ade2-101 suc2-Δ9 Gal+	This work
ABY08	MATα mfα1Δ∷LEU2 mfα2Δ∷lys2 kex2Δ2∷hisg ura3-52 his3-Δ200 trp1-Δ900 ade2-101 suc2-Δ9 Gal+	This work

S. D. Emr, University of California, San Diego; J. Thorner, University of California, Berkeley.