Table 3.

Properties of wild-type cells and cln mutants

		Mass at birth	Mass at SBF 50%	Mass at DNA repl.	Mass at bud ini.	Mass at division	TG1 (min)	Changed parameter	Comments (Experimental results in boldface type)
1	wild type	0.71	1.07	1.15	1.15	1.64	84		CT 146 min
	(daughter)		(71′)	(84′)	(84′)	(146′)			(time of occurrence of event)
	1st parent	0.93	1.07	1.17	1.16	1.67	39		CT 101 min
	2nd parent	0.95	1.08	1.18	1.17	1.68	37		CT 99 min
	3rd parent	0.96	1.08	1.18	1.17	1.69	36		CT 98 min
2	cln3	1.24	2.04	2.20	2.15	2.88	99	Dn3  = 0	Dirick, 1995, Fig. 3, size 1.7 × WT
3	cln3 sic1	1.09	1.85	1.28	1.90	2.54	28	Dn3  = 0	G1 short, size 1.5 × WT, smaller than cln3
								k′s,c1  = 0
								k″s,c1  = 0
4	CLN3D	0.44	0.45	0.49	0.52	1.02	17	Dn3  = 8	Yaglom, 1995, protein 8×, size 75% WT
									Cross, 1988, Fig. 3, Nash, 1988, Fig. 1, size 60% WT
	cln3 GAL-CLN3	0.43	0.43	0.46	0.50	0.99	14	Dn3  = 20	Tyers, 1992, Table 1, protein 20 × WT, size 44% WT
5	cln3 GAL-CLN3 sic1	0.42	0.42	0.45	0.49	0.98	12	Dn3  = 20	SBF activated early, G1 short, cells small
								k′s,c1  = 0
								k″s,c1  = 0
6	cln1 cln2	1.46	1.47	2.47	2.58	3.39	91	k″s,n2  = 0	Dirick, 1995, Fig. 3, size 3.2 × WT
7	cln1 cln2 sic1	0.81	1.12	0.97	1.29	1.89	31	k″s,n2  = 0	Dirick, 1995, Fig. 4, size between cln1 cln2 and WT
								k′s,c1  = 0
								k″s,c1  = 0
8	cln1 cln2	0.71	1.23	[11.66]	No bud	[14.44]		k″s,n2  = 0	Schwob, 1993, Fig. 5, G1 arrest
	clb5 clb6							k′s,b5  = 0	We consider cells arrested in G1 if mass at DNA replication exceeds 5
								k″s,b5  = 0
9	cln1 cln2	0.34	0.34	0.38	0.35	0.78	23	k′s,n2  = 0.1	Dirick, 1995, Fig. 6, size small, budding is
	GAL-CLN2		(1′)	(23′)	(6′)	(146′)		k″s,n2 = 0	advanced more than DNA replication when compared with WT
10	cln1 cln2	0.33	0.33	0.36	0.34	0.76	19	k′s,n2  = 0.1	SBF activated early, G1 short, cells small.
	GAL-CLN2 sic1							k″s,n2  = 0
								k′s,c1  = 0
								k″s,c1  = 0
11	cln1 cln2	0.39	0.39	0.48	0.40	0.90	38	k′s,n2  = 0.1	Birth size between GAL-CLN2 and GAL-SIC1
	MET-CLN2							k″s,n2  = 0	(0.80)
	GAL-SIC1							k′s,c1  = 0.1
								k″s,c1  = 0
12	cln1 cln2	0.20	No SBF	0.33	0.22	0.47	85	k′s,n2  = 0.1	Steady-state mass at birth = 0.20 (28% WT);
	MET-CLN2							k″s,n2  = 0	cells may not be viable at this size. See Fig. 7
	clb1 clb2							k′s,b2  = 0.1
	GAL-CLB2							k″s,b2  = 0

Note: to simulate mutants that synthesize cyclins constitutively, e.g., cln1 cln2 GAL-CLN2, we set the rate constant for regulated synthesis to zero (k″_s = 0) and the rate constant for unregulated synthesis to a uniform value (k′_s = 0.1) to represent a constant rate of expression from the GAL promoter. This is a neutral assumption, in the absence of any quantitative data about levels of mRNA expression driven by the GAL promoter.