TABLE 2.

Estimation of petite mutation rates per cell division

	Strain
	UCC8240	UCC8241	UCC8360	UCC8358	UCC8357
Genotype
MKT1	BY	RM	RM	RM	RM
SAL1	BY	BY	RM	BY	BY
CAT5	BY	BY	BY	RM	BY
MIP1	BY	BY	BY	BY	RM
Cell divisions
Two grandes	56	38	54	55	55
Petite and grande	3	11	4	4	4
Petite mutation rate (%)	5	22	7	7	7
P-value		<0.01a	0.03b	0.03b	0.03b

^aThe test compares UCC8241 to UCC8240.

^bThe test compares UCC8360, 8358 or 8357 to UCC8241.

Cells were pregrown in liquid YEPG medium for at least 24 hr to select for a pure population of grande cells. An aliquot of the saturated YEPG culture (1:1000 dilution) was inoculated into YEPD medium. After 10 hr of growth in YEPD, individual unbudded or small-budded cells were picked as mothers and placed at predefined positions on a solid YEPD plate. Newly formed daughter cells were separated from their mother cells by micromanipulation, and the mother and daughter cells were allowed to form independent colonies. The petite and grande status of each cell was inferred from the phenotype of the resulting colony. For MKT1, BY indicates the MKT1-30D allele, and RM indicates the MKT1-30G allele. For SAL1, BY indicates the sal1-1 allele, and RM indicates the wild-type allele. For CAT5, BY indicates the CAT5-91I allele, and RM indicates the CAT5-91M allele. For MIP1, BY indicates the MIP1-661A allele, and RM indicates the MIP1-661T allele.