Analysis of spontaneous, gamma ray- and ethylnitrosourea-induced hprt mutants in HL-60 cells with multiplex PCR

Table 4 Schematic diagram of the distribution of deletion within nine exons of the human HPRT gene

	Types of exons deletion								Mutation clones
	1	2	3	4	5	6	7/8	9	Number	Percent (%)
Spontaneous mutants									12	92.3
					—a				1	7.7
ENU-induced mutants									12	20.3
	—								3	5.1
			—						2	3.4
				—	—				4	6.8
					—				2	3.4
			—					—	1	1.7
	—	—	—						2	3.4
		—	—	—					2	3.4
				—	—	—	—		2	3.4
						—	—	—	1	1.7
		—	—				—	—	1	1.7
				—	—	—	—	—	3	5.1
		—	—	—	—	—	—	—	1	1.7
	—	—	—	—	—	—	—	—	16	27.1
		—	—	—	—			—	1	1.7
	—				—	—	—		1	1.7
		—			—				2	3.4
		—		—		—	—		2	3.4
					—	—			1	1.7
r-rays-induced mutants									18	38.3
			—						1	2.1
	—	—							1	2.1
			—	—					2	4.3
	—	—	—						2	4.3
						—	—	—	1	2.1
	—	—	—	—					1	2.1
					—	—	—	—	3	6.4
	—	—	—				—	—	1	2.1
				—	—	—	—	—	1	2.1
		—	—	—	—	—	—	—	2	4.3
	—	—	—	—	—	—	—	—	14	29.8

^adeletion of a exon.