Neonatal exposure of 17β-estradiol has no effects on mutagenicity of 7,12-dimethylbenz [a] anthracene in reproductive tissues of adult mice

Table 1 Summary of independent cII mutations in mammary gland and ovary of Big Blue transgenic mice exposed to E2 at the first 5 days of life and/or treated with DMBA at 6 months of age

Tissue	Type of mutation	Control		E2^a		DMBA^b		E2 + DMBA^{c, d}
Tissue	Type of mutation	Number	%	Number	%	Number	%	Number	%
Mammary gland	G:C → C:G	3	9	4	10	4	6	4	4
	G:C → A:T	14	43	18	45	5	8	8	9
	G:C → T:A	7	21	6	15	13	20	14	16
	A:T → T:A	1	3	4	10	33	50	48	53
	A:T → C:G	3	9	3	8	3	4	4	4
	A:T → G:C	2	6	1	2	5	8	9	10
	Frameshift	3	9	4	10	3	4	3	3
	Tandem	0	0	0	0	0	0	1	1
	Total mutants screened	33	100	40	100	66	100	91	100
Ovary	G:C → C:G	2	5	2	8	11	11	13	11
	G:C → A:T	16	42	11	44	12	12	19	17
	G:C → T:A	9	24	6	24	22	23	20	17
	A:T → T:A	3	8	1	4	37	38	37	33
	A:T → C:G	1	3	1	4	5	5	6	5
	A:T → G:C	2	5	0	0	9	9	10	9
	Frameshift	5	13	4	16	2	2	7	6
	Tandem	0	0	0	0	0	0	2	2
	Total mutants screened	38	100	25	100	98	100	114	100

^aNo significant difference from control group
^bSpectrum from DMBA-treated mice was significantly different from control and E2-only groups (p < 0.0001)
^cSpectrum from the mice exposed to E2 and DMBA was significantly different from control and E2-only groups (p < 0.01 in ovary and p < 0.0001 in mammary gland)
^dNo significant difference from DMBA group

ISSN: 1880-7062