Table 1.

Litter size and pup number of Per1^m/m; Per2^m/m doubly mutant and control mice.

Age (weeks)	Number of accumulated litters		n (Per1m/m;Per2m/m)	n (Control)	P value
	Per1m/m;Per2m/m	Control
Number of accumulated litters
8	0	0	12	11
12	0.50 ± 0.52	0.64 ± 0.50	12	11	0.53182939
16	1.25 ± 0.75	1.36 ± 0.67	12	11	0.70798791
20	2.00 ± 0.74	2.36 ± 0.67	12	11	0.23254607
24	2.75 ± 0.62	3.09 ± 0.70	12	11	0.22987128
28	3.42 ± 0.90	3.73 ± 0.79	12	11	0.39011313
32	3.92 ± 1.08	4.64 ± 0.67	12	11	0.07253613
36	4.17 ± 1.19	5.36 ± 0.92	12	11	0.01431332
40	4.58 ± 1.00	6.27 ± 1.19	12	11	0.00132172
44	4.92 ± 1.16	7.18 ± 1.25	12	11	0.00019715
48	5.08 ± 1.31	7.82 ± 1.25	12	11	4.6502E-05
52	5.25 ± 1.29	8.45 ± 1.29	12	11	6.6428E-06
Number of accumulated pups
8	0	0	12	11
12	3.58 ± 3.78	3.82 ± 3.79	12	11	0.88319599
16	8.58 ± 5.55	10.82 ± 5.13	12	11	0.32893069
20	14.08 ± 6.42	19.00 ± 6.45	12	11	0.0813109
24	19.75 ± 4.99	24.09 ± 7.12	12	11	0.10293094
28	24.08 ± 6.56	28.91 ± 7.42	12	11	0.11264827
32	27.17 ± 7.71	36.18 ± 8.75	12	11	0.01575296
36	28.42 ± 9.22	41.73 ± 10.04	12	11	0.00329245
40	30.83 ± 8.62	47.55 ± 11.80	12	11	0.00082026
44	33.00 ± 8.44	51.64 ± 11.58	12	11	0.00022759
48	33.42 ± 8.50	54.45 ± 12.13	12	11	8.5033E-05
52	33.92 ± 7.86	57.55 ± 12.23	12	11	1.604E-05