Table 1.

Singleton whole-body mutants in controls for specific-locus experiments

Laboratory*	No. of mutants	No. of offspring	Mutation frequency/locus, × 10−6
Harwell (4)	9	157,421	8.2 (4.0, 15.2)†
Neuherberg (10)	14	248,413	8.1 (4.7, 13.2)
Oak Ridge (12)	0	38,448	—
Oak Ridge‡	46	1,040,754	6.3 (4.7, 8.3)
Total	69	1,485,036	6.6 (5.2, 8.3)

This table excludes mutants recovered in clusters (i.e., progeny of invisible mosaics, see text). 

^*Reference number is in parentheses. Stocks of males used at all laboratories have a common origin at Oak Ridge. 

^†95% confidence limits in parentheses. 

^‡Ref. 7, 28/531,500 reported; ref. 9, 2/99,817 reported; this paper, 16/409,437 reported.