Table S1. Analysis of genomic stability in DNA-PKcs-deficient (D -/-/HC/LC), Artemis-deficient (A -/-/HC/LC), and control (HC/LC) B cells activated for CSR with α-CD40/IL-4 General genomic instability (T-FISH) IgH locus-specific genomic instability (IgH FISH)


Genotype

No DNAPKcs +/+ /p53 +/- 30 3 (10%) 3 (10%) 50 0 (0%) 0 (0%) 0/0 DNAPKcs +/+ /p53 -/- 30 1 (3.3%) 1 (3.3%) 50 0 (0%) 0 (0%) 0/0 DNAPKcs -/-/p53 +/+ 30 2 (6.7%) 2 (6.7%) 50 1 (2%) 1 (2%) 0/1 DNAPKcs -/-/p53 The percentage of chromosomal aberrations was calculated as (total number of aberrations/total number of metaphases) × 100. 

Table S2 .

 S2 Metaphases were hybridized with either a telomere probe (T-FISH, for quantification of general chromosome breaks) or with BAC probes flanking the IgH locus (3Ј Igh and 5Ј Igh probes; two-color IgH FISH; for detection of chromosomal breaks specifically at Igh).The percentage of chromosomal aberrations was calculated as (total number of aberrations/total number of metaphases) × 100. CB, chromosome break; cb, chromatid break; dic, dicentric. c Average and standard deviation of individual percentages. Analysis of genomic stability in DNA-PKcs 


						-/-/p53 -/-and control B cells after stimulation with LPS for 4 d
				General genomic instability (T-FISH)	IgH locus-specific genomic instability (IgH FISH)
	Genotype Stimulation 1 HC/LC HC/LC HC/LC DNAPKcs +/+ /p53 +/-DNAPKcs +/+ /p53 -/-DNAPKcs -/-/p53 +/+ DNAPKcs -/-/p53 -/-	. metaphases analyzed metaphases metaphases No. with chromosomal aberrations (%) No. analyzed metaphases No. chromosomal aberrations a (%) No. with aberrations No. aberrations Type of chromosomal aberrations b a metaphases No. metaphases analyzed No. No. metaphases % metaphases with 3'5'Igh end dissociation with IgH locus (%) analyzed breaks (%) (%) 30 1 (3.3%) 1 (3.3%) 1 dic 100 3 30 1 (3.3%) 1 (3.3%) 1 cb 100 1 30 3 (10%) 3 (10%) 3 CB 100 1 30 0 (0%) 0 (0%) 50 0 (0%) 30 0 (0%) 0 (0%) 50 1 (2%) 30 3 (10%) 3(10%) 50 0 (0%) 30 9 (30%) 10 (33.3%) 50 9 (18%)	% Igh 3'5 No. IgH locus breaks (%) end-dissociated IgH 3 1 1 0 (0%) 1 (2%) 0 (0%) 9 (18%)	No. IgH locus breaks translocated/total no. IgH locus breaks No. translocated IgH locus breaks/total no. IgH locus breaks 0/3 1/1 0/1 0/0 1/1 0/0 1/9
	HC/LC	30		1 (3%)	1 (3%)	1 CB	100	0	0	-
	HC/LC Stimulation 2	30		3 (10%)	3 (10%)	2 CB, 1 cb	100	0	0	-
	All HC/LC stimulations (n = 5) c DNAPKcs +/+ /p53 -/-DNAPKcs -/-/p53 -/-	30 30	6.0 ± 3.7 11 (36.7%) 6.0 ± 3.7 2 (6.7%)	3 (10%) 12 (40%)	50 50	1.0 ± 1.2 1 (2%) 7 (14%)	1.0 ± 1.2 1 (2%) 7 (14%)	1/1 2/7
	A -/-/HC/LC A /HC/LC A /HC/LC -/-A -/-/HC/LC -/-Stimulation 3	30 30 30 30		7 (23.3%) 7 (23.3%) 7 (23.2%) 7 (23%)	10 (33.3%) 7 (23.3%) 8 (26.6%) 10 (33%)	9 CB, 1 dic 7 CB 6 CB,1 dic, 1RT 7 CB, 3 dic	100 100 100 100	10 7 12 6	10 7 12 6	3/10 6/12 1/6 3/7
	All A	-/-/HC/LC stimulations (n = 4)		23.3 ± 0.0	26.7 ± 4.7			8.7 ± 2.7	8.7 ± 2.7
	D -/-/HC/LC D -/-/HC/LC D -/-/HC/LC D -/-/HC/LC	30 30 30 30		11 (36.6%) 12 (40%) 12 (40%) 6 (20%)	11 (36.6%) 16 (53.3%) 16 (53.3%) 8 (26%)	10 CB, 1 dic 14 CB, 2 cb 15 CB, 1 dic 7 CB, 1 cb	100 100 100 100	24 17 22 15	30 17 24 16	2/30 7/17 2/24 4/16
	All D -/-/HC/LC stimulations (n = 4)		34.2 ± 9.6	42.5 ± 13.2			19.5 ± 4.2	21.7 ± 6.5

a b 


  Metaphases were hybridized with either a telomere probe (T-FISH, for quantification of general chromosome breaks) or with BAC probes flanking the IgH locus (3Ј Igh and 5Ј Igh probes; two-color IgH FISH; for detection of chromosomal breaks specifically at Igh). 


	-/-	30	11 (36.7%)	13 (43.3%)	50	5 (10%)	6 (12%)	1/6
	Stimulation 4							
	DNAPKcs +/+ /p53 +/-DNAPKcs +/+ /p53 -/-DNAPKcs -/-/p53 +/+ DNAPKcs -/-/p53 -/-	30 30 30 30	2 (6.7%) 3 (10%) 3 (10%) 14 (46.7%)	2 (6.7%) 3 (10%) 3 (10%) 17 (56.7%)	50 50 50 50	0 (0%) 0 (0%) 1 (2%) 7 (14%)	0 (0%) 0 (0%) 1 (2%) 7 (14%)	0/0 0/0 /1 /7
	Stimulation 5							
	DNAPKcs +/+ /p53 +/-DNAPKcs +/+ /p53 -/-DNAPKcs -/-/p53 +/+ DNAPKcs -/-/p53 -/-	30 30 30 30	0 (0%) 2 (6.7%) 4 (13.3%) 17 (56.7%)	0 (0%) 2 (6.7%) 4 (13.3%) 20 (66.7%)	50 50 50 50	1 (2%) 1 (2%) 2 (4%) 5 (10%)	1 (2%) 1 (2%) 2 (4%) 5 (10%)	/1 /1 /2 /5

a 
a The percentage of chromosomal aberrations was calculated as (total number of aberrations/total number of metaphases) × 100. b CB, chromosome break; cb, chromatid break; dic, dicentric; fg, fragment.
Table S1. Analysis of genomic stability in DNA-PKcs-deficient (D -/-/HC/LC), Artemis-deficient (A -/-/HC/LC), and control (HC/LC) B cells activated for CSR with α-CD40/IL-4 General genomic instability (T-FISH) IgH locus-specific genomic instability (IgH FISH)