A

TRF1-LT-CreWildtype-LT-Cre

53B

P1

+ T

el

Martinez_5435_Supplementary Fig 1A-C

0

20

40

60

80

100

NT ATMi(KU55933)

caffeine

53B

P1

po

siti

ve c

ells

(%

)

n=2 MEF189 cells

n=2 MEF246 cells

n=2 MEF179 cells

n=2 MEF195 cells

n=2 MEF156 cells

n=2 MEF226 cells

TRF1-LT-CreWildtype-LT-Cre

p<0.0001

p<0.0001

p=0.1p=0.04

p=0.07

TRF1-LT-CreWildtype-LT-Cre

0

20

40

60

80

100

Cel

ls w

ith

> 4

TIF

s (

%)

n=2 MEF13 cells

n=2 MEF21 cells

n=2 MEF17 cells

ATMi(KU55933)

NT NT caffeine

n=2 MEF15 cells

p<0.0001

p<0.0001

B

C

Martinez_5435_Supplementary Fig 2A,B

Martinez_5435_Supplementary Fig 3A-D

C

D

TIN

2T

IN2

+ T

RF

1T

RF

1

Wildtype-LT-Cre TRF1-LT-Cre

TRF2 + TRF1 TRF2 + TRF1

POT1 + TRF1POT1 + TRF1

Wildtype-LT-Cre TRF1-LT-Cre

A B

Martinez_5435_Supplementary Fig 4A-C

Martinez_5435_Supplementary Fig 5A,B

Martinez_5435_Supplementary Fig 5C-F

C D

E

F

Martinez_5435_Supplementary Fig 6A,B

Martinez_5435_Supplementary Fig 7