Elongated telomeres in scid mice.
Severe combined immunodeficiency (scid) mice are deficient in the enzyme DNA-PK (DNA-dependent protein kinase) as a result of the mutation in the gene encoding the catalytic subunit (DNA-PKcs) of this enzyme. DNA-PKcs is a member of the phosphatidylinositol 3-kinase superfamily, which includes the human protein ATM (ataxia telangiectasia mutated) and the yeast protein Tel1. Using Q-FISH (quantitative fluorescence in situ hybridization), we show here that scid mice from four different genetic backgrounds have, on average, 1.5-2 times longer telomeres than those of corresponding wild-type mice. Our results point to the possibility that DNA-PKcs may, directly or indirectly, be involved in telomere length regulation in mammalian cells.
The Terry Fox Laboratory, British Columbia Cancer Research Center, 601 West 10th Avenue, Vancouver, British Columbia, V5Z 1L3, Canada.
P
P
Hande
P
P
Slijepcevic
A
A
Silver
S
S
Bouffler
P
P
van Buul
P
P
Bryant
P
P
Lansdorp
D000818:Animals; D003433:Crosses, Genetic; D005260:Female; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D016513:Mice, SCID; D012091:Repetitive Sequences, Nucleic Acid; D013045:Species Specificity; D016615:Telomere / Q000235:genetics*