V(D)J recombination: broken DNA molecules with covalently sealed (hairpin) coding ends in scid mouse thymocytes.
Lymphoid cells from scid mice initiate V(D)J recombination normally but have a severely reduced ability to join coding segments. Thymocytes from scid mice contain broken DNA molecules at the TCR delta locus that have coding ends, as well as molecules with signal ends, whereas in normal mice we previously detected only signal ends. Remarkably, these coding (but not signal) ends are sealed into hairpin structures. The formation of hairpins at coding ends may be a universal, early step in V(D)J recombination; this would provide a simple explanation for the origin of P nucleotides in coding joints. These findings may shed light on the mechanism of cleavage and suggest a possible role for the scid factor.
Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892.
D B
DB
Roth
J P
JP
Menetski
P B
PB
Nakajima
M J
MJ
Bosma
M
M
Gellert
D000818:Animals; D003062:Codon; D004247:DNA / Q000032:analysis; D004270:DNA, Circular; D015180:Electrophoresis, Gel, Two-Dimensional; D016694:Gene Rearrangement, delta-Chain T-Cell Antigen Receptor / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID / Q000235:genetics*; D009690:Nucleic Acid Conformation; D012150:Polymorphism, Restriction Fragment Length; D011995:Recombination, Genetic; D012045:Regulatory Sequences, Nucleic Acid
D003062:Codon; D004270:DNA, Circular; D004247:DNA