Selective expression of RAG-2 in chicken B cells undergoing immunoglobulin gene conversion.
Chickens create their immunoglobulin (Ig) repertoires during B cell development in the bursa of Fabricius by intrachromosomal gene conversion. Recent evidence has suggested that Ig gene conversion may involve cis-acting DNA elements related to those involved in V(D)J recombination. Therefore, we have examined the potential role of the V(D)J recombination activating genes, RAG-1 and RAG-2, in regulating chicken Ig gene conversion. In contrast to the coexpression of RAG-1 and RAG-2 observed in mammalian B cells that undergo V(D)J recombination, chicken B cells isolated from the bursa of Fabricius express high levels of the RAG-2 mRNA but do not express RAG-1 mRNA. The developmental and phenotypic characteristics of the bursal lymphocytes and chicken B cell lines that express RAG-2 mRNA demonstrate that selective RAG-2 expression occurs specifically in B cells undergoing Ig diversification by gene conversion. These data suggest that RAG-2 plays a fundamental role in Ig-specific gene conversion.
Carlson
L M
LM
Howard Hughes Medical Institute, University of Michigan Medical Center, Ann Arbor 48109.
Oettinger
M A
MA
Schatz
D G
DG
Masteller
E L
EL
Hurley
E A
EA
McCormack
W T
WT
Baltimore
D
D
Thompson
C B
CB
D000199:Actins / Q000235:genetics; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D015152:Blotting, Northern; D002060:Bursa of Fabricius; D002460:Cell Line; D002645:Chickens; D003001:Cloning, Molecular; D005434:Flow Cytometry; D005785:Gene Conversion; D015870:Gene Expression; D005786:Gene Expression Regulation; D005803:Genes, Immunoglobulin; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D011995:Recombination, Genetic; D013154:Spleen / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology
D000199:Actins; D012333:RNA, Messenger