RAG2:GFP knockin mice reveal novel aspects of RAG2 expression in primary and peripheral lymphoid tissues.
We generated mice in which a functional RAG2:GFP fusion gene is knocked in to the endogenous RAG2 locus. In bone marrow and thymus, RAG2:GFP expression occurs in appropriate stages of developing B and T cells as well as in immature bone marrow IgM+ B cells. RAG2:GFP also is expressed in IgD+ B cells following cross-linking of IgM on immature IgM+ IgD+ B cells generated in vitro. RAG2:GFP expression is undetectable in most immature splenic B cells; however, in young RAG2:GFP mice, there are substantial numbers of splenic RAG2:GFP+ cells that mostly resemble pre-B cells. The latter population decreases in size with age but reappears following immunization of older RAG2:GFP mice. We discuss the implications of these findings for current models of receptor assembly and diversification.
Monroe
R J
RJ
Howard Hughes Medical Institute, The Children's Hospital, The Center for Blood Research and Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Seidl
K J
KJ
Gaertner
F
F
Han
S
S
Chen
F
F
Sekiguchi
J
J
Wang
J
J
Ferrini
R
R
Davidson
L
L
Kelsoe
G
G
Alt
F W
FW
D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism; D004268:DNA-Binding Proteins; D005786:Gene Expression Regulation; D049452:Green Fluorescent Proteins; D018960:Hyaluronan Receptors / Q000032:analysis; D007114:Immunization; D007072:Immunoglobulin D / Q000032:analysis; D008164:Luminescent Proteins / Q000096:biosynthesis*; D008214:Lymphocytes / Q000502:physiology; D008221:Lymphoid Tissue / Q000378:metabolism*; D051379:Mice; D011947:Receptors, Antigen, B-Cell / Q000502:physiology; D015375:Receptors, Interleukin-2 / Q000032:analysis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis*; D011995:Recombination, Genetic
D004268:DNA-Binding Proteins; D018960:Hyaluronan Receptors; D007072:Immunoglobulin D; D008164:Luminescent Proteins; C499308:Rag2 protein, mouse; D011947:Receptors, Antigen, B-Cell; D015375:Receptors, Interleukin-2; D011993:Recombinant Fusion Proteins; C064655:V(D)J recombination activating protein 2; D049452:Green Fluorescent Proteins