ONTOGENY OF B CELLS IN THE CHICKEN I. Sequential Development of Clonal Diversity in the Bursa

摘要: The initial development and distribution of lymphocytes expressing surface IgM (sIgM) specific antigen-binding cells (ABC) were studied in the chicken an attempt to gain information on process by which B-cell diversity is generated. antigens used sheep erythrocytes (SE), keyhole limpet hemocyanin (KLH), poly-L(Tyr, Glu)poly-D,L-Ala-poly-L-Lys (TGAL). results indicate that generation total sIgM-positive population begins bursa clones ABC develop a fixed sequential pattern not influenced either deprivation or deliberate exposure exogenous antigens. Cells bearing sIgM immunofluorescence (IgM-positive cells) detected first 12th day incubation, KLH-ABC TGAL-ABC 16th day, SE-ABC 18th day. doubling time bursal was determined be approximately 10 h before significant antigen-independent seeding spleen began few days hatching. Clonal expansion also appeared antigen independent as blood ceased abruptly after bursectomy at Specific observed multiple follicles small foci among much larger within individual follicle. Intravenously infused homed embryonic but bursa. are interpreted favoring hypothetical model stem give rise B predetermined expression variable region genes.