Rearrangement of chicken immunoglobulin genes is not an ongoing process in the embryonic bursa of Fabricius.
We report a molecular analysis of the chicken Ig loci in single bursal follicles from 3- to 7-week-old chickens. Each follicle contained between 10(5) and 3 X 10(5) cells. The Ig gene rearrangement patterns obtained were compared to the pattern observed with the corresponding total bursal DNA. The results obtained for the light chain locus imply that a very small number (two on average) of rearrangement events takes place in each follicle. For the heavy chain locus similar results were obtained, each follicle showing a more restricted pattern than the total bursa. These data favor a model in which each follicle is colonized by a very few prebursal stem cells that are committed to a particular Ig gene rearrangement at the very beginning of the development of the embryonic bursa. The role of the bursa as the organ in which such a committed stem cell population for the B-cell lineage arises is discussed.
D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology*; D002060:Bursa of Fabricius / Q000166:cytology / Q000196:embryology* / Q000276:immunology; D002642:Chick Embryo; D003520:Cyclophosphamide / Q000494:pharmacology; D004262:DNA Restriction Enzymes; D006579:Heterozygote; D007127:Immunoglobulin Constant Regions / Q000235:genetics; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007147:Immunoglobulin Light Chains / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000235:genetics; D007146:Immunoglobulin lambda-Chains / Q000235:genetics*; D007148:Immunoglobulin mu-Chains / Q000235:genetics*; D011110:Polymorphism, Genetic; D011995:Recombination, Genetic
D007127:Immunoglobulin Constant Regions; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D007146:Immunoglobulin lambda-Chains; D007148:Immunoglobulin mu-Chains; D003520:Cyclophosphamide; D004262:DNA Restriction Enzymes