Both class switch recombination (CSR) and somatic hypermutation (SHM) require transcription and the trans-acting factor activation-induced cytidine deaminase (AID), and must be up-regulated during antigen-dependent differentiation of B lymphocytes. To test the role of the heavy chain 3' enhancers in both CSR and SHM, we used a BAC transgene of the entire heavy chain constant region locus. Using...

Heavy chain diseases are a family of rare, systemic syndromes typically associated with or representing a variant of a B-cell neoplasm. Their characteristic feature is production of a mutated immunoglobulin heavy chain incapable of either partnering with light chains in the formation of a full immunoglobulin molecule or of being degraded by the proteasome. The abnormal heavy chain is detected i...

The dwarf mutant is an autosomal recessive mutation of the mouse which causes a defective development of those anterior pituitary cells responsible for the production of thyroid-stimulating hormone, growth hormone, and prolactin. These mice are thus genetically hypothyroid and provide a model system in which one can investigate the influence of thyroid hormone on the transitions of the myosin h...

immunoproliferative small intestinal disease (ipsid) is the syndrome associated with mediterranean lymphoma (a rare form of non-hodgkin’s lymphoma). many of the patients diagnosed with secretory ipsid have variable level of abnormal immunoglobulins in serum or other bodily fluids, identified as truncated alpha heavy chain globulins. most cases are characterized by a loss of ability to synthesiz...

Immunoproliferative small intestinal disease (IPSID) is the syndrome associated with Mediterranean lymphoma (a rare form of non-Hodgkin’s lymphoma). Many of the patients diagnosed with secretory IPSID have variable level of abnormal immunoglobulins in serum or other bodily fluids, identified as truncated alpha heavy chain globulins. Most cases are characterized by a loss of ability to synthesiz...

We have deduced the 1675-amino acid sequence of rat clathrin heavy chain from cDNA clones and predict a protein of Mr 191,569. We have established the polarity of the heavy chain and assigned sequence positions to several structural landmarks of the clathrin leg. The terminal domain at the distal end of the clathrin leg is at the amino terminus of the heavy chain. It is connected to the distal ...

Immunoglobulin heavy chain genes were found in wild mice (Mus musculus) that could best be explained as recombinants of immunoglobulin genotypes. In wild mice from Kitty Hawk, N. C., two new heavy chain linkage groups, G(3,5,7,8)H(9,11)F(f)A(-) and G(3,5,8)H(9,11)F(f)A(-), were found, each of which genetically controls both the 3 and 5 distinct immunoglobulin determinants. In inbred strains the...

Since the discovery of antibody-producing B cells in chickens six decades ago, chickens have been a model for B-cell development in gut-associated lymphoid tissue species. Here we describe targeting of the immunoglobulin light chain locus by homologous recombination in chicken primordial germ cells (PGCs) and generation of VJCL knockout chickens. In contrast to immunoglobulin heavy chain knocko...