The VH replacement process is a RAG-mediated secondary recombination in which the variable region of a rearranged VHDJH is replaced by a different germline VH gene. In almost all human and mouse VH genes, two sequence features appear to be crucial for VH replacement. First, an embedded heptamer, which is located near the 3' end of the rearranged VH gene, serves as a cryptic recombination signal sequence (3'cRSS) for the VH replacement process.
View Article and Find Full Text PDFJ Anim Sci Biotechnol
June 2012
This review focuses on the diversity of immunoglobulin (Ig) genes and Ig isotypes that are expressed in domestic animals. Four livestock species-cattle, sheep, pigs, and horses-express a full range of Ig heavy chains (IgHs), including μ, δ, γ, ϵ, and α. Two poultry species (chickens and ducks) express three IgH isotypes, μ, υ, and α, but not δ.
View Article and Find Full Text PDFAvicenna J Med Biotechnol
April 2009
A highly efficient cloning vector was constructed for cloning PCR products by inserting an 80 bp DNA fragment into pGEM-5zf (+) vector. The Xcm I digestion of this vector gave rise to a 3' overhanging deoxythymidine offering the possibility of cloning PCR products with 3' adenosine overhang created by Taq DNA polymerase. Furthermore, two EcoR I sites were added to the construct for identification of recombinant plasmids using a single restriction enzyme.
View Article and Find Full Text PDF