ZFIN ID: ZDB-PUB-060927-7
Initiation of V(D)J recombination in zebrafish (Danio rerio) ovaries
Zhong, H., Li, Z., Lin, S., and Chang, Y.
Date: 2007
Source: Molecular immunology   44(7): 1795-1803 (Journal)
Registered Authors: Lin, Shuo, Zhong, Hanbing
Keywords: Germline gene rearrangement, Ligation-mediated PCR, Non-homologous end joining, Recombination ends, And V(D)J recombination
MeSH Terms:
  • Animals
  • Base Sequence
  • DNA-Binding Proteins/genetics*
  • Female
  • Gene Expression*
  • Gene Rearrangement
  • Genes, Immunoglobulin/genetics*
  • Homeodomain Proteins/genetics*
  • Molecular Sequence Data
  • Ovary/chemistry
  • Ovary/immunology*
  • RNA, Messenger/analysis
  • RNA, Messenger/metabolism
  • Recombination, Genetic
  • Zebrafish/genetics
  • Zebrafish/immunology*
PubMed: 16996591 Full text @ Mol. Immunol.
The assembly of mammalian antigen receptor genes is a lymphoid-specific process. However, rearranged immunoglobulin genes can also be recovered from non-lymphoid tissues of cartilaginous fish. This event, known as germline rearrangement, has been speculated to arise from recombination-activating gene (RAG)-mediated recombination in germ cells. In this report, we demonstrate that zebrafish (Danio rerio) oocytes expressing high levels of RAG-RNA can readily initiate recombination cleavage at immunoglobulin gene loci, providing direct evidence for an ongoing process of attempted germline rearrangement in zebrafish ovaries. This attempted rearrangement is largely unproductive, yielding no accumulation of germline-joined immunoglobulin genes in zebrafish, which is consistent with their general absence in this species. Our data, therefore, substantiate the speculation that RAG might have been derived from a transposase, invading germ cells of ancient species, and later become a dedicated recombinase only expressed in developing lymphocytes.