• Register
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.


Leaving Community

Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.


B-cell development fails in the absence of the Pbx1 proto-oncogene.

Pbx1, a homeodomain transcription factor that was originally identified as the product of a proto-oncogene in acute pre-B-cell leukemia, is a global regulator of embryonic development. However, embryonic lethality in its absence has prevented an assessment of its role in B-cell development. Here, using Rag1-deficient blastocyst complementation assays, we demonstrate that Pbx1 null embryonic stem (ES) cells fail to generate common lymphoid progenitors (CLPs) resulting in a complete lack of B and NK cells, and a partial impairment of T-cell development in chimeric mice. A critical role for Pbx1 was confirmed by rescue of B-cell development from CLPs following restoration of its expression in Pbx1-deficient ES cells. In adoptive transfer experiments, B-cell development from Pbx1-deficient fetal liver cells was also severely compromised, but not erased, since transient B lymphopoiesis was detected in Rag-deficient recipients. Conditional inactivation of Pbx1 in pro-B (CD19(+)) cells and thereafter revealed that Pbx1 is not necessary for B-cell development to proceed from the pro-B-cell stage. Thus, Pbx1 critically functions at a stage between hematopoietic stem cell development and B-cell commitment and, therefore, is one of the earliest-acting transcription factors that regulate de novo B-lineage lymphopoiesis.

Pubmed ID: 17244677


  • Sanyal M
  • Tung JW
  • Karsunky H
  • Zeng H
  • Selleri L
  • Weissman IL
  • Herzenberg LA
  • Cleary ML



Publication Data

May 15, 2007

Associated Grants

  • Agency: NIAID NIH HHS, Id: AI047458
  • Agency: NCI NIH HHS, Id: CA42971
  • Agency: NCI NIH HHS, Id: CA90735
  • Agency: NICHD NIH HHS, Id: HD43997

Mesh Terms

  • Animals
  • B-Lymphocytes
  • Blastocyst
  • Chimera
  • Gene Expression Regulation, Developmental
  • Genes, RAG-1
  • Hematopoietic Stem Cells
  • Homeodomain Proteins
  • Liver
  • Lymphopoiesis
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Transcription Factors