Jh (BALB/c)

Constitutive Knockout

Jh Constitutive Knockout Mouse Model

BALB/c Background

  • Model #
  • Genotype
  • Nomenclature
  • 1147-F
  • 1147-M
  • B cell deficient mice are useful for basic mechanistic studies of immunologic mechanisms as well as host mice in syngeneic tumor studies using immunogenic test articles.
  • Carries a deletion of the endogenous murine J segments of the Ig heavy chain locus
  • In homozygotes, all four JH gene segments are absent, resulting in cells that cannot produce a complete, recombined version of the variable region of the heavy chain
  • Have no detectable IgM or IgG in the sera
  • A low level (about 1% of normal) of rearrangement of the light chain kappa gene family is detected in total bone marrow
  • Cells of the B lineage are drastically altered both in developmental progression and in cell quantity
  • Contain no mature (immunoglobulin-bearing) B-lymphocytes in the spleen, bone marrow, lymph nodes, peripheral blood or peritoneum
  • T-lymphocyte development appears to proceed normally, based on surface phenotype and quantity of cells in the spleen; splenic lymphocytes are enriched for T cells due to the B cell deficit
  • Provides a null background useful for gene replacement experimentation in normal immune response and autoimmune diseases
  • Useful for studying non-B cell activity in pathogen-induced disease and mechanisms of antibody gene assembly and expression
  • For use in syngeneic experiments, the Jh mouse is 96% congenic to the BALB/c background and may successfully engraft some cell lines of BALB/c origin
  • Model 17758 is a similar model on the C57BL/6NTac background which may be used for syngeneic tumor experiments using cell lines derived from B6.
  • Tumor growth kinetics may vary in immunodeficient mice compared to wild type mice of the same strain. A pilot study to evaluate tumor growth is best practice.
Orders by weight: Taconic cannot accept orders by weight for this model. Please note that shipments may contain animals with a larger weight variation.

Genetic Background:

BALB/c Background


The Jh mouse was developed by Dennis Huszar et al. at GenPharm International. The model was created by targeting the Jh gene in AB01 embryonic stem cells derived from 129/SvEv mice and injecting the targeted cells into C57BL/6J blastocysts. Heterozygotes on a C57BL/6J background were intercrossed to generate homozygous targeted mutation mice. Yale University received stock from GenPharm in 1992. The mice were then backcrossed several generations to a C.B-Igh-1 b congenic background. The mice were then backcrossed two generations (N2) to a BALB/c inbred background and intercrossed to homozygosity. The colony is maintained through homozygous matings. 

The Jh mouse permits clinically relevant dosing of immunogenic test articles in syngeneic tumor model systems Download the Taconic Biosciences' Infographic:
The Jh mouse permits clinically relevant dosing of immunogenic test articles in syngeneic tumor model systems
See how the Jh mouse can enable syngeneic tumor studies for drugs with immunogenicity problems.


Wild type for Nnt mutation





Initial Publication:

Chen J, Trounstine M, Alt FW, Young F, Kurahara C, Loring JF, Huszar D. (1993) Immunoglobulin Gene Rearrangement in B Cell Deficient Mice Generated by Targeted Deletion of the JH Locus. Int Immunol,5(6): 647-656.

Conditions of Use for Taconic Transgenic Models™
Taconic Transgenic Models™ (Models) are produced and distributed under rights to patents and intellectual property licensed from various institutions. Taconic sells the Models to purchasers, grants to each purchaser a right under Taconic's rights in such licensed patents and intellectual property to use the purchased Model in consideration of purchasers' acknowledgement of and agreement to the Terms and Conditions for Taconic Models, Products and Services and the following terms of use:
  • Title to these Models and biological materials derived from them remains with Taconic.
  • The Models will be used for research purposes only.
  • The Models will not be bred or cross-bred except to obtain embryos or fetuses required for research purposes unless additional rights have been granted in writing by Taconic.
  • The Models and biological materials derived from them will not be distributed to third parties or used for commercial purposes.
  • Non-profit purchasers may not use this Model and/or biological materials derived from it in sponsored research or contract research studies unless it is purchased at the for-profit price.

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