HMG box transcription factor gene Hbp1 is expressed in germ cells of the developing mouse testis

Authors

  • James M. Smith,

    1. Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
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  • Josephine Bowles,

    1. Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
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  • Megan Wilson,

    1. Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
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  • Peter Koopman

    Corresponding author
    1. Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
    2. Australian Research Council Centre of Excellence in Biotechnology and Development, The University of Queensland, Brisbane, Queensland, Australia
    • Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
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Abstract

HMG box containing protein 1 (HBP1) is a high mobility group domain transcriptional repressor that regulates proliferation in differentiated tissues. We have found mouse Hbp1 to be expressed strongly in the embryonic mouse testis from approximately 12.5 days post coitum, compared with low levels of expression in the embryonic ovary. Expression of Hbp1 is maintained in the developing testis beyond the onset of spermatogenesis after birth. Whole-mount in situ hybridisation analysis showed that expression of Hbp1 in the XY gonad is localized within the developing testis cords, the precursors of the seminiferous tubules. Expression of Hbp1 is not apparent in testis cords of gonads from homozygous We mutant embryos, which lack germ cells. In situ hybridisation analysis on cryosectioned embryonic testis indicated that Hbp1 expression resembles that of the germ cell marker Oct4. We conclude that Hbp1 is up-regulated specifically in germ cells of the developing XY gonad. The expression of Hbp1 in XY germ cells appears to correlate with the onset of mitotic arrest in these cells. Developmental Dynamics 230:366–370, 2004. © 2004 Wiley-Liss, Inc.

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