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Generation dependent reduction of tTA expression in double transgenic NZL‐2/tTA CMV mice
Author(s) -
Fedorov Lev M.,
Tyrsin Oleg Yu.,
Sakk Olena,
Ganscher Alla,
Rapp Ulf R.
Publication year - 2001
Publication title -
genesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.093
H-Index - 110
eISSN - 1526-968X
pISSN - 1526-954X
DOI - 10.1002/gene.10007
Subject(s) - transgene , transactivation , luciferase , genetically modified mouse , microbiology and biotechnology , reporter gene , biology , gene expression , in vivo , gene , transfection , chemistry , biochemistry , genetics
Summary: Despite the overall successful application of the tet‐system to regulate gene expression in vitro and in vivo, nothing is known so far about the long‐term stability of this system in transgenic mice. In this study, mice of generation F2, F3, F4, or F10 of two independent tTA CMV transgenic lines were bred with NZL‐2 mice containing a tTA‐responsive bidirectional promoter that allows the simultaneous expression of two reporter genes encoding luciferase and β‐galactosidase. Analysis of the expression of transgenes in double transgenic mice revealed a dramatic reduction of tTA transactivator mRNA over time. As a consequence, the expression of both reporter genes was gradually reduced from generation to generation in tissues of embryonic and adult NZL‐2/tTA CMV mice. Luciferase activity in NZL‐2/tTA CMV (F10) mice was reduced 8–10‐fold compared to NZL‐2/ tTA CMV (F2) mice, and β‐galactosidase expression was no longer detectable. In summary, we describe the long‐term instability of the tet‐system in our NZL‐2/tTA CMV double transgenic mice. The molecular basis of this observation and experimental tools to overcome this limitation need to be addressed in future. genesis 31:78–84, 2001. © 2001 Wiley‐Liss, Inc.