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Transgenic Research

, Volume 21, Issue 2, pp 415–428 | Cite as

A doxycycline-inducible, tissue-specific aromatase-expressing transgenic mouse

  • Jenny D. Y. Chow
  • John T. Price
  • Margaret M. Bills
  • Evan R. Simpson
  • Wah Chin Boon
Technical Report

Abstract

Aromatase converts androgens to estrogens and it is expressed in gonads and non-reproductive tissues (e.g. brain and adipose tissues). As circulating levels of estrogens in males are low, we hypothesize that local estrogen production is important for the regulation of physiological functions (e.g. metabolism) and pathological development (e.g. breast and prostate cancers) by acting in a paracrine and/or intracrine manner. We generated a tissue-specific doxycycline-inducible, aromatase transgenic mouse to test this hypothesis. The transgene construct (pTetOAROM) consists of a full-length human aromatase cDNA (hAROM) and a luciferase gene under the control of a bi-directional tetracycline-responsive promoter (pTetO), which is regulated by transactivators (rtTA or tTA) and doxycycline. Our in vitro studies using MBA-MB-231tet cells stably expressing rtTA, showed that doxycycline treatment induced transgene expression of hAROM transcripts by 17-fold (P = 0.01), aromatase activity by 26-fold, (P = 0.0008) and luciferase activity by 9.6-fold (P = 0.0006). Pronuclear microinjection of the transgene generated four pTetOAROM founder mice. A male founder was bred with a female mammary gland-specific rtTA mouse (MMTVrtTA) to produce MMTVrtTA-pTetOAROM double-transgenic mice. Upon doxycycline treatment via drinking water, human aromatase expression was detected by RT-PCR, specifically in mammary glands, salivary glands and seminal vesicles of double-stransgenic mice. Luciferase expression and activity was detected in these tissues by in vivo bioluminescence imaging, in vitro luciferase assay and RT-PCR. In summary, we generated a transgenic mouse model that expresses the human aromatase transgene in a temporal- and spatial-specific manner, which will be a useful model to study the physiological importance of local estrogen production.

Keywords

Conditional transgenic Aromatase Luciferase Doxycycline Tet-ON MMTV 

Abbreviations

dox

Doxycycline

hAROM

Human aromatase gene/cDNA

luc

Firefly luciferase cDNA

MMTV

Mouse mammary tumour virus (promoter)

pTetO

Tetracycline-responsive promoter

rtTA

Reverse transactivation

Notes

Acknowledgments

This work was supported by Australian NH&MRC Project Grant, #494813 to WC Boon, #395525 R Douglas Wright Fellowship to JT Price and NHMRC Equipment Grant #467202 to JT Price and by # 338510 and Program Grant # 441100, as well as a Program Grant from the Victorian Breast Cancer Research Consortium Inc to ER Simpson.

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Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Jenny D. Y. Chow
    • 1
    • 2
  • John T. Price
    • 3
  • Margaret M. Bills
    • 3
  • Evan R. Simpson
    • 1
    • 3
  • Wah Chin Boon
    • 1
    • 2
    • 4
  1. 1.Prince Henry’s InstituteClaytonAustralia
  2. 2.Department of Anatomy and Developmental BiologyMonash UniversityClaytonAustralia
  3. 3.Department Biochemistry and Molecular BiologyMonash UniversityClaytonAustralia
  4. 4.Florey Neuroscience InstitutesThe University of MelbourneParkvilleAustralia

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