Germ line activation of the Tie2 and SMMHC promoters causes noncell-specific deletion of floxed alleles - PubMed (original) (raw)

Germ line activation of the Tie2 and SMMHC promoters causes noncell-specific deletion of floxed alleles

Willem J de Lange et al. Physiol Genomics. 2008.

Abstract

Tissue-specific knockouts generated through Cre-loxP recombination have become an important tool to manipulate the mouse genome. Normally, two successive rounds of breeding are performed to generate mice carrying two floxed target-gene alleles and a transgene expressing Cre-recombinase tissue-specifically. We show herein that two promoters commonly used to generate endothelium-specific (Tie2) and smooth muscle-specific [smooth muscle myosin heavy chain (Smmhc)] knockout mice exhibit activity in the female and male germ lines, respectively. This can result in the inheritance of a null allele in the second generation that is not tissue specific. Careful experimental design is required therefore to ensure that tissue-specific knockouts are indeed tissue specific and that appropriate controls are used to compare strains.

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Figures

Fig. 1.

Fig. 1.

Genotyping of Tie2-cre and peroxisome proliferator-activated receptor-γ (PPARG) mice. A: schematic showing the 3 alleles of Pparg. The positions of PCR primers, location of loxP sites (filled triangles), and the expected PCR product sizes are indicated. Genotyping of the Pparg floxed allele and the eCre or sCre transgenes was performed as previously described (13, 17). WT, wild type. B: PCR genotyping for Pparg and Tie2-Cre is shown. Lanes 1–2 are offspring of a 1st cross (♂eCre+ × ♀PPARGF/F); lanes 3–11 are offspring of a 2nd cross where eCre was passed through the male (♂PPARGF/+ eCre+ × ♀PPARGF/F); lanes 12–15 are offspring of a 2nd cross where eCre was passed through the female (♂PPARGF/F × ♀PPARGF/+ eCre+). C: table shows the number of mice distributed by genotype. The expected number of animals is indicated in brackets. F2male−cre and F2female−cre represent the eCre transgene transmitted to F2 generation through the male and female germ line, respectively.

Fig. 2.

Fig. 2.

RT-PCR assay. A: schematic of the mRNA species generated from the 3 alleles shown in Fig. 1_A_. The primers used for RT-PCR are shown along with their expected size. B. aortic RT-PCR products generated from F2 endothelial-null offspring. Lanes 1–4 are RT-PCR products generated from samples where eCre was passed through the male; lanes 5–8 are RT-PCR products generated from samples where eCre was passed through the female. The animal genotype as assessed by tail genomic DNA is indicated below the figure. Total RNA was isolated from thoracic aorta using TriReagent (Molecular Research Center), DNase I treated and repurified using RNeasy spin columns (Qiagen). cDNA was generated by reverse transcription PCR using Superscript III (Invitrogen); 10 ng of reverse transcribed RNA was PCR amplified using primers 1-forward (F): AGACCACTCGCATTCCTTTGACAT and 3-reverse (R): TCCGGCAGTTAAGATCACACC.

Fig. 3.

Fig. 3.

Genotyping of smooth muscle myosin heavy chain (SMMHC)-cre and PPARG mice. PCR genotyping for Pparg and SMMHC-cre is shown. Lanes 1–4 are offspring of a 1st cross (♂sCre+ × ♀PPARGF/F); lanes 5–16 are offspring of a 2nd cross where sCre was passed through the male (♂PPARGF/+ sCre+ × ♀PPARGF/F). The table shows the number of mice distributed by genotype. The expected number of animals is indicated in brackets. F2male−cre represent the eCre transgene transmitted to F2 generation through the male germ line.

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References

    1. BagnallAJ, Kelland NF, Gulliver-Sloan F, Davenport AP, Gray GA, Yanagisawa M, Webb DJ, Kotelevtsev YV. Deletion of endothelial cell endothelin B receptors does not affect blood pressure or sensitivity to salt. Hypertension 48: 286–293, 2006 - PubMed
    1. BrarenR, Hu H, Kim YH, Beggs HE, Reichardt LF, Wang R. Endothelial FAK is essential for vascular network stability, cell survival, and lamellipodial formation. J Cell Biol 172: 151–162, 2006 - PMC - PubMed
    1. CattelinoA, Liebner S, Gallini R, Zanetti A, Balconi G, Corsi A, Bianco P, Wolburg H, Moore R, Oreda B, Kemler R, Dejana E. The conditional inactivation of the beta-catenin gene in endothelial cells causes a defective vascular pattern and increased vascular fragility. J Cell Biol 162: 1111–1122, 2003 - PMC - PubMed
    1. ConstienR, Forde A, Liliensiek B, Grone HJ, Nawroth P, Hammerling G, Arnold B. Characterization of a novel EGFP reporter mouse to monitor Cre recombination as demonstrated by a Tie2 Cre mouse line. Genesis 30: 36–44, 2001 - PubMed
    1. De MartinoC, Capanna E, Nicotra MR, Natali PG. Immunochemical localization of contractile proteins in mammalian meiotic chromosomes. Cell Tissue Res 213: 159–178, 1980 - PubMed

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