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Inducing Cre-lox Recombination in Mouse Cerebral Cortex Through In Utero Electroporation
Published on: November 17, 2017
A non-specific effect associated with conditional transgene expression based on Cre-loxP strategy in mice
Linghua Qiu1, Jaime A Rivera-Pérez, Zuoshang Xu
1Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.
Plos One
|May 17, 2011
Summary
Conditional gene expression using Cre-loxP in mice can lead to unexpected microcephaly. This is linked to transgene copy number and arrangement, not miRNA function, necessitating caution in interpreting such studies.
Area of Science:
- Genetics and Genomics
- Developmental Biology
- Neuroscience
Background:
- Cre-loxP recombination is a standard tool for conditional gene expression in transgenic mice.
- This system has been crucial for research in cancer, neurodevelopment, and neurodegeneration.
Purpose of the Study:
- To investigate the effects of conditionally expressing microRNAs (miRNAs) using the Cre-loxP system in mice.
- To identify potential issues with this approach when applied to neural progenitor cells.
Main Methods:
- Generation of multiple independent transgenic mouse lines with loxP-flanked miRNA expression cassettes.
- Analysis of Cre-mediated recombination in neural progenitor cells.
- Correlation of phenotypic outcomes (microcephaly) with transgene copy number, arrangement, and miRNA expression levels.
Main Results:
- Cre-mediated recombination in neural progenitor cells resulted in microcephaly in 50% of the transgenic lines.
- The observed microcephaly was not linked to miRNA type, quantity, or target knockdown.
- A strong correlation was found between microcephaly and the presence of multiple tandem transgene copies and inverted repeats.
Conclusions:
- The Cre-loxP system for generating inducible transgenic alleles requires careful interpretation.
- Structural anomalies of transgenes, such as inverted repeats, can cause significant off-target effects like cell death and developmental defects.
- Previous conclusions drawn from studies using this method, particularly regarding neural development, may need reevaluation.
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