A LacZ reporter gene expression atlas for 313 adult KOMP mutant mouse lines
- David B West1,4,
- Ravi K Pasumarthi2,
- Brian Baridon2,
- Esi Djan2,
- Amanda Trainor2,
- Stephen Griffey2,
- Eric Engelhard3,
- Jared Rapp2,
- Bowen Li2,
- Pieter de Jong1 and
- Kent Lloyd2
- ↵* Corresponding author; email: dwest{at}chori.org
Abstract
Expression of the bacterial beta-galactosidase (LacZ) reporter in the vector used for the Knockout Mouse Project (KOMP) is driven by the endogenous promoter of the target gene. In tissues from mice with the KOMP allele, histochemical staining for LacZ can be used to determine gene expression patterns. With this technique, we have produced a comprehensive resource of gene expression using both whole mount (WM) and frozen section (FS) LacZ staining in 66 tissues from 315 unique KOMP mutant mouse lines. Of these, ~80% of mutants showed specific staining in one or more tissues, while ~20% showed no specific staining, ~13% had staining in only one tissue, while ~25% had staining in >6 tissues. The highest frequency of specific staining occurred in the brain (~50%), male gonads (42%) and kidney (39%). The WM method was useful for rapidly identifying whole organ and some substructure staining, while the FS method often revealed substructure and cellular staining specificity. Reproducibility of the WM method was better than FS but both methods had greater than 90% repeatability in biological replicates. Non-specific LacZ staining occurs in some tissues due to the presence of bacteria or endogenous enzyme activity. However, this can be effectively distinguished from reporter gene activity by the combination of the WM and FS methods. After careful annotation, LacZ staining patterns in a high percentage of mutants revealed unique structure-function not previously reported for many of these genes. Of particular interest are substructures stained in the brain, kidney, heart and lung and in distributed peripheral tissues including blood vessels, ducts and epithelium, smooth & skeletal muscle and cartilage. The validation of methods for LacZ staining, annotation, and expression analysis reported here provide unique insights into function of genes for which little is currently known.
- Received September 9, 2014.
- Accepted January 5, 2015.
- Published by Cold Spring Harbor Laboratory Press
This article is distributed exclusively by Cold Spring Harbor Laboratory Press for the first six months after the full-issue publication date (see http://genome.cshlp.org/site/misc/terms.xhtml). After six months, it is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/.
