Disruption of overlapping transcripts in the ROSA βgeo 26 gene trap strain leads to widespread expression of β-galactosidase in mouse embryos and hematopoietic cells

Disruption of overlapping transcripts in the ROSA βgeo 26 gene trap strain leads to widespread expression of β-galactosidase in mouse embryos and hematopoietic cells

^*Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109; and ^§Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305

Abstract

The ROSAβgeo26 (ROSA26) mouse strain was produced by random retroviral gene trapping in embryonic stem cells. Staining of ROSA26 tissues and fluorescence-activated cell sorter-Gal analysis of hematopoietic cells demonstrates ubiquitous expression of the proviral βgeo reporter gene, and bone marrow transfer experiments illustrate the general utility of this strain for chimera and transplantation studies. The gene trap vector has integrated into a region that produces three transcripts. Two transcripts, lost in ROSA26 homozygous animals, originate from a common promoter and share identical 5′ ends, but neither contains a significant ORF. The third transcript, originating from the reverse strand, shares antisense sequences with one of the noncoding transcripts. This third transcript potentially encodes a novel protein of at least 505 amino acids that is conserved in humans and in Caenorhabditis elegans.

Footnotes

↵ † Present address: Lexicon Genetics, 4000 Research Forest Park, The Woodlands, TX 77381.
↵ ‡ Present address: Ben May Institute for Cancer Research, University of Chicago, Chicago, IL 60637.
↵ ¶ Present address: Department of Molecular and Cellular Engineering, University of Pennsylvania Medical School, Philadelphia, PA 19104.
↵ ‖ To whom reprint requests should be addressed. e-mail: psoriano{at}fhcrc.org.
R. L. Brinster, University of Pennsylvania, Philadelphia, PA
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. U83173U83173, U83174U83174, U83175U83175, and U83176U83176).
ABBREVIATIONS:

ES cell,

embryonic stem cell;

FACS-Gal,

fluorescence-activated cell sorter-Gal;

β-gal,

β-galactosidase;

X-Gal,

5-bromo-4-chloro-3-indolyl β-d-galactoside;

FDG,

fluorescein di-β-d-galactopyranoside;

RACE,

rapid amplification of cDNA ends;

E,

embryonic day;

AS,

antisense;

SA,

splice acceptor;

RT–PCR,

reverse transcription-coupled PCR;

BM,

bone marrow;

PGK,

phosphoglycerate kinase-1