Transgenic mice expressing Cre-recombinase specifically in M- or S-cone photoreceptors.
OBJECTIVE
To establish lines of transgenic mice that express Cre-recombinase in M- or S-cone photoreceptors for generating cone photoreceptor-specific (conditional) mutants.


METHODS
Five kilobases of 5' upstream sequence of the mouse red-green (M) opsin gene or 0.5 kb of the mouse blue (S) opsin gene was cloned into a Cre-expression plasmid. Transgenic mice were generated and characterized, and appropriate lines were established. The Cre-transgenic mice were crossed with ROSA26-lacZ mice (containing floxed beta-galactosidase gene) and analyzed to determine Cre-recombinase activity.


RESULTS
Immunofluorescence study showed successful targeting of Cre-recombinase expression to cone photoreceptors. Double staining with anti-Cre antibody and anti-M- or anti-S-opsin antibody revealed specificity of Cre expression in M-opsin- and/or S-opsin-positive photoreceptors. Mating with ROSA26-lacZ mice demonstrated that Cre-recombinase was functionally active in M- or S-cones.


CONCLUSIONS
Lines of transgenic mice that specifically express functional Cre-recombinase in M- or S-cones were established in this study. Because mutations in several widely expressed genes lead to photoreceptor degeneration, these transgenic mice should be valuable in generating conditional mutants to investigate the function of various genes specifically in cone photoreceptors.
Akimoto
Masayuki
M
Department of Ophthalmology, the W. K. Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan 48105, USA.
Filippova
Elena
E
Gage
Philip J
PJ
Zhu
Xuemei
X
Craft
Cheryl M
CM
Swaroop
Anand
A
D000818:Animals; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D005822:Genetic Vectors; D019426:Integrases / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D010957:Plasmids; D017949:Retinal Cone Photoreceptor Cells / Q000201:enzymology*; D017299:Rod Opsins / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism
D017299:Rod Opsins; D014764:Viral Proteins; C095855:long-wavelength opsin; C095854:middle-wavelength opsin; C095853:short-wavelength opsin; C045073:Cre recombinase; D019426:Integrases; D001616:beta-Galactosidase