Expression of Cre recombinase in retinal Müller cells.
OBJECTIVE
In an effort to generate inducible RPE-specific Cre mice using a 3.0-kb human vitelliform macular dystrophy-2 (VMD2) promoter, we identified a mouse line with unanticipated Cre activity in the neural retina, including Müller glial cells. Müller cells play important roles in the function and maintenance of the retina, and this mouse line would be potentially useful for conditional gene targeting in Müller glia. We therefore characterized the timing, inducibility, and cell specificity of Cre expression, as well as Müller cell-specific efficiency of Cre-mediated recombination in this mouse line.


METHODS
Transgenic mice carrying cassettes of human P(VMD2)-rtTA and TRE-cre were generated. Cre expression was characterized using a Cre-activatable lacZ reporter mouse line (R26R) and a floxed interleukin six signal transducing receptor (gp130) mouse line.


RESULTS
beta-Galactosidase (beta-gal) assay and immunohistochemical analysis of VMD2-cre/R26R double transgenic mice indicated that Cre activity was detected in cells located in the inner nuclear layer, with prominent expression of beta-gal in Müller cells. Cre activity was also detected in photoreceptors in the outer nuclear layer. PCR analysis demonstrated that Cre-mediated recombination initiated by embryonic day 15. Immunohistochemical analysis indicated that Cre-mediated deletion of floxed gp130 gene occurred in 52% of the retinal Müller cells. Retinal function and morphology were normal in 10-month-old VMD2-cre mice.


CONCLUSIONS
We generated a transgenic cre mouse that is useful to study gene activation and inactivation in retinal Müller cells.
Ueki
Yumi
Y
Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
Ash
John D
JD
Zhu
Meili
M
Zheng
Lixing
L
Le
Yun-Zheng
YZ
D000818:Animals; D000075002:Bestrophins; D018118:Chloride Channels / Q000235:genetics; D004596:Electroretinography; D005136:Eye Proteins / Q000235:genetics; D019426:Integrases / Q000378:metabolism* / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D009457:Neuroglia / Q000201:enzymology; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic; D012160:Retina / Q000502:physiology; D055351:Retinal Neurons / Q000201:enzymology*
C113133:BEST1 protein, human; D000075002:Bestrophins; D018118:Chloride Channels; D005136:Eye Proteins; C045073:Cre recombinase; D019426:Integrases