Purpose:
Müller cells display a complex behavior during the retinal healing process. They are hypothesized to participate in regenerative, neuroprotective, and deleterious responses. Our first step toward testing these hypotheses is to identify a regulatory sequence that can drive Müller cell-specific gene expression. We tested whether a 5’ regulatory region of the retinaldehyde binding protein 1 (Rlbp1/Cralbp) gene drives Müller cell-specific expression of green fluorescent protein (GFP) in vivo.
Methods:
Transgenic mice were generated by injecting a construct carrying a 3-kb fragment of the Rlbp1 5’ untranslated region (UTR) linked to the GFP cDNA. We defined spatial and temporal activity of the 5’ UTR by comparing GFP expression in ocular tissue during development, adulthood, and degeneration.
Results:
We generated three lines and propagated the one with the strongest GFP expression. GFP is expressed in Müller cells in post-natal and adult retinas (Figure) as well as during the early stages of retinal degeneration.
Conclusions:
Preliminary data suggest that a 3-kb regulatory region of the Rlbp1 gene drives Müller cell-specific gene expression in a cell-type specific and robust manner. We believe that the Rlbp1:GFP line is a powerful tool to visualize Müller cell function during retinal development, homeostasis, and degeneration. Moreover, the discovery a Müller-specific regulatory sequence represents a breakthrough toward future genetic manipulation of Müller cells.
Keywords: glia • retinal degenerations: cell biology • genetics