Abstract
Abstract: :
Purpose: To examine the spatial and temporal expression of Krüppel–like factor 6 (KLF6) in the mouse cornea and lens throughout developmental and postnatal stages. KLF6, like Sp1, is a transcription factor that contains three zinc fingers and interacts with GC boxes in the promoter elements of various genes. Methods: C57BL6 mice were set up for timed mating. Embryos on embryonic (E) days 10.5, 12.5, 15.5, and 18.5 and eyes from mice at birth, and on postnatal (P) days 7, 11, 15, 30, and 60 were collected, fixed in 4% paraformaldehyde and processed for paraffin sections. Immunohistochemistry was performed using a polyclonal antibody for KLF6. Digoxigenin–labeled RNA probes were prepared and in situ hybridization experiments were carried out to detect transcript of KLF6. Relative quantitative reverse transcription (RT)–PCR was performed using the total RNA isolated from eyes enucleated at each embryonic stage, and from the corneas and lenses dissected from the eyes at postnatal stages. Results: Nuclear staining for KLF6 protein was evident at E15.5 in the corneal epithelium and the stroma. KLF6 protein was also observed at E18.5 in the nuclei of corneal endothelial and lens epithelial cells. The KLF6 transcript was found in the lens pit at E10.5, in the ectoderm and mesenchyme at E12.5, and in the mesothelium at E15.5. The level of KLF6 protein and mRNA in corneal layers remained relatively constant until P60. The KLF6 mRNA levels in the lens epithelium were high during embryonic stages but gradually declined with development. Conclusions: KLF6 is expressed in both the cornea and the lens. Its expression in the lens is temporally regulated, suggesting an important role of this transcription factor in the lens development.
Keywords: cornea: basic science • transcription factors • gene/expression