Abstract
Purpose: :
Hyperoxia-induced photoreceptor degeneration occurs preferentially in the inferior retina of C57BL/6J mice (1). This study investigates differences in gene expression between inferior and superior retina of adult, hyperoxia-naïve C57BL/6J mouse, aiming to identify genes responsible for this regional difference in vulnerability.
Methods: :
C57BL/6J mice were raised in dim cyclic illumination (12 hr 5 lux, 12 hr dark). Retinas were obtained from young adult (83-90d old) mice and RNA was extracted from superior and inferior regions. The RNA from two animals (1 male and 1 female) was extracted, purified and hybridized to an Affymetrix MouseGene 1.0 ST Array to elucidate gene expression. Experiments were run in duplicate and analysis of the expression patterns was performed using GeneSpring and Partek Genomics Suite softwares. Real time PCR was used to verify the expression of control genes as well as of genes of interest.
Results: :
17 genes met the criteria of a twofold difference in expression and P<0.05 on a 1-way ANOVA analysis. Very little functional information is available concerning any of these 17 genes, however. 127 genes, 26 of which are known genes, had a P value < 0.05 and fold difference > 1.5. These include opn1sw (S-cone opsin), which has a prominent distribution in the inferior hemisphere (2); Edn2 (endothelin 2) which has been reported recently to play a role in delivering stress signals to Muller cells (3); and Optc (opticin) which is mapped to a region associated with the age-related macular degeneration (AMD) (4).
Conclusions: :
These microarray data provided clues to previously unknown factors and pathways which may be responsible for the vulnerability of inferior retina to hyperoxic stress, and a step toward to the identification of therapeutic targets.1. Smit-McBride Z, Oltjen SL, LaVail MM, & Hjelmeland LM (2007) Investigative Ophthalmology & Visual Science 48, 405-411.2. Linberg KA, Lewis GP, Shaaw C, Rex TS, & Fisher SK (2001) Journal of Comparative Neurology. 430, 343-356.3. Rattner A & Nathans J (2005) Journal of Neuroscience 25, 4540-4549.4. Friedman JS, Faucher M, Hiscott P, Biron VL, Malenfant M, Turcotte P, Raymond V, & Walter MA (2002) Hum. Mol. Genet. 11, 1333-1342.
Keywords: gene microarray • retina • protective mechanisms