Abstract
Abstract: :
Purpose:Powerful evidence from animal models suggests that postnatal ocular growth is under the control of local (within the eye) factors that regulate the rate of scleral extracellular matrix remodeling and the rate of ocular elongation. In order to identify some of the factors involved in the regulation of visually guided ocular growth, a gene microarray analysis was employed to identify genes that were up– and down–regulated in the retinas, retinal pigmented epithelium and choroids of chick eyes that were decelerating in the rate of ocular growth ("recovering" from myopia) as compared with contralateral control eyes. Methods:Form–deprivation myopia was induced in the right eye of newly hatched chicks by the application of translucent occluders. Following 10 days of deprivation, occluders were removed and chicks were provided unrestricted vision for an additional 1– 4 days (recovery). Following one and four days of recovery, chicks were sacrificed, retinas, RPE and choroids were isolated and mRNA extracted using a standard protocol. Following amplication and labeling of RNA, microarray analyses were conducted using a chicken immune system 4000 gene microarray (FHCRC Genomics Resource, Seattle WA). Results: A total of 41 genes were either up– or down regulated in experimental eyes which exhibited at least a 2.5 fold change over contralateral control eyes. Following one day of recovery only one gene was highly up–regulated (+12.3 fold) and no genes were significantly (>=2.5 fold) downregulated. Following four days of recovery, 37 genes were down–regulated and 3 genes were up–regulated. Conclusions:The identification of candidate genes that are up–and down–regulated in response to visually induced changes in ocular growth may elucidate mechanisms involved in the control of postnatal ocular growth and the development of myopia.
Keywords: myopia • gene microarray • emmetropization