Mp. Feldkaemper et al., Changes in retinal and choroidal gene expression during development of refractive errors in chicks, INV OPHTH V, 41(7), 2000, pp. 1623-1628
PURPOSE. During growth, the retina analyzes the projected image to achieve
a close match between eye length and focal length. Because the messengers r
eleased by retina and choroid are largely unknown, genes that are different
ly expressed in response to changes in the retinal image were identified. I
n addition, because glucagon may be important in the visual control of eye
growth, the transcript levels of proglucagon were studied.
METHODS. Reverse transcription-polymerase chain reaction differential displ
ay was used to identify genes that were differentially expressed in chick e
yes that were deprived of sharp vision or treated with positive or negative
lenses. Differences were analyzed through sequencing and database searches
and confirmed by Northern blot analyses.
RESULTS. Combining 40 and 33 arbitrary primers with 3 oligo-dT-primers, app
roximately 48% and 40% of the retinal and choroidal mRNAs were screened, re
spectively. Twelve differences were detected in retinal tissue and five in
choroidal tissue after 6 to 24 hours of exposure to defocus. Only one of 10
sequenced products could be identified as cytochrome-e oxidase, subunit I.
Northern blot analysis confirmed its twofold upregulation after positive l
ens wear and also changes in four other unknown genes. Finally, it was show
n that retinal glucagon mRNA content increased after treatment with positiv
e lenses.
CONCLUSIONS. Visual conditions that induce refractive errors produce change
s in gene expression in retina and choroid within 1 day. In line with previ
ous immunohistochemical data, it was found that the amount of glucagon mRNA
was upregulated during wearing of positive lenses.