Background Retina is important in converting light into neural signals,but little is known about the regulatory genesessential for the retinal morphological formation,development and functional differentiation.This study aimed to investigatethe mRNA expression patterns and cellular or subcellular distribution of 33 differentially expressed genes in the retinabelonging to the early and middle-late embryogenesis stages as well as the early adult stage during human development.Methods In situ hybridization and real-time fluorescent quantitative reverse transcription polymerase chain reaction(FQ-RT-PCR) were used to assay 33 differentially expressed genes which were screened out using microarray analysisand were not present in the retinal cDNA or the Expressed Sequence Tags (EST) database of the National Eye Institute(NEI) Genebank.Results Nine of the 33 genes belonged to EST or the unknown cDNA fragments,and the remaining belonged to thenovel genes in the retina.During the human retinal development 17 genes were down-regulated,6 were up-regulatedand the remaining 10 were relatively unchanged.Most of the genes expressed in all layers of the retina at the gestationstage,and in the fully developed retina some genes examined did show higher expression level in certain specific cellsand structures such as retinal ganglion cells or the outer segment of photoreceptor cells.Conclusion The gene expression profile during retinal development possesses temporal and spatial distributionfeatures,which can provide experimental evidence for further research of the functions of those genes.Chin Med J 2007;120(19):1716-1719 Background Retina is important in converting light into neural signals, but little known to the regulatory genesessential for the retinal morphological formation, development and functional differentiation. This study aimed to investigate the mRNA expression patterns and cellular or subcellular distribution of 33 differentially expressed genes in the retinabelonging to the early and middle-late embryogenesis stages as well as the early adult stage during human development. Methods In situ hybridization and real-time fluorescent quantitative reverse transcription polymerase chain reaction (FQ-RT-PCR) were used to assay 33 differentially expressed genes which were screened out using microarray analysis and were not present in the retinal cDNA or the Expressed Sequence Tags (EST) database of the National Eye Institute (NEI) Genebank. Results Nine of the 33 genes belonged to EST or the unknown cDNA fragments, and the remaining belonged to thenovel genes in the retina.During the human retinal d Evelopment 17 genes were down-regulated, 6 were up-regulated and the remaining 10 were relatively unchanged. Host of the genes expressed in all layers of the retina at the gestation stage, and in the fully developed retina some genes examined did show higher expression level in certain specific cells and structures such as retinal ganglion cells or the outer segment of photoreceptor cells. Contact The Gene expression profile during retinal development possesses temporal and spatial distribution features, which can provide experimental evidence for further research of the functions of those genes. Chin Med J 2007 ; 120 (19): 1716-1719