Expression profiles analysis of differential genes in rat visual cortex depending upon postnatal days by microarray / 中华实验眼科杂志

ABSTRACT

Background Visual adaptive mechanism of mammalian is close responsible for the development of visual cortex.The various genes with different biological functions in different developing stages of visual cortex participate in regulation of visual development.To investigate the differential expression profiles of various genes in different ages of rat cortex can offer basis and evidence for the study of visual development.Objective Present study aimed to investigate the genes that changed continuously in the postnatal developmental process of rat visual cortex by microarray analysis of visual cortex RNA.Methods Sixty clean SD rats were grouped numbered and randomized into the postnatal day 0 group (P0,n =20),before eye opening group (postnatal day 10,P10,n =15),before the critical period of visual cortex growth group (postnatal day 20,P20,n =15) and the end of development of visual cortex group(postnatal day 45,P45,n=15).The rats were sacrificed at corresponding time point respectively,and the fresh visual cortex were obtained for the extraction of total RNA and microarray analysis.Genes exhibiting changes in expression by≥2.0 folds were further confirmed using real-time PCR(RT-PCR).In order to evaluate the association of differential gene expression with growth,the postnatal stages were paired as 36 groups with the 3 pairs for each target gene (P45/P0,P20/P0,P10/P0).Results Microarray analysis showed that the gene with differential ratio ≥ 2.0 folds in rat visual cortex included Akap7,Asam,Casp3,Cxcr4,Egr1,Ennp2,Fabp7,Gpr88,Inpp5d,Rpsa,Stk32c and Vamp1.Real-time PCR verified that 24 genes form 26 probe sets had the same-phase regulating tendency,including 20 up-regulating probe sets and 6 down-regulating probe sets.The homodromous expressing tendency was seen in Akap7,Asam,Casp3,Cxcr4,Egr1,Ennp2,Fabp7,Inpp5d,Rpsa and Vamp1 genes between microarray analysis and RT-PCR.However,reverse expressions were found in the P45/P0 of Gpr88 and Stk32c genes,showing the up-regulation in the microarray analysis and down-regulation in RT-PCR.The concordant rate of gene expression between microarray analysis and RT-PCR was 94.44％.The expressing genes mainly functioned nervous system development,(metal) ion binding/transport,metabolism,regulation of neuronal synaptic plasticity.Conclusions New relevant candidate genes of age-associated rat visual cortex can be identified by microarray analysis,which provide a clue for the research of visual plasticity.