Screen The Genes Related To Mouse Brain Development And Injury By High Density CDNA Microarrys

The relationship between brain development and injury attracts the attention of manyneuroscientists. A number of genes related to development are found to participate into thepathological and physiological courses of brain injury, while, a few genes ever highlyexpressed in developmental period show a potential prospect to facilitate recovering thebrain injury by suitable genetic engineering, especially those genes related to axon growthand guidance, neuron differntiation and migration. The mRNA within the brain is threetimes more than other organs of the body. The complexity of the structure and function ofthe brain informs a rather complexed molecular basis, numerous genes may be involoved ina simple incident of development or injury . Genechip technique is a advanced molecularbiological platform which can profile the dynamic changes of more than ten thousands ofgenes just by several genechips. In this study, expressed genes in bilateral lateral geniculatebodies while optic nerve was undergoing eight various stages of either development orinjury, were screened by high density developmental cDNA microarrys to identify genesrelated to brain development and injury. The main results were summed up as follows:1. The foundation of developmental and injury animal model:1.1 KM-mice just before or after birth were used to be developmental models, andadult mice removed left eye to be injury models, while normal adult mice were taken ascontrols.1.2 Astrocytes in bilateral lateral geniculate bodies were profiled by GFAPimmunohistochenistry staining at the stages of E15, E18, P0, P7, I1, I7, I14, I21. Nonepositive cell was observered in embry stages. Several light stained single-processed positivecells appeared on the day P0. Obvious GFAP response was observered after injuried, thepeak appeared on the day I7, and reduced on the day I 21.1.3 Neurons was described by brillant_cresyl violet staining. There was a continuousmorphological change of neurons from embryo to adult: The neurons were becoming bigger,darker, more scattered, and Nissl's bodies in neurons were becoming clearer and coarser. 2第三军医大学博士学位论文1.4 Nerve fibers were demonstrated by electron microscope: There were only a fewnon-myelinated nerve fibers appeared in embryo stages; Myelinated nerve fibers wereobservered on P0; Collapsed myelinated nerve fibers appeared in all injury stages.1.5 In a word, the morphological changes of neurons, astrocytes and nerve fibers inLGN among developmental and injury stages were very obvious, which potentiallyreflected a lot of genes expression changes. Furthermore, the animal models used in thisresearch were easily operated, high survival rated, well repeated, and less interfered. Itmight be a suitable animal model for studying genes related to brain development andinjury.2. Results of genes ralated to brain development and injury described bygenechips:2.1 Total RNA of bilateral LGNs were extracted by modified trice extraction method.Most RNA samples were pure enough to be applied directly for gengchip hybridization.2.2 Expressed genes in LGN while optic nerves were undergoing 8 various stages ofeither development or injury were screened by high density genechips. Among the total7680 genes on the developmental chip, 3604 genes were deteched at least one time pointeither in developmental period or injury; 2041 genes were found to be differentiallyexpressed, including 1095 higher expressed genes(Ratio≥2) and 946 lower expressedgenes (Ratio≤0.5); And 1563 non-differentially expressed genes(2>Ratio>0.5) were alsofound in this research.2.3 Differentially expressed gene Blot1808(Rp15) was vertificated by RT-PCR, theresult of RT-PCR was similar to genechip.2.4 The 1095 higher expressed genes were classificated according to their function,665(51.19%) of which were entirely unknown , the others were sorted into 17 groups whosefunction varied from regulating transcript, signal transduction, synthesis of protein,materi...