The Comparison Expression Of Sim2 And MAD2B In Brain In Newborn And Adult Rats

Sim2 is one of essential genes which cause Down syndrome. The researches discovered that over expression of Sim2 could promote the neuron's apotosis and suppress the neuron's differentiation. The dual ways participate in the occurrence of Down syndrome. We find a new kind of Sim2 interaction protein, MAD2B, by using doule yeast hybrid method. However, now the Sim2 and MAD2B expression situation have not been reported in the central nervous system. Our experiment's purpose were to detect Sim2 and MAD2B expression in central nervous system in newborn and grown rats and compare newborn rats with grown rats whether different on Sim2 and MAD2B expression quantity.The rats were divided into seven groups: born after 1days, 3days, 6days, 12days, 24days, 48days and 5 months. Each group is four rats. Immunohistochemical SABC staining method was used to showing expression and distribution of Sim2 and MAD2B in the central nervous system in rats. First antibody was omitted as a negative control group . Other steps same to experimental group. Using the high-definition pathological graphic analysis system(HPIAS)for the dyeing slice's image acquisition and analysis. The gray analysis of positive cells was scaled using ImageJ software and statistical analysis was using GraphPad Prism 5 Demo software.The results showed that:1. Sim2 positive-neurons have not been found in the brain of newborn rats (born aftern 1d, 3d, 6d, 12d, 24d, 48d).2. Many Sim2 positive-neurons have been found in the hippocampus, corpus striation and cortex of grown rats. The positive products are yellow brown and distributes in the cytoblastema. Any positive products have not been found in the cell nucleus.3. The gray analysis of Sim2 positive-cells area were scaled in the newborn and grown rats. We discovered that the grown rats'positive cells area have statistics significance difference with the newborn rats(P<0.05).4. Some weak positive products have been found in the brain of newborn rats (born aftern 1d, 3d, 6d, 12d, 24d, 48d). The positive products mainly concentrated in the glial cells and nerve fiber (waiting for further confirmation). However ,any MAD2B positive-neuron have not been found.5. Many MAD2B positive-neurons have been found in the hippocampus, corpus striation and cortex of grown rats. The positive products are yellow brown and distributes in the cytoblastema. Any positive products have not been found in the cell nucleus.6. The gray analysis of the MAD2B positive-cells area were scaled in the newborn and grown rats. We discovered that the grown rats'positive cell area have statistics significance difference with the newborn rats (P<0.05).In summary, our experiment illuminate that Sim2 and MAD2B do not express in the brain in newborn rats. But Sim2 and MAD2B express in the hippocampus, corpus striation and cortex of grown rats. This discoveries lay the foundation for finding whether Sim2 and MAD2B coexistence in neuron and the Sim2-- MAD2B signal iter's founction in Down syndrome.