| DNA chip is also known as DNA Microarray. It has been sweeping through the world and has found wide applications in life science since its invention in the middle of 1990's. Roxarsone is a kind of man-made organic compound contains Arsenic element, which has been used for years as an additive in animal's diet to accelerate animal growth. In order to research its mechanism in stimulating broiler's growth and its toxicity, we have firstly constructed and sequenced two cDNA libraries: the breast muscle cDNA library and the liver cDNA library, from Silkie Fowl. 6,023 and 4,839 ESTs of non-redundancy genes are founded in breast muscle and liver tissue respectively by bioinformatical analysis. Totally, 10,862 genes were singled out from the two libraries for our cDNA Microarray manufacture. These genes were amplified by PCR in large volume, purified and detected by electrophoresis; the weak and multiple bands mixed in PCR product were discarded. 9,216 high quality cDNA PCR products were used for making MicroarraysTo find out the appropriate conditions for the best Microarray manufacturing, we have compared and analyzed four types of printing solvent (3 X SSC, 50% DMSO, 3XSSC+1.5M Betaine and MSP) and seven printing substrates (UltraGAPS?Substrates, GAPS II Substrates, SuperAmine Barcoded Substrates, SuperAmine Substrates, Baio Amine Slides, PL-100C Poly-L-Lysine Slides and POLY-PREP?Slides) , which come from five different companies with the SpotBot?spotting robot. Our experiment results indicate that the combination of four slides, UltraGAPS?GAPS II , SuperAmine and SuperAmine Barcoded with 3 X SSC+1.5M Betaine can produce the best printing and hybridization results under the optimized circumstances. At the same time, we give a comprehensive comparison and analysis of the purification methods of PCR products, the appropriate spotting space and the concentration of arrayed DNA in printing solutions, the best printing environment conditions, the appropriate treatment of substrates after printing, the labeling methods of probe, the conditions of hybridization and post-hybridization washing. We successfully produced Microarrays with 30,000 spots per substrate with our optimized conditions.To study Roxarsone' s mechanism in stimulating animal growth and its toxicity, 112 three-week old chickens were randomly divided into four groups and were fed with different diets, which contain 45mg/kg 300mg/kg. 600mg/kg and 0mg/kg of Roxarsone respectively. Data analysis shows that the body weight gain and net weight gain in week 4, 5, and 6 have significantly difference ( P<0.05 ) between groups except for the body weight between the group of 300mg/kg and the control group in week 4. Chickens in 45mg/kg group significantly grew much faster than any other groups (P<0.05 ), while the growth of 300mg/kg group and the group of 600mg/kg were significantly slower than the control group during this time. These relationships have changed a little in week 7 due to the slower growth rate of the group 45mg/kg and the control group, and the number of samples is relatively small in some extent. Chickens in the 45mg/kg group have the highest feed conversion ratio (2.29), followed by the control group (2.38), the 300mg/kg group (2.42) and the 600mg/kg group (2.62 ). Our research results indicate that properly concentration of Roxarsone in chicken's diet can consistently and significantly increase broiler's body weightover control, greatly improving diet efficiency, while high concentration of Roxarsone in feedstuff may impede the growth of chickens. Total Arsenic test results in both liver tissue and the breast muscle tissue indicate that the total Arsenic in liver is much higher than that of in the breast muscle, and the residuals of total Arsenic increased significantly with dosage, while increased a little with time; the control group has much lower total Arsenic concentration in both liver and breast muscle, while the concentration of total Arsenic in the 300mg/kg group and the 600mg/kg group are significantly higher tha...
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