Digital Gene Expression Profiles Of Growth Trait In Mandarin Fish Siniperca Chuatsi

Mandarin fish Siniperca chuatsi belongs to Perciformes, is one of the most valuable freshwater fish in China, as economically relevant traits, growth traits determine production cost and profitability. Recent years, the fish in great demand as the people’s living standard improving, so it’s a good strategy to improve the mandarin fish farming industry through culturing faster growth mandarin fish.Nevertheless, the weak of molecular genetic basis, lacking of genome sequence information and less known about the molecular mechanism in mandarin fish restricts its molecular assisted breeding practice. As a result, in this study, liver and brain are dis Sted from the biggest and smallest fish, respectively. Then total RNA is isolated from liver and brain, after that four tag libraries of mandarin fish are constructed in parallel using the Digital Gene Expression Tag Profile Kit(Illumina). Through analyzing the Digital Gene Expression Profile(DGE) based on the data of transcriptome library of Mandarin fish constructed in our laboratory, we can acquire large number growth traits candidate genes. These works can help us to reveal the molecular mechanism of growth regulation at transcriptional level, and also can provide large information for us to study relative gene function and molecular breeding practice. The main results and conclusions are listed below.1. The high sequencing quality of DGE was ensured in this study. Four samples were sequenced in this study, including brain and liver tissues come from smallest and biggest mandarin fish, respectively. Result showed that 41040945 tags were obtained from the library, after impurity were detected, 38650216 clean tags were received,which accounted for 94.17% of the total number of Tags. More than 6M data were obtained from each sample, which suggested the amount of data can meet the needs of the information analysis. In addition, all the four samples data obtained from the DGE analysis were great depth coverage to the transcriptome reference genetic library,which indicated these data were good enough to solve the scientific issue.2. Based on the transcriptome data, 2171 differentially expressed genes were obtained from the DGE data, including 413 genes come from brain and 1758 genes come from liver. After GO and KEGG analysis, the results showed that these differentially expressed genes were involved in growth axis pathway, TCA cycle pathway, appetite regulation pathway, energy metabolism pathway and myogenesis3. pathway. Most of these differentially expressed genes were associated with the growth traits, and which could be used as potential growth related candidate genes.These candidate genes also can play an important role in molecular assisted selection and functional gene research.In order to detect the veracity of the DGE analysis, six differentially expressed genes were random selected to test using real time PCR.Results showed that all the genes were consistent with the predict change state. Which suggested both the results of this study and analysis are the same reliable, also the research could lay a solid basis for study of aquatic products breeding and gene functions.