Gene expression pattern in 100ª²day porcine foetus thymus

    CHEN Yanª²Jiong1,2, DENG Yaª²Jun1,2, YE Lin3, GENG Jiaª²Ning2, LI Shengª²Bin1,2

    1Department of Forensic Medicine, Medical College, Xi¬ðan Jiaotong University, Xi¬ðan 710061, China, 2Beijing Genomics Institute, Beijing 101300, China, 3Hangzhou Genomics Institute, Hangzhou 310007,China

    ¡¾Abstract¡¿ AIM: To get a better understanding of the thymus development and differentiation£¬we constructed the gene expression pattern of 100ª²day foetus porcine thymus(FTY). METHODS: 11712 randomly picked clones from FTY cDNA library were singleª²pass sequenced. After contamination was removed, 7071 cleaned ESTs were used for gene expression analysis. RESULTS: After clustering the 7071 cleaned ESTs by PHRAP, 959 contigs(size>1) and 3074 singletons were obtained. Blast search showed that 806 contigs and 1669 singletons (totally 5442 ESTs) had homologues in nonredundant nucleic acid database, the Swissª²Prot database and Unigene database of human, cattle and mouse. The 1629 ESTs without similarities were considered novel. According to function, the known genes were classified into 7 group and 36.99% of ESTs were classified into the gene expression group. The thymus functional genes were expressed in a certain degree (accounting for 7.55%). Comparative expression analysis showed that the gene expression pattern of FTY was very similar to human infant thymus gene expression profile and different from that of adult human. Blast search found that 58 of 109 novel sequences with both poly A and ORF prediction had homologues to human genome sequence. CONCLUSION: EST strategy is economical and virtual in finding new genes. The 100ª²day porcine thymus is still at a developmental stage. ......