Analysis Of Expressed Sequence Tags Of Heart Tissues From Two Breeds Of Pigs

EST(Expression sequence tag) is a 60-500bp sequence, which is acquired by sequencing a randomly picked cDNA clone from a cDNA library from its 3 prime or 5 prime end.In mammalian genomes, the most part of sequences are non-expressed "junk" sequences. ESTS Sequencing can acquire the expressed part of genome, the genes fast and efficiently. ESTs can be used to recognize genes, such as new gene family member of the same species, similar function genes of different species, alternative splicing forms of the same genes. ESTs are also used in gene prediction and genome mapping. Large-scale EST sequencing can denote expression level of genes in a specific tissue or development stage. Comparing the gene expression profiles among different tissues or development stages can help to understand the functions and relationship of genes.To study the expression profiles in the heart tissues of domestic pigs, five un-normalized cDNA libraries from Danish adult female Landrace heart, biceps femoris, aorta, left ventricle tissues and Chinese adult female Erhualian heart tissue were constructed. Totally 35180 ESTS were randomly sequenced. Using functional clustering and statistic methods, three gene clusters and 47 genes highly expressed in Landrace heart tissue were found, these genes are corresponding to the chaperone activity, motor activity and physiology process, implying the functional importance of the protection and movement process in heart. Between the two pig breeds, most of the differentially expressed genes are related with energy metabolism and catalytic activity, of which the majority are highly expressed in Landrace. The results indicated that the physiological activities of Landrace heart are more active and effective than Erhualian heart.