Sequencing of porcine genes using full-length enriched cDNA libraries: Contribution to annotation of the draft sequence of pig genome

H. Uenishi, T. Morozumi, D. Toki, M. Tanaka-Matsuda, T. Eguchi-Ogawa, L. Rund, L.B. Schook
Plant and Animal Genome XVIII Conference, January 10-14, 2010, San Diego, CA


Comprehensive determination of nucleotide sequences of expressed genes is useful for genome annotation as well as investigation of correlation between genes and traits. We have performed large-scale EST analysis in pigs by using 28 full-length-enriched cDNA libraries derived from 25 kinds of tissues and cells, including four tissues (brain, ovary, colon, and hypothalamus) derived from pigs that were cloned from a Duroc individual, T. J. Tabasco, which has been subjected to genome sequencing. To date, we have obtained more than 270,000 high-quality EST reads from 5´-ends of the cDNA clones. By comparison with the human, mouse, dog and cattle gene catalogues the ESTs thus obtained were estimated to correspond to 15,000 genes at least. The cDNA clones represented contigs and singlets that were generated by assembling of the EST reads were subjected to full-length determination of the inserts. The cDNA sequencing was conducted mainly by a primer-walking method, but we also used in part a method of transposon shotgun sequencing combined with clone pooling. We have finished sequencing of 19,515 cDNA clones, which are regarded to correspond to more than 11,000 different loci on the pig genome. The ESTs and cDNA sequences derived from the full-length-enriched libraries are valuable for estimation of gene locations on the draft sequence of pig genome.