Abstract:
Genomic imprinting is an epigenetic phenomenon in which the levels of allelic expression is dependent upon parental origin. In mammals >100 genes have been shown to be imprinted, mainly by studies in humans and mice. Studies in other mammals for imprinted genes are relatively sparse and have generally been limited to either an ad hoc single gene analysis or analyses on "unnatural" systems such as uniparental embryos. Some genes are imprinted in all tissues throughout all stages of development whereas others are imprinted in e.g. a particular stage of development. Imprinted genes play important roles in many stages of development, and dysregulation of imprinted genes can result in diseases such as cancer and neurological disorders. Since the pig is one of the most widely used model organism for human diseases and biomedical research; a comprehensive investigation of imprinted genes in pigs would contribute to achieve a detailed understanding of the evolution of imprinted genes in relation to their key role in brain development, regulation of growth and reproduction. High-throughput DNA sequencing of transcriptomes is a powerful tool to distinguish allele specific expression, hereby making it a very valuable method for detecting imprinted genes. This study aims to detect the whole range of imprinted genes (the imprintome) in the placenta of pigs. Pig cDNA from placenta of a clone of the pig genome sequenced (TJ Tabasco) was paired-end sequenced by the Illumina GA2 technology. These RNA-seq sequences will be compared against SNPs for which TJ Tabasco is known to be heterozygous, to detect mono-allelic expression. Results from these analyses will be presented and related to the imprintome of other mammals.