Guanine Nucleotide Binding Protein (GNAS Complex Locus) Gene Produces Biallelically Expressed and Paternally Expressed Transcripts in Pigs

Imprinted loci are a subset of genes expressed only from one parental allele. Guanine nucleotide binding protein (GNAS complex locus) produces a few different proteins and noncoding RNAs. It is imprinted in mice and humans, while in pigs imprinting status of only one of them - NESP55 (neuroendocrine secretory protein-55) has been established. In the present study we aimed to establish imprinting status of the other two GNAS transcripts. We collected a panel of tissues (muscle, liver, kidney cortex, heart, fat, ovary, brain, blood) from the animals (aged 40-210 days) heterozygous in rs#333005482 polymorphism. We performed several RT -PCRs (Reverse Transcription Polymerase Chain Reactions) with variant specific primers and sequenced the cDNA products obtained. We observed only paternal allele in all tissues at all developmental stages after sequencing with primers specific to variant 8 of GNAS gene and both alleles when sequencing with primers specific to variant 6. Our results show for the first time that, in pigs, GNAS complex locus produces biallelically expressed and paternally expressed transcripts, in the same way as previously demonstrated in mice and humans