- Baran, Yael;
- Subramaniam, Meena;
- Biton, Anne;
- Tukiainen, Taru;
- Tsang, Emily K;
- Rivas, Manuel A;
- Pirinen, Matti;
- Gutierrez-Arcelus, Maria;
- Smith, Kevin S;
- Kukurba, Kim R;
- Zhang, Rui;
- Eng, Celeste;
- Torgerson, Dara G;
- Urbanek, Cydney;
- Consortium, the GTEx;
- Li, Jin Billy;
- Rodriguez-Santana, Jose R;
- Burchard, Esteban G;
- Seibold, Max A;
- MacArthur, Daniel G;
- Montgomery, Stephen B;
- Zaitlen, Noah A;
- Lappalainen, Tuuli
Genomic imprinting is an important regulatory mechanism that silences one of the parental copies of a gene. To systematically characterize this phenomenon, we analyze tissue specificity of imprinting from allelic expression data in 1582 primary tissue samples from 178 individuals from the Genotype-Tissue Expression (GTEx) project. We characterize imprinting in 42 genes, including both novel and previously identified genes. Tissue specificity of imprinting is widespread, and gender-specific effects are revealed in a small number of genes in muscle with stronger imprinting in males. IGF2 shows maternal expression in the brain instead of the canonical paternal expression elsewhere. Imprinting appears to have only a subtle impact on tissue-specific expression levels, with genes lacking a systematic expression difference between tissues with imprinted and biallelic expression. In summary, our systematic characterization of imprinting in adult tissues highlights variation in imprinting between genes, individuals, and tissues.