© ISTOCK.COM/OLIANA/ANNA_LENIThroughout the genomes of mammals and plants, certain genes carry marks that indicate whether they came from mom or dad. Typically, these marks are methyl groups that regulate gene expression so that one parent’s allele is selectively expressed. Together, these imprinted genes make up the imprintome.
Scientists used to search for imprinted genes one by one, but thanks to modern sequencing techniques, they can now scan entire genomes. The precise size of the imprintome is uncertain. Estimates suggest there are approximately 100 to 150 or so imprinted genes in humans and in mice, and 90 or more in the plant model Arabidopsis thaliana. Many imprinted regions of the genome can contain sequence variants linked to human diseases, such as diabetes. Because only one copy of an imprinted gene is expressed, loss-of-function mutations are more likely to cause problems in an imprinted situation.
Identifying a full list of imprinted genes for humans and model organisms will give scientists a springboard to characterize the mechanisms and functions of imprinting, says Ian Morison of ...
