RNA is complementary to the DNA sequence from which it is transcribed. Therefore, interactions between DNA and RNA provide a simple mechanism of genetic self-detection within nuclei. Imprinted RNAs could enable alleles of maternal and paternal origin to detect whether they are the same (homozygous) or different (heterozygous), and thereby provide strategic information about expected relatedness to siblings.
Haig, DavidengEngland2013/10/18 06:00Biol Lett. 2013 Oct 16;9(6):20130199. doi: 10.1098/rsbl.2013.0199. Print 2013.