Small RNA molecules that regulate and stabilize the expression of certain genes in humans may also promote and preserve variations in gene expression between individuals and ethnic groups.

Jian Lu and Andrew Clark at Cornell University in Ithaca, New York, examined the expression profiles of protein-coding genes that are influenced by microRNAs (miRNAs) and were obtained from multiple human populations. The authors compared these profiles with those of genes not targeted by miRNAs. Expression of some of the miRNA-regulated genes varied little across populations, or between humans, chimpanzees and macaques. However, most differed from one individual to another and between ethnic groups.

Genome Res. http://dx.doi.org/10.1101/gr.132514.111 (2012)