MicroRNA expression in primate postnatal brain through lifespan

While multiple studies have reported the accelerated evolution of brain gene expression in the human lineage, the mechanisms underlying such change remain poorly understood. Here we address this issue from a developmental perspective, by analyzing mRNA and microRNA (miRNA) expression in two brain regions within macaques, chimpanzees and humans throughout their lifespan. We find that developmental profiles of trans-regulators, such as miRNA, as well as their target genes, show the fastest rates of human-specific evolutionary change. Changes in expression of a few key regulators may be a major driving force behind human brain evolution. Human, chimpanzee and rhesus macaque post-mortem brain samples from the prefrontal cortex and cerebellar cortex were collected. The age ranges of the individuals in all three species covered the respective species' postnatal maturation period from infancy to old adulthood. RNA extracted from the dissected tissue was hybridized to B72.