The human neocortex is characterized by protracted developmental intervals of synaptogenesis and myelination, which allow for an extended period of learning. The molecular basis of these and other postnatal developmental changes in the human cerebral cortex remain incompletely understood. Recently, a new large class of mammalian genes, encoding nonmessenger, long nonprotein-coding ribonucleic acid (lncRNA) molecules has been discovered. Although their function remains uncertain, numerous lncRNAs have primate-specific sequences and/or show evidence of rapid, lineage-specific evolution, making them potentially relevant to the evolution of unique human neural properties.
To examine the hypothesis that lncRNA expression varies with age, potentially paralleling known developmental trends in synaptogenesis, myelination, and energetics, a team led by researchers at Wayne State University quantified levels of nearly 6000 lncRNAs in 36 surgically resected human neocortical samples (primarily derived from temporal cortex) spanning infancy to adulthood. Their analysis identified 8 lncRNA genes with distinct developmental expression patterns. These lncRNA genes contained anthropoid-specific exons, as well as splice sites and polyadenylation signals that resided in primate-specific sequences. The team believes their study is the first to describe developmental expression profiles of lncRNA in surgically resected in vivo human brain tissue. Future analysis of the functional relevance of these transcripts to neural development and energy metabolism is warranted.
- Lipovich L, Tarca AL, Cai J, Jia H, Chugani HT, Sterner KN, Grossman LI, Uddin M, Hof PR, Sherwood CC, Kuzawa CW, Goodman M, Wildman DE. (2013) Developmental Changes in the Transcriptome of Human Cerebral Cortex Tissue: Long Noncoding RNA Transcripts. Cereb Cortex [Epub ahead of print]. [abstract]