title: An RNA gene expressed during cortical development evolved rapidly in humans.
abstract: The developmental and evolutionary mechanisms behind the emergence of human-specific brain features remain largely unknown. However, the recent ability to compare our genome to that of our closest relative, the chimpanzee, provides new avenues to link genetic and phenotypic changes in the evolution of the human brain. We devised a ranking of regions in the human genome that show significant evolutionary acceleration. Here we report that the most dramatic of these 'human accelerated regions', HAR1, is part of a novel RNA gene (HAR1F) that is expressed specifically in Cajal-Retzius neurons in the developing human neocortex from 7 to 19 gestational weeks, a crucial period for cortical neuron specification and migration. HAR1F is co-expressed with reelin, a product of Cajal-Retzius neurons that is of fundamental importance in specifying the six-layer structure of the human cortex. HAR1 and the other human accelerated regions provide new candidates in the search for uniquely human biology.
authors.affiliation: Center for Biomolecular Science & Engineering, Department of Molecular, Cell & Developmental Biology, University of California, Santa Cruz, California 95064, USA.
authors.forename: Katherine S
authors.initials: KS
authors.lastname: Pollard
authors.forename: Sofie R
authors.initials: SR
authors.lastname: Salama
authors.forename: Nelle
authors.initials: N
authors.lastname: Lambert
authors.forename: Marie-Alexandra
authors.initials: MA
authors.lastname: Lambot
authors.forename: Sandra
authors.initials: S
authors.lastname: Coppens
authors.forename: Jakob S
authors.initials: JS
authors.lastname: Pedersen
authors.forename: Sol
authors.initials: S
authors.lastname: Katzman
authors.forename: Bryan
authors.initials: B
authors.lastname: King
authors.forename: Courtney
authors.initials: C
authors.lastname: Onodera
authors.forename: Adam
authors.initials: A
authors.lastname: Siepel
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Kern
authors.forename: Colette
authors.initials: C
authors.lastname: Dehay
authors.forename: Haller
authors.initials: H
authors.lastname: Igel
authors.forename: Manuel
authors.initials: M
authors.lastname: Ares
authors.forename: Pierre
authors.initials: P
authors.lastname: Vanderhaeghen
authors.forename: David
authors.initials: D
authors.lastname: Haussler
mesh_terms: D000375:Aging / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000196:embryology* / Q000378:metabolism*; D019143:Evolution, Molecular; D016326:Extracellular Matrix Proteins / Q000235:genetics; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008251:Macaca / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D019579:Neocortex / Q000033:anatomy & histology / Q000196:embryology / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics; D009690:Nucleic Acid Conformation; D009928:Organ Specificity; D020871:RNA Stability; D022661:RNA, Untranslated / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000091042:Reelin Protein; D012697:Serine Endopeptidases / Q000235:genetics; D013997:Time Factors
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D009419:Nerve Tissue Proteins; D022661:RNA, Untranslated; D000091042:Reelin Protein; C000717127:RELN protein, human; D012697:Serine Endopeptidases