An RNA gene expressed during cortical development evolved rapidly in humans.
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.
Pollard
Katherine S
KS
Center for Biomolecular Science & Engineering, Department of Molecular, Cell & Developmental Biology, University of California, Santa Cruz, California 95064, USA.
Salama
Sofie R
SR
Lambert
Nelle
N
Lambot
Marie-Alexandra
MA
Coppens
Sandra
S
Pedersen
Jakob S
JS
Katzman
Sol
S
King
Bryan
B
Onodera
Courtney
C
Siepel
Adam
A
Kern
Andrew D
AD
Dehay
Colette
C
Igel
Haller
H
Ares
Manuel
M
Vanderhaeghen
Pierre
P
Haussler
David
D
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
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