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Human and African ape myosin heavy chain content and the evolution of hominin skeletal muscle. Comp Biochem Physiol A Mol Integr Physiol 2023; 281:111415. [PMID: 36931425 DOI: 10.1016/j.cbpa.2023.111415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/13/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023]
Abstract
Humans are unique among terrestrial mammals in our manner of walking and running, reflecting 7 to 8 Ma of musculoskeletal evolution since diverging with the genus Pan. One component of this is a shift in our skeletal muscle biology towards a predominance of myosin heavy chain (MyHC) I isoforms (i.e. slow fibers) across our pelvis and lower limbs, which distinguishes us from chimpanzees. Here, new MyHC data from 35 pelvis and hind limb muscles of a Western gorilla (Gorilla gorilla) are presented. These data are combined with a similar chimpanzee dataset to assess the MyHC I content of humans in comparison to African apes (chimpanzees and gorillas) and other terrestrial mammals. The responsiveness of human skeletal muscle to behavioral interventions is also compared to the human-African ape differential. Humans are distinct from African apes and among a small group of terrestrial mammals whose pelvis and hind/lower limb muscle is slow fiber dominant, on average. Behavioral interventions, including immobilization, bed rest, spaceflight and exercise, can induce modest decreases and increases in human MyHC I content (i.e. -9.3% to 2.3%, n = 2033 subjects), but these shifts are much smaller than the mean human-African ape differential (i.e. 31%). Taken together, these results indicate muscle fiber content is likely an evolvable trait under selection in the hominin lineage. As such, we highlight potential targets of selection in the genome (e.g. regions that regulate MyHC content) that may play an important role in hominin skeletal muscle evolution.
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2
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A Systematic Review of the Human Accelerated Regions in Schizophrenia and Related Disorders: Where the Evolutionary and Neurodevelopmental Hypotheses Converge. Int J Mol Sci 2023; 24:ijms24043597. [PMID: 36835010 PMCID: PMC9962562 DOI: 10.3390/ijms24043597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/03/2023] [Accepted: 02/07/2023] [Indexed: 02/15/2023] Open
Abstract
Schizophrenia is a psychiatric disorder that results from genetic and environmental factors interacting and disrupting neurodevelopmental trajectories. Human Accelerated Regions (HARs) are evolutionarily conserved genomic regions that have accumulated human-specific sequence changes. Thus, studies on the impact of HARs in the context of neurodevelopment, as well as with respect to adult brain phenotypes, have increased considerably in the last few years. Through a systematic approach, we aim to offer a comprehensive review of HARs' role in terms of human brain development, configuration, and cognitive abilities, as well as whether HARs modulate the susceptibility to neurodevelopmental psychiatric disorders such as schizophrenia. First, the evidence in this review highlights HARs' molecular functions in the context of the neurodevelopmental regulatory genetic machinery. Second, brain phenotypic analyses indicate that HAR genes' expression spatially correlates with the regions that suffered human-specific cortical expansion, as well as with the regional interactions for synergistic information processing. Lastly, studies based on candidate HAR genes and the global "HARome" variability describe the involvement of these regions in the genetic background of schizophrenia, but also in other neurodevelopmental psychiatric disorders. Overall, the data considered in this review emphasise the crucial role of HARs in human-specific neurodevelopment processes and encourage future research on this evolutionary marker for a better understanding of the genetic basis of schizophrenia and other neurodevelopmental-related psychiatric disorders. Accordingly, HARs emerge as interesting genomic regions that require further study in order to bridge the neurodevelopmental and evolutionary hypotheses in schizophrenia and other related disorders and phenotypes.
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Linker SB, Narvaiza I, Hsu JY, Wang M, Qiu F, Mendes APD, Oefner R, Kottilil K, Sharma A, Randolph-Moore L, Mejia E, Santos R, Marchetto MC, Gage FH. Human-specific regulation of neural maturation identified by cross-primate transcriptomics. Curr Biol 2022; 32:4797-4807.e5. [PMID: 36228612 DOI: 10.1016/j.cub.2022.09.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 07/08/2022] [Accepted: 09/14/2022] [Indexed: 11/06/2022]
Abstract
Unique aspects of human behavior are often attributed to differences in the relative size and organization of the human brain: these structural aspects originate during early development. Recent studies indicate that human neurodevelopment is considerably slower than that in other nonhuman primates, a finding that is termed neoteny. One aspect of neoteny is the slow onset of action potentials. However, which molecular mechanisms play a role in this process remain unclear. To examine the evolutionary constraints on the rate of neuronal maturation, we have generated transcriptional data tracking five time points, from the neural progenitor state to 8-week-old neurons, in primates spanning the catarrhine lineage, including Macaca mulatta, Gorilla gorilla, Pan paniscus, Pan troglodytes, and Homo sapiens. Despite finding an overall similarity of many transcriptional signatures, species-specific and clade-specific distinctions were observed. Among the genes that exhibited human-specific regulation, we identified a key pioneer transcription factor, GATA3, that was uniquely upregulated in humans during the neuronal maturation process. We further examined the regulatory nature of GATA3 in human cells and observed that downregulation quickened the speed of developing spontaneous action potentials, thereby modulating the human neotenic phenotype. These results provide evidence for the divergence of gene regulation as a key molecular mechanism underlying human neoteny.
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Affiliation(s)
- Sara B Linker
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 North Pines Road, La Jolla, CA 92037, USA
| | - Iñigo Narvaiza
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 North Pines Road, La Jolla, CA 92037, USA
| | - Jonathan Y Hsu
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 North Pines Road, La Jolla, CA 92037, USA
| | - Meiyan Wang
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 North Pines Road, La Jolla, CA 92037, USA
| | - Fan Qiu
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 North Pines Road, La Jolla, CA 92037, USA
| | - Ana P D Mendes
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 North Pines Road, La Jolla, CA 92037, USA
| | - Ruth Oefner
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 North Pines Road, La Jolla, CA 92037, USA
| | - Kalyani Kottilil
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 North Pines Road, La Jolla, CA 92037, USA
| | - Amandeep Sharma
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 North Pines Road, La Jolla, CA 92037, USA
| | - Lynne Randolph-Moore
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 North Pines Road, La Jolla, CA 92037, USA
| | - Eunice Mejia
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 North Pines Road, La Jolla, CA 92037, USA
| | - Renata Santos
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 North Pines Road, La Jolla, CA 92037, USA; Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Laboratory of Dynamics of Neuronal Structure in Health and Disease, 102 rue de la Santé, 75014 Paris, France; Institut des Sciences Biologiques, CNRS, 16 rue Pierre et Marie Curie, 75005 Paris, France
| | - Maria C Marchetto
- Department of Anthropology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Center for Academic Research and Training in Anthropogeny (CARTA), University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
| | - Fred H Gage
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 North Pines Road, La Jolla, CA 92037, USA.
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4
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Schmidt ERE, Polleux F. Genetic Mechanisms Underlying the Evolution of Connectivity in the Human Cortex. Front Neural Circuits 2022; 15:787164. [PMID: 35069126 PMCID: PMC8777274 DOI: 10.3389/fncir.2021.787164] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/09/2021] [Indexed: 12/22/2022] Open
Abstract
One of the most salient features defining modern humans is our remarkable cognitive capacity, which is unrivaled by any other species. Although we still lack a complete understanding of how the human brain gives rise to these unique abilities, the past several decades have witnessed significant progress in uncovering some of the genetic, cellular, and molecular mechanisms shaping the development and function of the human brain. These features include an expansion of brain size and in particular cortical expansion, distinct physiological properties of human neurons, and modified synaptic development. Together they specify the human brain as a large primate brain with a unique underlying neuronal circuit architecture. Here, we review some of the known human-specific features of neuronal connectivity, and we outline how novel insights into the human genome led to the identification of human-specific genetic modifiers that played a role in the evolution of human brain development and function. Novel experimental paradigms are starting to provide a framework for understanding how the emergence of these human-specific genomic innovations shaped the structure and function of neuronal circuits in the human brain.
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Affiliation(s)
- Ewoud R. E. Schmidt
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
- *Correspondence: Ewoud R. E. Schmidt
| | - Franck Polleux
- Department of Neuroscience, Columbia University, New York, NY, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States
- Kavli Institute for Brain Science, Columbia University, New York, NY, United States
- Franck Polleux
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5
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Liu J, Mosti F, Silver DL. Human brain evolution: Emerging roles for regulatory DNA and RNA. Curr Opin Neurobiol 2021; 71:170-177. [PMID: 34861533 PMCID: PMC8756680 DOI: 10.1016/j.conb.2021.11.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 09/03/2021] [Accepted: 11/02/2021] [Indexed: 12/18/2022]
Abstract
Humans diverge from other primates in numerous ways, including their neuroanatomy and cognitive capacities. Human-specific features are particularly prominent in the cerebral cortex, which has undergone an expansion in size and acquired unique cellular composition and circuitry. Human-specific gene expression is postulated to explain neocortical anatomical differences across evolution. In particular, noncoding regulatory loci are strongly linked to human traits, including progenitor proliferation and cortical size. In this review, we highlight emerging noncoding elements implicated in human cortical evolution, including roles for regulatory DNA and RNA. Further, we discuss the association of human-specific genetic changes with neurodevelopmental diseases.
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Affiliation(s)
- Jing Liu
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Federica Mosti
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Debra L Silver
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA; Duke Regeneration Center and Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC 277710, USA.
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6
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Ferrari R, Grandi N, Tramontano E, Dieci G. Retrotransposons as Drivers of Mammalian Brain Evolution. Life (Basel) 2021; 11:life11050376. [PMID: 33922141 PMCID: PMC8143547 DOI: 10.3390/life11050376] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 12/11/2022] Open
Abstract
Retrotransposons, a large and diverse class of transposable elements that are still active in humans, represent a remarkable force of genomic innovation underlying mammalian evolution. Among the features distinguishing mammals from all other vertebrates, the presence of a neocortex with a peculiar neuronal organization, composition and connectivity is perhaps the one that, by affecting the cognitive abilities of mammals, contributed mostly to their evolutionary success. Among mammals, hominids and especially humans display an extraordinarily expanded cortical volume, an enrichment of the repertoire of neural cell types and more elaborate patterns of neuronal connectivity. Retrotransposon-derived sequences have recently been implicated in multiple layers of gene regulation in the brain, from transcriptional and post-transcriptional control to both local and large-scale three-dimensional chromatin organization. Accordingly, an increasing variety of neurodevelopmental and neurodegenerative conditions are being recognized to be associated with retrotransposon dysregulation. We review here a large body of recent studies lending support to the idea that retrotransposon-dependent evolutionary novelties were crucial for the emergence of mammalian, primate and human peculiarities of brain morphology and function.
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Affiliation(s)
- Roberto Ferrari
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy;
| | - Nicole Grandi
- Laboratory of Molecular Virology, Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, 09042 Monserrato, Italy; (N.G.); (E.T.)
| | - Enzo Tramontano
- Laboratory of Molecular Virology, Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, 09042 Monserrato, Italy; (N.G.); (E.T.)
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, 09042 Monserrato, Italy
| | - Giorgio Dieci
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy;
- Correspondence:
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7
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Franchini LF. Genetic Mechanisms Underlying Cortical Evolution in Mammals. Front Cell Dev Biol 2021; 9:591017. [PMID: 33659245 PMCID: PMC7917222 DOI: 10.3389/fcell.2021.591017] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 01/08/2021] [Indexed: 12/13/2022] Open
Abstract
The remarkable sensory, motor, and cognitive abilities of mammals mainly depend on the neocortex. Thus, the emergence of the six-layered neocortex in reptilian ancestors of mammals constitutes a fundamental evolutionary landmark. The mammalian cortex is a columnar epithelium of densely packed cells organized in layers where neurons are generated mainly in the subventricular zone in successive waves throughout development. Newborn cells move away from their site of neurogenesis through radial or tangential migration to reach their specific destination closer to the pial surface of the same or different cortical area. Interestingly, the genetic programs underlying neocortical development diversified in different mammalian lineages. In this work, I will review several recent studies that characterized how distinct transcriptional programs relate to the development and functional organization of the neocortex across diverse mammalian lineages. In some primates such as the anthropoids, the neocortex became extremely large, especially in humans where it comprises around 80% of the brain. It has been hypothesized that the massive expansion of the cortical surface and elaboration of its connections in the human lineage, has enabled our unique cognitive capacities including abstract thinking, long-term planning, verbal language and elaborated tool making capabilities. I will also analyze the lineage-specific genetic changes that could have led to the modification of key neurodevelopmental events, including regulation of cell number, neuronal migration, and differentiation into specific phenotypes, in order to shed light on the evolutionary mechanisms underlying the diversity of mammalian brains including the human brain.
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Affiliation(s)
- Lucía Florencia Franchini
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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8
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Caporale AL, Gonda CM, Franchini LF. Transcriptional Enhancers in the FOXP2 Locus Underwent Accelerated Evolution in the Human Lineage. Mol Biol Evol 2019; 36:2432-2450. [PMID: 31359064 DOI: 10.1093/molbev/msz173] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 04/26/2019] [Accepted: 07/16/2019] [Indexed: 12/11/2022] Open
Abstract
Unique human features such as complex language are the result of molecular evolutionary changes that modified developmental programs of our brain. The human-specific evolution of the forkhead box P2 (FOXP2) gene coding region has been linked to the emergence of speech and language in the human kind. However, little is known about how the expression of FOXP2 is regulated and if its regulatory machinery evolved in a lineage-specific manner in humans. In order to identify FOXP2 regulatory regions containing human-specific changes we used databases of human accelerated non-coding sequences or HARs. We found that the topologically associating domain (TAD) determined using developing human cerebral cortex containing the FOXP2 locus includes two clusters of 12 HARs, placing the locus occupied by FOXP2 among the top regions showing fast acceleration rates in non-coding regions in the human genome. Using in vivo enhancer assays in zebrafish, we found that at least five FOXP2-HARs behave as transcriptional enhancers throughout different developmental stages. In addition, we found that at least two FOXP2-HARs direct the expression of the reporter gene EGFP to foxP2 expressing regions and cells. Moreover, we uncovered two FOXP2-HARs showing reporter expression gain of function in the nervous system when compared with the chimpanzee ortholog sequences. Our results indicate that regulatory sequences in the FOXP2 locus underwent a human-specific evolutionary process suggesting that the transcriptional machinery controlling this gene could have also evolved differentially in the human lineage.
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Affiliation(s)
- Alfredo Leandro Caporale
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Consejo de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Catalina M Gonda
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Consejo de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Lucía Florencia Franchini
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Consejo de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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9
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Doan RN, Shin T, Walsh CA. Evolutionary Changes in Transcriptional Regulation: Insights into Human Behavior and Neurological Conditions. Annu Rev Neurosci 2019; 41:185-206. [PMID: 29986162 DOI: 10.1146/annurev-neuro-080317-062104] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Understanding the biological basis for human-specific cognitive traits presents both immense challenges and unique opportunities. Although the question of what makes us human has been investigated with several different methods, the rise of comparative genomics, epigenomics, and medical genetics has provided tools to help narrow down and functionally assess the regions of the genome that seem evolutionarily relevant along the human lineage. In this review, we focus on how medical genetic cases have provided compelling functional evidence for genes and loci that appear to have interesting evolutionary signatures in humans. Furthermore, we examine a special class of noncoding regions, human accelerated regions (HARs), that have been suggested to show human-lineage-specific divergence, and how the use of clinical and population data has started to provide functional information to examine these regions. Finally, we outline methods that provide new insights into functional noncoding sequences in evolution.
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Affiliation(s)
- Ryan N Doan
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts 02115, USA; .,Allen Discovery Center for Human Brain Evolution, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Howard Hughes Medical Institute, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Taehwan Shin
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts 02115, USA; .,Allen Discovery Center for Human Brain Evolution, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Christopher A Walsh
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts 02115, USA; .,Allen Discovery Center for Human Brain Evolution, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Howard Hughes Medical Institute, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Departments of Pediatrics and Neurology, Harvard Medical School, Boston, Massachusetts 02138, USA
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10
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Levchenko A, Kanapin A, Samsonova A, Gainetdinov RR. Human Accelerated Regions and Other Human-Specific Sequence Variations in the Context of Evolution and Their Relevance for Brain Development. Genome Biol Evol 2018; 10:166-188. [PMID: 29149249 PMCID: PMC5767953 DOI: 10.1093/gbe/evx240] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2017] [Indexed: 12/24/2022] Open
Abstract
The review discusses, in a format of a timeline, the studies of different types of genetic variants, present in Homo sapiens, but absent in all other primate, mammalian, or vertebrate species, tested so far. The main characteristic of these variants is that they are found in regions of high evolutionary conservation. These sequence variations include single nucleotide substitutions (called human accelerated regions), deletions, and segmental duplications. The rationale for finding such variations in the human genome is that they could be responsible for traits, specific to our species, of which the human brain is the most remarkable. As became obvious, the vast majority of human-specific single nucleotide substitutions are found in noncoding, likely regulatory regions. A number of genes, associated with these human-specific alleles, often through novel enhancer activity, were in fact shown to be implicated in human-specific development of certain brain areas, including the prefrontal cortex. Human-specific deletions may remove regulatory sequences, such as enhancers. Segmental duplications, because of their large size, create new coding sequences, like new functional paralogs. Further functional study of these variants will shed light on evolution of our species, as well as on the etiology of neurodevelopmental disorders.
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Affiliation(s)
- Anastasia Levchenko
- Institute of Translational Biomedicine, Saint Petersburg State University, Russia
| | - Alexander Kanapin
- Institute of Translational Biomedicine, Saint Petersburg State University, Russia
- Department of Oncology, University of Oxford, United Kingdom
| | - Anastasia Samsonova
- Institute of Translational Biomedicine, Saint Petersburg State University, Russia
- Department of Oncology, University of Oxford, United Kingdom
| | - Raul R Gainetdinov
- Institute of Translational Biomedicine, Saint Petersburg State University, Russia
- Skolkovo Institute of Science and Technology, Skolkovo, Moscow, Russia
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11
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Montgomery SH, Mundy NI, Barton RA. Brain evolution and development: adaptation, allometry and constraint. Proc Biol Sci 2017; 283:rspb.2016.0433. [PMID: 27629025 DOI: 10.1098/rspb.2016.0433] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 08/19/2016] [Indexed: 01/08/2023] Open
Abstract
Phenotypic traits are products of two processes: evolution and development. But how do these processes combine to produce integrated phenotypes? Comparative studies identify consistent patterns of covariation, or allometries, between brain and body size, and between brain components, indicating the presence of significant constraints limiting independent evolution of separate parts. These constraints are poorly understood, but in principle could be either developmental or functional. The developmental constraints hypothesis suggests that individual components (brain and body size, or individual brain components) tend to evolve together because natural selection operates on relatively simple developmental mechanisms that affect the growth of all parts in a concerted manner. The functional constraints hypothesis suggests that correlated change reflects the action of selection on distributed functional systems connecting the different sub-components, predicting more complex patterns of mosaic change at the level of the functional systems and more complex genetic and developmental mechanisms. These hypotheses are not mutually exclusive but make different predictions. We review recent genetic and neurodevelopmental evidence, concluding that functional rather than developmental constraints are the main cause of the observed patterns.
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Affiliation(s)
- Stephen H Montgomery
- Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Nicholas I Mundy
- Department of Zoology, University of Cambridge, St Andrews Street, Cambridge CB2 3EJ, UK
| | - Robert A Barton
- Evolutionary Anthropology Research Group, Durham University, Dawson Building, South Road, Durham DH1 3LE, UK
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12
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Abstract
What made us human? Gene expression changes clearly played a significant part in human evolution, but pinpointing the causal regulatory mutations is hard. Comparative genomics enabled the identification of human accelerated regions (HARs) and other human-specific genome sequences. The major challenge in the past decade has been to link diverged sequences to uniquely human biology. This review discusses approaches to this problem, progress made at the molecular level, and prospects for moving towards genetic causes for uniquely human biology.
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Affiliation(s)
- Lucía F Franchini
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Katherine S Pollard
- Gladstone Institutes, San Francisco, CA, 94158, USA. .,Department of Epidemiology & Biostatistics, Institute for Human Genetics, Institute for Computational Health Sciences, University of California, San Francisco, CA, 94158, USA.
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13
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Enhancing our brains: Genomic mechanisms underlying cortical evolution. Semin Cell Dev Biol 2017; 76:23-32. [PMID: 28864345 DOI: 10.1016/j.semcdb.2017.08.045] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 08/24/2017] [Indexed: 12/31/2022]
Abstract
Our most distinguishing higher cognitive functions are controlled by the cerebral cortex. Comparative studies detail abundant anatomical and cellular features unique to the human developing and adult neocortex. Emerging genomic studies have further defined vast differences distinguishing developing human neocortices from related primates. These human-specific changes can affect gene function and/or expression, and result from structural variations such as chromosomal deletions and duplications, or from point mutations in coding and noncoding regulatory regions. Here, we review this rapidly growing field which aims to identify and characterize genetic loci unique to the human cerebral cortex. We catalog known human-specific genomic changes distinct from other primates, including those whose function has been interrogated in animal models. We also discuss how new model systems and technologies such as single cell RNA sequencing, primate iPSCs, and gene editing, are enabling the field to gain unprecedented resolution into function of these human-specific changes. Some neurological disorders are thought to uniquely present in humans, thus reinforcing the need to comprehensively understand human-specific gene expression in the developing brain.
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14
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Michaelson JJ, Shin MK, Koh JY, Brueggeman L, Zhang A, Katzman A, McDaniel L, Fang M, Pufall M, Pieper AA. Neuronal PAS Domain Proteins 1 and 3 Are Master Regulators of Neuropsychiatric Risk Genes. Biol Psychiatry 2017; 82:213-223. [PMID: 28499489 PMCID: PMC6901278 DOI: 10.1016/j.biopsych.2017.03.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/17/2017] [Accepted: 03/21/2017] [Indexed: 12/17/2022]
Abstract
BACKGROUND NPAS3 has been established as a robust genetic risk factor in major mental illness. In mice, loss of neuronal PAS domain protein 3 (NPAS3) impairs postnatal hippocampal neurogenesis, while loss of the related protein NPAS1 promotes it. These and other findings suggest a critical role for NPAS proteins in neuropsychiatric functioning, prompting interest in the molecular pathways under their control. METHODS We used RNA sequencing coupled with chromatin immunoprecipitation sequencing to identify genes directly regulated by NPAS1 and NPAS3 in the hippocampus of wild-type, Npas1-/-, and Npas3-/- mice. Computational integration with human genetic and expression data revealed the disease relevance of NPAS-regulated genes and pathways. Specific findings were confirmed at the protein level by Western blot. RESULTS This is the first in vivo, transcriptome-scale investigation of genes regulated by NPAS1 and NPAS3. These transcription factors control an ensemble of genes that are themselves also major regulators of neuropsychiatric function. Specifically, Fmr1 (fragile X syndrome) and Ube3a (Angelman syndrome) are transcriptionally regulated by NPAS3, as is the neurogenesis regulator Notch. Dysregulation of these pathways was confirmed at the protein level. Furthermore, NPAS1/3 targets show increased human genetic burden for schizophrenia and intellectual disability. CONCLUSIONS Together, these data provide a clear, unbiased view of the full spectrum of genes regulated by NPAS1 and NPAS3 and show that these transcription factors are master regulators of neuropsychiatric function. These findings expose the molecular pathophysiology of NPAS1/3 mutations and provide a striking example of the shared, combinatorial nature of molecular pathways that underlie diagnostically distinct neuropsychiatric conditions.
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Affiliation(s)
- Jacob J Michaelson
- Department of Psychiatry, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa College of Engineering, University of Iowa, Iowa City, Iowa; Department of Communication Sciences and Disorders, University of Iowa College of Liberal Arts and Sciences, University of Iowa, Iowa City, Iowa; Iowa Institute of Human Genetics, University of Iowa, Iowa City, Iowa; Genetics Cluster Initiative, University of Iowa, Iowa City, Iowa; The DeLTA Center, University of Iowa, Iowa City, Iowa; University of Iowa Informatics Initiative, University of Iowa, Iowa City, Iowa.
| | - Min-Kyoo Shin
- Department of Psychiatry, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Jin-Young Koh
- Department of Psychiatry, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Leo Brueggeman
- Department of Psychiatry, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Angela Zhang
- Department of Psychiatry, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Aaron Katzman
- Department of Psychiatry, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Latisha McDaniel
- Department of Psychiatry, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Mimi Fang
- Department of Biochemistry, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Miles Pufall
- Department of Biochemistry, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Andrew A Pieper
- Department of Psychiatry, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa; Department of Neurology, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa; Free Radical and Radiation Biology Program, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa; Department of Veterans Affairs, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa; Pappajohn Biomedical Institute, University of Iowa, Iowa City, Iowa; Weill Cornell Autism Research Program, Weill Cornell Medicine, Cornell University, New York, New York
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15
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Sousa AMM, Meyer KA, Santpere G, Gulden FO, Sestan N. Evolution of the Human Nervous System Function, Structure, and Development. Cell 2017; 170:226-247. [PMID: 28708995 DOI: 10.1016/j.cell.2017.06.036] [Citation(s) in RCA: 216] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 04/21/2017] [Accepted: 06/22/2017] [Indexed: 12/22/2022]
Abstract
The nervous system-in particular, the brain and its cognitive abilities-is among humans' most distinctive and impressive attributes. How the nervous system has changed in the human lineage and how it differs from that of closely related primates is not well understood. Here, we consider recent comparative analyses of extant species that are uncovering new evidence for evolutionary changes in the size and the number of neurons in the human nervous system, as well as the cellular and molecular reorganization of its neural circuits. We also discuss the developmental mechanisms and underlying genetic and molecular changes that generate these structural and functional differences. As relevant new information and tools materialize at an unprecedented pace, the field is now ripe for systematic and functionally relevant studies of the development and evolution of human nervous system specializations.
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Affiliation(s)
- André M M Sousa
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | - Kyle A Meyer
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | - Gabriel Santpere
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | - Forrest O Gulden
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | - Nenad Sestan
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA; Department of Genetics, Yale School of Medicine, New Haven, CT, USA; Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA; Section of Comparative Medicine, Yale School of Medicine, New Haven, CT, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale School of Medicine, New Haven, CT, USA; Yale Child Study Center, Yale School of Medicine, New Haven, CT, USA; Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT, USA.
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16
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Harrison PW, Montgomery SH. Genetics of Cerebellar and Neocortical Expansion in Anthropoid Primates: A Comparative Approach. BRAIN, BEHAVIOR AND EVOLUTION 2017; 89:274-285. [PMID: 28683440 PMCID: PMC5637284 DOI: 10.1159/000477432] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 05/10/2017] [Accepted: 05/10/2017] [Indexed: 12/15/2022]
Abstract
What adaptive changes in brain structure and function underpin the evolution of increased cognitive performance in humans and our close relatives? Identifying the genetic basis of brain evolution has become a major tool in answering this question. Numerous cases of positive selection, altered gene expression or gene duplication have been identified that may contribute to the evolution of the neocortex, which is widely assumed to play a predominant role in cognitive evolution. However, the components of the neocortex co-evolve with other functionally interdependent regions of the brain, most notably in the cerebellum. The cerebellum is linked to a range of cognitive tasks and expanded rapidly during hominoid evolution. Here we present data that suggest that, across anthropoid primates, protein-coding genes with known roles in cerebellum development were just as likely to be targeted by selection as genes linked to cortical development. Indeed, based on currently available gene ontology data, protein-coding genes with known roles in cerebellum development are more likely to have evolved adaptively during hominoid evolution. This is consistent with phenotypic data suggesting an accelerated rate of cerebellar expansion in apes that is beyond that predicted from scaling with the neocortex in other primates. Finally, we present evidence that the strength of selection on specific genes is associated with variation in the volume of either the neocortex or the cerebellum, but not both. This result provides preliminary evidence that co-variation between these brain components during anthropoid evolution may be at least partly regulated by selection on independent loci, a conclusion that is consistent with recent intraspecific genetic analyses and a mosaic model of brain evolution that predicts adaptive evolution of brain structure.
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Affiliation(s)
- Peter W. Harrison
- Department of Genetics, Evolution and Environment, University College London, London, UK
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, UK
| | - Stephen H. Montgomery
- Department of Genetics, Evolution and Environment, University College London, London, UK
- Department of Zoology, University of Cambridge, Cambridge, UK
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17
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Meyer KA, Marques-Bonet T, Sestan N. Differential Gene Expression in the Human Brain Is Associated with Conserved, but Not Accelerated, Noncoding Sequences. Mol Biol Evol 2017; 34:1217-1229. [PMID: 28204568 PMCID: PMC5400397 DOI: 10.1093/molbev/msx076] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Previous studies have found that genes which are differentially expressed within the developing human brain disproportionately neighbor conserved noncoding sequences (CNSs) that have an elevated substitution rate in humans and in other species. One explanation for this general association of differential expression with accelerated CNSs is that genes with pre-existing patterns of differential expression have been preferentially targeted by species-specific regulatory changes. Here we provide support for an alternative explanation: genes that neighbor a greater number of CNSs have a higher probability of differential expression and a higher probability of neighboring a CNS with lineage-specific acceleration. Thus, neighboring an accelerated element from any species signals that a gene likely neighbors many CNSs. We extend the analyses beyond the prenatal time points considered in previous studies to demonstrate that this association persists across developmental and adult periods. Examining differential expression between non-neural tissues suggests that the relationship between the number of CNSs a gene neighbors and its differential expression status may be particularly strong for expression differences among brain regions. In addition, by considering this relationship, we highlight a recently defined set of putative human-specific gain-of-function sequences that, even after adjusting for the number of CNSs neighbored by genes, shows a positive relationship with upregulation in the brain compared with other tissues examined.
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Affiliation(s)
- Kyle A. Meyer
- Department of Neuroscience and Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT
| | - Tomas Marques-Bonet
- Institute of Evolutionary Biology (UPF-CSIC), PRBB, Barcelona, Spain
- Catalan Institution of Research and Advanced Studies (ICREA), Passeig de Lluís Companys, Barcelona, Spain
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Nenad Sestan
- Department of Neuroscience and Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT
- Departments of Genetics and Psychiatry, Section of Comparative Medicine, Program in Cellular Neuroscience, Neurodegeneration and Repair, and Yale Child Study Center, Yale School of Medicine, New Haven, CT
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18
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Orquera DP, Nasif S, Low MJ, Rubinstein M, de Souza FSJ. Essential function of the transcription factor Rax in the early patterning of the mammalian hypothalamus. Dev Biol 2016; 416:212-224. [PMID: 27212025 DOI: 10.1016/j.ydbio.2016.05.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 05/08/2016] [Accepted: 05/16/2016] [Indexed: 12/31/2022]
Abstract
The hypothalamus is a region of the anterior forebrain that controls basic aspects of vertebrate physiology, but the genes involved in its development are still poorly understood. Here, we investigate the function of the homeobox gene Rax/Rx in early hypothalamic development using a conditional targeted inactivation strategy in the mouse. We found that lack of Rax expression prior to embryonic day 8.5 (E8.5) caused a general underdevelopment of the hypothalamic neuroepithelium, while inactivation at later timepoints had little effect. The early absence of Rax impaired neurogenesis and prevented the expression of molecular markers of the dorsomedial hypothalamus, including neuropeptides Proopiomelanocortin and Somatostatin. Interestingly, the expression domains of genes expressed in the ventromedial hypothalamus and infundibulum invaded dorsal hypothalamic territory, showing that Rax is needed for the proper dorsoventral patterning of the developing medial hypothalamus. The phenotypes caused by the early loss of Rax are similar to those of eliminating the expression of the morphogen Sonic hedgehog (Shh) specifically from the hypothalamus. Consistent with this similarity in phenotypes, we observed that Shh and Rax are coexpressed in the rostral forebrain at late head fold stages and that loss of Rax caused a downregulation of Shh expression in the dorsomedial portion of the hypothalamus.
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Affiliation(s)
- Daniela P Orquera
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, 1428 Buenos Aires, Argentina
| | - Sofia Nasif
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, 1428 Buenos Aires, Argentina
| | - Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105, United States
| | - Marcelo Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, 1428 Buenos Aires, Argentina; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105, United States; Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina.
| | - Flávio S J de Souza
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, 1428 Buenos Aires, Argentina; Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina.
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19
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Abstract
As a species, we possess unique biological features that distinguish us from other primates. Here, we review recent efforts to identify changes in gene regulation that drove the evolution of novel human phenotypes. We discuss genotype-directed comparisons of human and nonhuman primate genomes to identify human-specific genetic changes that may encode new regulatory functions. We also review phenotype-directed approaches, which use comparisons of gene expression or regulatory function in homologous human and nonhuman primate cells and tissues to identify changes in expression levels or regulatory activity that may be due to genetic changes in humans. Together, these studies are beginning to reveal the landscape of regulatory innovation in human evolution and point to specific regulatory changes for further study. Finally, we highlight two novel strategies to model human-specific regulatory functions in vivo: primate induced pluripotent stem cells and the generation of humanized mice by genome editing.
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Affiliation(s)
- Steven K Reilly
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510;
| | - James P Noonan
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510; .,Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut 06511.,Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, Connecticut 06510
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20
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Silver DL. Genomic divergence and brain evolution: How regulatory DNA influences development of the cerebral cortex. Bioessays 2015; 38:162-71. [PMID: 26642006 DOI: 10.1002/bies.201500108] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The cerebral cortex controls our most distinguishing higher cognitive functions. Human-specific gene expression differences are abundant in the cerebral cortex, yet we have only begun to understand how these variations impact brain function. This review discusses the current evidence linking non-coding regulatory DNA changes, including enhancers, with neocortical evolution. Functional interrogation using animal models reveals converging roles for our genome in key aspects of cortical development including progenitor cell cycle and neuronal signaling. New technologies, including iPS cells and organoids, offer potential alternatives to modeling evolutionary modifications in a relevant species context. Several diseases rooted in the cerebral cortex uniquely manifest in humans compared to other primates, thus highlighting the importance of understanding human brain differences. Future studies of regulatory loci, including those implicated in disease, will collectively help elucidate key cellular and genetic mechanisms underlying our distinguishing cognitive traits.
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Affiliation(s)
- Debra L Silver
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA.,Department of Cell Biology, Duke University Medical Center, Durham, NC, USA.,Department of Neurobiology, Duke University Medical Center, Durham, NC, USA.,Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC, USA
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21
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Franchini LF, Pollard KS. Genomic approaches to studying human-specific developmental traits. Development 2015; 142:3100-12. [DOI: 10.1242/dev.120048] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Changes in developmental regulatory programs drive both disease and phenotypic differences among species. Linking human-specific traits to alterations in development is challenging, because we have lacked the tools to assay and manipulate regulatory networks in human and primate embryonic cells. This field was transformed by the sequencing of hundreds of genomes – human and non-human – that can be compared to discover the regulatory machinery of genes involved in human development. This approach has identified thousands of human-specific genome alterations in developmental genes and their regulatory regions. With recent advances in stem cell techniques, genome engineering, and genomics, we can now test these sequences for effects on developmental gene regulation and downstream phenotypes in human cells and tissues.
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Affiliation(s)
- Lucía F. Franchini
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1428, Argentina
| | - Katherine S. Pollard
- Gladstone Institutes, San Francisco, CA 94158, USA
- Institute for Human Genetics, Department of Epidemiology & Biostatistics, University of California, San Francisco, CA 94158, USA
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22
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Abstract
The recent finding that the human version of a neurodevelopmental enhancer of the Wnt receptor Frizzled 8 (FZD8) gene alters neural progenitor cell cycle timing and brain size is a step forward to understanding human brain evolution. The human brain is distinctive in terms of its cognitive abilities as well as its susceptibility to neurological disease. Identifying which of the millions of genomic changes that occurred during human evolution led to these and other uniquely human traits is extremely challenging. Recent studies have demonstrated that many of the fastest evolving regions of the human genome function as gene regulatory enhancers during embryonic development and that the human‐specific mutations in them might alter expression patterns. However, elucidating molecular and cellular effects of sequence or expression pattern changes is a major obstacle to discovering the genetic bases of the evolution of our species. There is much work to do before human‐specific genetic and genomic changes are linked to complex human traits. Also watch the Video Abstract.
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Affiliation(s)
- Lucía F Franchini
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Katherine S Pollard
- Gladstone Institutes, San Francisco, CA, USA.,Institute for Human Genetics, Department of Epidemiology & Biostatistics, University of California, San Francisco, CA, USA
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23
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Lower NPAS3 expression during the later stages of abnormal lung development in rat congenital diaphragmatic hernia. Pediatr Surg Int 2015; 31:659-63. [PMID: 25862168 DOI: 10.1007/s00383-015-3703-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/23/2015] [Indexed: 10/23/2022]
Abstract
PURPOSE Congenital diaphragmatic hernia (CDH) is characterized by a developmental defect in the diaphragm, pulmonary hypoplasia and pulmonary hypertension. NPAS3 is a PAS domain transcription factor regulating Drosophila tracheogenesis. NPAS3 null mice develop pulmonary hypoplasia in utero and die after birth due to respiratory failure. We aimed to evaluate NPAS3 expression during normal and abnormal lung development due to CDH. METHODS CDH was induced by administering 100 mg/ml nitrofen to time-pregnant dams on embryonic day (E) 9 of gestation. Lungs were isolated on E15, E18 and E21 and NPAS3 localization was determined by immunohistochemistry and quantified using Western blotting. RESULTS We found that only E21 hypoplastic CDH lungs have reduced expression of NPAS3 in the terminal saccules. Western blotting confirmed the down-regulation of NPAS3 protein in the nitrofen-induced hypoplastic lungs. CONCLUSIONS We demonstrate for the first time that nitrofen-induced hypoplastic CDH lungs have reduced NPAS3 expression in the terminal saccules during the later stages of abnormal lung development. Our findings suggest that NPAS3 is associated with pulmonary hypoplasia in CDH.
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24
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Boyd JL, Skove SL, Rouanet JP, Pilaz LJ, Bepler T, Gordân R, Wray GA, Silver DL. Human-chimpanzee differences in a FZD8 enhancer alter cell-cycle dynamics in the developing neocortex. Curr Biol 2015; 25:772-779. [PMID: 25702574 DOI: 10.1016/j.cub.2015.01.041] [Citation(s) in RCA: 170] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 08/28/2014] [Accepted: 01/16/2015] [Indexed: 12/14/2022]
Abstract
The human neocortex differs from that of other great apes in several notable regards, including altered cell cycle, prolonged corticogenesis, and increased size [1-5]. Although these evolutionary changes most likely contributed to the origin of distinctively human cognitive faculties, their genetic basis remains almost entirely unknown. Highly conserved non-coding regions showing rapid sequence changes along the human lineage are candidate loci for the development and evolution of uniquely human traits. Several studies have identified human-accelerated enhancers [6-14], but none have linked an expression difference to a specific organismal trait. Here we report the discovery of a human-accelerated regulatory enhancer (HARE5) of FZD8, a receptor of the Wnt pathway implicated in brain development and size [15, 16]. Using transgenic mice, we demonstrate dramatic differences in human and chimpanzee HARE5 activity, with human HARE5 driving early and robust expression at the onset of corticogenesis. Similar to HARE5 activity, FZD8 is expressed in neural progenitors of the developing neocortex [17-19]. Chromosome conformation capture assays reveal that HARE5 physically and specifically contacts the core Fzd8 promoter in the mouse embryonic neocortex. To assess the phenotypic consequences of HARE5 activity, we generated transgenic mice in which Fzd8 expression is under control of orthologous enhancers (Pt-HARE5::Fzd8 and Hs-HARE5::Fzd8). In comparison to Pt-HARE5::Fzd8, Hs-HARE5::Fzd8 mice showed marked acceleration of neural progenitor cell cycle and increased brain size. Changes in HARE5 function unique to humans thus alter the cell-cycle dynamics of a critical population of stem cells during corticogenesis and may underlie some distinctive anatomical features of the human brain.
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Affiliation(s)
- J Lomax Boyd
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Stephanie L Skove
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Jeremy P Rouanet
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Louis-Jan Pilaz
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Tristan Bepler
- Center for Genomic and Computational Biology, Duke University, Durham, NC 27708, USA
| | - Raluca Gordân
- Center for Genomic and Computational Biology, Duke University, Durham, NC 27708, USA; Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC 27710, USA
| | - Gregory A Wray
- Center for Genomic and Computational Biology, Duke University, Durham, NC 27708, USA; Department of Biology, Duke University, Durham, NC 27708, USA; Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Debra L Silver
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA; Duke Institute for Brain Sciences, Durham, NC 27710 USA.
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25
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Enard W. Mouse models of human evolution. Curr Opin Genet Dev 2014; 29:75-80. [DOI: 10.1016/j.gde.2014.08.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 08/13/2014] [Accepted: 08/23/2014] [Indexed: 10/24/2022]
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26
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Hubisz MJ, Pollard KS. Exploring the genesis and functions of Human Accelerated Regions sheds light on their role in human evolution. Curr Opin Genet Dev 2014; 29:15-21. [PMID: 25156517 DOI: 10.1016/j.gde.2014.07.005] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 07/23/2014] [Accepted: 07/25/2014] [Indexed: 12/31/2022]
Abstract
Human accelerated regions (HARs) are DNA sequences that changed very little throughout mammalian evolution, but then experienced a burst of changes in humans since divergence from chimpanzees. This unexpected evolutionary signature is suggestive of deeply conserved function that was lost or changed on the human lineage. Since their discovery, the actual roles of HARs in human evolution have remained somewhat elusive, due to their being almost exclusively non-coding sequences with no annotation. Ongoing research is beginning to crack this problem by leveraging new genome sequences, functional genomics data, computational approaches, and genetic assays to reveal that many HARs are developmental gene regulatory elements and RNA genes, most of which evolved their uniquely human mutations through positive selection before divergence of archaic hominins and diversification of modern humans.
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Affiliation(s)
- Melissa J Hubisz
- Department of Biological Statistics and Computational Biology, Cornell University, 102D Weill Hall, Ithaca, NY 14853, USA
| | - Katherine S Pollard
- Gladstone Institutes, Division of Biostatistics & Institute for Human Genetics, University of California, 1650 Owens Street, San Francisco, CA 94158, USA.
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27
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Keeney JG, Dumas L, Sikela JM. The case for DUF1220 domain dosage as a primary contributor to anthropoid brain expansion. Front Hum Neurosci 2014; 8:427. [PMID: 25009482 PMCID: PMC4067907 DOI: 10.3389/fnhum.2014.00427] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 05/28/2014] [Indexed: 12/14/2022] Open
Abstract
Here we present the hypothesis that increasing copy number (dosage) of sequences encoding DUF1220 protein domains is a major contributor to the evolutionary increase in brain size, neuron number, and cognitive capacity that is associated with the primate order. We further propose that this relationship is restricted to the anthropoid sub-order of primates, with DUF1220 copy number markedly increasing in monkeys, further in apes, and most extremely in humans where the greatest number of copies (~272 haploid copies) is found. We show that this increase closely parallels the increase in brain size and neuron number that has occurred among anthropoid primate species. We also provide evidence linking DUF1220 copy number to brain size within the human species, both in normal populations and in individuals associated with brain size pathologies (1q21-associated microcephaly and macrocephaly). While we believe these and other findings presented here strongly suggest increase in DUF1220 copy number is a key contributor to anthropoid brain expansion, the data currently available rely largely on correlative measures that, though considerable, do not yet provide direct evidence for a causal connection. Nevertheless, we believe the evidence presented is sufficient to provide the basis for a testable model which proposes that DUF1220 protein domain dosage increase is a main contributor to the increase in brain size and neuron number found among the anthropoid primate species and that is at its most extreme in human.
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Affiliation(s)
- Jonathon G Keeney
- Department of Biochemistry and Molecular Genetics and Human Medical Genetics and Neuroscience Programs, University of Colorado School of Medicine, Anschutz Medical Campus Aurora, CO, USA
| | - Laura Dumas
- Department of Biochemistry and Molecular Genetics and Human Medical Genetics and Neuroscience Programs, University of Colorado School of Medicine, Anschutz Medical Campus Aurora, CO, USA
| | - James M Sikela
- Department of Biochemistry and Molecular Genetics and Human Medical Genetics and Neuroscience Programs, University of Colorado School of Medicine, Anschutz Medical Campus Aurora, CO, USA
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28
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Rubinstein M, de Souza FSJ. Evolution of transcriptional enhancers and animal diversity. Philos Trans R Soc Lond B Biol Sci 2013; 368:20130017. [PMID: 24218630 DOI: 10.1098/rstb.2013.0017] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Deciphering the genetic bases that drive animal diversity is one of the major challenges of modern biology. Although four decades ago it was proposed that animal evolution was mainly driven by changes in cis-regulatory DNA elements controlling gene expression rather than in protein-coding sequences, only now are powerful bioinformatics and experimental approaches available to accelerate studies into how the evolution of transcriptional enhancers contributes to novel forms and functions. In the introduction to this Theme Issue, we start by defining the general properties of transcriptional enhancers, such as modularity and the coexistence of tight sequence conservation with transcription factor-binding site shuffling as different mechanisms that maintain the enhancer grammar over evolutionary time. We discuss past and current methods used to identify cell-type-specific enhancers and provide examples of how enhancers originate de novo, change and are lost in particular lineages. We then focus in the central part of this Theme Issue on analysing examples of how the molecular evolution of enhancers may change form and function. Throughout this introduction, we present the main findings of the articles, reviews and perspectives contributed to this Theme Issue that together illustrate some of the great advances and current frontiers in the field.
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Affiliation(s)
- Marcelo Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, , C1428ADN Buenos Aires, Argentina
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