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Liu J, Mosti F, Zhao HT, Sotelo-Fonseca JE, Escobar-Tomlienovich CF, Lollis D, Musso CM, Mao Y, Massri AJ, Doll HM, Sousa AM, Wray GA, Schmidt E, Silver DL. A human-specific enhancer fine-tunes radial glia potency and corticogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.10.588953. [PMID: 38645099 PMCID: PMC11030412 DOI: 10.1101/2024.04.10.588953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Humans evolved an extraordinarily expanded and complex cerebral cortex, associated with developmental and gene regulatory modifications 1-3 . Human accelerated regions (HARs) are highly conserved genomic sequences with human-specific nucleotide substitutions. Although there are thousands of annotated HARs, their functional contribution to human-specific cortical development is largely unknown 4,5 . HARE5 is a HAR transcriptional enhancer of the WNT signaling receptor Frizzled8 (FZD8) active during brain development 6 . Here, using genome-edited mouse and primate models, we demonstrate that human (Hs) HARE5 fine-tunes cortical development and connectivity by controlling the proliferative and neurogenic capacity of neural progenitor cells (NPCs). Hs-HARE5 knock-in mice have significantly enlarged neocortices containing more neurons. By measuring neural dynamics in vivo we show these anatomical features correlate with increased functional independence between cortical regions. To understand the underlying developmental mechanisms, we assess progenitor fate using live imaging, lineage analysis, and single-cell RNA sequencing. This reveals Hs-HARE5 modifies radial glial progenitor behavior, with increased self-renewal at early developmental stages followed by expanded neurogenic potential. We use genome-edited human and chimpanzee (Pt) NPCs and cortical organoids to assess the relative enhancer activity and function of Hs-HARE5 and Pt-HARE5. Using these orthogonal strategies we show four human-specific variants in HARE5 drive increased enhancer activity which promotes progenitor proliferation. These findings illustrate how small changes in regulatory DNA can directly impact critical signaling pathways and brain development. Our study uncovers new functions for HARs as key regulatory elements crucial for the expansion and complexity of the human cerebral cortex.
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2
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Cubillos P, Ditzer N, Kolodziejczyk A, Schwenk G, Hoffmann J, Schütze TM, Derihaci RP, Birdir C, Köllner JE, Petzold A, Sarov M, Martin U, Long KR, Wimberger P, Albert M. The growth factor EPIREGULIN promotes basal progenitor cell proliferation in the developing neocortex. EMBO J 2024; 43:1388-1419. [PMID: 38514807 PMCID: PMC11021537 DOI: 10.1038/s44318-024-00068-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 03/23/2024] Open
Abstract
Neocortex expansion during evolution is linked to higher numbers of neurons, which are thought to result from increased proliferative capacity and neurogenic potential of basal progenitor cells during development. Here, we show that EREG, encoding the growth factor EPIREGULIN, is expressed in the human developing neocortex and in gorilla cerebral organoids, but not in the mouse neocortex. Addition of EPIREGULIN to the mouse neocortex increases proliferation of basal progenitor cells, whereas EREG ablation in human cortical organoids reduces proliferation in the subventricular zone. Treatment of cortical organoids with EPIREGULIN promotes a further increase in proliferation of gorilla but not of human basal progenitor cells. EPIREGULIN competes with the epidermal growth factor (EGF) to promote proliferation, and inhibition of the EGF receptor abrogates the EPIREGULIN-mediated increase in basal progenitor cells. Finally, we identify putative cis-regulatory elements that may contribute to the observed inter-species differences in EREG expression. Our findings suggest that species-specific regulation of EPIREGULIN expression may contribute to the increased neocortex size of primates by providing a tunable pro-proliferative signal to basal progenitor cells in the subventricular zone.
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Affiliation(s)
- Paula Cubillos
- Center for Regenerative Therapies TU Dresden, TUD Dresden University of Technology, 01307, Dresden, Germany
| | - Nora Ditzer
- Center for Regenerative Therapies TU Dresden, TUD Dresden University of Technology, 01307, Dresden, Germany
| | - Annika Kolodziejczyk
- Center for Regenerative Therapies TU Dresden, TUD Dresden University of Technology, 01307, Dresden, Germany
| | - Gustav Schwenk
- Center for Regenerative Therapies TU Dresden, TUD Dresden University of Technology, 01307, Dresden, Germany
| | - Janine Hoffmann
- Center for Regenerative Therapies TU Dresden, TUD Dresden University of Technology, 01307, Dresden, Germany
| | - Theresa M Schütze
- Center for Regenerative Therapies TU Dresden, TUD Dresden University of Technology, 01307, Dresden, Germany
| | - Razvan P Derihaci
- Department of Gynecology and Obstetrics, TU Dresden, 01307, Dresden, Germany
- National Center for Tumor Diseases, 01307, Dresden, Germany
| | - Cahit Birdir
- Department of Gynecology and Obstetrics, TU Dresden, 01307, Dresden, Germany
- Center for feto/neonatal Health, TU Dresden, 01307, Dresden, Germany
| | - Johannes Em Köllner
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
| | - Andreas Petzold
- DRESDEN-concept Genome Center, Center for Molecular and Cellular Bioengineering, TUD Dresden University of Technology, 01307, Dresden, Germany
| | - Mihail Sarov
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
| | - Ulrich Martin
- Leibniz Research Laboratories for Biotechnology and Artificial Organs, Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, 30625, Hannover, Germany
- REBIRTH-Cluster of Excellence, Hannover, Germany
| | - Katherine R Long
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, SE1 1UL, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, SE1 1UL, United Kingdom
| | - Pauline Wimberger
- Department of Gynecology and Obstetrics, TU Dresden, 01307, Dresden, Germany
- National Center for Tumor Diseases, 01307, Dresden, Germany
| | - Mareike Albert
- Center for Regenerative Therapies TU Dresden, TUD Dresden University of Technology, 01307, Dresden, Germany.
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3
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Fernández V, Borrell V. Epi-regulate my brain: unlocking mechanisms of brain growth evolution. EMBO J 2024; 43:1385-1387. [PMID: 38528183 PMCID: PMC11021529 DOI: 10.1038/s44318-024-00083-8] [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: 03/15/2024] [Accepted: 03/15/2024] [Indexed: 03/27/2024] Open
Abstract
A new study sheds light on the mechanisms of cerebral cortex expansion during evolution.
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Affiliation(s)
- Virginia Fernández
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas & Universidad Miguel Hernández, Sant Joan d'Alacant, 03550, Spain
| | - Víctor Borrell
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas & Universidad Miguel Hernández, Sant Joan d'Alacant, 03550, Spain.
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4
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Kawasaki H. Investigation of the mechanisms underlying the development and evolution of folds of the cerebrum using gyrencephalic ferrets. J Comp Neurol 2024; 532:e25615. [PMID: 38587214 DOI: 10.1002/cne.25615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 02/22/2024] [Accepted: 03/24/2024] [Indexed: 04/09/2024]
Abstract
The mammalian cerebrum has changed substantially during evolution, characterized by increases in neurons and glial cells and by the expansion and folding of the cerebrum. While these evolutionary alterations are thought to be crucial for acquiring higher cognitive functions, the molecular mechanisms underlying the development and evolution of the mammalian cerebrum remain only partially understood. This is, in part, because of the difficulty in analyzing these mechanisms using mice only. To overcome this limitation, genetic manipulation techniques for the cerebrum of gyrencephalic carnivore ferrets have been developed. Furthermore, successful gene knockout in the ferret cerebrum has been accomplished through the application of the CRISPR/Cas9 system. This review mainly highlights recent research conducted using gyrencephalic carnivore ferrets to investigate the mechanisms underlying the development and evolution of cortical folds.
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Affiliation(s)
- Hiroshi Kawasaki
- Department of Medical Neuroscience, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
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5
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Moffat A, Schuurmans C. The Control of Cortical Folding: Multiple Mechanisms, Multiple Models. Neuroscientist 2023:10738584231190839. [PMID: 37621149 DOI: 10.1177/10738584231190839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
The cerebral cortex develops through a carefully conscripted series of cellular and molecular events that culminate in the production of highly specialized neuronal and glial cells. During development, cortical neurons and glia acquire a precise cellular arrangement and architecture to support higher-order cognitive functioning. Decades of study using rodent models, naturally gyrencephalic animal models, human pathology specimens, and, recently, human cerebral organoids, reveal that rodents recapitulate some but not all the cellular and molecular features of human cortices. Whereas rodent cortices are smooth-surfaced or lissencephalic, larger mammals, including humans and nonhuman primates, have highly folded/gyrencephalic cortices that accommodate an expansion in neuronal mass and increase in surface area. Several genes have evolved to drive cortical gyrification, arising from gene duplications or de novo origins, or by alterations to the structure/function of ancestral genes or their gene regulatory regions. Primary cortical folds arise in stereotypical locations, prefigured by a molecular "blueprint" that is set up by several signaling pathways (e.g., Notch, Fgf, Wnt, PI3K, Shh) and influenced by the extracellular matrix. Mutations that affect neural progenitor cell proliferation and/or neurogenesis, predominantly of upper-layer neurons, perturb cortical gyrification. Below we review the molecular drivers of cortical folding and their roles in disease.
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Affiliation(s)
- Alexandra Moffat
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Carol Schuurmans
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
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6
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Umu SU, Paynter VM, Trondsen H, Buschmann T, Rounge TB, Peterson KJ, Fromm B. Accurate microRNA annotation of animal genomes using trained covariance models of curated microRNA complements in MirMachine. CELL GENOMICS 2023; 3:100348. [PMID: 37601971 PMCID: PMC10435380 DOI: 10.1016/j.xgen.2023.100348] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 03/15/2023] [Accepted: 05/26/2023] [Indexed: 08/22/2023]
Abstract
The annotation of microRNAs depends on the availability of transcriptomics data and expert knowledge. This has led to a gap between the availability of novel genomes and high-quality microRNA complements. Using >16,000 microRNAs from the manually curated microRNA gene database MirGeneDB, we generated trained covariance models for all conserved microRNA families. These models are available in our tool MirMachine, which annotates conserved microRNAs within genomes. We successfully applied MirMachine to a range of animal species, including those with large genomes and genome duplications and extinct species, where small RNA sequencing is hard to achieve. We further describe a microRNA score of expected microRNAs that can be used to assess the completeness of genome assemblies. MirMachine closes a long-persisting gap in the microRNA field by facilitating automated genome annotation pipelines and deeper studies into the evolution of genome regulation, even in extinct organisms.
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Affiliation(s)
- Sinan Uğur Umu
- Department of Pathology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Vanessa M. Paynter
- The Arctic University Museum of Norway, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Håvard Trondsen
- Department of Pathology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | | | - Trine B. Rounge
- Department of Research, Cancer Registry of Norway, Oslo, Norway
- Centre for Bioinformatics, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Kevin J. Peterson
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| | - Bastian Fromm
- The Arctic University Museum of Norway, UiT - The Arctic University of Norway, Tromsø, Norway
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7
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Fernández V, Borrell V. Developmental mechanisms of gyrification. Curr Opin Neurobiol 2023; 80:102711. [DOI: 10.1016/j.conb.2023.102711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 02/09/2023] [Accepted: 02/23/2023] [Indexed: 03/31/2023]
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8
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Cremisi F, Vignali R. Translational control in cortical development. Front Neuroanat 2023; 16:1087949. [PMID: 36699134 PMCID: PMC9868627 DOI: 10.3389/fnana.2022.1087949] [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: 11/02/2022] [Accepted: 12/19/2022] [Indexed: 01/11/2023] Open
Abstract
Differentiation of specific neuronal types in the nervous system is worked out through a complex series of gene regulation events. Within the mammalian neocortex, the appropriate expression of key transcription factors allocates neurons to different cortical layers according to an inside-out model and endows them with specific properties. Precise timing is required to ensure the proper sequential appearance of key transcription factors that dictate the identity of neurons within the different cortical layers. Recent evidence suggests that aspects of this time-controlled regulation of gene products rely on post-transcriptional control, and point at micro-RNAs (miRs) and RNA-binding proteins as important players in cortical development. Being able to simultaneously target many different mRNAs, these players may be involved in controlling the global expression of gene products in progenitors and post-mitotic cells, in a gene expression framework where parallel to transcriptional gene regulation, a further level of control is provided to refine and coordinate the appearance of the final protein products. miRs and RNA-binding proteins (RBPs), by delaying protein appearance, may play heterochronic effects that have recently been shown to be relevant for the full differentiation of cortical neurons and for their projection abilities. Such heterochronies may be the base for evolutionary novelties that have enriched the spectrum of cortical cell types within the mammalian clade.
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Affiliation(s)
- Federico Cremisi
- Laboratory of Biology, Department of Sciences, Scuola Normale Superiore, Pisa, Italy,*Correspondence: Robert Vignali Federico Cremisi
| | - Robert Vignali
- Department of Biology, University of Pisa, Pisa, Italy,*Correspondence: Robert Vignali Federico Cremisi
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Abstract
The current understanding of neurological diseases is derived mostly from direct analysis of patients and from animal models of disease. However, most patient studies do not capture the earliest stages of disease development and offer limited opportunities for experimental intervention, so rarely yield complete mechanistic insights. The use of animal models relies on evolutionary conservation of pathways involved in disease and is limited by an inability to recreate human-specific processes. In vitro models that are derived from human pluripotent stem cells cultured in 3D have emerged as a new model system that could bridge the gap between patient studies and animal models. In this Review, we summarize how such organoid models can complement classical approaches to accelerate neurological research. We describe our current understanding of neurodevelopment and how this process differs between humans and other animals, making human-derived models of disease essential. We discuss different methodologies for producing organoids and how organoids can be and have been used to model neurological disorders, including microcephaly, Zika virus infection, Alzheimer disease and other neurodegenerative disorders, and neurodevelopmental diseases, such as Timothy syndrome, Angelman syndrome and tuberous sclerosis. We also discuss the current limitations of organoid models and outline how organoids can be used to revolutionize research into the human brain and neurological diseases. In this Review, Eichmüller and Knoblich discuss how human brain organoids can recapitulate the unique processes that occur in human brain development and how they can complement classical approaches to revolutionize research into neurological diseases. Development of the human brain involves unique processes that are relevant to neurological disease but cannot be studied in animal models, so alternative model systems are required. Organoids are 3D human cell culture models that originate from pluripotent stem cells and recapitulate the hallmarks of human neurodevelopment, enabling studies of human brain development in vitro. Specific mutations can be introduced into organoids to study their effects on neurodevelopment; combined with high-throughput screening methods, this approach can determine the disease relevance of mutations in human tissue. To study specific diseases, brain organoids can be generated from induced pluripotent stem cells from individual patients, thereby preserving the specific genetic background of the individual and generating an insightful model. Through recapitulation of previously inaccessible periods of human brain development, brain organoids have enabled identification of novel mechanisms that underlie neurodevelopmental, neurodegenerative and infectious diseases. Combining organoids, patient research and animal models enables us to take full advantage of each of these systems and will provide unprecedented insights into neurodevelopment and neurological diseases.
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Espinós A, Fernández‐Ortuño E, Negri E, Borrell V. Evolution of genetic mechanisms regulating cortical neurogenesis. Dev Neurobiol 2022; 82:428-453. [PMID: 35670518 PMCID: PMC9543202 DOI: 10.1002/dneu.22891] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/26/2022] [Accepted: 05/24/2022] [Indexed: 11/20/2022]
Abstract
The size of the cerebral cortex increases dramatically across amniotes, from reptiles to great apes. This is primarily due to different numbers of neurons and glial cells produced during embryonic development. The evolutionary expansion of cortical neurogenesis was linked to changes in neural stem and progenitor cells, which acquired increased capacity of self‐amplification and neuron production. Evolution works via changes in the genome, and recent studies have identified a small number of new genes that emerged in the recent human and primate lineages, promoting cortical progenitor proliferation and increased neurogenesis. However, most of the mammalian genome corresponds to noncoding DNA that contains gene‐regulatory elements, and recent evidence precisely points at changes in expression levels of conserved genes as key in the evolution of cortical neurogenesis. Here, we provide an overview of basic cellular mechanisms involved in cortical neurogenesis across amniotes, and discuss recent progress on genetic mechanisms that may have changed during evolution, including gene expression regulation, leading to the expansion of the cerebral cortex.
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Affiliation(s)
- Alexandre Espinós
- Instituto de Neurociencias CSIC ‐ UMH, 03550 Sant Joan d'Alacant Spain
| | | | - Enrico Negri
- Instituto de Neurociencias CSIC ‐ UMH, 03550 Sant Joan d'Alacant Spain
| | - Víctor Borrell
- Instituto de Neurociencias CSIC ‐ UMH, 03550 Sant Joan d'Alacant Spain
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11
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Fromm B, Zhong X, Tarbier M, Friedländer MR, Hackenberg M. The limits of human microRNA annotation have been met. RNA (NEW YORK, N.Y.) 2022; 28:781-785. [PMID: 35236776 PMCID: PMC9074900 DOI: 10.1261/rna.079098.122] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Over the last few years, the number of microRNAs in the human genome has become a controversially debated issue. Several publications reported thousands of putative novel microRNAs not included in the curated microRNA gene database MirGeneDB and the repository miRBase. Recently, by using sequencing of ∼300 human tissues and cell lines, the human RNA atlas, an expanded inventory of human RNA annotations, was published, reporting thousands of putative microRNAs. We, the developers of established microRNA prediction tools and hosts of MirGeneDB, raise concerns about the frequently applied prediction and functional validation strategies, briefly discussing the drawbacks of false positive detections. By means of quantifying well-established biogenesis-derived features, we show that the reported novel microRNAs essentially represent false-positives and argue that the human microRNA complement, at about 550 microRNA genes, is already near complete. Output of available tools must be curated as false predictions will misguide scientists looking for biomarkers or therapeutic targets.
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Affiliation(s)
- Bastian Fromm
- The Arctic University Museum of Norway, UiT-The Arctic University of Norway, 9006 Tromsø, Norway
| | - Xiangfu Zhong
- Department of Biosciences and Nutrition, Karolinska Institute, 14183 Huddinge, Sweden
| | - Marcel Tarbier
- Science for Life Laboratory, Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, 17165 Solna, Sweden
| | - Marc R Friedländer
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691 Stockholm, Sweden
| | - Michael Hackenberg
- Department of Genetics, Faculty of Sciences, MNAT Excellence Unit, University of Granada, 18071 Granada, Spain
- Biotechnology Institute, CIBM, 18100 Armilla (Granada), Spain
- Biohealth Research Institute (ibs. GRANADA), University Hospitals of Granada, University of Granada, 18014 Granada, Spain
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12
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Kumamoto T, Ohtaka-Maruyama C. Visualizing Cortical Development and Evolution: A Toolkit Update. Front Neurosci 2022; 16:876406. [PMID: 35495046 PMCID: PMC9039325 DOI: 10.3389/fnins.2022.876406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 03/17/2022] [Indexed: 11/13/2022] Open
Abstract
Visualizing the process of neural circuit formation during neurogenesis, using genetically modified animals or somatic transgenesis of exogenous plasmids, has become a key to decipher cortical development and evolution. In contrast to the establishment of transgenic animals, the designing and preparation of genes of interest into plasmids are simple and easy, dispensing with time-consuming germline modifications. These advantages have led to neuron labeling based on somatic transgenesis. In particular, mammalian expression plasmid, CRISPR-Cas9, and DNA transposon systems, have become widely used for neuronal visualization and functional analysis related to lineage labeling during cortical development. In this review, we discuss the advantages and limitations of these recently developed techniques.
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13
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Shinmyo Y, Hamabe-Horiike T, Saito K, Kawasaki H. Investigation of the Mechanisms Underlying the Development and Evolution of the Cerebral Cortex Using Gyrencephalic Ferrets. Front Cell Dev Biol 2022; 10:847159. [PMID: 35386196 PMCID: PMC8977464 DOI: 10.3389/fcell.2022.847159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Accepted: 02/23/2022] [Indexed: 11/13/2022] Open
Abstract
The mammalian cerebral cortex has changed significantly during evolution. As a result of the increase in the number of neurons and glial cells in the cerebral cortex, its size has markedly expanded. Moreover, folds, called gyri and sulci, appeared on its surface, and its neuronal circuits have become much more complicated. Although these changes during evolution are considered to have been crucial for the acquisition of higher brain functions, the mechanisms underlying the development and evolution of the cerebral cortex of mammals are still unclear. This is, at least partially, because it is difficult to investigate these mechanisms using mice only. Therefore, genetic manipulation techniques for the cerebral cortex of gyrencephalic carnivore ferrets were developed recently. Furthermore, gene knockout was achieved in the ferret cerebral cortex using the CRISPR/Cas9 system. These techniques enabled molecular investigations using the ferret cerebral cortex. In this review, we will summarize recent findings regarding the mechanisms underlying the development and evolution of the mammalian cerebral cortex, mainly focusing on research using ferrets.
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Affiliation(s)
- Yohei Shinmyo
- Department of Medical Neuroscience, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Toshihide Hamabe-Horiike
- Department of Medical Neuroscience, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Kengo Saito
- Department of Medical Neuroscience, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Hiroshi Kawasaki
- Department of Medical Neuroscience, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
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