1
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Ichiyama-Kobayashi S, Hata K, Wakamori K, Takahata Y, Murakami T, Yamanaka H, Takano H, Yao R, Uzawa N, Nishimura R. Chromatin profiling identifies chondrocyte-specific Sox9 enhancers important for skeletal development. JCI Insight 2024; 9:e175486. [PMID: 38855864 DOI: 10.1172/jci.insight.175486] [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: 09/06/2023] [Accepted: 05/01/2024] [Indexed: 06/11/2024] Open
Abstract
The transcription factor SRY-related HMG box 9 (Sox9) is essential for chondrogenesis. Mutations in and around SOX9 cause campomelic dysplasia (CD) characterized by skeletal malformations. Although the function of Sox9 in this context is well studied, the mechanisms that regulate Sox9 expression in chondrocytes remain to be elucidated. Here, we have used genome-wide profiling to identify 2 Sox9 enhancers located in a proximal breakpoint cluster responsible for CD. Enhancer activity of E308 (located 308 kb 5' upstream) and E160 (located 160 kb 5' upstream) correlated with Sox9 expression levels, and both enhancers showed a synergistic effect in vitro. While single deletions in mice had no apparent effect, simultaneous deletion of both E308 and E160 caused a dwarf phenotype, concomitant with a reduction of Sox9 expression in chondrocytes. Moreover, bone morphogenetic protein 2-dependent chondrocyte differentiation of limb bud mesenchymal cells was severely attenuated in E308/E160 deletion mice. Finally, we found that an open chromatin region upstream of the Sox9 gene was reorganized in the E308/E160 deletion mice to partially compensate for the loss of E308 and E160. In conclusion, our findings reveal a mechanism of Sox9 gene regulation in chondrocytes that might aid in our understanding of the pathophysiology of skeletal disorders.
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Affiliation(s)
- Sachi Ichiyama-Kobayashi
- Department of Molecular and Cellular Biochemistry
- Department of Oral and Maxillofacial Oncology and Surgery, and
| | - Kenji Hata
- Department of Molecular and Cellular Biochemistry
| | - Kanta Wakamori
- Department of Molecular and Cellular Biochemistry
- Department of Oral and Maxillofacial Oncology and Surgery, and
| | - Yoshifumi Takahata
- Department of Molecular and Cellular Biochemistry
- Genome Editing Research and Development Unit, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | | | - Hitomi Yamanaka
- Department of Cell Biology, Cancer Institute, Japanese Foundation for Cancer Research, Koto-ku, Tokyo, Japan
| | - Hiroshi Takano
- Department of Cell Biology, Cancer Institute, Japanese Foundation for Cancer Research, Koto-ku, Tokyo, Japan
| | - Ryoji Yao
- Department of Cell Biology, Cancer Institute, Japanese Foundation for Cancer Research, Koto-ku, Tokyo, Japan
| | - Narikazu Uzawa
- Department of Oral and Maxillofacial Oncology and Surgery, and
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2
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Roberts JB, Rice SJ. Osteoarthritis as an Enhanceropathy: Gene Regulation in Complex Musculoskeletal Disease. Curr Rheumatol Rep 2024; 26:222-234. [PMID: 38430365 PMCID: PMC11116181 DOI: 10.1007/s11926-024-01142-z] [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] [Accepted: 02/07/2024] [Indexed: 03/03/2024]
Abstract
PURPOSE OF REVIEW Osteoarthritis is a complex and highly polygenic disease. Over 100 reported osteoarthritis risk variants fall in non-coding regions of the genome, ostensibly conferring functional effects through the disruption of regulatory elements impacting target gene expression. In this review, we summarise the progress that has advanced our knowledge of gene enhancers both within the field of osteoarthritis and more broadly in complex diseases. RECENT FINDINGS Advances in technologies such as ATAC-seq have facilitated our understanding of chromatin states in specific cell types, bolstering the interpretation of GWAS and the identification of effector genes. Their application to osteoarthritis research has revealed enhancers as the principal regulatory element driving disease-associated changes in gene expression. However, tissue-specific effects in gene regulatory mechanisms can contribute added complexity to biological interpretation. Understanding gene enhancers and their altered activity in specific cell and tissue types is the key to unlocking the genetic complexity of osteoarthritis. The use of single-cell technologies in osteoarthritis research is still in its infancy. However, such tools offer great promise in improving our functional interpretation of osteoarthritis GWAS and the identification of druggable targets. Large-scale collaborative efforts will be imperative to understand tissue and cell-type specific molecular mechanisms underlying enhancer function in disease.
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Affiliation(s)
- Jack B Roberts
- Skeletal Research Group, International Centre for Life, Biosciences Institute, Newcastle University, Newcastle Upon Tyne, NE1 3BZ, UK
| | - Sarah J Rice
- Skeletal Research Group, International Centre for Life, Biosciences Institute, Newcastle University, Newcastle Upon Tyne, NE1 3BZ, UK.
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3
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Chen KQ, Kawakami H, Anderson A, Corcoran D, Soni A, Nishinakamura R, Kawakami Y. Sall genes regulate hindlimb initiation in mouse embryos. Genetics 2024; 227:iyae029. [PMID: 38386912 PMCID: PMC11075541 DOI: 10.1093/genetics/iyae029] [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: 01/15/2024] [Revised: 01/15/2024] [Accepted: 02/14/2024] [Indexed: 02/24/2024] Open
Abstract
Vertebrate limbs start to develop as paired protrusions from the lateral plate mesoderm at specific locations of the body with forelimb buds developing anteriorly and hindlimb buds posteriorly. During the initiation process, limb progenitor cells maintain active proliferation to form protrusions and start to express Fgf10, which triggers molecular processes for outgrowth and patterning. Although both processes occur in both types of limbs, forelimbs (Tbx5), and hindlimbs (Isl1) utilize distinct transcriptional systems to trigger their development. Here, we report that Sall1 and Sall4, zinc finger transcription factor genes, regulate hindlimb initiation in mouse embryos. Compared to the 100% frequency loss of hindlimb buds in TCre; Isl1 conditional knockouts, Hoxb6Cre; Isl1 conditional knockout causes a hypomorphic phenotype with only approximately 5% of mutants lacking the hindlimb. Our previous study of SALL4 ChIP-seq showed SALL4 enrichment in an Isl1 enhancer, suggesting that SALL4 acts upstream of Isl1. Removing 1 allele of Sall4 from the hypomorphic Hoxb6Cre; Isl1 mutant background caused loss of hindlimbs, but removing both alleles caused an even higher frequency of loss of hindlimbs, suggesting a genetic interaction between Sall4 and Isl1. Furthermore, TCre-mediated conditional double knockouts of Sall1 and Sall4 displayed a loss of expression of hindlimb progenitor markers (Isl1, Pitx1, Tbx4) and failed to develop hindlimbs, demonstrating functional redundancy between Sall1 and Sall4. Our data provides genetic evidence that Sall1 and Sall4 act as master regulators of hindlimb initiation.
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Affiliation(s)
- Katherine Q Chen
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Hiroko Kawakami
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA
- Developmental Biology Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Aaron Anderson
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Dylan Corcoran
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Aditi Soni
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ryuichi Nishinakamura
- Department of Kidney Development, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan
| | - Yasuhiko Kawakami
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA
- Developmental Biology Center, University of Minnesota, Minneapolis, MN 55455, USA
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4
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Lee S, Ahn H, Kim H, Lee K, Kim S, Lee JH. Identification of potential key variants in mandibular premolar hypodontia through whole-exome sequencing. Front Genet 2023; 14:1248326. [PMID: 37745851 PMCID: PMC10514915 DOI: 10.3389/fgene.2023.1248326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 08/29/2023] [Indexed: 09/26/2023] Open
Abstract
Determining genotype-phenotype correlations in patients with hypodontia is important for understanding disease pathogenesis, although only a few studies have elucidated it. We aimed to identify genetic variants linked to non-syndromic bilateral mandibular second premolar hypodontia in a Korean population for the first time by specifying the phenotype of hypodontia. Twenty unrelated individuals with non-syndromic bilateral mandibular second premolar hypodontia were enrolled for whole-exome sequencing. Using a tooth agenesis gene set panel consisting of 112 genes based on literature, potential candidate variants were screened through variant filtering and prioritization. We identified 13 candidate variants in 12 genes, including a stop-gain variant (c.4750C>T) in LAMA3. Through the functional enrichment analysis of the prioritized genes, several terms related to tooth development were enriched in a protein-protein interaction network of candidate genes for mandibular premolar hypodontia. The hypodontia group also had approximately 2-fold as many mutated variants in all four genes related to these key terms, which are CDH1, ITGB4, LAMA3, LAMB3, as those in the 100 healthy control group individuals. The relationship between enriched terms and pathways and mandibular premolar hypodontia was also investigated. In addition, we identified some known oligodontia variants in patients with hypodontia, strengthening the possibility of synergistic effects in other genes. This genetic investigation may be a worthwhile preliminary attempt to reveal the pathogenesis of tooth agenesis and sets a background for future studies.
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Affiliation(s)
- Shinyeop Lee
- Department of Prosthodontics, College of Dentistry, Yonsei University, Seoul, Republic of Korea
| | - Hyunsoo Ahn
- Graduate School of Artificial Intelligence, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Hyeonhye Kim
- Tufts University School of Medicine, Boston, MA, United States
| | - Kwanghwan Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Sanguk Kim
- Graduate School of Artificial Intelligence, Pohang University of Science and Technology, Pohang, Republic of Korea
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Jae Hoon Lee
- Department of Prosthodontics, College of Dentistry, Yonsei University, Seoul, Republic of Korea
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5
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Cell-specific alterations in Pitx1 regulatory landscape activation caused by the loss of a single enhancer. Nat Commun 2021; 12:7235. [PMID: 34903763 PMCID: PMC8668926 DOI: 10.1038/s41467-021-27492-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 11/24/2021] [Indexed: 11/17/2022] Open
Abstract
Developmental genes are frequently controlled by multiple enhancers sharing similar specificities. As a result, deletions of such regulatory elements have often failed to reveal their full function. Here, we use the Pitx1 testbed locus to characterize in detail the regulatory and cellular identity alterations following the deletion of one of its enhancers (Pen). By combining single cell transcriptomics and an in-embryo cell tracing approach, we observe an increased fraction of Pitx1 non/low-expressing cells and a decreased fraction of Pitx1 high-expressing cells. We find that the over-representation of Pitx1 non/low-expressing cells originates from a failure of the Pitx1 locus to coordinate enhancer activities and 3D chromatin changes. This locus mis-activation induces a localized heterochrony and a concurrent loss of irregular connective tissue, eventually leading to a clubfoot phenotype. This data suggests that, in some cases, redundant enhancers may be used to locally enforce a robust activation of their host regulatory landscapes.
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6
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Muthuirulan P, Zhao D, Young M, Richard D, Liu Z, Emami A, Portilla G, Hosseinzadeh S, Cao J, Maridas D, Sedlak M, Menghini D, Cheng L, Li L, Ding X, Ding Y, Rosen V, Kiapour AM, Capellini TD. Joint disease-specificity at the regulatory base-pair level. Nat Commun 2021; 12:4161. [PMID: 34230488 PMCID: PMC8260791 DOI: 10.1038/s41467-021-24345-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 06/16/2021] [Indexed: 02/06/2023] Open
Abstract
Given the pleiotropic nature of coding sequences and that many loci exhibit multiple disease associations, it is within non-coding sequence that disease-specificity likely exists. Here, we focus on joint disorders, finding among replicated loci, that GDF5 exhibits over twenty distinct associations, and we identify causal variants for two of its strongest associations, hip dysplasia and knee osteoarthritis. By mapping regulatory regions in joint chondrocytes, we pinpoint two variants (rs4911178; rs6060369), on the same risk haplotype, which reside in anatomical site-specific enhancers. We show that both variants have clinical relevance, impacting disease by altering morphology. By modeling each variant in humanized mice, we observe joint-specific response, correlating with GDF5 expression. Thus, we uncouple separate regulatory variants on a common risk haplotype that cause joint-specific disease. By broadening our perspective, we finally find that patterns of modularity at GDF5 are also found at over three-quarters of loci with multiple GWAS disease associations.
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Affiliation(s)
| | - Dewei Zhao
- Department of Orthopedics, Affiliated Zhongshan Hospital of Dalian University, Dalian, China
| | - Mariel Young
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Daniel Richard
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Zun Liu
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Alireza Emami
- Department of Orthopaedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Gabriela Portilla
- Department of Orthopaedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Shayan Hosseinzadeh
- Department of Orthopaedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jiaxue Cao
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA.,Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - David Maridas
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, USA
| | - Mary Sedlak
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Danilo Menghini
- Department of Orthopaedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Liangliang Cheng
- Department of Orthopedics, Affiliated Zhongshan Hospital of Dalian University, Dalian, China
| | - Lu Li
- Department of Orthopedics, Affiliated Zhongshan Hospital of Dalian University, Dalian, China
| | - Xinjia Ding
- Department of Surgery, the Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Yan Ding
- Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Vicki Rosen
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, USA
| | - Ata M Kiapour
- Department of Orthopaedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Terence D Capellini
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA. .,Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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7
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Tran TQ, Kioussi C. Pitx genes in development and disease. Cell Mol Life Sci 2021; 78:4921-4938. [PMID: 33844046 PMCID: PMC11073205 DOI: 10.1007/s00018-021-03833-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/05/2021] [Accepted: 03/31/2021] [Indexed: 12/17/2022]
Abstract
Homeobox genes encode sequence-specific transcription factors (SSTFs) that recognize specific DNA sequences and regulate organogenesis in all eukaryotes. They are essential in specifying spatial and temporal cell identity and as a result, their mutations often cause severe developmental defects. Pitx genes belong to the PRD class of the highly evolutionary conserved homeobox genes in all animals. Vertebrates possess three Pitx paralogs, Pitx1, Pitx2, and Pitx3 while non-vertebrates have only one Pitx gene. The ancient role of regulating left-right (LR) asymmetry is conserved while new functions emerge to afford more complex body plan and functionalities. In mouse, Pitx1 regulates hindlimb tissue patterning and pituitary development. Pitx2 is essential for the development of the oral cavity and abdominal wall while regulates the formation and symmetry of other organs including pituitary, heart, gut, lung among others by controlling growth control genes upon activation of the Wnt/ß-catenin signaling pathway. Pitx3 is essential for lens development and migration and survival of the dopaminergic neurons of the substantia nigra. Pitx gene mutations are linked to various congenital defects and cancers in humans. Pitx gene family has the potential to offer a new approach in regenerative medicine and aid in identifying new drug targets.
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Affiliation(s)
- Thai Q Tran
- Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, 97331, USA
| | - Chrissa Kioussi
- Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, 97331, USA.
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8
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Delgado I, Giovinazzo G, Temiño S, Gauthier Y, Balsalobre A, Drouin J, Torres M. Control of mouse limb initiation and antero-posterior patterning by Meis transcription factors. Nat Commun 2021; 12:3086. [PMID: 34035267 PMCID: PMC8149412 DOI: 10.1038/s41467-021-23373-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Accepted: 04/21/2021] [Indexed: 12/31/2022] Open
Abstract
Meis1 and Meis2 are homeodomain transcription factors that regulate organogenesis through cooperation with Hox proteins. Elimination of Meis genes after limb induction has shown their role in limb proximo-distal patterning; however, limb development in the complete absence of Meis function has not been studied. Here, we report that Meis1/2 inactivation in the lateral plate mesoderm of mouse embryos leads to limb agenesis. Meis and Tbx factors converge in this function, extensively co-binding with Tbx to genomic sites and co-regulating enhancers of Fgf10, a critical factor in limb initiation. Limbs with three deleted Meis alleles show proximal-specific skeletal hypoplasia and agenesis of posterior skeletal elements. This failure in posterior specification results from an early role of Meis factors in establishing the limb antero-posterior prepattern required for Shh activation. Our results demonstrate roles for Meis transcription factors in early limb development and identify their involvement in previously undescribed interaction networks that regulate organogenesis.
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Affiliation(s)
- Irene Delgado
- Cardiovascular Development Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Giovanna Giovinazzo
- Cardiovascular Development Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Susana Temiño
- Cardiovascular Development Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Yves Gauthier
- Laboratoire de Génétique Moléculaire, Institut de Recherches Cliniques de Montréal, Montreal, QC, Canada
| | - Aurelio Balsalobre
- Laboratoire de Génétique Moléculaire, Institut de Recherches Cliniques de Montréal, Montreal, QC, Canada
| | - Jacques Drouin
- Laboratoire de Génétique Moléculaire, Institut de Recherches Cliniques de Montréal, Montreal, QC, Canada
| | - Miguel Torres
- Cardiovascular Development Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain.
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9
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Abstract
The vertebrate limb continues to serve as an influential model of growth, morphogenesis and pattern formation. With this Review, we aim to give an up-to-date picture of how a population of undifferentiated cells develops into the complex pattern of the limb. Focussing largely on mouse and chick studies, we concentrate on the positioning of the limbs, the formation of the limb bud, the establishment of the principal limb axes, the specification of pattern, the integration of pattern formation with growth and the determination of digit number. We also discuss the important, but little understood, topic of how gene expression is interpreted into morphology.
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Affiliation(s)
- Caitlin McQueen
- Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Matthew Towers
- Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
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10
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Bian Q, Cheng YH, Wilson JP, Su EY, Kim DW, Wang H, Yoo S, Blackshaw S, Cahan P. A single cell transcriptional atlas of early synovial joint development. Development 2020; 147:dev.185777. [PMID: 32580935 DOI: 10.1242/dev.185777] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 06/09/2020] [Indexed: 12/14/2022]
Abstract
Synovial joint development begins with the formation of the interzone, a region of condensed mesenchymal cells at the site of the prospective joint. Recently, lineage-tracing strategies have revealed that Gdf5-lineage cells native to and from outside the interzone contribute to most, if not all, of the major joint components. However, there is limited knowledge of the specific transcriptional and signaling programs that regulate interzone formation and fate diversification of synovial joint constituents. To address this, we have performed single cell RNA-Seq analysis of 7329 synovial joint progenitor cells from the developing murine knee joint from E12.5 to E15.5. By using a combination of computational analytics, in situ hybridization and in vitro characterization of prospectively isolated populations, we have identified the transcriptional profiles of the major developmental paths for joint progenitors. Our freely available single cell transcriptional atlas will serve as a resource for the community to uncover transcriptional programs and cell interactions that regulate synovial joint development.
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Affiliation(s)
- Qin Bian
- Institute for Cell Engineering, Johns Hopkins School of Medicine, Baltimore MD 21205, USA.,Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore MD 21205, USA
| | - Yu-Hao Cheng
- Institute for Cell Engineering, Johns Hopkins School of Medicine, Baltimore MD 21205, USA.,Department of Molecular Biology and Genetics, Johns Hopkins School of Medicine, Baltimore MD 21205, USA
| | - Jordan P Wilson
- Institute for Cell Engineering, Johns Hopkins School of Medicine, Baltimore MD 21205, USA
| | - Emily Y Su
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore MD 21205, USA
| | - Dong Won Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore MD 21205, USA
| | - Hong Wang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore MD 21205, USA
| | - Sooyeon Yoo
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore MD 21205, USA
| | - Seth Blackshaw
- Institute for Cell Engineering, Johns Hopkins School of Medicine, Baltimore MD 21205, USA.,Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore MD 21205, USA
| | - Patrick Cahan
- Institute for Cell Engineering, Johns Hopkins School of Medicine, Baltimore MD 21205, USA .,Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore MD 21205, USA.,Department of Molecular Biology and Genetics, Johns Hopkins School of Medicine, Baltimore MD 21205, USA
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11
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Richard D, Liu Z, Cao J, Kiapour AM, Willen J, Yarlagadda S, Jagoda E, Kolachalama VB, Sieker JT, Chang GH, Muthuirulan P, Young M, Masson A, Konrad J, Hosseinzadeh S, Maridas DE, Rosen V, Krawetz R, Roach N, Capellini TD. Evolutionary Selection and Constraint on Human Knee Chondrocyte Regulation Impacts Osteoarthritis Risk. Cell 2020; 181:362-381.e28. [PMID: 32220312 PMCID: PMC7179902 DOI: 10.1016/j.cell.2020.02.057] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 12/10/2019] [Accepted: 02/26/2020] [Indexed: 02/06/2023]
Abstract
During human evolution, the knee adapted to the biomechanical demands of bipedalism by altering chondrocyte developmental programs. This adaptive process was likely not without deleterious consequences to health. Today, osteoarthritis occurs in 250 million people, with risk variants enriched in non-coding sequences near chondrocyte genes, loci that likely became optimized during knee evolution. We explore this relationship by epigenetically profiling joint chondrocytes, revealing ancient selection and recent constraint and drift on knee regulatory elements, which also overlap osteoarthritis variants that contribute to disease heritability by tending to modify constrained functional sequence. We propose a model whereby genetic violations to regulatory constraint, tolerated during knee development, lead to adult pathology. In support, we discover a causal enhancer variant (rs6060369) present in billions of people at a risk locus (GDF5-UQCC1), showing how it impacts mouse knee-shape and osteoarthritis. Overall, our methods link an evolutionarily novel aspect of human anatomy to its pathogenesis.
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Affiliation(s)
- Daniel Richard
- Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Zun Liu
- Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Jiaxue Cao
- Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Ata M Kiapour
- Orthopaedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Jessica Willen
- Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | | | - Evelyn Jagoda
- Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Vijaya B Kolachalama
- Department of Medicine, Boston University School of Medicine, Boston, MA 02115, USA; Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02115, USA; Hariri Institute for Computing and Computational Science and Engineering, Boston University, Boston, MA 02115, USA
| | - Jakob T Sieker
- Orthopaedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Pathology and Laboratory Medicine, Tufts Medical Center, Boston, MA 02111, USA
| | - Gary H Chang
- Department of Medicine, Boston University School of Medicine, Boston, MA 02115, USA
| | | | - Mariel Young
- Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Anand Masson
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Johannes Konrad
- Orthopaedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Shayan Hosseinzadeh
- Orthopaedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - David E Maridas
- Developmental Biology, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Vicki Rosen
- Developmental Biology, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Roman Krawetz
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Neil Roach
- Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Terence D Capellini
- Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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12
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Cooper KL. Developmental and Evolutionary Allometry of the Mammalian Limb Skeleton. Integr Comp Biol 2020; 59:1356-1368. [PMID: 31180500 DOI: 10.1093/icb/icz082] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The variety of limb skeletal proportions enables a remarkable diversity of behaviors that include powered flight in bats and flipper-propelled swimming in whales using extremes of a range of homologous limb architectures. Even within human limbs, bone lengths span more than an order of magnitude from the short finger and toe bones to the long arm and leg bones. Yet all of this diversity arises from embryonic skeletal elements that are each a very similar size at formation. In this review article, I survey what is and is not yet known of the development and evolution of skeletal proportion at multiple hierarchical levels of biological organization. These include the cellular parameters of skeletal elongation in the cartilage growth plate, genes associated with differential growth, and putative gene regulatory mechanisms that would allow both covariant and independent evolution of the forelimbs and hindlimbs and of individual limb segments. Although the genetic mechanisms that shape skeletal proportion are still largely unknown, and most of what is known is limited to mammals, it is becoming increasingly apparent that the diversity of bone lengths is an emergent property of a complex system that controls elongation of individual skeletal elements using a genetic toolkit shared by all.
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Affiliation(s)
- Kimberly L Cooper
- Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093-0377, USA
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13
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Zhao X, Yang X. Retinoic Acid Promotes Retinoic Acid Signaling by Suppression of Pitx1 In Tendon Cells: A Possible Mechanism of a Clubfoot-Like Phenotype Induced by Retinoic Acid. Med Sci Monit 2019; 25:6980-6989. [PMID: 31527569 PMCID: PMC6761847 DOI: 10.12659/msm.917740] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Background The pathogenesis of idiopathic congenital clubfoot (CCF) is unknown. Although some familial patients have Pitx1 mutations, and the Pitx1+/− genotype causes a clubfoot-like phenotype in mice, the mechanism of Pitx1-induced CCF is unknown. Material/Methods We used tibialis anterior tendon samples to detect the expression of Pitx1 in idiopathic and neurogenic clubfoot patients. After obtaining Sprague-Dawley (SD) rat Achilles tendon cells, the expression of Pitx1 was knocked down by SiRNA. After 48 h of culture, mass spectrometry was used to quantitatively analyze proteins. Then, Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to assess the downstream pathway of PITX1. The relationship between Pitx1 and the promoter region of deacetylase 1 (Sirtuin-1 and Sirt1) was examined by luciferase and ChIP assays. Results We found that Pitx1 expression in the tendon samples of idiopathic CCF patients was downregulated. Mass spectrometry analysis revealed that the inhibition of Pitx1 induced the downregulation of Sirt1 expression in tendon cells. Luciferase and ChIP assays confirmed that Pitx1 binds to the promoter region of SIRT1 and promotes Sirt1 gene transcription. Further results showed that, after the inhibition of Pitx1 in tendon cells, CRABP2 acetylation increased, the nuclear import of CRABP2 was enhanced, and the expression of RARβ2 increased. After the inhibition of Pitx1, RARβ2 expression was further increased by RA treatment in tendon cells. In the presence of retinoic acid, the expression of Pitx1 was inhibited in tendon cells. Conclusions Pitx1 binds to the promoter region of SIRT1 and promotes the transcription of SIRT1. Positive feedback occurs between RA signaling and Pitx1.
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Affiliation(s)
- Xiang Zhao
- Department of Pediatric Orthopaedics, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (mainland)
| | - Xuan Yang
- Department of Pediatric Orthopaedics, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (mainland)
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14
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Genomic Evidence for Local Adaptation of Hunter-Gatherers to the African Rainforest. Curr Biol 2019; 29:2926-2935.e4. [DOI: 10.1016/j.cub.2019.07.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/26/2019] [Accepted: 07/04/2019] [Indexed: 12/18/2022]
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15
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Pigeon foot feathering reveals conserved limb identity networks. Dev Biol 2019; 454:128-144. [PMID: 31247188 DOI: 10.1016/j.ydbio.2019.06.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 06/19/2019] [Accepted: 06/20/2019] [Indexed: 12/15/2022]
Abstract
The tetrapod limb is a stunning example of evolutionary diversity, with dramatic variation not only among distantly related species, but also between the serially homologous forelimbs (FLs) and hindlimbs (HLs) within species. Despite this variation, highly conserved genetic and developmental programs underlie limb development and identity in all tetrapods, raising the question of how limb diversification is generated from a conserved toolkit. In some breeds of domestic pigeon, shifts in the expression of two conserved limb identity transcription factors, PITX1 and TBX5, are associated with the formation of feathered HLs with partial FL identity. To determine how modulation of PITX1 and TBX5 expression affects downstream gene expression, we compared the transcriptomes of embryonic limb buds from pigeons with scaled and feathered HLs. We identified a set of differentially expressed genes enriched for genes encoding transcription factors, extracellular matrix proteins, and components of developmental signaling pathways with important roles in limb development. A subset of the genes that distinguish scaled and feathered HLs are also differentially expressed between FL and scaled HL buds in pigeons, pinpointing a set of gene expression changes downstream of PITX1 and TBX5 in the partial transformation from HL to FL identity. We extended our analyses by comparing pigeon limb bud transcriptomes to chicken, anole lizard, and mammalian datasets to identify deeply conserved PITX1- and TBX5-responsive components of the limb identity program. Our analyses reveal a suite of predominantly low-level gene expression changes that are conserved across amniotes to regulate the identity of morphologically distinct limbs.
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Yamamoto S, Uchida Y, Ohtani T, Nozaki E, Yin C, Gotoh Y, Yakushiji-Kaminatsui N, Higashiyama T, Suzuki T, Takemoto T, Shiraishi YI, Kuroiwa A. Hoxa13 regulates expression of common Hox target genes involved in cartilage development to coordinate the expansion of the autopodal anlage. Dev Growth Differ 2019; 61:228-251. [PMID: 30895612 PMCID: PMC6850407 DOI: 10.1111/dgd.12601] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 02/04/2023]
Abstract
To elucidate the role of Hox genes in limb cartilage development, we identified the target genes of HOXA11 and HOXA13 by ChIP‐Seq. The ChIP DNA fragment contained evolutionarily conserved sequences and multiple highly conserved HOX binding sites. A substantial portion of the HOXA11 ChIP fragment overlapped with the HOXA13 ChIP fragment indicating that both factors share common targets. Deletion of the target regions neighboring Bmp2 or Tshz2 reduced their expression in the autopod suggesting that they function as the limb bud‐specific enhancers. We identified the Hox downstream genes as exhibiting expression changes in the Hoxa13 knock out (KO) and Hoxd11‐13 deletion double mutant (Hox13 dKO) autopod by Genechip analysis. The Hox downstream genes neighboring the ChIP fragment were defined as the direct targets of Hox. We analyzed the spatial expression pattern of the Hox target genes that encode two different categories of transcription factors during autopod development and Hox13dKO limb bud. (a) Bcl11a, encoding a repressor of cartilage differentiation, was expressed in the E11.5 autopod and was substantially reduced in the Hox13dKO. (b) The transcription factors Aff3, Bnc2, Nfib and Runx1t1 were expressed in the zeugopodal cartilage but not in the autopod due to the repressive or relatively weak transcriptional activity of Hox13 at E11.5. Interestingly, the expression of these genes was later observed in the autopodal cartilage at E12.5. These results indicate that Hox13 transiently suspends the cartilage differentiation in the autopodal anlage via multiple pathways until establishing the paddle‐shaped structure required to generate five digits.
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Affiliation(s)
- Shiori Yamamoto
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya-shi, Aichi-ken, Japan
| | - Yuji Uchida
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya-shi, Aichi-ken, Japan
| | - Tomomi Ohtani
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya-shi, Aichi-ken, Japan
| | - Erina Nozaki
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya-shi, Aichi-ken, Japan
| | - Chunyang Yin
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya-shi, Aichi-ken, Japan
| | - Yoshihiro Gotoh
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya-shi, Aichi-ken, Japan
| | | | - Tetsuya Higashiyama
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya-shi, Aichi-ken, Japan.,Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Nagoya-shi, Aichi-ken, Japan
| | - Takamasa Suzuki
- Department of Biological Chemistry, College of Bioscience and Biotechnology, Chubu University, Kasugai-shi, Aichi-ken, Japan
| | - Tatsuya Takemoto
- Laboratory for Embryology, Institute for Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Yo-Ichi Shiraishi
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya-shi, Aichi-ken, Japan
| | - Atsushi Kuroiwa
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya-shi, Aichi-ken, Japan
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Yakushiji-Kaminatsui N, Lopez-Delisle L, Bolt CC, Andrey G, Beccari L, Duboule D. Similarities and differences in the regulation of HoxD genes during chick and mouse limb development. PLoS Biol 2018; 16:e3000004. [PMID: 30475793 PMCID: PMC6283595 DOI: 10.1371/journal.pbio.3000004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 12/06/2018] [Accepted: 11/09/2018] [Indexed: 12/22/2022] Open
Abstract
In all tetrapods examined thus far, the development and patterning of limbs require the activation of gene members of the HoxD cluster. In mammals, they are regulated by a complex bimodal process that controls first the proximal patterning and then the distal structure. During the shift from the former to the latter regulation, this bimodal regulatory mechanism allows the production of a domain with low Hoxd gene expression, at which both telomeric (T-DOM) and centromeric regulatory domains (C-DOM) are silent. These cells generate the future wrist and ankle articulations. We analyzed the implementation of this regulatory mechanism in chicken, i.e., in an animal for which large morphological differences exist between fore- and hindlimbs. We report that although this bimodal regulation is globally conserved between the mouse and the chick, some important modifications evolved at least between these two model systems, in particular regarding the activity of specific enhancers, the width of the TAD boundary separating the two regulations, and the comparison between the forelimb versus hindlimb regulatory controls. At least one aspect of these regulations seems to be more conserved between chick and bats than with mouse, which may relate to the extent to which forelimbs and hindlimbs of these various animals differ in their morphologies. A comparison of Hox gene regulation during the development of limbs in birds and mammals reveals that whereas the characteristic bimodal regulatory system, based on large chromatin domains, is largely conserved between these morphologically distinct structures, some differences are revealed in the way this is implemented in various vertebrates. The shapes of limbs vary greatly among tetrapod species, even between the forelimbs and hindlimbs of the same animal. Hox genes regulate the proper growth and patterning of tetrapod limbs. In order to evaluate whether variations in the complex regulation of a cluster of Hox genes—the Hoxd genes—during limb development contribute to the differences in limb shape, we compared their transcriptional control during limb bud development in the forelimbs and hindlimbs of mouse and chicken embryos. We found that the regulatory mechanism underlying Hoxd gene expression is highly conserved, but some clear differences exist. For instance, we observed a variation in the topologically associating domain (TAD; a self-interacting genomic region) boundary interval between the mouse and the chick, as well as differences in the activity of a conserved enhancer element situated within the telomeric regulatory domain. In contrast to the mouse, the chicken enhancer has a stronger activity in the forelimb buds than in the hindlimb buds, which is correlated with the striking differences in the mRNA levels of the genes. We conclude that differences in both the timing and duration of TAD activities and in the width of their boundary may parallel the important decrease in Hoxd gene transcription in chick hindlimb buds versus forelimb buds. These differences may also account for the slightly distinct regulatory strategies implemented by mammals and birds at this locus.
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Affiliation(s)
| | - Lucille Lopez-Delisle
- School of Life Sciences, Federal Institute of Technology, Lausanne, Lausanne, Switzerland
| | - Christopher Chase Bolt
- School of Life Sciences, Federal Institute of Technology, Lausanne, Lausanne, Switzerland
| | - Guillaume Andrey
- School of Life Sciences, Federal Institute of Technology, Lausanne, Lausanne, Switzerland
| | - Leonardo Beccari
- Department of Genetics and Evolution, University of Geneva, Geneva 4, Switzerland
| | - Denis Duboule
- School of Life Sciences, Federal Institute of Technology, Lausanne, Lausanne, Switzerland
- Department of Genetics and Evolution, University of Geneva, Geneva 4, Switzerland
- * E-mail:
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18
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Dynamic 3D chromatin architecture contributes to enhancer specificity and limb morphogenesis. Nat Genet 2018; 50:1463-1473. [PMID: 30262816 PMCID: PMC10154999 DOI: 10.1038/s41588-018-0221-x] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 08/02/2018] [Indexed: 12/20/2022]
Abstract
The regulatory specificity of enhancers and their interaction with gene promoters is thought to be controlled by their sequence and the binding of transcription factors. By studying Pitx1, a regulator of hindlimb development, we show that dynamic changes in chromatin conformation can restrict the activity of enhancers. Inconsistent with its hindlimb-restricted expression, Pitx1 is controlled by an enhancer (Pen) that shows activity in forelimbs and hindlimbs. By Capture Hi-C and three-dimensional modeling of the locus, we demonstrate that forelimbs and hindlimbs have fundamentally different chromatin configurations, whereby Pen and Pitx1 interact in hindlimbs and are physically separated in forelimbs. Structural variants can convert the inactive into the active conformation, thereby inducing Pitx1 misexpression in forelimbs, causing partial arm-to-leg transformation in mice and humans. Thus, tissue-specific three-dimensional chromatin conformation can contribute to enhancer activity and specificity in vivo and its disturbance can result in gene misexpression and disease.
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Shh signaling influences the phenotype of Pitx1-/- hindlimbs. Dev Biol 2018; 439:65-68. [PMID: 29705333 DOI: 10.1016/j.ydbio.2018.04.024] [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: 08/22/2017] [Revised: 04/24/2018] [Accepted: 04/25/2018] [Indexed: 11/23/2022]
Abstract
Forelimbs (FLs) and hindlimbs (HLs) develop under the instructive and integrated guidance of signaling centers and transcription factor (TF) action. The development of structures specific to each limb type depends on the limb-specific modulation of these integrated components. Pitx1 is a transcription factor gene expressed in HL, absent in FL, and required for HL-specific patterning and development, in particular for formation of anterior HL skeletal elements. Pitx1 achieves this function by direct TF action on the core limb program, which is largely shared between FL and HL. Shh signaling plays a crucial role in anterior-posterior (AP) patterning in both FL and HL. The present work assessed the relationship between Shh signaling and Pitx1 action for AP patterning. We found that reducing the gene dosage of Shh in the context of the Pitx1-/- HL decreases the severity of the Pitx1-/- phenotype, in particular, the loss of anterior limb structures and the shortening of femur length. However, this did not rescue HL-specific patterning features. Thus, Pitx1 action integrates Shh signaling but not for limb-type-specific patterning.
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20
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Jain D, Nemec S, Luxey M, Gauthier Y, Bemmo A, Balsalobre A, Drouin J. Regulatory integration of Hox factor activity with T-box factors in limb development. Development 2018; 145:dev.159830. [PMID: 29490982 DOI: 10.1242/dev.159830] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 02/16/2018] [Indexed: 01/26/2023]
Abstract
In tetrapods, Tbx4, Tbx5 and Hox cluster genes are crucial for forelimb and hindlimb development and mutations in these genes are responsible for congenital limb defects. The molecular basis of their integrated mechanisms of action in the context of limb development remains poorly understood. We studied Tbx4 and Hoxc10 owing to their overlapping loss-of-function phenotypes and colocalized expression in mouse hindlimb buds. We report an extensive overlap between Tbx4 and Hoxc10 genome occupancy and their putative target genes. Tbx4 and Hoxc10 interact directly with each other, have the ability to bind to a previously unrecognized T-box-Hox composite DNA motif and show synergistic activity when acting on reporter genes. Pitx1, the master regulator for hindlimb specification, also shows extensive genomic colocalization with Tbx4 and Hoxc10. Genome occupancy by Tbx4 in hindlimb buds is similar to Tbx5 occupancy in forelimbs. By contrast, another Hox factor, Hoxd13, also interacts with Tbx4/Tbx5 but antagonizes Tbx4/Tbx5-dependent transcriptional activity. Collectively, the modulation of Tbx-dependent activity by Hox factors acting on common DNA targets may integrate different developmental processes for the balanced formation of proportionate limbs.
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Affiliation(s)
- Deepak Jain
- Laboratoire de Génétique Moléculaire, Institut de Recherches Cliniques de Montréal, Montréal, QC, H2W 1R7 Canada.,Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6 Canada
| | - Stephen Nemec
- Laboratoire de Génétique Moléculaire, Institut de Recherches Cliniques de Montréal, Montréal, QC, H2W 1R7 Canada.,Department of Experimental Medicine, McGill University, Montreal, QC, H4A 3J1 Canada
| | - Maëva Luxey
- Laboratoire de Génétique Moléculaire, Institut de Recherches Cliniques de Montréal, Montréal, QC, H2W 1R7 Canada
| | - Yves Gauthier
- Laboratoire de Génétique Moléculaire, Institut de Recherches Cliniques de Montréal, Montréal, QC, H2W 1R7 Canada
| | - Amandine Bemmo
- Laboratoire de Génétique Moléculaire, Institut de Recherches Cliniques de Montréal, Montréal, QC, H2W 1R7 Canada
| | - Aurelio Balsalobre
- Laboratoire de Génétique Moléculaire, Institut de Recherches Cliniques de Montréal, Montréal, QC, H2W 1R7 Canada
| | - Jacques Drouin
- Laboratoire de Génétique Moléculaire, Institut de Recherches Cliniques de Montréal, Montréal, QC, H2W 1R7 Canada .,Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6 Canada.,Department of Experimental Medicine, McGill University, Montreal, QC, H4A 3J1 Canada.,Departement de Biochimie, Faculté de Médecine, Université de Montréal, Montréal, QC, H3J 3J7 Canada
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