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Ferner K. Development of the pulmonary vasculature in the gray short-tailed opossum (Monodelphis domestica)-3D reconstruction by microcomputed tomography. Anat Rec (Hoboken) 2024. [PMID: 38993078 DOI: 10.1002/ar.25542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 06/17/2024] [Accepted: 06/30/2024] [Indexed: 07/13/2024]
Abstract
In the marsupial gray short-tailed opossum (Monodelphis domestica), the majority of lung development, including the maturation of pulmonary vasculature, takes place in ventilated functioning state during the postnatal period. The current study uses X-ray computed tomography (μCT) to three-dimensionally reconstruct the vascular trees of the pulmonary artery and pulmonary vein in 15 animals from neonate to postnatal day 57. The final 3D reconstructions of the pulmonary artery and pulmonary vein in the neonate and at 21, 35, and 57 dpn were transformed into a centerline model of the vascular trees. Based on the reconstructions, the generation of end-branching vessels, the median and maximum generation, and the number of vessels were calculated for the lungs. The pulmonary vasculature follows the lung anatomy with six pulmonary lobes indicated by the bronchial tree. The pulmonary arteries follow the bronchial tree closely, in contrast to the pulmonary veins, which run between the pulmonary segments. At birth the pulmonary vasculature has a simple branching pattern with a few vessel generations. Compared with the bronchial tree, the pulmonary vasculature appears to be more developed and extends to the large terminal air spaces. The pulmonary vasculature shows a marked gain in volume and a progressive increase in vascular complexity and density. The gray short-tailed opossum resembles the assumed mammalian ancestor and is suitable to inform on the evolution of the mammalian lung. Vascular genesis in the marsupial bears resemblance to developmental patterns described in eutherians. Lung development in general seems to be highly conservative within mammalian evolution.
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Affiliation(s)
- Kirsten Ferner
- Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Berlin, Germany
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2
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Ferner K. Development of the terminal air spaces in the gray short-tailed opossum (Monodelphis domestica)- 3D reconstruction by microcomputed tomography. PLoS One 2024; 19:e0292482. [PMID: 38363783 PMCID: PMC10871483 DOI: 10.1371/journal.pone.0292482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 01/13/2024] [Indexed: 02/18/2024] Open
Abstract
Marsupials are born with structurally immature lungs when compared to eutherian mammals. The gray short-tailed opossum (Monodelphis domestica) is born at the late canalicular stage of lung development. Despite the high degree of immaturity, the lung is functioning as respiratory organ, however supported by the skin for gas exchange during the first postnatal days. Consequently, the majority of lung development takes place in ventilated functioning state during the postnatal period. Microcomputed tomography (μCT) was used to three-dimensionally reconstruct the terminal air spaces in order to reveal the timeline of lung morphogenesis. In addition, lung and air space volume as well as surface area were determined to assess the functional relevance of the structural changes in the developing lung. The development of the terminal air spaces was examined in 35 animals from embryonic day 13, during the postnatal period (neonate to 57 days) and in adults. At birth, the lung of Monodelphis domestica consists of few large terminal air spaces, which are poorly subdivided and open directly from short lobar bronchioles. During the first postnatal week the number of smaller terminal air spaces increases and numerous septal ridges indicate a process of subdivision, attaining the saccular stage by 7 postnatal days. The 3D reconstructions of the terminal air spaces demonstrated massive increases in air sac number and architectural complexity during the postnatal period. Between 28 and 35 postnatal days alveolarization started. Respiratory bronchioles, alveolar ducts and a typical acinus developed. The volume of the air spaces and the surface area for gas exchange increased markedly with alveolarization. The structural transformation from large terminal sacs to the final alveolar lung in the gray short-tailed opossum follows similar patterns as described in other marsupial and placental mammals. The processes involved in sacculation and alveolarization during lung development seem to be highly conservative within mammalian evolution.
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Affiliation(s)
- Kirsten Ferner
- Department Evolutionary Morphology, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Museum für Naturkunde, Berlin, Germany
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Brannan EO, Hartley GA, O’Neill RJ. Mechanisms of Rapid Karyotype Evolution in Mammals. Genes (Basel) 2023; 15:62. [PMID: 38254952 PMCID: PMC10815390 DOI: 10.3390/genes15010062] [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: 12/12/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/24/2024] Open
Abstract
Chromosome reshuffling events are often a foundational mechanism by which speciation can occur, giving rise to highly derivative karyotypes even amongst closely related species. Yet, the features that distinguish lineages prone to such rapid chromosome evolution from those that maintain stable karyotypes across evolutionary time are still to be defined. In this review, we summarize lineages prone to rapid karyotypic evolution in the context of Simpson's rates of evolution-tachytelic, horotelic, and bradytelic-and outline the mechanisms proposed to contribute to chromosome rearrangements, their fixation, and their potential impact on speciation events. Furthermore, we discuss relevant genomic features that underpin chromosome variation, including patterns of fusions/fissions, centromere positioning, and epigenetic marks such as DNA methylation. Finally, in the era of telomere-to-telomere genomics, we discuss the value of gapless genome resources to the future of research focused on the plasticity of highly rearranged karyotypes.
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Affiliation(s)
- Emry O. Brannan
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA; (E.O.B.); (G.A.H.)
| | - Gabrielle A. Hartley
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA; (E.O.B.); (G.A.H.)
| | - Rachel J. O’Neill
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA; (E.O.B.); (G.A.H.)
- Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269, USA
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4
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Abstract
Computational reconstruction of ancestral mammalian karyotypes revealed a comprehensive picture of the chromosome rearrangements that occurred over the evolutionary history of mammals. Ancient gene order, in some cases extending to full chromosomes, was found conserved for more than 300 My, demonstrating strong evolutionary constraint against rearrangements in some regions. Conserved segments of chromosomes are enriched for genes that control developmental processes. Therefore, Darwinian selection likely maintains ancient gene combinations while allowing for genomic innovations within or near chromosomal sites that break and rearrange over evolutionary time. The revealed relationship between the three-dimensional structure of chromosomes and the evolutionary stability of chromosome segments provides additional insights into the mechanisms of chromosome evolution and diseases associated with genome rearrangements. Decrypting the rearrangements that drive mammalian chromosome evolution is critical to understanding the molecular bases of speciation, adaptation, and disease susceptibility. Using 8 scaffolded and 26 chromosome-scale genome assemblies representing 23/26 mammal orders, we computationally reconstructed ancestral karyotypes and syntenic relationships at 16 nodes along the mammalian phylogeny. Three different reference genomes (human, sloth, and cattle) representing phylogenetically distinct mammalian superorders were used to assess reference bias in the reconstructed ancestral karyotypes and to expand the number of clades with reconstructed genomes. The mammalian ancestor likely had 19 pairs of autosomes, with nine of the smallest chromosomes shared with the common ancestor of all amniotes (three still conserved in extant mammals), demonstrating a striking conservation of synteny for ∼320 My of vertebrate evolution. The numbers and types of chromosome rearrangements were classified for transitions between the ancestral mammalian karyotype, descendent ancestors, and extant species. For example, 94 inversions, 16 fissions, and 14 fusions that occurred over 53 My differentiated the therian from the descendent eutherian ancestor. The highest breakpoint rate was observed between the mammalian and therian ancestors (3.9 breakpoints/My). Reconstructed mammalian ancestor chromosomes were found to have distinct evolutionary histories reflected in their rates and types of rearrangements. The distributions of genes, repetitive elements, topologically associating domains, and actively transcribed regions in multispecies homologous synteny blocks and evolutionary breakpoint regions indicate that purifying selection acted over millions of years of vertebrate evolution to maintain syntenic relationships of developmentally important genes and regulatory landscapes of gene-dense chromosomes.
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Ramos L, Antunes A. Decoding sex: Elucidating sex determination and how high-quality genome assemblies are untangling the evolutionary dynamics of sex chromosomes. Genomics 2022; 114:110277. [PMID: 35104609 DOI: 10.1016/j.ygeno.2022.110277] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 12/22/2021] [Accepted: 01/26/2022] [Indexed: 11/28/2022]
Abstract
Sexual reproduction is a diverse and widespread process. In gonochoristic species, the differentiation of sexes occurs through diverse mechanisms, influenced by environmental and genetic factors. In most vertebrates, a master-switch gene is responsible for triggering a sex determination network. However, only a few genes have acquired master-switch functions, and this process is associated with the evolution of sex-chromosomes, which have a significant influence in evolution. Additionally, their highly repetitive regions impose challenges for high-quality sequencing, even using high-throughput, state-of-the-art techniques. Here, we review the mechanisms involved in sex determination and their role in the evolution of species, particularly vertebrates, focusing on sex chromosomes and the challenges involved in sequencing these genomic elements. We also address the improvements provided by the growth of sequencing projects, by generating a massive number of near-gapless, telomere-to-telomere, chromosome-level, phased assemblies, increasing the number and quality of sex-chromosome sequences available for further studies.
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Affiliation(s)
- Luana Ramos
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450-208 Porto, Portugal; Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Agostinho Antunes
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450-208 Porto, Portugal; Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal.
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6
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Waters PD, Patel HR, Ruiz-Herrera A, Álvarez-González L, Lister NC, Simakov O, Ezaz T, Kaur P, Frere C, Grützner F, Georges A, Graves JAM. Microchromosomes are building blocks of bird, reptile, and mammal chromosomes. Proc Natl Acad Sci U S A 2021; 118:e2112494118. [PMID: 34725164 PMCID: PMC8609325 DOI: 10.1073/pnas.2112494118] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2021] [Indexed: 12/11/2022] Open
Abstract
Microchromosomes, once considered unimportant shreds of the chicken genome, are gene-rich elements with a high GC content and few transposable elements. Their origin has been debated for decades. We used cytological and whole-genome sequence comparisons, and chromosome conformation capture, to trace their origin and fate in genomes of reptiles, birds, and mammals. We find that microchromosomes as well as macrochromosomes are highly conserved across birds and share synteny with single small chromosomes of the chordate amphioxus, attesting to their origin as elements of an ancient animal genome. Turtles and squamates (snakes and lizards) share different subsets of ancestral microchromosomes, having independently lost microchromosomes by fusion with other microchromosomes or macrochromosomes. Patterns of fusions were quite different in different lineages. Cytological observations show that microchromosomes in all lineages are spatially separated into a central compartment at interphase and during mitosis and meiosis. This reflects higher interaction between microchromosomes than with macrochromosomes, as observed by chromosome conformation capture, and suggests some functional coherence. In highly rearranged genomes fused microchromosomes retain most ancestral characteristics, but these may erode over evolutionary time; surprisingly, de novo microchromosomes have rapidly adopted high interaction. Some chromosomes of early-branching monotreme mammals align to several bird microchromosomes, suggesting multiple microchromosome fusions in a mammalian ancestor. Subsequently, multiple rearrangements fueled the extraordinary karyotypic diversity of therian mammals. Thus, microchromosomes, far from being aberrant genetic elements, represent fundamental building blocks of amniote chromosomes, and it is mammals, rather than reptiles and birds, that are atypical.
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Affiliation(s)
- Paul D Waters
- School of Biotechnology and Biomolecular Science, Faculty of Science, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Hardip R Patel
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT 2601, Australia
| | - Aurora Ruiz-Herrera
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
- Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
| | - Lucía Álvarez-González
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
- Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
| | - Nicholas C Lister
- School of Biotechnology and Biomolecular Science, Faculty of Science, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Oleg Simakov
- Department of Neurosciences and Developmental Biology, University of Vienna, 1010 Vienna, Austria
| | - Tariq Ezaz
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia
| | - Parwinder Kaur
- UWA School of Agriculture and Environment, The University of Western Australia, Crawley, WA 6009, Australia
| | - Celine Frere
- Global Change Ecology Research Group, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia
| | - Frank Grützner
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5000, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia
| | - Jennifer A Marshall Graves
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia;
- School of Life Sciences, La Trobe University, Bundoora, VIC 3068, Australia
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7
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Stein WD, Hoshen MB. During evolution from the earliest tetrapoda, newly-recruited genes are increasingly paralogues of existing genes and distribute non-randomly among the chromosomes. BMC Genomics 2021; 22:794. [PMID: 34736418 PMCID: PMC8570013 DOI: 10.1186/s12864-021-08066-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 09/28/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The present availability of full genome sequences of a broad range of animal species across the whole range of evolutionary history enables one to ask questions as to the distribution of genes across the chromosomes. Do newly recruited genes, as new clades emerge, distribute at random or at non-random locations? RESULTS We extracted values for the ages of the human genes and for their current chromosome locations, from published sources. A quantitative analysis showed that the distribution of newly-added genes among and within the chromosomes appears to be increasingly non-random if one observes animals along the evolutionary series from the precursors of the tetrapoda through to the great apes, whereas the oldest genes are randomly distributed. CONCLUSIONS Randomization will result from chromosome evolution, but less and less time is available for this process as evolution proceeds. Much of the bunching of recently-added genes arises from new gene formation as paralogues in gene families, near the location of genes that were recruited in the preceding phylostratum. As examples we cite the KRTAP, ZNF, OR and some minor gene families. We show that bunching can also result from the evolution of the chromosomes themselves when, as for the KRTAP genes, blocks of genes that had previously been on disparate chromosomes become linked together.
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Affiliation(s)
- Wilfred D Stein
- Silberman Institute of Life Sciences, Hebrew University, 91904, Jerusalem, Israel.
| | - Moshe B Hoshen
- Bioinformatics Department, Jerusalem College of Technology, Tal Campus, Beit HaDfus 7, 95483, Jerusalem, Israel
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8
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Zhou Y, Shearwin-Whyatt L, Li J, Song Z, Hayakawa T, Stevens D, Fenelon JC, Peel E, Cheng Y, Pajpach F, Bradley N, Suzuki H, Nikaido M, Damas J, Daish T, Perry T, Zhu Z, Geng Y, Rhie A, Sims Y, Wood J, Haase B, Mountcastle J, Fedrigo O, Li Q, Yang H, Wang J, Johnston SD, Phillippy AM, Howe K, Jarvis ED, Ryder OA, Kaessmann H, Donnelly P, Korlach J, Lewin HA, Graves J, Belov K, Renfree MB, Grutzner F, Zhou Q, Zhang G. Platypus and echidna genomes reveal mammalian biology and evolution. Nature 2021; 592:756-762. [PMID: 33408411 PMCID: PMC8081666 DOI: 10.1038/s41586-020-03039-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 07/30/2020] [Indexed: 12/13/2022]
Abstract
Egg-laying mammals (monotremes) are the only extant mammalian outgroup to therians (marsupial and eutherian animals) and provide key insights into mammalian evolution1,2. Here we generate and analyse reference genomes of the platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus), which represent the only two extant monotreme lineages. The nearly complete platypus genome assembly has anchored almost the entire genome onto chromosomes, markedly improving the genome continuity and gene annotation. Together with our echidna sequence, the genomes of the two species allow us to detect the ancestral and lineage-specific genomic changes that shape both monotreme and mammalian evolution. We provide evidence that the monotreme sex chromosome complex originated from an ancestral chromosome ring configuration. The formation of such a unique chromosome complex may have been facilitated by the unusually extensive interactions between the multi-X and multi-Y chromosomes that are shared by the autosomal homologues in humans. Further comparative genomic analyses unravel marked differences between monotremes and therians in haptoglobin genes, lactation genes and chemosensory receptor genes for smell and taste that underlie the ecological adaptation of monotremes.
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Affiliation(s)
- Yang Zhou
- BGI-Shenzhen, Shenzhen, China
- Villum Center for Biodiversity Genomics, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Linda Shearwin-Whyatt
- School of Biological Sciences, The Environment Institute, The University of Adelaide, Adelaide, South Australia, Australia
| | - Jing Li
- MOE Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Zhenzhen Song
- BGI-Shenzhen, Shenzhen, China
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China
| | - Takashi Hayakawa
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
- Japan Monkey Centre, Inuyama, Japan
| | - David Stevens
- School of Biological Sciences, The Environment Institute, The University of Adelaide, Adelaide, South Australia, Australia
| | - Jane C Fenelon
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Emma Peel
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Yuanyuan Cheng
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Filip Pajpach
- School of Biological Sciences, The Environment Institute, The University of Adelaide, Adelaide, South Australia, Australia
| | - Natasha Bradley
- School of Biological Sciences, The Environment Institute, The University of Adelaide, Adelaide, South Australia, Australia
| | | | - Masato Nikaido
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan
| | - Joana Damas
- The Genome Center, University of California, Davis, CA, USA
| | - Tasman Daish
- School of Biological Sciences, The Environment Institute, The University of Adelaide, Adelaide, South Australia, Australia
| | - Tahlia Perry
- School of Biological Sciences, The Environment Institute, The University of Adelaide, Adelaide, South Australia, Australia
| | - Zexian Zhu
- MOE Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Yuncong Geng
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Arang Rhie
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ying Sims
- Tree of Life Programme, Wellcome Sanger Institute, Cambridge, UK
| | - Jonathan Wood
- Tree of Life Programme, Wellcome Sanger Institute, Cambridge, UK
| | - Bettina Haase
- The Vertebrate Genome Lab, The Rockefeller University, New York, NY, USA
| | | | - Olivier Fedrigo
- The Vertebrate Genome Lab, The Rockefeller University, New York, NY, USA
| | - Qiye Li
- BGI-Shenzhen, Shenzhen, China
| | - Huanming Yang
- BGI-Shenzhen, Shenzhen, China
- James D. Watson Institute of Genome Sciences, Hangzhou, China
- University of the Chinese Academy of Sciences, Beijing, China
- Guangdong Provincial Academician Workstation of BGI Synthetic Genomics, BGI-Shenzhen, Shenzhen, China
| | - Jian Wang
- BGI-Shenzhen, Shenzhen, China
- James D. Watson Institute of Genome Sciences, Hangzhou, China
| | - Stephen D Johnston
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, Queensland, Australia
| | - Adam M Phillippy
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Kerstin Howe
- Tree of Life Programme, Wellcome Sanger Institute, Cambridge, UK
| | - Erich D Jarvis
- Laboratory of Neurogenetics of Language, The Rockefeller University, New York, NY, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | | | - Henrik Kaessmann
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Peter Donnelly
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | - Harris A Lewin
- The Genome Center, University of California, Davis, CA, USA
- Department of Evolution and Ecology, College of Biological Sciences, University of California, Davis, CA, USA
- Department of Reproduction and Population Health, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Jennifer Graves
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia
- School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
| | - Katherine Belov
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Marilyn B Renfree
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Frank Grutzner
- School of Biological Sciences, The Environment Institute, The University of Adelaide, Adelaide, South Australia, Australia.
| | - Qi Zhou
- MOE Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China.
- Department of Neuroscience and Developmental Biology, University of Vienna, Vienna, Austria.
- Center for Reproductive Medicine, The 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
| | - Guojie Zhang
- BGI-Shenzhen, Shenzhen, China.
- Villum Center for Biodiversity Genomics, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China.
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9
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Deakin JE, Potter S. Marsupial chromosomics: bridging the gap between genomes and chromosomes. Reprod Fertil Dev 2020; 31:1189-1202. [PMID: 30630589 DOI: 10.1071/rd18201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 12/05/2018] [Indexed: 12/12/2022] Open
Abstract
Marsupials have unique features that make them particularly interesting to study, and sequencing of marsupial genomes is helping to understand their evolution. A decade ago, it was a huge feat to sequence the first marsupial genome. Now, the advances in sequencing technology have made the sequencing of many more marsupial genomes possible. However, the DNA sequence is only one component of the structures it is packaged into: chromosomes. Knowing the arrangement of the DNA sequence on each chromosome is essential for a genome assembly to be used to its full potential. The importance of combining sequence information with cytogenetics has previously been demonstrated for rapidly evolving regions of the genome, such as the sex chromosomes, as well as for reconstructing the ancestral marsupial karyotype and understanding the chromosome rearrangements involved in the Tasmanian devil facial tumour disease. Despite the recent advances in sequencing technology assisting in genome assembly, physical anchoring of the sequence to chromosomes is required to achieve a chromosome-level assembly. Once chromosome-level assemblies are achieved for more marsupials, we will be able to investigate changes in the packaging and interactions between chromosomes to gain an understanding of the role genome architecture has played during marsupial evolution.
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Affiliation(s)
- Janine E Deakin
- Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia
| | - Sally Potter
- Research School of Biology, Australian National University, Acton, ACT 2601, Australia
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10
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Abstract
Marsupial genomes, which are packaged into large chromosomes, provide a powerful resource for studying the mechanisms of genome evolution. The extensive and valuable body of work on marsupial cytogenetics, combined more recently with genome sequence data, has enabled prediction of the 2n = 14 karyotype ancestral to all marsupial families. The application of both chromosome biology and genome sequencing, or chromosomics, has been a necessary approach for various aspects of mammalian genome evolution, such as understanding sex chromosome evolution and the origin and evolution of transmissible tumors in Tasmanian devils. The next phase of marsupial genome evolution research will employ chromosomics approaches to begin addressing fundamental questions in marsupial genome evolution and chromosome evolution more generally. The answers to these complex questions will impact our understanding across a broad range of fields, including the genetics of speciation, genome adaptation to environmental stressors, and species management.
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Affiliation(s)
- Janine E Deakin
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory 2617, Australia;
| | - Rachel J O'Neill
- Department of Molecular and Cell Biology and Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut 06269, USA;
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11
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The methylation and telomere landscape in two families of marsupials with different rates of chromosome evolution. Chromosome Res 2018; 26:317-332. [PMID: 30539406 DOI: 10.1007/s10577-018-9593-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/22/2018] [Accepted: 11/23/2018] [Indexed: 02/07/2023]
Abstract
Two marsupial families exemplify divergent rates of karyotypic change. The Dasyurid family has an extremely conserved karyotype. In contrast, there is significant chromosomal variation within the Macropodidae family, best exemplified by members of the genus Petrogale (rock-wallabies). Both families are also distinguished by their telomere landscape (length and epigenetics), with the dasyurids having a unique telomere length dimorphism not observed in other marsupials and hypothesised to be regulated in a parent-of-origin fashion. Previous work has shown that proximal ends of chromosomes are enriched in cytosine methylation in dasyurids, but that the chromosomes of a macropod, the tammar wallaby, have DNA methylation enrichment of pericentric regions. Using a combination of telomere and 5-methylcytosine immunofluorescence staining, we investigated the telomere landscape of four dasyurid and three Petrogale species. As part of this study, we also further examined the parent-of-origin hypothesis for the regulation of telomere length dimorphism in dasyurids, using epigenetic modifications known to differentiate the active maternal X chromosome, including 5-methylcytosine methylation and histone modifications H3K4me2, H3K9ac and H4Kac. Our results give further support to the parent-of-origin hypothesis for the regulation of telomere length dimorphism in dasyurids, where the paternally derived X chromosome in females was associated with long telomeres and the maternally derived with short telomeres. In contrast to the tammar wallaby, rock-wallabies demonstrated a similar 5-methylcytosine staining pattern across all chromosomes to that of dasyurids, suggesting that DNA methylation of telomeric regions is not responsible for differences in the rates of chromosome evolution between these two families.
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12
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Kasai F, O'Brien PCM, Pereira JC, Ferguson-Smith MA. Marsupial chromosome DNA content and genome size assessed from flow karyotypes: invariable low autosomal GC content. ROYAL SOCIETY OPEN SCIENCE 2018; 5:171539. [PMID: 30224977 PMCID: PMC6124049 DOI: 10.1098/rsos.171539] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 08/06/2018] [Indexed: 06/08/2023]
Abstract
Extensive chromosome homologies revealed by cross-species chromosome painting between marsupials have suggested a high level of genome conservation during evolution. Surprisingly, it has been reported that marsupial genome sizes vary by more than 1.2 Gb between species. We have shown previously that individual chromosome sizes and GC content can be measured in flow karyotypes, and have applied this method to compare four marsupial species. Chromosome sizes and GC content were calculated for the grey short-tailed opossum (2n = 18), tammar wallaby (2n = 16), Tasmanian devil (2n = 14) and fat-tailed dunnart (2n = 14), resulting in genome sizes of 3.41, 3.31, 3.17 and 3.25 Gb, respectively. The findings under the same conditions allow a comparison between the four species, indicating that the genomes of these four species are 1-8% larger than human. We show that marsupial genomes are characterized by a low GC content invariable between autosomes and distinct from the higher GC content of the marsupial × chromosome.
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Affiliation(s)
- Fumio Kasai
- Author for correspondence: Fumio Kasai e-mail:
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13
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Johnson RN, O'Meally D, Chen Z, Etherington GJ, Ho SYW, Nash WJ, Grueber CE, Cheng Y, Whittington CM, Dennison S, Peel E, Haerty W, O'Neill RJ, Colgan D, Russell TL, Alquezar-Planas DE, Attenbrow V, Bragg JG, Brandies PA, Chong AYY, Deakin JE, Di Palma F, Duda Z, Eldridge MDB, Ewart KM, Hogg CJ, Frankham GJ, Georges A, Gillett AK, Govendir M, Greenwood AD, Hayakawa T, Helgen KM, Hobbs M, Holleley CE, Heider TN, Jones EA, King A, Madden D, Graves JAM, Morris KM, Neaves LE, Patel HR, Polkinghorne A, Renfree MB, Robin C, Salinas R, Tsangaras K, Waters PD, Waters SA, Wright B, Wilkins MR, Timms P, Belov K. Adaptation and conservation insights from the koala genome. Nat Genet 2018; 50:1102-1111. [PMID: 29967444 PMCID: PMC6197426 DOI: 10.1038/s41588-018-0153-5] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 04/30/2018] [Indexed: 11/16/2022]
Abstract
The koala, the only extant species of the marsupial family Phascolarctidae, is classified as 'vulnerable' due to habitat loss and widespread disease. We sequenced the koala genome, producing a complete and contiguous marsupial reference genome, including centromeres. We reveal that the koala's ability to detoxify eucalypt foliage may be due to expansions within a cytochrome P450 gene family, and its ability to smell, taste and moderate ingestion of plant secondary metabolites may be due to expansions in the vomeronasal and taste receptors. We characterized novel lactation proteins that protect young in the pouch and annotated immune genes important for response to chlamydial disease. Historical demography showed a substantial population crash coincident with the decline of Australian megafauna, while contemporary populations had biogeographic boundaries and increased inbreeding in populations affected by historic translocations. We identified genetically diverse populations that require habitat corridors and instituting of translocation programs to aid the koala's survival in the wild.
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Affiliation(s)
- Rebecca N Johnson
- Australian Museum Research Institute, Australian Museum, Sydney, New South Wales, Australia.
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia.
| | - Denis O'Meally
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia
- Animal Research Centre, Faculty of Science, Health, Education & Engineering, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Zhiliang Chen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, New South Wales, Australia
| | | | - Simon Y W Ho
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia
| | - Will J Nash
- Earlham Institute, Norwich Research Park, Norwich, UK
| | - Catherine E Grueber
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia
- San Diego Zoo Global, San Diego, CA, USA
| | - Yuanyuan Cheng
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia
- UQ Genomics Initiative, University of Queensland, St Lucia, Queensland, Australia
| | - Camilla M Whittington
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia
| | - Siobhan Dennison
- Australian Museum Research Institute, Australian Museum, Sydney, New South Wales, Australia
| | - Emma Peel
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia
| | | | - Rachel J O'Neill
- Department of Molecular and Cell Biology and Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA
| | - Don Colgan
- Australian Museum Research Institute, Australian Museum, Sydney, New South Wales, Australia
| | - Tonia L Russell
- Ramaciotti Centre for Genomics, University of New South Wales, Kensington, New South Wales, Australia
| | | | - Val Attenbrow
- Australian Museum Research Institute, Australian Museum, Sydney, New South Wales, Australia
| | - Jason G Bragg
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
- National Herbarium of New South Wales, Royal Botanic Gardens & Domain Trust, Sydney, New South Wales, Australia
| | - Parice A Brandies
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia
| | - Amanda Yoon-Yee Chong
- Earlham Institute, Norwich Research Park, Norwich, UK
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Janine E Deakin
- Institute for Applied Ecology, University of Canberra, Bruce, Australian Capital Territory, Australia
| | - Federica Di Palma
- Earlham Institute, Norwich Research Park, Norwich, UK
- Department of Biological Sciences, University of East Anglia, Norwich, UK
| | - Zachary Duda
- Department of Molecular and Cell Biology and Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA
| | - Mark D B Eldridge
- Australian Museum Research Institute, Australian Museum, Sydney, New South Wales, Australia
| | - Kyle M Ewart
- Australian Museum Research Institute, Australian Museum, Sydney, New South Wales, Australia
| | - Carolyn J Hogg
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia
| | - Greta J Frankham
- Australian Museum Research Institute, Australian Museum, Sydney, New South Wales, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Bruce, Australian Capital Territory, Australia
| | - Amber K Gillett
- Australia Zoo Wildlife Hospital, Beerwah, Queensland, Australia
| | - Merran Govendir
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia
| | - Alex D Greenwood
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
- Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Takashi Hayakawa
- Department of Wildlife Science (Nagoya Railroad Co., Ltd.), Primate Research Institute, Kyoto University, Inuyama, Japan
- Japan Monkey Centre, Inuyama, Japan
| | - Kristofer M Helgen
- Australian Museum Research Institute, Australian Museum, Sydney, New South Wales, Australia
- School of Biological Sciences, Environment Institute, Centre for Applied Conservation Science, and ARC Centre of Excellence for Australian Biodiversity and Heritage, University of Adelaide, Adelaide, South Australia, Australia
| | - Matthew Hobbs
- Australian Museum Research Institute, Australian Museum, Sydney, New South Wales, Australia
| | - Clare E Holleley
- Australian National Wildlife Collection, National Research Collections Australia, CSIRO, Canberra, Australian Capital Territory, Australia
| | - Thomas N Heider
- Department of Molecular and Cell Biology and Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA
| | - Elizabeth A Jones
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia
| | - Andrew King
- Australian Museum Research Institute, Australian Museum, Sydney, New South Wales, Australia
| | - Danielle Madden
- Animal Research Centre, Faculty of Science, Health, Education & Engineering, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Jennifer A Marshall Graves
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
- Institute for Applied Ecology, University of Canberra, Bruce, Australian Capital Territory, Australia
- School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia
| | - Katrina M Morris
- The Roslin Institute and R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, UK
| | - Linda E Neaves
- Australian Museum Research Institute, Australian Museum, Sydney, New South Wales, Australia
- Royal Botanic Garden Edinburgh, Edinburgh, UK
| | - Hardip R Patel
- John Curtin School of Medical Research, Australian National University, Acton, Australian Capital Territory, Australia
| | - Adam Polkinghorne
- Animal Research Centre, Faculty of Science, Health, Education & Engineering, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Marilyn B Renfree
- School of BioSciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Charles Robin
- School of BioSciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Ryan Salinas
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, New South Wales, Australia
| | - Kyriakos Tsangaras
- Department of Translational Genetics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Paul D Waters
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, New South Wales, Australia
| | - Shafagh A Waters
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, New South Wales, Australia
| | - Belinda Wright
- Australian Museum Research Institute, Australian Museum, Sydney, New South Wales, Australia
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia
| | - Marc R Wilkins
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, New South Wales, Australia
- Ramaciotti Centre for Genomics, University of New South Wales, Kensington, New South Wales, Australia
| | - Peter Timms
- Faculty of Science, Health, Education & Engineering, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Katherine Belov
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia
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Abstract
Making my career in Australia exposed me to the tyranny of distance, but it gave me opportunities to study our unique native fauna. Distantly related animal species present genetic variation that we can use to explore the most fundamental biological structures and processes. I have compared chromosomes and genomes of kangaroos and platypus, tiger snakes and emus, devils (Tasmanian) and dragons (lizards). I particularly love the challenges posed by sex chromosomes, which, apart from determining sex, provide stunning examples of epigenetic control and break all the evolutionary rules that we currently understand. Here I describe some of those amazing animals and the insights on genome structure, function, and evolution they have afforded us. I also describe my sometimes-random walk in science and the factors and people who influenced my direction. Being a woman in science is still not easy, and I hope others will find encouragement and empathy in my story.
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Affiliation(s)
- Jennifer A. Marshall Graves
- School of Life Science, La Trobe University, Melbourne, Victoria 3086, Australia
- Australia Institute of Applied Ecology, University of Canberra, ACT 2617, Australia
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15
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Deakin JE. Chromosome Evolution in Marsupials. Genes (Basel) 2018; 9:E72. [PMID: 29415454 PMCID: PMC5852568 DOI: 10.3390/genes9020072] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 01/30/2018] [Accepted: 02/01/2018] [Indexed: 12/17/2022] Open
Abstract
Marsupials typically possess very large, distinctive chromosomes that make them excellent subjects for cytogenetic analysis, and the high level of conservation makes it relatively easy to track chromosome evolution. There are two speciose marsupial families with contrasting rates of karyotypic evolution that could provide insight into the mechanisms driving genome reshuffling and speciation. The family Dasyuridae displays exceptional karyotype conservation with all karyotyped species possessing a 2n = 14 karyotype similar to that predicted for the ancestral marsupial. In contrast, the family Macropodidae has experienced a higher rate of genomic rearrangement and one genus of macropods, the rock-wallabies (Petrogale), has experienced extensive reshuffling. For at least some recently diverged Petrogale species, there is still gene flow despite hybrid fertility issues, making this species group an exceptional model for studying speciation. This review highlights the unique chromosome features of marsupial chromosomes, particularly for these two contrasting families, and the value that a combined cytogenetics, genomics, and epigenomics approach will have for testing models of genome evolution and speciation.
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Affiliation(s)
- Janine E Deakin
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2617, Australia.
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16
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Taylor RL, Zhang Y, Schöning JP, Deakin JE. Identification of candidate genes for devil facial tumour disease tumourigenesis. Sci Rep 2017; 7:8761. [PMID: 28821767 PMCID: PMC5562891 DOI: 10.1038/s41598-017-08908-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/14/2017] [Indexed: 12/11/2022] Open
Abstract
Devil facial tumour (DFT) disease, a transmissible cancer where the infectious agent is the tumour itself, has caused a dramatic decrease in Tasmanian devil numbers in the wild. The purpose of this study was to take a candidate gene/pathway approach to identify potentially perturbed genes or pathways in DFT. A fusion of chromosome 1 and X is posited as the initial event leading to the development of DFT, with the rearranged chromosome 1 material now stably maintained as the tumour spreads through the population. This hypothesis makes chromosome 1 a prime chromosome on which to search for mutations involved in tumourigenesis. As DFT1 has a Schwann cell origin, we selected genes commonly implicated in tumour pathways in human nerve cancers, or cancers more generally, to determine whether they were rearranged in DFT1, and mapped them using molecular cytogenetics. Many cancer-related genes were rearranged, such as the region containing the tumour suppressor NF2 and a copy gain for ERBB3, a member of the epidermal growth factor receptor family of receptor tyrosine kinases implicated in proliferation and invasion of tumours in humans. Our mapping results have provided strong candidates not previously detected by sequencing DFT1 genomes.
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Affiliation(s)
- Robyn L Taylor
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - Yiru Zhang
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Jennifer P Schöning
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia.,Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Queensland, 4067, Australia
| | - Janine E Deakin
- Institute for Applied Ecology, University of Canberra, Canberra, ACT, 2617, Australia.
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17
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Deakin JE. Implications of monotreme and marsupial chromosome evolution on sex determination and differentiation. Gen Comp Endocrinol 2017; 244:130-138. [PMID: 26431612 DOI: 10.1016/j.ygcen.2015.09.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 09/15/2015] [Accepted: 09/26/2015] [Indexed: 12/30/2022]
Abstract
Studies of chromosomes from monotremes and marsupials endemic to Australasia have provided important insight into the evolution of their genomes as well as uncovering fundamental differences in their sex determination/differentiation pathways. Great advances have been made this century into solving the mystery of the complicated sex chromosome system in monotremes. Monotremes possess multiple different X and Y chromosomes and a candidate sex determining gene has been identified. Even greater advancements have been made for marsupials, with reconstruction of the ancestral karyotype enabling the evolutionary history of marsupial chromosomes to be determined. Furthermore, the study of sex chromosomes in intersex marsupials has afforded insight into differences in the sexual differentiation pathway between marsupials and eutherians, together with experiments showing the insensitivity of the mammary glands, pouch and scrotum to exogenous hormones, led to the hypothesis that there is a gene (or genes) on the X chromosome responsible for the development of either pouch or scrotum. This review highlights the major advancements made towards understanding chromosome evolution and how this has impacted on our understanding of sex determination and differentiation in these interesting mammals.
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Affiliation(s)
- Janine E Deakin
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia.
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18
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Suárez-Villota EY, Haro RE, Vargas RA, Gallardo MH. The ancestral chromosomes of Dromiciops gliroides (Microbiotheridae), and its bearings on the karyotypic evolution of American marsupials. Mol Cytogenet 2016; 9:59. [PMID: 27489568 PMCID: PMC4971695 DOI: 10.1186/s13039-016-0270-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 07/25/2016] [Indexed: 11/12/2022] Open
Abstract
Background The low-numbered 14-chromosome karyotype of marsupials has falsified the fusion hypothesis claiming ancestrality from a 22-chromosome karyotype. Since the 14-chromosome condition of the relict Dromiciops gliroides is reminecent of ancestrality, its interstitial traces of past putative fusions and heterochromatin banding patterns were studied and added to available marsupials’ cytogenetic data. Fluorescent in situ hybridization (FISH) and self-genomic in situ hybridization (self-GISH) were used to detect telomeric and repetitive sequences, respectively. These were complemented with C-, fluorescent banding, and centromere immunodetection over mitotic spreads. The presence of interstitial telomeric sequences (ITS) and diploid numbers were reconstructed and mapped onto the marsupial phylogenetic tree. Results No interstitial, fluorescent signals, but clearly stained telomeric regions were detected by FISH and self-GISH. Heterochromatin distribution was sparse in the telomeric/subtelomeric regions of large submetacentric chromosomes. Large AT-rich blocks were detected in the long arm of four submetacentrics and CG-rich block in the telomeric regions of all chromosomes. The ancestral reconstructions both ITS presence and diploid numbers suggested that ITS are unrelated to fusion events. Conclusion Although the lack of interstitial signals in D. gliroides’ karyotype does not prove absence of past fusions, our data suggests its non-rearranged plesiomorphic condition. Electronic supplementary material The online version of this article (doi:10.1186/s13039-016-0270-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elkin Y Suárez-Villota
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Casilla 567, Valdivia, Chile
| | - Ronie E Haro
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Casilla 567, Valdivia, Chile
| | - Rodrigo A Vargas
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Casilla 567, Valdivia, Chile
| | - Milton H Gallardo
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Casilla 567, Valdivia, Chile
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19
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Deakin JE, Edwards MJ, Patel H, O'Meally D, Lian J, Stenhouse R, Ryan S, Livernois AM, Azad B, Holleley CE, Li Q, Georges A. Anchoring genome sequence to chromosomes of the central bearded dragon (Pogona vitticeps) enables reconstruction of ancestral squamate macrochromosomes and identifies sequence content of the Z chromosome. BMC Genomics 2016; 17:447. [PMID: 27286959 PMCID: PMC4902969 DOI: 10.1186/s12864-016-2774-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 05/25/2016] [Indexed: 12/30/2022] Open
Abstract
Background Squamates (lizards and snakes) are a speciose lineage of reptiles displaying considerable karyotypic diversity, particularly among lizards. Understanding the evolution of this diversity requires comparison of genome organisation between species. Although the genomes of several squamate species have now been sequenced, only the green anole lizard has any sequence anchored to chromosomes. There is only limited gene mapping data available for five other squamates. This makes it difficult to reconstruct the events that have led to extant squamate karyotypic diversity. The purpose of this study was to anchor the recently sequenced central bearded dragon (Pogona vitticeps) genome to chromosomes to trace the evolution of squamate chromosomes. Assigning sequence to sex chromosomes was of particular interest for identifying candidate sex determining genes. Results By using two different approaches to map conserved blocks of genes, we were able to anchor approximately 42 % of the dragon genome sequence to chromosomes. We constructed detailed comparative maps between dragon, anole and chicken genomes, and where possible, made broader comparisons across Squamata using cytogenetic mapping information for five other species. We show that squamate macrochromosomes are relatively well conserved between species, supporting findings from previous molecular cytogenetic studies. Macrochromosome diversity between members of the Toxicofera clade has been generated by intrachromosomal, and a small number of interchromosomal, rearrangements. We reconstructed the ancestral squamate macrochromosomes by drawing upon comparative cytogenetic mapping data from seven squamate species and propose the events leading to the arrangements observed in representative species. In addition, we assigned over 8 Mbp of sequence containing 219 genes to the Z chromosome, providing a list of genes to begin testing as candidate sex determining genes. Conclusions Anchoring of the dragon genome has provided substantial insight into the evolution of squamate genomes, enabling us to reconstruct ancestral macrochromosome arrangements at key positions in the squamate phylogeny, demonstrating that fusions between macrochromosomes or fusions of macrochromosomes and microchromosomes, have played an important role during the evolution of squamate genomes. Assigning sequence to the sex chromosomes has identified NR5A1 as a promising candidate sex determining gene in the dragon. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2774-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Janine E Deakin
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia.
| | - Melanie J Edwards
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia
| | - Hardip Patel
- John Curtin School of Medical Research, Australian National University, Canberra, ACT 2601, Australia
| | - Denis O'Meally
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia
| | - Jinmin Lian
- China National GeneBank, BGI-Shenzhen, Shenzhen, 518083, China
| | - Rachael Stenhouse
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia
| | - Sam Ryan
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia
| | - Alexandra M Livernois
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia
| | - Bhumika Azad
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia.,John Curtin School of Medical Research, Australian National University, Canberra, ACT 2601, Australia
| | - Clare E Holleley
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia
| | - Qiye Li
- China National GeneBank, BGI-Shenzhen, Shenzhen, 518083, China.,Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, Copenhagen, 1350, Denmark
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia
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20
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Deakin JE, Kruger-Andrzejewska M. Marsupials as models for understanding the role of chromosome rearrangements in evolution and disease. Chromosoma 2016; 125:633-44. [PMID: 27255308 DOI: 10.1007/s00412-016-0603-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 05/19/2016] [Accepted: 05/23/2016] [Indexed: 12/28/2022]
Abstract
Chromosome rearrangements have been implicated in diseases, such as cancer, and speciation, but it remains unclear whether rearrangements are causal or merely a consequence of these processes. Two marsupial families with very different rates of karyotype evolution provide excellent models in which to study the role of chromosome rearrangements in a disease and evolutionary context. The speciose family Dasyuridae displays remarkable karyotypic conservation, with all species examined to date possessing nearly identical karyotypes. Despite the seemingly high degree of chromosome stability within this family, they appear prone to developing tumours, including transmissible devil facial tumours. In contrast, chromosome rearrangements have been frequent in the evolution of the species-rich family Macropodidae, which displays a high level of karyotypic diversity. In particular, the genus Petrogale (rock-wallabies) displays an extraordinary level of chromosome rearrangement among species. For six parapatric Petrogale species, it appears that speciation has essentially been caught in the act, providing an opportunity to determine whether chromosomal rearrangements are a cause or consequence of speciation in this system. This review highlights the reasons that these two marsupial families are excellent models for testing hypotheses for hotspots of chromosome rearrangement and deciphering the role of chromosome rearrangements in disease and speciation.
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Affiliation(s)
- Janine E Deakin
- Institute for Applied Ecology, University of Canberra, Canberra, ACT, 2617, Australia.
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21
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Global DNA Methylation patterns on marsupial and devil facial tumour chromosomes. Mol Cytogenet 2015; 8:74. [PMID: 26435750 PMCID: PMC4591559 DOI: 10.1186/s13039-015-0176-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 09/19/2015] [Indexed: 12/19/2022] Open
Abstract
Background Despite DNA methylation being one of the most widely studied epigenetic modifications in eukaryotes, only a few studies have examined the global methylation status of marsupial chromosomes. The emergence of devil facial tumour disease (DFTD), a clonally transmissible cancer spreading through the Tasmanian devil population, makes it a particularly pertinent time to determine the methylation status of marsupial and devil facial tumour chromosomes. DNA methylation perturbations are known to play a role in genome instability in human tumours. One of the interesting features of the devil facial tumour is its remarkable karyotypic stability over time as only four strains with minor karyotypic differences having been reported. The cytogenetic monitoring of devil facial tumour (DFT) samples collected over an eight year period and detailed molecular cytogenetic analysis performed on the different DFT strains enables chromosome rearrangements to be correlated with methylation status as the tumour evolves. Results We used immunofluorescent staining with an antibody to 5-methylcytosine on metaphase chromosomes prepared from fibroblast cells of three distantly related marsupials, including the Tasmanian devil, as well as DFTD chromosomes prepared from samples collected from different years and representing different karyotypic strains. Staining of chromosomes from male and female marsupial cell lines indicate species-specific differences in global methylation patterns but with the most intense staining regions corresponding to telomeric and/or centromeric regions of autosomes. In males, the X chromosome was hypermethylated as was one X in females. Similarly, telomeric regions on DFTD chromosomes and regions corresponding to material from one of the two X chromosomes were hypermethylated. No difference in global methylation in samples of the same strain taken in different years was observed. Conclusions The methylation patterns on DFTD chromosomes suggests that the hypermethylated active X was shattered in the formation of the tumour chromosomes, with atypical areas of methylation on DFTD chromosomes corresponding to locations of X chromosome material from the shattered X. The incredibly stable broad methylation patterns observed between strains and over time may reflect the overall genomic stability of the devil facial tumour. Electronic supplementary material The online version of this article (doi:10.1186/s13039-015-0176-x) contains supplementary material, which is available to authorized users.
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22
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Badenhorst D, Hillier LW, Literman R, Montiel EE, Radhakrishnan S, Shen Y, Minx P, Janes DE, Warren WC, Edwards SV, Valenzuela N. Physical Mapping and Refinement of the Painted Turtle Genome (Chrysemys picta) Inform Amniote Genome Evolution and Challenge Turtle-Bird Chromosomal Conservation. Genome Biol Evol 2015; 7:2038-50. [PMID: 26108489 PMCID: PMC4524486 DOI: 10.1093/gbe/evv119] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/19/2015] [Indexed: 01/04/2023] Open
Abstract
Comparative genomics continues illuminating amniote genome evolution, but for many lineages our understanding remains incomplete. Here, we refine the assembly (CPI 3.0.3 NCBI AHGY00000000.2) and develop a cytogenetic map of the painted turtle (Chrysemys picta-CPI) genome, the first in turtles and in vertebrates with temperature-dependent sex determination. A comparison of turtle genomes with those of chicken, selected nonavian reptiles, and human revealed shared and novel genomic features, such as numerous chromosomal rearrangements. The largest conserved syntenic blocks between birds and turtles exist in four macrochromosomes, whereas rearrangements were evident in these and other chromosomes, disproving that turtles and birds retain fully conserved macrochromosomes for greater than 300 Myr. C-banding revealed large heterochromatic blocks in the centromeric region of only few chromosomes. The nucleolar-organizing region (NOR) mapped to a single CPI microchromosome, whereas in some turtles and lizards the NOR maps to nonhomologous sex-chromosomes, thus revealing independent translocations of the NOR in various reptilian lineages. There was no evidence for recent chromosomal fusions as interstitial telomeric-DNA was absent. Some repeat elements (CR1-like, Gypsy) were enriched in the centromeres of five chromosomes, whereas others were widespread in the CPI genome. Bacterial artificial chromosome (BAC) clones were hybridized to 18 of the 25 CPI chromosomes and anchored to a G-banded ideogram. Several CPI sex-determining genes mapped to five chromosomes, and homology was detected between yet other CPI autosomes and the globally nonhomologous sex chromosomes of chicken, other turtles, and squamates, underscoring the independent evolution of vertebrate sex-determining mechanisms.
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Affiliation(s)
- Daleen Badenhorst
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University
| | | | - Robert Literman
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University
| | | | | | - Yingjia Shen
- The Genome Institute at Washington University, St Louis
| | - Patrick Minx
- The Genome Institute at Washington University, St Louis
| | - Daniel E Janes
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University Department of Organismic and Evolutionary Biology, Harvard University
| | | | - Scott V Edwards
- Department of Organismic and Evolutionary Biology, Harvard University
| | - Nicole Valenzuela
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University
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23
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Tracing the evolution of amniote chromosomes. Chromosoma 2014; 123:201-16. [PMID: 24664317 PMCID: PMC4031395 DOI: 10.1007/s00412-014-0456-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 03/03/2014] [Accepted: 03/04/2014] [Indexed: 01/09/2023]
Abstract
A great deal of diversity in chromosome number and arrangement is observed across the amniote phylogeny. Understanding how this diversity is generated is important for determining the role of chromosomal rearrangements in generating phenotypic variation and speciation. Gaining this understanding is achieved by reconstructing the ancestral genome arrangement based on comparisons of genome organization of extant species. Ancestral karyotypes for several amniote lineages have been reconstructed, mainly from cross-species chromosome painting data. The availability of anchored whole genome sequences for amniote species has increased the evolutionary depth and confidence of ancestral reconstructions from those made solely from chromosome painting data. Nonetheless, there are still several key lineages where the appropriate data required for ancestral reconstructions is lacking. This review highlights the progress that has been made towards understanding the chromosomal changes that have occurred during amniote evolution and the reconstruction of ancestral karyotypes.
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