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Gable SM, Bushroe NA, Mendez JM, Wilson A, Pinto BJ, Gamble T, Tollis M. Differential Conservation and Loss of Chicken Repeat 1 (CR1) Retrotransposons in Squamates Reveal Lineage-Specific Genome Dynamics Across Reptiles. Genome Biol Evol 2024; 16:evae157. [PMID: 39031594 DOI: 10.1093/gbe/evae157] [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: 02/14/2024] [Revised: 07/09/2024] [Accepted: 07/11/2024] [Indexed: 07/22/2024] Open
Abstract
Transposable elements (TEs) are repetitive DNA sequences which create mutations and generate genetic diversity across the tree of life. In amniote vertebrates, TEs have been mainly studied in mammals and birds, whose genomes generally display low TE diversity. Squamates (Order Squamata; including ∼11,000 extant species of lizards and snakes) show as much variation in TE abundance and activity as they do in species and phenotypes. Despite this high TE activity, squamate genomes are remarkably uniform in size. We hypothesize that novel, lineage-specific genome dynamics have evolved over the course of squamate evolution. To understand the interplay between TEs and host genomes, we analyzed the evolutionary history of the chicken repeat 1 (CR1) retrotransposon, a TE family found in most tetrapod genomes which is the dominant TE in most reptiles. We compared 113 squamate genomes to the genomes of turtles, crocodilians, and birds and used ancestral state reconstruction to identify shifts in the rate of CR1 copy number evolution across reptiles. We analyzed the repeat landscapes of CR1 in squamate genomes and determined that shifts in the rate of CR1 copy number evolution are associated with lineage-specific variation in CR1 activity. We then used phylogenetic reconstruction of CR1 subfamilies across amniotes to reveal both recent and ancient CR1 subclades across the squamate tree of life. The patterns of CR1 evolution in squamates contrast other amniotes, suggesting key differences in how TEs interact with different host genomes and at different points across evolutionary history.
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Affiliation(s)
- Simone M Gable
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Nicholas A Bushroe
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Jasmine M Mendez
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Adam Wilson
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Brendan J Pinto
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ, USA
- Department of Zoology, Milwaukee Public Museum, Milwaukee, WI, USA
| | - Tony Gamble
- Department of Zoology, Milwaukee Public Museum, Milwaukee, WI, USA
- Department of Biological Sciences, Marquette University, Milwaukee, WI, USA
- Bell Museum of Natural History, University of Minnesota, St. Paul, MN, USA
| | - Marc Tollis
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
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Gable SM, Bushroe N, Mendez J, Wilson A, Pinto B, Gamble T, Tollis M. Differential Conservation and Loss of CR1 Retrotransposons in Squamates Reveals Lineage-Specific Genome Dynamics across Reptiles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.09.579686. [PMID: 38405926 PMCID: PMC10888918 DOI: 10.1101/2024.02.09.579686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Transposable elements (TEs) are repetitive DNA sequences which create mutations and generate genetic diversity across the tree of life. In amniotic vertebrates, TEs have been mainly studied in mammals and birds, whose genomes generally display low TE diversity. Squamates (Order Squamata; ~11,000 extant species of lizards and snakes) show as much variation in TE abundance and activity as they do in species and phenotypes. Despite this high TE activity, squamate genomes are remarkably uniform in size. We hypothesize that novel, lineage-specific dynamics have evolved over the course of squamate evolution to constrain genome size across the order. Thus, squamates may represent a prime model for investigations into TE diversity and evolution. To understand the interplay between TEs and host genomes, we analyzed the evolutionary history of the CR1 retrotransposon, a TE family found in most tetrapod genomes. We compared 113 squamate genomes to the genomes of turtles, crocodilians, and birds, and used ancestral state reconstruction to identify shifts in the rate of CR1 copy number evolution across reptiles. We analyzed the repeat landscapes of CR1 in squamate genomes and determined that shifts in the rate of CR1 copy number evolution are associated with lineage-specific variation in CR1 activity. We then used phylogenetic reconstruction of CR1 subfamilies across amniotes to reveal both recent and ancient CR1 subclades across the squamate tree of life. The patterns of CR1 evolution in squamates contrast other amniotes, suggesting key differences in how TEs interact with different host genomes and at different points across evolutionary history.
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Affiliation(s)
- Simone M. Gable
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Nicholas Bushroe
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Jasmine Mendez
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Adam Wilson
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Brendan Pinto
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ, USA
- Department of Zoology, Milwaukee Public Museum, Milwaukee, WI, USA
| | - Tony Gamble
- Department of Zoology, Milwaukee Public Museum, Milwaukee, WI, USA
- Department of Biological Sciences, Marquette University, Milwaukee, WI, USA
- Bell Museum of Natural History, University of Minnesota, St. Paul, MN, USA
| | - Marc Tollis
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
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Genome Evolution and the Future of Phylogenomics of Non-Avian Reptiles. Animals (Basel) 2023; 13:ani13030471. [PMID: 36766360 PMCID: PMC9913427 DOI: 10.3390/ani13030471] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/13/2023] [Accepted: 01/15/2023] [Indexed: 02/01/2023] Open
Abstract
Non-avian reptiles comprise a large proportion of amniote vertebrate diversity, with squamate reptiles-lizards and snakes-recently overtaking birds as the most species-rich tetrapod radiation. Despite displaying an extraordinary diversity of phenotypic and genomic traits, genomic resources in non-avian reptiles have accumulated more slowly than they have in mammals and birds, the remaining amniotes. Here we review the remarkable natural history of non-avian reptiles, with a focus on the physical traits, genomic characteristics, and sequence compositional patterns that comprise key axes of variation across amniotes. We argue that the high evolutionary diversity of non-avian reptiles can fuel a new generation of whole-genome phylogenomic analyses. A survey of phylogenetic investigations in non-avian reptiles shows that sequence capture-based approaches are the most commonly used, with studies of markers known as ultraconserved elements (UCEs) especially well represented. However, many other types of markers exist and are increasingly being mined from genome assemblies in silico, including some with greater information potential than UCEs for certain investigations. We discuss the importance of high-quality genomic resources and methods for bioinformatically extracting a range of marker sets from genome assemblies. Finally, we encourage herpetologists working in genomics, genetics, evolutionary biology, and other fields to work collectively towards building genomic resources for non-avian reptiles, especially squamates, that rival those already in place for mammals and birds. Overall, the development of this cross-amniote phylogenomic tree of life will contribute to illuminate interesting dimensions of biodiversity across non-avian reptiles and broader amniotes.
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Card DC, Van Camp AG, Santonastaso T, Jensen-Seaman MI, Anthony NM, Edwards SV. Structure and evolution of the squamate major histocompatibility complex as revealed by two Anolis lizard genomes. Front Genet 2022; 13:979746. [PMID: 36425073 PMCID: PMC9679377 DOI: 10.3389/fgene.2022.979746] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 10/20/2022] [Indexed: 11/10/2022] Open
Abstract
The major histocompatibility complex (MHC) is an important genomic region for adaptive immunity and has long been studied in ecological and evolutionary contexts, such as disease resistance and mate and kin selection. The MHC has been investigated extensively in mammals and birds but far less so in squamate reptiles, the third major radiation of amniotes. We localized the core MHC genomic region in two squamate species, the green anole (Anolis carolinensis) and brown anole (A. sagrei), and provide the first detailed characterization of the squamate MHC, including the presence and ordering of known MHC genes in these species and comparative assessments of genomic structure and composition in MHC regions. We find that the Anolis MHC, located on chromosome 2 in both species, contains homologs of many previously-identified mammalian MHC genes in a single core MHC region. The repetitive element composition in anole MHC regions was similar to those observed in mammals but had important distinctions, such as higher proportions of DNA transposons. Moreover, longer introns and intergenic regions result in a much larger squamate MHC region (11.7 Mb and 24.6 Mb in the green and brown anole, respectively). Evolutionary analyses of MHC homologs of anoles and other representative amniotes uncovered generally monophyletic relationships between species-specific homologs and a loss of the peptide-binding domain exon 2 in one of two mhc2β gene homologs of each anole species. Signals of diversifying selection in each anole species was evident across codons of mhc1, many of which appear functionally relevant given known structures of this protein from the green anole, chicken, and human. Altogether, our investigation fills a major gap in understanding of amniote MHC diversity and evolution and provides an important foundation for future squamate-specific or vertebrate-wide investigations of the MHC.
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Affiliation(s)
- Daren C. Card
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States
- Museum of Comparative Zoology, Harvard University, Cambridge, MA, United States
- *Correspondence: Daren C. Card,
| | - Andrew G. Van Camp
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States
- Museum of Comparative Zoology, Harvard University, Cambridge, MA, United States
| | - Trenten Santonastaso
- Department of Biological Sciences, University of New Orleans, New Orleans, LA, United States
| | | | - Nicola M. Anthony
- Department of Biological Sciences, University of New Orleans, New Orleans, LA, United States
| | - Scott V. Edwards
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States
- Museum of Comparative Zoology, Harvard University, Cambridge, MA, United States
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Factors Regulating the Activity of LINE1 Retrotransposons. Genes (Basel) 2021; 12:genes12101562. [PMID: 34680956 PMCID: PMC8535693 DOI: 10.3390/genes12101562] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 12/15/2022] Open
Abstract
LINE-1 (L1) is a class of autonomous mobile genetic elements that form somatic mosaicisms in various tissues of the organism. The activity of L1 retrotransposons is strictly controlled by many factors in somatic and germ cells at all stages of ontogenesis. Alteration of L1 activity was noted in a number of diseases: in neuropsychiatric and autoimmune diseases, as well as in various forms of cancer. Altered activity of L1 retrotransposons for some pathologies is associated with epigenetic changes and defects in the genes involved in their repression. This review discusses the molecular genetic mechanisms of the retrotransposition and regulation of the activity of L1 elements. The contribution of various factors controlling the expression and distribution of L1 elements in the genome occurs at all stages of the retrotransposition. The regulation of L1 elements at the transcriptional, post-transcriptional and integration into the genome stages is described in detail. Finally, this review also focuses on the evolutionary aspects of L1 accumulation and their interplay with the host regulation system.
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Impact of Repetitive DNA Elements on Snake Genome Biology and Evolution. Cells 2021; 10:cells10071707. [PMID: 34359877 PMCID: PMC8303610 DOI: 10.3390/cells10071707] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 12/11/2022] Open
Abstract
The distinctive biology and unique evolutionary features of snakes make them fascinating model systems to elucidate how genomes evolve and how variation at the genomic level is interlinked with phenotypic-level evolution. Similar to other eukaryotic genomes, large proportions of snake genomes contain repetitive DNA, including transposable elements (TEs) and satellite repeats. The importance of repetitive DNA and its structural and functional role in the snake genome, remain unclear. This review highlights the major types of repeats and their proportions in snake genomes, reflecting the high diversity and composition of snake repeats. We present snakes as an emerging and important model system for the study of repetitive DNA under the impact of sex and microchromosome evolution. We assemble evidence to show that certain repetitive elements in snakes are transcriptionally active and demonstrate highly dynamic lineage-specific patterns as repeat sequences. We hypothesize that particular TEs can trigger different genomic mechanisms that might contribute to driving adaptive evolution in snakes. Finally, we review emerging approaches that may be used to study the expression of repetitive elements in complex genomes, such as snakes. The specific aspects presented here will stimulate further discussion on the role of genomic repeats in shaping snake evolution.
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Vassetzky NS, Kosushkin SA, Korchagin VI, Ryskov AP. New Ther1-derived SINE Squam3 in scaled reptiles. Mob DNA 2021; 12:10. [PMID: 33752750 PMCID: PMC7983390 DOI: 10.1186/s13100-021-00238-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/25/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND SINEs comprise a significant part of animal genomes and are used to study the evolution of diverse taxa. Despite significant advances in SINE studies in vertebrates and higher eukaryotes in general, their own evolution is poorly understood. RESULTS We have discovered and described in detail a new Squam3 SINE specific for scaled reptiles (Squamata). The subfamilies of this SINE demonstrate different distribution in the genomes of squamates, which together with the data on similar SINEs in the tuatara allowed us to propose a scenario of their evolution in the context of reptilian evolution. CONCLUSIONS Ancestral SINEs preserved in small numbers in most genomes can give rise to taxa-specific SINE families. Analysis of this aspect of SINEs can shed light on the history and mechanisms of SINE variation in reptilian genomes.
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Affiliation(s)
- Nikita S Vassetzky
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia.
| | - Sergei A Kosushkin
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Vitaly I Korchagin
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| | - Alexey P Ryskov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
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Suh A, Smeds L, Ellegren H. Abundant recent activity of retrovirus-like retrotransposons within and among flycatcher species implies a rich source of structural variation in songbird genomes. Mol Ecol 2017; 27:99-111. [DOI: 10.1111/mec.14439] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 11/01/2017] [Accepted: 11/06/2017] [Indexed: 01/01/2023]
Affiliation(s)
- Alexander Suh
- Department of Evolutionary Biology; Evolutionary Biology Centre (EBC); Uppsala University; Uppsala Sweden
| | - Linnéa Smeds
- Department of Evolutionary Biology; Evolutionary Biology Centre (EBC); Uppsala University; Uppsala Sweden
| | - Hans Ellegren
- Department of Evolutionary Biology; Evolutionary Biology Centre (EBC); Uppsala University; Uppsala Sweden
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9
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Chen S, Yu M, Chu X, Li W, Yin X, Chen L. Cold-induced retrotransposition of fish LINEs. J Genet Genomics 2017; 44:385-394. [PMID: 28869113 DOI: 10.1016/j.jgg.2017.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 07/18/2017] [Accepted: 07/21/2017] [Indexed: 12/22/2022]
Abstract
Classes of retrotransposons constitute a large portion of metazoan genome. There have been cases reported that genomic abundance of retrotransposons is correlated with the severity of low environmental temperatures. However, the molecular mechanisms underlying such correlation are unknown. We show here by cell transfection assays that retrotransposition (RTP) of a long interspersed nuclear element (LINE) from an Antarctic notothenioid fish Dissostichus mawsoni (dmL1) could be activated by low temperature exposure, causing increased dmL1 copies in the host cell genome. The cold-induced dmL1 propagation was demonstrated to be mediated by the mitogen-activated protein kinases (MAPK)/p38 signaling pathway, which is activated by accumulation of reactive oxygen species (ROS) in cold-stressed conditions. Surprisingly, dmL1 transfected cells showed an increase in the number of viable cells after prolonged cold exposures than non-transfected cells. Features of cold inducibility of dmL1 were recapitulated in LINEs of zebrafish origin both in cultured cell lines and tissues, suggesting existence of a common cold-induced LINE amplification in fishes. The findings reveal an important function of LINEs in temperature adaptation and provid insights into the MAPK/p38 stress responsive pathway that shapes LINE composition in fishes facing cold stresses.
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Affiliation(s)
- Shue Chen
- Key Laboratory of Aquaculture Resources and Utilization, Ministry of Education, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306, China; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Mengchao Yu
- Key Laboratory of Aquaculture Resources and Utilization, Ministry of Education, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Xu Chu
- Key Laboratory of Aquaculture Resources and Utilization, Ministry of Education, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Wenhao Li
- Key Laboratory of Aquaculture Resources and Utilization, Ministry of Education, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Xiujuan Yin
- Key Laboratory of Aquaculture Resources and Utilization, Ministry of Education, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Liangbiao Chen
- Key Laboratory of Aquaculture Resources and Utilization, Ministry of Education, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306, China; Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
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Abstract
Genome size in mammals and birds shows remarkably little interspecific variation compared with other taxa. However, genome sequencing has revealed that many mammal and bird lineages have experienced differential rates of transposable element (TE) accumulation, which would be predicted to cause substantial variation in genome size between species. Thus, we hypothesize that there has been covariation between the amount of DNA gained by transposition and lost by deletion during mammal and avian evolution, resulting in genome size equilibrium. To test this model, we develop computational methods to quantify the amount of DNA gained by TE expansion and lost by deletion over the last 100 My in the lineages of 10 species of eutherian mammals and 24 species of birds. The results reveal extensive variation in the amount of DNA gained via lineage-specific transposition, but that DNA loss counteracted this expansion to various extents across lineages. Our analysis of the rate and size spectrum of deletion events implies that DNA removal in both mammals and birds has proceeded mostly through large segmental deletions (>10 kb). These findings support a unified "accordion" model of genome size evolution in eukaryotes whereby DNA loss counteracting TE expansion is a major determinant of genome size. Furthermore, we propose that extensive DNA loss, and not necessarily a dearth of TE activity, has been the primary force maintaining the greater genomic compaction of flying birds and bats relative to their flightless relatives.
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11
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Detection of LINE RT elements in the olive flounder (Paralichthys olivaceus) genome and expression analysis after infection with S. parauberis. Genes Genomics 2016. [DOI: 10.1007/s13258-016-0457-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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12
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Mezzasalma M, Visone V, Petraccioli A, Odierna G, Capriglione T, Guarino FM. Non-random accumulation of LINE1-like sequences on differentiated snake W chromosomes. J Zool (1987) 2016. [DOI: 10.1111/jzo.12355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- M. Mezzasalma
- Department of Biology; University of Naples Federico II; Naples Italy
| | - V. Visone
- Department of Biology; University of Naples Federico II; Naples Italy
| | - A. Petraccioli
- Department of Biology; University of Naples Federico II; Naples Italy
| | - G. Odierna
- Department of Biology; University of Naples Federico II; Naples Italy
| | - T. Capriglione
- Department of Biology; University of Naples Federico II; Naples Italy
| | - F. M. Guarino
- Department of Biology; University of Naples Federico II; Naples Italy
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13
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Abstract
Retrotransposons carrying tyrosine recombinases (YR) are widespread in eukaryotes. The first described tyrosine recombinase mobile element, DIRS1, is a retroelement from the slime mold Dictyostelium discoideum. The YR elements are bordered by terminal repeats related to their replication via free circular dsDNA intermediates. Site-specific recombination is believed to integrate the circle without creating duplications of the target sites. Recently a large number of YR retrotransposons have been described, including elements from fungi (mucorales and basidiomycetes), plants (green algae) and a wide range of animals including nematodes, insects, sea urchins, fish, amphibia and reptiles. YR retrotransposons can be divided into three major groups: the DIRS elements, PAT-like and the Ngaro elements. The three groups form distinct clades on phylogenetic trees based on alignments of reverse transcriptase/ribonuclease H (RT/RH) and YR sequences, and also having some structural distinctions. A group of eukaryote DNA transposons, cryptons, also carry tyrosine recombinases. These DNA transposons do not encode a reverse transcriptase. They have been detected in several pathogenic fungi and oomycetes. Sequence comparisons suggest that the crypton YRs are related to those of the YR retrotransposons. We suggest that the YR retrotransposons arose from the combination of a crypton-like YR DNA transposon and the RT/RH encoding sequence of a retrotransposon. This acquisition must have occurred at a very early point in the evolution of eukaryotes.
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Schmid M, Smith J, Burt DW, Aken BL, Antin PB, Archibald AL, Ashwell C, Blackshear PJ, Boschiero C, Brown CT, Burgess SC, Cheng HH, Chow W, Coble DJ, Cooksey A, Crooijmans RPMA, Damas J, Davis RVN, de Koning DJ, Delany ME, Derrien T, Desta TT, Dunn IC, Dunn M, Ellegren H, Eöry L, Erb I, Farré M, Fasold M, Fleming D, Flicek P, Fowler KE, Frésard L, Froman DP, Garceau V, Gardner PP, Gheyas AA, Griffin DK, Groenen MAM, Haaf T, Hanotte O, Hart A, Häsler J, Hedges SB, Hertel J, Howe K, Hubbard A, Hume DA, Kaiser P, Kedra D, Kemp SJ, Klopp C, Kniel KE, Kuo R, Lagarrigue S, Lamont SJ, Larkin DM, Lawal RA, Markland SM, McCarthy F, McCormack HA, McPherson MC, Motegi A, Muljo SA, Münsterberg A, Nag R, Nanda I, Neuberger M, Nitsche A, Notredame C, Noyes H, O'Connor R, O'Hare EA, Oler AJ, Ommeh SC, Pais H, Persia M, Pitel F, Preeyanon L, Prieto Barja P, Pritchett EM, Rhoads DD, Robinson CM, Romanov MN, Rothschild M, Roux PF, Schmidt CJ, Schneider AS, Schwartz MG, Searle SM, Skinner MA, Smith CA, Stadler PF, Steeves TE, Steinlein C, Sun L, Takata M, Ulitsky I, Wang Q, Wang Y, Warren WC, Wood JMD, Wragg D, Zhou H. Third Report on Chicken Genes and Chromosomes 2015. Cytogenet Genome Res 2015; 145:78-179. [PMID: 26282327 PMCID: PMC5120589 DOI: 10.1159/000430927] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Michael Schmid
- Department of Human Genetics, University of Würzburg, Würzburg, Germany
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Major Histocompatibility Complex Genes Map to Two Chromosomes in an Evolutionarily Ancient Reptile, the Tuatara Sphenodon punctatus. G3-GENES GENOMES GENETICS 2015; 5:1439-51. [PMID: 25953959 PMCID: PMC4502378 DOI: 10.1534/g3.115.017467] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Major histocompatibility complex (MHC) genes are a central component of the vertebrate immune system and usually exist in a single genomic region. However, considerable differences in MHC organization and size exist between different vertebrate lineages. Reptiles occupy a key evolutionary position for understanding how variation in MHC structure evolved in vertebrates, but information on the structure of the MHC region in reptiles is limited. In this study, we investigate the organization and cytogenetic location of MHC genes in the tuatara (Sphenodon punctatus), the sole extant representative of the early-diverging reptilian order Rhynchocephalia. Sequencing and mapping of 12 clones containing class I and II MHC genes from a bacterial artificial chromosome library indicated that the core MHC region is located on chromosome 13q. However, duplication and translocation of MHC genes outside of the core region was evident, because additional class I MHC genes were located on chromosome 4p. We found a total of seven class I sequences and 11 class II β sequences, with evidence for duplication and pseudogenization of genes within the tuatara lineage. The tuatara MHC is characterized by high repeat content and low gene density compared with other species and we found no antigen processing or MHC framework genes on the MHC gene-containing clones. Our findings indicate substantial differences in MHC organization in tuatara compared with mammalian and avian MHCs and highlight the dynamic nature of the MHC. Further sequencing and annotation of tuatara and other reptile MHCs will determine if the tuatara MHC is representative of nonavian reptiles in general.
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16
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Suh A, Churakov G, Ramakodi MP, Platt RN, Jurka J, Kojima KK, Caballero J, Smit AF, Vliet KA, Hoffmann FG, Brosius J, Green RE, Braun EL, Ray DA, Schmitz J. Multiple lineages of ancient CR1 retroposons shaped the early genome evolution of amniotes. Genome Biol Evol 2014; 7:205-17. [PMID: 25503085 PMCID: PMC4316615 DOI: 10.1093/gbe/evu256] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Chicken repeat 1 (CR1) retroposons are long interspersed elements (LINEs) that are ubiquitous within amniote genomes and constitute the most abundant family of transposed elements in birds, crocodilians, turtles, and snakes. They are also present in mammalian genomes, where they reside as numerous relics of ancient retroposition events. Yet, despite their relevance for understanding amniote genome evolution, the diversity and evolution of CR1 elements has never been studied on an amniote-wide level. We reconstruct the temporal and quantitative activity of CR1 subfamilies via presence/absence analyses across crocodilian phylogeny and comparative analyses of 12 crocodilian genomes, revealing relative genomic stasis of retroposition during genome evolution of extant Crocodylia. Our large-scale phylogenetic analysis of amniote CR1 subfamilies suggests the presence of at least seven ancient CR1 lineages in the amniote ancestor; and amniote-wide analyses of CR1 successions and quantities reveal differential retention (presence of ancient relics or recent activity) of these CR1 lineages across amniote genome evolution. Interestingly, birds and lepidosaurs retained the fewest ancient CR1 lineages among amniotes and also exhibit smaller genome sizes. Our study is the first to analyze CR1 evolution in a genome-wide and amniote-wide context and the data strongly suggest that the ancestral amniote genome contained myriad CR1 elements from multiple ancient lineages, and remnants of these are still detectable in the relatively stable genomes of crocodilians and turtles. Early mammalian genome evolution was thus characterized by a drastic shift from CR1 prevalence to dominance and hyperactivity of L2 LINEs in monotremes and L1 LINEs in therians.
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Affiliation(s)
- Alexander Suh
- Institute of Experimental Pathology (ZMBE), University of Münster, Germany Department of Evolutionary Biology (EBC), Uppsala University, Sweden
| | - Gennady Churakov
- Institute of Experimental Pathology (ZMBE), University of Münster, Germany
| | - Meganathan P Ramakodi
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University Present address: Cancer Prevention and Control Program, Fox Chase Cancer Center, Philadelphia, PA Present address: Department of Biology, Temple University, Philadelphia, PA
| | - Roy N Platt
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University Department of Biological Sciences, Texas Tech University
| | - Jerzy Jurka
- Genetic Information Research Institute, Mountain View, California
| | - Kenji K Kojima
- Genetic Information Research Institute, Mountain View, California
| | | | - Arian F Smit
- Institute for Systems Biology, Seattle, Washington
| | | | - Federico G Hoffmann
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University
| | - Jürgen Brosius
- Institute of Experimental Pathology (ZMBE), University of Münster, Germany
| | - Richard E Green
- Department of Biomolecular Engineering, University of California
| | - Edward L Braun
- Department of Biology and Genetics Institute, University of Florida
| | - David A Ray
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University Department of Biological Sciences, Texas Tech University
| | - Jürgen Schmitz
- Institute of Experimental Pathology (ZMBE), University of Münster, Germany
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McGlothlin JW, Chuckalovcak JP, Janes DE, Edwards SV, Feldman CR, Brodie ED, Pfrender ME, Brodie ED. Parallel evolution of tetrodotoxin resistance in three voltage-gated sodium channel genes in the garter snake Thamnophis sirtalis. Mol Biol Evol 2014; 31:2836-46. [PMID: 25135948 PMCID: PMC4209135 DOI: 10.1093/molbev/msu237] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Members of a gene family expressed in a single species often experience common selection pressures. Consequently, the molecular basis of complex adaptations may be expected to involve parallel evolutionary changes in multiple paralogs. Here, we use bacterial artificial chromosome library scans to investigate the evolution of the voltage-gated sodium channel (Nav) family in the garter snake Thamnophis sirtalis, a predator of highly toxic Taricha newts. Newts possess tetrodotoxin (TTX), which blocks Nav’s, arresting action potentials in nerves and muscle. Some Thamnophis populations have evolved resistance to extremely high levels of TTX. Previous work has identified amino acid sites in the skeletal muscle sodium channel Nav1.4 that confer resistance to TTX and vary across populations. We identify parallel evolution of TTX resistance in two additional Nav paralogs, Nav1.6 and 1.7, which are known to be expressed in the peripheral nervous system and should thus be exposed to ingested TTX. Each paralog contains at least one TTX-resistant substitution identical to a substitution previously identified in Nav1.4. These sites are fixed across populations, suggesting that the resistant peripheral nerves antedate resistant muscle. In contrast, three sodium channels expressed solely in the central nervous system (Nav1.1–1.3) showed no evidence of TTX resistance, consistent with protection from toxins by the blood–brain barrier. We also report the exon–intron structure of six Nav paralogs, the first such analysis for snake genes. Our results demonstrate that the molecular basis of adaptation may be both repeatable across members of a gene family and predictable based on functional considerations.
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Affiliation(s)
- Joel W McGlothlin
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA Department of Biology, University of Virginia
| | - John P Chuckalovcak
- Department of Biology, University of Virginia Bio-Rad Laboratories, Hercules, CA
| | - Daniel E Janes
- Department of Organismic and Evolutionary Biology, Harvard University Division of Genetics and Developmental Biology, National Institutes of Health, Bethesda, MD
| | - Scott V Edwards
- Department of Organismic and Evolutionary Biology, Harvard University
| | | | | | - Michael E Pfrender
- Department of Biological Sciences and Environmental Change Initiative, University of Notre Dame
| | - Edmund D Brodie
- Department of Biology, University of Virginia Mountain Lake Biological Station, University of Virginia
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18
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Chalopin D, Fan S, Simakov O, Meyer A, Schartl M, Volff JN. Evolutionary active transposable elements in the genome of the coelacanth. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2013; 322:322-33. [DOI: 10.1002/jez.b.22521] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 05/22/2013] [Accepted: 06/17/2013] [Indexed: 12/30/2022]
Affiliation(s)
- Domitille Chalopin
- Institut de Génomique Fonctionnelle de Lyon; Ecole Normale Supérieure de Lyon; CNRS UMR 5242; Université Lyon 1; Lyon France
| | - Shaohua Fan
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology; University of Konstanz; Konstanz Germany
- Konstanz Research School Chemical Biology; University of Konstanz; Konstanz Germany
| | - Oleg Simakov
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology; University of Konstanz; Konstanz Germany
- European Molecular Biology Laboratory; Heidelberg Germany
| | - Axel Meyer
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology; University of Konstanz; Konstanz Germany
- Konstanz Research School Chemical Biology; University of Konstanz; Konstanz Germany
| | - Manfred Schartl
- Department Physiological Chemistry, Biocenter; University of Wuerzburg; Wuerzburg Germany
| | - Jean-Nicolas Volff
- Institut de Génomique Fonctionnelle de Lyon; Ecole Normale Supérieure de Lyon; CNRS UMR 5242; Université Lyon 1; Lyon France
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19
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Arkhipova IR, Rodriguez F. Genetic and epigenetic changes involving (retro)transposons in animal hybrids and polyploids. Cytogenet Genome Res 2013; 140:295-311. [PMID: 23899811 DOI: 10.1159/000352069] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Transposable elements (TEs) are discrete genetic units that have the ability to change their location within chromosomal DNA, and constitute a major and rapidly evolving component of eukaryotic genomes. They can be subdivided into 2 distinct types: retrotransposons, which use an RNA intermediate for transposition, and DNA transposons, which move only as DNA. Rapid advances in genome sequencing significantly improved our understanding of TE roles in genome shaping and restructuring, and studies of transcriptomes and epigenomes shed light on the previously unknown molecular mechanisms underlying genetic and epigenetic TE controls. Knowledge of these control systems may be important for better understanding of reticulate evolution and speciation in the context of bringing different genomes together by hybridization and perturbing the established regulatory balance by ploidy changes. See also sister article focusing on plants by Bento et al. in this themed issue.
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Affiliation(s)
- I R Arkhipova
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA 02543, USA. iarkhipova @ mbl.edu
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20
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Bradley Shaffer H, Minx P, Warren DE, Shedlock AM, Thomson RC, Valenzuela N, Abramyan J, Amemiya CT, Badenhorst D, Biggar KK, Borchert GM, Botka CW, Bowden RM, Braun EL, Bronikowski AM, Bruneau BG, Buck LT, Capel B, Castoe TA, Czerwinski M, Delehaunty KD, Edwards SV, Fronick CC, Fujita MK, Fulton L, Graves TA, Green RE, Haerty W, Hariharan R, Hernandez O, Hillier LW, Holloway AK, Janes D, Janzen FJ, Kandoth C, Kong L, de Koning APJ, Li Y, Literman R, McGaugh SE, Mork L, O'Laughlin M, Paitz RT, Pollock DD, Ponting CP, Radhakrishnan S, Raney BJ, Richman JM, St John J, Schwartz T, Sethuraman A, Spinks PQ, Storey KB, Thane N, Vinar T, Zimmerman LM, Warren WC, Mardis ER, Wilson RK. The western painted turtle genome, a model for the evolution of extreme physiological adaptations in a slowly evolving lineage. Genome Biol 2013; 14:R28. [PMID: 23537068 PMCID: PMC4054807 DOI: 10.1186/gb-2013-14-3-r28] [Citation(s) in RCA: 228] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 03/15/2013] [Accepted: 03/28/2013] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND We describe the genome of the western painted turtle, Chrysemys picta bellii, one of the most widespread, abundant, and well-studied turtles. We place the genome into a comparative evolutionary context, and focus on genomic features associated with tooth loss, immune function, longevity, sex differentiation and determination, and the species' physiological capacities to withstand extreme anoxia and tissue freezing. RESULTS Our phylogenetic analyses confirm that turtles are the sister group to living archosaurs, and demonstrate an extraordinarily slow rate of sequence evolution in the painted turtle. The ability of the painted turtle to withstand complete anoxia and partial freezing appears to be associated with common vertebrate gene networks, and we identify candidate genes for future functional analyses. Tooth loss shares a common pattern of pseudogenization and degradation of tooth-specific genes with birds, although the rate of accumulation of mutations is much slower in the painted turtle. Genes associated with sex differentiation generally reflect phylogeny rather than convergence in sex determination functionality. Among gene families that demonstrate exceptional expansions or show signatures of strong natural selection, immune function and musculoskeletal patterning genes are consistently over-represented. CONCLUSIONS Our comparative genomic analyses indicate that common vertebrate regulatory networks, some of which have analogs in human diseases, are often involved in the western painted turtle's extraordinary physiological capacities. As these regulatory pathways are analyzed at the functional level, the painted turtle may offer important insights into the management of a number of human health disorders.
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Affiliation(s)
- H Bradley Shaffer
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA 90095-1606, USA
- La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, University of California, Los Angeles, Los Angeles, CA 90095-1496, USA
| | - Patrick Minx
- The Genome Institute, Washington University School of Medicine, Campus Box 8501, 4444 Forest Park Avenue, St Louis, MO 63108, USA
| | - Daniel E Warren
- Department of Biology, Saint Louis University, St Louis, MO 63103, USA
| | - Andrew M Shedlock
- College of Charleston Biology Department and Grice Marine Laboratory, Charleston, SC 29424, USA
- Medical University of South Carolina College of Graduate Studies and Center for Marine Biomedicine and Environmental Sciences, Charleston, SC 29412, USA
| | - Robert C Thomson
- Department of Biology, University of Hawaii at Manoa, Honolulu, HI 96822, USA
| | - Nicole Valenzuela
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - John Abramyan
- Faculty of Dentistry, Life Sciences Institute University of British Columbia, Vancouver BC, Canada
| | - Chris T Amemiya
- Benaroya Research Institute at Virginia Mason, Seattle, WA 98101 USA
| | - Daleen Badenhorst
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Kyle K Biggar
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, ON, Canada K1S 5B6, Canada
| | - Glen M Borchert
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
- Department of Biological Sciences, Life Sciences Building, University of South Alabama, Mobile, AL 36688-0002, USA
| | | | - Rachel M Bowden
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Edward L Braun
- Department of Biology, University of Florida, Gainesville, FL 32611 USA
| | - Anne M Bronikowski
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Benoit G Bruneau
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA
- Cardiovascular Research Institute and Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Leslie T Buck
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada M5S 3G5, Canada
| | - Blanche Capel
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Todd A Castoe
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA
- Department of Biology, University of Texas at Arlington, Arlington, TX 76019, USA
| | - Mike Czerwinski
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Kim D Delehaunty
- The Genome Institute, Washington University School of Medicine, Campus Box 8501, 4444 Forest Park Avenue, St Louis, MO 63108, USA
| | - Scott V Edwards
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Catrina C Fronick
- The Genome Institute, Washington University School of Medicine, Campus Box 8501, 4444 Forest Park Avenue, St Louis, MO 63108, USA
| | - Matthew K Fujita
- Department of Biology, University of Texas at Arlington, Arlington, TX 76019, USA
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Lucinda Fulton
- The Genome Institute, Washington University School of Medicine, Campus Box 8501, 4444 Forest Park Avenue, St Louis, MO 63108, USA
| | - Tina A Graves
- The Genome Institute, Washington University School of Medicine, Campus Box 8501, 4444 Forest Park Avenue, St Louis, MO 63108, USA
| | - Richard E Green
- Baskin School of Engineering University of California, Santa Cruz Santa Cruz, CA 95064, USA
| | - Wilfried Haerty
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, Henry Wellcome Building of Gene Function, University of Oxford, Oxford, OX13PT, UK
| | - Ramkumar Hariharan
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojapura, Thycaud P.O, Thiruvananthapuram, Kerala 695014, India
| | - Omar Hernandez
- FUDECI, Fundación para el Desarrollo de las Ciencias Físicas, Matemáticas y Naturales. Av, Universidad, Bolsa a San Francisco, Palacio de Las Academias, Caracas, Venezuela
| | - LaDeana W Hillier
- The Genome Institute, Washington University School of Medicine, Campus Box 8501, 4444 Forest Park Avenue, St Louis, MO 63108, USA
| | - Alisha K Holloway
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA
| | - Daniel Janes
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Fredric J Janzen
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Cyriac Kandoth
- The Genome Institute, Washington University School of Medicine, Campus Box 8501, 4444 Forest Park Avenue, St Louis, MO 63108, USA
| | - Lesheng Kong
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, Henry Wellcome Building of Gene Function, University of Oxford, Oxford, OX13PT, UK
| | - AP Jason de Koning
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Yang Li
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, Henry Wellcome Building of Gene Function, University of Oxford, Oxford, OX13PT, UK
| | - Robert Literman
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | | | - Lindsey Mork
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Michelle O'Laughlin
- The Genome Institute, Washington University School of Medicine, Campus Box 8501, 4444 Forest Park Avenue, St Louis, MO 63108, USA
| | - Ryan T Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - David D Pollock
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Chris P Ponting
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, Henry Wellcome Building of Gene Function, University of Oxford, Oxford, OX13PT, UK
| | - Srihari Radhakrishnan
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
- Bioinformatics and Computational Biology Laboratory, Iowa State University, Ames, IA 50011, USA
| | - Brian J Raney
- Center for Biomolecular Science and Engineering, School of Engineering, University of California Santa Cruz (UCSC), Santa Cruz, CA 95064, USA
| | - Joy M Richman
- Faculty of Dentistry, Life Sciences Institute University of British Columbia, Vancouver BC, Canada
| | - John St John
- Baskin School of Engineering University of California, Santa Cruz Santa Cruz, CA 95064, USA
| | - Tonia Schwartz
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
- Bioinformatics and Computational Biology Laboratory, Iowa State University, Ames, IA 50011, USA
| | - Arun Sethuraman
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
- Bioinformatics and Computational Biology Laboratory, Iowa State University, Ames, IA 50011, USA
| | - Phillip Q Spinks
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA 90095-1606, USA
- La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, University of California, Los Angeles, Los Angeles, CA 90095-1496, USA
| | - Kenneth B Storey
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, ON, Canada K1S 5B6, Canada
| | - Nay Thane
- The Genome Institute, Washington University School of Medicine, Campus Box 8501, 4444 Forest Park Avenue, St Louis, MO 63108, USA
| | - Tomas Vinar
- Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska Dolina, Bratislava 84248, Slovakia
| | - Laura M Zimmerman
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Wesley C Warren
- The Genome Institute, Washington University School of Medicine, Campus Box 8501, 4444 Forest Park Avenue, St Louis, MO 63108, USA
| | - Elaine R Mardis
- The Genome Institute, Washington University School of Medicine, Campus Box 8501, 4444 Forest Park Avenue, St Louis, MO 63108, USA
| | - Richard K Wilson
- The Genome Institute, Washington University School of Medicine, Campus Box 8501, 4444 Forest Park Avenue, St Louis, MO 63108, USA
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21
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Miller HC, Biggs PJ, Voelckel C, Nelson NJ. De novo sequence assembly and characterisation of a partial transcriptome for an evolutionarily distinct reptile, the tuatara (Sphenodon punctatus). BMC Genomics 2012; 13:439. [PMID: 22938396 PMCID: PMC3478169 DOI: 10.1186/1471-2164-13-439] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 08/24/2012] [Indexed: 02/08/2023] Open
Abstract
Background The tuatara (Sphenodon punctatus) is a species of extraordinary zoological interest, being the only surviving member of an entire order of reptiles which diverged early in amniote evolution. In addition to their unique phylogenetic placement, many aspects of tuatara biology, including temperature-dependent sex determination, cold adaptation and extreme longevity have the potential to inform studies of genome evolution and development. Despite increasing interest in the tuatara genome, genomic resources for the species are still very limited. We aimed to address this by assembling a transcriptome for tuatara from an early-stage embryo, which will provide a resource for genome annotation, molecular marker development and studies of development and adaptation in tuatara. Results We obtained 30 million paired-end 50 bp reads from an Illumina Genome Analyzer and assembled them with Velvet and Oases using a range of kmers. After removing redundancy and filtering out low quality transcripts, our transcriptome dataset contained 32911 transcripts, with an N50 of 675 and a mean length of 451 bp. Almost 50% (15965) of these transcripts could be annotated by comparison with the NCBI non-redundant (NR) protein database or the chicken, green anole and zebrafish UniGene sets. A scan of candidate genes and repetitive elements revealed genes involved in immune function, sex differentiation and temperature-sensitivity, as well as over 200 microsatellite markers. Conclusions This dataset represents a major increase in genomic resources for the tuatara, increasing the number of annotated gene sequences from just 60 to almost 16,000. This will facilitate future research in sex determination, genome evolution, local adaptation and population genetics of tuatara, as well as inform studies on amniote evolution.
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Affiliation(s)
- Hilary C Miller
- Allan Wilson Centre for Molecular Ecology and Evolution, School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand.
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22
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St John JA, Braun EL, Isberg SR, Miles LG, Chong AY, Gongora J, Dalzell P, Moran C, Bed'hom B, Abzhanov A, Burgess SC, Cooksey AM, Castoe TA, Crawford NG, Densmore LD, Drew JC, Edwards SV, Faircloth BC, Fujita MK, Greenwold MJ, Hoffmann FG, Howard JM, Iguchi T, Janes DE, Khan SY, Kohno S, de Koning AJ, Lance SL, McCarthy FM, McCormack JE, Merchant ME, Peterson DG, Pollock DD, Pourmand N, Raney BJ, Roessler KA, Sanford JR, Sawyer RH, Schmidt CJ, Triplett EW, Tuberville TD, Venegas-Anaya M, Howard JT, Jarvis ED, Guillette LJ, Glenn TC, Green RE, Ray DA. Sequencing three crocodilian genomes to illuminate the evolution of archosaurs and amniotes. Genome Biol 2012; 13:415. [PMID: 22293439 PMCID: PMC3334581 DOI: 10.1186/gb-2012-13-1-415] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The International Crocodilian Genomes Working Group (ICGWG) will sequence and assemble the American alligator (Alligator mississippiensis), saltwater crocodile (Crocodylus porosus) and Indian gharial (Gavialis gangeticus) genomes. The status of these projects and our planned analyses are described.
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23
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Suh A, Paus M, Kiefmann M, Churakov G, Franke FA, Brosius J, Kriegs JO, Schmitz J. Mesozoic retroposons reveal parrots as the closest living relatives of passerine birds. Nat Commun 2011; 2:443. [PMID: 21863010 PMCID: PMC3265382 DOI: 10.1038/ncomms1448] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Accepted: 07/21/2011] [Indexed: 12/03/2022] Open
Abstract
The relationships of passerines (such as the well-studied zebra finch) with non-passerine birds is one of the great enigmas of avian phylogenetic research, because decades of extensive morphological and molecular studies yielded highly inconsistent results between and within data sets. Here we show the first application of the virtually homoplasy-free retroposon insertions to this controversy. Our study examined ~200,000 retroposon-containing loci from various avian genomes and retrieved 51 markers resolving early bird phylogeny. Among these, we obtained statistically significant evidence that parrots are the closest and falcons the second-closest relatives of passerines, together constituting the Psittacopasserae and the Eufalconimorphae, respectively. Our new and robust phylogenetic framework has substantial implications for the interpretation of various conclusions drawn from passerines as model organisms. This includes insights of relevance to human neuroscience, as vocal learning (that is, birdsong) probably evolved in the psittacopasseran ancestor, >30 million years earlier than previously assumed.
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Affiliation(s)
- Alexander Suh
- Institute of Experimental Pathology (ZMBE), University of Münster, Von-Esmarch-Strasse 56, D-48149 Münster, Germany.
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24
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Novick PA, Smith JD, Floumanhaft M, Ray DA, Boissinot S. The evolution and diversity of DNA transposons in the genome of the Lizard Anolis carolinensis. Genome Biol Evol 2010; 3:1-14. [PMID: 21127169 PMCID: PMC3014272 DOI: 10.1093/gbe/evq080] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2010] [Indexed: 01/19/2023] Open
Abstract
DNA transposons have considerably affected the size and structure of eukaryotic genomes and have been an important source of evolutionary novelties. In vertebrates, DNA transposons are discontinuously distributed due to the frequent extinction and recolonization of these genomes by active elements. We performed a detailed analysis of the DNA transposons in the genome of the lizard Anolis carolinensis, the first non-avian reptile to have its genome sequenced. Elements belonging to six of the previously recognized superfamilies of elements (hAT, Tc1/Mariner, Helitron, PIF/Harbinger, Polinton/Maverick, and Chapaev) were identified. However, only four (hAT, Tc1/Mariner, Helitron, and Chapaev) of these superfamilies have successfully amplified in the anole genome, producing 67 distinct families. The majority (57/67) are nonautonomous and demonstrate an extraordinary diversity of structure, resulting from frequent interelement recombination and incorporation of extraneous DNA sequences. The age distribution of transposon families differs among superfamilies and reveals different dynamics of amplification. Chapaev is the only superfamily to be extinct and is represented only by old copies. The hAT, Tc1/Mariner, and Helitron superfamilies show different pattern of amplification, yet they are predominantly represented by young families, whereas divergent families are exceedingly rare. Although it is likely that some elements, in particular long ones, are subjected to purifying selection and do not reach fixation, the majority of families are neutral and accumulate in the anole genome in large numbers. We propose that the scarcity of old copies in the anole genome results from the rapid decay of elements, caused by a high rate of DNA loss.
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Affiliation(s)
- Peter A. Novick
- Department of Biology, Queens College, the City University of New York
- Graduate School and University Center, the City University of New York
| | - Jeremy D. Smith
- Department of Biochemistry and Molecular Biology, Mississippi State University
| | - Mark Floumanhaft
- Department of Biology, Queens College, the City University of New York
| | - David A. Ray
- Department of Biochemistry and Molecular Biology, Mississippi State University
| | - Stéphane Boissinot
- Department of Biology, Queens College, the City University of New York
- Graduate School and University Center, the City University of New York
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Organ CL, Canoville A, Reisz RR, Laurin M. Paleogenomic data suggest mammal-like genome size in the ancestral amniote and derived large genome size in amphibians. J Evol Biol 2010; 24:372-80. [PMID: 21091812 DOI: 10.1111/j.1420-9101.2010.02176.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
An unsolved question in evolutionary genomics is whether amniote genomes have been expanding or contracting since the common ancestor of this diverse group. Here, we report on the polarity of amniote genome size evolution using genome size estimates for 14 extinct tetrapod genera from the Paleozoic and early Mesozoic Eras using osteocyte lacunae size as a correlate. We find substantial support for a phylogenetically controlled regression model relating genome size to osteocyte lacunae size (P of slopes <0.01, r²=0.65, phylogenetic signal λ=0.83). Genome size appears to have been homogeneous across Paleozoic crown-tetrapod lineages (average haploid genome size 2.9-3.7 pg) with values similar to those of extant mammals. The differentiation in genome size and underlying architecture among extant tetrapod lineages likely evolved in the Mesozoic and Cenozoic Eras, with expansion in amphibians, contractions along the diapsid lineage, and no directional change within the synapsid lineage leading to mammals.
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Affiliation(s)
- C L Organ
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA.
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Janes DE, Organ CL, Fujita MK, Shedlock AM, Edwards SV. Genome evolution in Reptilia, the sister group of mammals. Annu Rev Genomics Hum Genet 2010; 11:239-64. [PMID: 20590429 DOI: 10.1146/annurev-genom-082509-141646] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The genomes of birds and nonavian reptiles (Reptilia) are critical for understanding genome evolution in mammals and amniotes generally. Despite decades of study at the chromosomal and single-gene levels, and the evidence for great diversity in genome size, karyotype, and sex chromosome diversity, reptile genomes are virtually unknown in the comparative genomics era. The recent sequencing of the chicken and zebra finch genomes, in conjunction with genome scans and the online publication of the Anolis lizard genome, has begun to clarify the events leading from an ancestral amniote genome--predicted to be large and to possess a diverse repeat landscape on par with mammals and a birdlike sex chromosome system--to the small and highly streamlined genomes of birds. Reptilia exhibit a wide range of evolutionary rates of different subgenomes and, from isochores to mitochondrial DNA, provide a critical contrast to the genomic paradigms established in mammals.
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Affiliation(s)
- Daniel E Janes
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
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Thompson ML, Gauna AE, Williams ML, Ray DA. Multiple chicken repeat 1 lineages in the genomes of oestroid flies. Gene 2009; 448:40-5. [PMID: 19716865 DOI: 10.1016/j.gene.2009.08.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 08/03/2009] [Accepted: 08/14/2009] [Indexed: 11/24/2022]
Abstract
Retrotransposons including CR1 (chicken repeat 1) elements are important factors in genome evolution. They also mobilize in a genome in a way that makes them useful for phylogenetic analysis and species identification. This study was designed to identify lineages of CR1 elements in the genomes of forensically important oestroid flies and to further characterize one family, Sbul.CR1B. CR1 fragments from several taxa were amplified, cloned, sequenced and analyzed to identify different lineages of elements. A variety of retrotransposon families were recovered that exhibit similarity to known retrotransposon families. A number of these lineages may have given rise to taxon-specific subfamilies that have been recently active in oestroid fly genomes. One element from Sarcophaga bullata was analyzed in detail to reconstruct a partial Open Reading Frame containing both the reverse transcriptase (RT) and endonuclease (EN) domains. These domains were used to identify conserved amino acid regions in the recovered consensus via comparison to known non-LTR retrotransposons. Phylogenetic analysis of the RT domain revealed the recovered ORF in S. bullata compares favorably with previously documented CR1-like elements. This work will serve as the basis for additional analyses targeted at developing a simple, efficient marker system for the identification of forensically important carrion flies.
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Plötner J, Köhler F, Uzzell T, Beerli P, Schreiber R, Guex GD, Hotz H. Evolution of serum albumin intron-1 is shaped by a 5' truncated non-long terminal repeat retrotransposon in western Palearctic water frogs (Neobatrachia). Mol Phylogenet Evol 2009; 53:784-91. [PMID: 19665056 DOI: 10.1016/j.ympev.2009.07.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 07/30/2009] [Accepted: 07/31/2009] [Indexed: 10/20/2022]
Abstract
A 5' truncated non-LTR CR1-like retrotransposon, named RanaCR1, was identified in the serum albumin intron-1 (SAI-1) of at least seven species of western Palearctic water frogs (WPWF). Based on sequence similarity of the carboxy-terminal region (CTR) of ORF2 and/or the highly conserved 3' untranslated region (3' UTR), RanaCR1-like elements occur also in the genome of Xenopus tropicalis and Rana temporaria. Unlike other CR1 elements, RanaCR1 contains a CA microsatellite in its 3' UTR. The low nucleotide diversity of the 3' UTR compared to the CTR and to SAI-1 suggests that this region still plays a role in WPWF, either as a structure-stabilizing element, or within a species-specific transcriptional network. Length variation of water frog SAI-1 sequences is caused by deletions that extend in some cases beyond the 5' or 3' ends of RanaCR1, probably a result of selection for structural and functional stability of the primary transcript. The impact of RanaCR1 on SAI-1 evolution is also indicated by the significant negative correlation between the length of both SAI-1 and RanaCR1 and the percentage GC content of RanaCR1. Both SAI-1 and RanaCR1 sequences support the sister group relationship of R. perezi and R. saharica, which are placed in the phylogenetic tree at a basal position, the sister clade to other water frog taxa. It also supports the monophyly of the R. lessonae group; of Anatolian water frogs (R. cf. bedriagae), which are not conspecific with R. bedriagae, and of the European ridibunda group. Within the ridibunda clade, Greek frogs are clearly separated, supporting the hypothesis that Balkan water frogs represent a distinct species. Frogs from Atyrau (Kazakhstan), the type locality of R. ridibunda, were heterozygous for a ridibunda and a cf. bedriagae specific allele.
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Affiliation(s)
- Jörg Plötner
- Museum für Naturkunde, Leibniz-Institut für Evolutions - und Biodiversitätsforschung an der Humboldt-Universität zu Berlin, Invalidenstrasse 43, 10115 Berlin, Germany.
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Chapus C, Edwards SV. Genome evolution in Reptilia: in silico chicken mapping of 12,000 BAC-end sequences from two reptiles and a basal bird. BMC Genomics 2009; 10 Suppl 2:S8. [PMID: 19607659 PMCID: PMC2966332 DOI: 10.1186/1471-2164-10-s2-s8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND With the publication of the draft chicken genome and the recent production of several BAC clone libraries from non-avian reptiles and birds, it is now possible to undertake more detailed comparative genomic studies in Reptilia. Of interest in particular are the genomic events that transformed the large, repeat-rich genomes of mammals and non-avian reptiles into the minimalist chicken genome. We have used paired BAC end sequences (BESs) from the American alligator (Alligator mississippiensis), painted turtle (Chrysemys picta) and emu (Dromaius novaehollandiae) to investigate patterns of sequence divergence, gene and retroelement content, and microsynteny between these species and chicken. RESULTS From a total of 11,967 curated BESs, we successfully mapped 725, 773 and 2597 sequences in alligator, turtle, and emu, respectively, to sites in the draft chicken genome using a stringent BLAST protocol. Most commonly, sequences mapped to a single site in the chicken genome. Of 1675, 1828 and 2936 paired BESs obtained for alligator, turtle, and emu, respectively, a total of 34 (alligator, 2%), 24 (turtle, 1.3%) and 479 (emu, 16.3%) pairs were found to map with high confidence and in the correct orientation and with BAC-sized intermarker distances to single chicken chromosomes, including 25 such paired hits in emu mapping to the chicken Z chromosome. By determining the insert sizes of a subset of BAC clones from these three species, we also found a significant correlation between the intermarker distance in alligator and turtle and in chicken, with slopes as expected on the basis of the ratio of the genome sizes. CONCLUSION Our results suggest that a large number of small-scale chromosomal rearrangements and deletions in the lineage leading to chicken have drastically reduced the number of detected syntenies observed between the chicken and alligator, turtle, and emu genomes and imply that small deletions occurring widely throughout the genomes of reptilian and avian ancestors led to the ~50% reduction in genome size observed in birds compared to reptiles. We have also mapped and identified likely gene regions in hundreds of new BAC clones from these species.
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Affiliation(s)
- Charles Chapus
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| | - Scott V Edwards
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
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Shan X, Ray DA, Bunge JA, Peterson DG. A bacterial artificial chromosome library for the Australian saltwater crocodile (Crocodylus porosus) and its utilization in gene isolation and genome characterization. BMC Genomics 2009; 10 Suppl 2:S9. [PMID: 19607660 PMCID: PMC2966330 DOI: 10.1186/1471-2164-10-s2-s9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Background Crocodilians (Order Crocodylia) are an ancient vertebrate group of tremendous ecological, social, and evolutionary importance. They are the only extant reptilian members of Archosauria, a monophyletic group that also includes birds, dinosaurs, and pterosaurs. Consequently, crocodilian genomes represent a gateway through which the molecular evolution of avian lineages can be explored. To facilitate comparative genomics within Crocodylia and between crocodilians and other archosaurs, we have constructed a bacterial artificial chromosome (BAC) library for the Australian saltwater crocodile, Crocodylus porosus. This is the first BAC library for a crocodile and only the second BAC resource for a crocodilian. Results The C. porosus BAC library consists of 101,760 individually archived clones stored in 384-well microtiter plates. NotI digestion of random clones indicates an average insert size of 102 kb. Based on a genome size estimate of 2778 Mb, the library affords 3.7 fold (3.7×) coverage of the C. porosus genome. To investigate the utility of the library in studying sequence distribution, probes derived from CR1a and CR1b, two crocodilian CR1-like retrotransposon subfamilies, were hybridized to C. porosus macroarrays. The results indicate that there are a minimum of 20,000 CR1a/b elements in C. porosus and that their distribution throughout the genome is decidedly non-random. To demonstrate the utility of the library in gene isolation, we probed the C. porosus macroarrays with an overgo designed from a C-mos (oocyte maturation factor) partial cDNA. A BAC containing C-mos was identified and the C-mos locus was sequenced. Nucleotide and amino acid sequence alignment of the C. porosus C-mos coding sequence with avian and reptilian C-mos orthologs reveals greater sequence similarity between C. porosus and birds (specifically chicken and zebra finch) than between C. porosus and squamates (green anole). Conclusion We have demonstrated the utility of the Crocodylus porosus BAC library as a tool in genomics research. The BAC library should expedite complete genome sequencing of C. porosus and facilitate detailed analysis of genome evolution within Crocodylia and between crocodilians and diverse amniote lineages including birds, mammals, and other non-avian reptiles.
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Affiliation(s)
- Xueyan Shan
- Mississippi Genome Exploration Laboratory, Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS, USA.
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Valenzuela N. The painted turtle, Chrysemys picta: a model system for vertebrate evolution, ecology, and human health. Cold Spring Harb Protoc 2009; 2009:pdb.emo124. [PMID: 20147199 DOI: 10.1101/pdb.emo124] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Painted turtles (Chrysemys picta) are representatives of a vertebrate clade whose biology and phylogenetic position hold a key to our understanding of fundamental aspects of vertebrate evolution. These features make them an ideal emerging model system. Extensive ecological and physiological research provide the context in which to place new research advances in evolutionary genetics, genomics, evolutionary developmental biology, and ecological developmental biology which are enabled by current resources, such as a bacterial artificial chromosome (BAC) library of C. picta, and the imminent development of additional ones such as genome sequences and cDNA and expressed sequence tag (EST) libraries. This integrative approach will allow the research community to continue making advances to provide functional and evolutionary explanations for the lability of biological traits found not only among reptiles but vertebrates in general. Moreover, because humans and reptiles share a common ancestor, and given the ease of using nonplacental vertebrates in experimental biology compared with mammalian embryos, painted turtles are also an emerging model system for biomedical research. For example, painted turtles have been studied to understand many biological responses to overwintering and anoxia, as potential sentinels for environmental xenobiotics, and as a model to decipher the ecology and evolution of sexual development and reproduction. Thus, painted turtles are an excellent reptilian model system for studies with human health, environmental, ecological, and evolutionary significance.
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Affiliation(s)
- Nicole Valenzuela
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA.
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Liu GE, Jiang L, Tian F, Zhu B, Song J. Calibration of mutation rates reveals diverse subfamily structure of galliform CR1 repeats. Genome Biol Evol 2009; 1:119-30. [PMID: 20333183 PMCID: PMC2817409 DOI: 10.1093/gbe/evp014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2009] [Indexed: 11/12/2022] Open
Abstract
Chicken Repeat 1 (CR1) repeats are the most abundant family of repeats in the chicken genome, with more than 200,000 copies accounting for approximately 80% of the chicken interspersed repeats. CR1 repeats are believed to have arisen from the retrotransposition of a small number of master elements, which gave rise to the 22 CR1 subfamilies as previously reported in Repbase. We performed a global assessment of the divergence distributions, phylogenies, and consensus sequences of CR1 repeats in the chicken genome. We identified and validated 57 chicken CR1 subfamilies and further analyzed the correlation between these subfamilies and their regional GC contents. We also discovered one novel lineage-specific CR1 subfamilies in turkeys when compared with chickens. We built an evolutionary tree of these subfamilies and concluded that CR1 repeats may play an important role in reshaping the structure of bird genomes.
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Affiliation(s)
- George E Liu
- Bovine Functional Genomics Laboratory, Animal and Natural Resources Institute, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland, USA.
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Novikova OS, Blinov AG. Origin, evolution, and distribution of different groups of non-LTR retrotransposons among eukaryotes. RUSS J GENET+ 2009. [DOI: 10.1134/s102279540902001x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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34
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Piskurek O, Nishihara H, Okada N. The evolution of two partner LINE/SINE families and a full-length chromodomain-containing Ty3/Gypsy LTR element in the first reptilian genome of Anolis carolinensis. Gene 2008; 441:111-8. [PMID: 19118606 DOI: 10.1016/j.gene.2008.11.030] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 11/18/2008] [Accepted: 11/25/2008] [Indexed: 02/01/2023]
Abstract
Transposable elements have been characterized in a number of vertebrates, including whole genomes of mammals, birds, and fishes. The Anolis carolinensis draft assembly provides the first opportunity to study retroposons in a reptilian genome. Here, we identified and reconstructed a number of retroposons based on database searches: Five Sauria short interspersed element (SINE) subfamilies, 5S-Sauria SINE chimeras, Anolis Bov-B long interspersed element (LINE), Anolis SINE 2, Anolis LINE 2, Anolis LINE 1, Anolis CR 1, and a chromodomain-containing Ty3/Gypsy LTR element. We focused on two SINE families (Anolis Sauria SINE and Anolis SINE 2) and their partner LINE families (Anolis Bov-B LINE and Anolis LINE 2). We demonstrate that each SINE/LINE pair is distributed similarly and predict that the retrotransposition of evolutionarily younger Sauria SINE members is via younger Bov-B LINE members while a correlation also exists between their respective evolutionarily older SINE/LINE members. The evolutionarily youngest Sauria SINE sequences evolved as part of novel rolling-circle transposons. The evolutionary time frame when Bov-B LINEs and Sauria SINEs were less active in their retrotransposition is characterized by a high retrotransposition burst of Anolis SINE 2 and Anolis LINE 2 elements. We also characterized the first full-length chromoviral LTR element in amniotes (Amn-ichi). This newly identified chromovirus is widespread in the Anolis genome and has been very well preserved, indicating that it is still active. Transposable elements in the Anolis genome account for approximately 20% of the total DNA sequence, whereas the proportion is more than double that in many mammalian genomes in which such elements have important biological functions. Nevertheless, 20% transposable element coverage is sufficient to predict that Anolis retroposons and other mobile elements also may have biologically and evolutionarily relevant functions. The new SINEs and LINEs and other ubiquitous genomic elements characterized in the Anolis genome will prove very useful for studies in comparative genomics, phylogenetics, and functional genetics.
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Affiliation(s)
- Oliver Piskurek
- Department of Biological Sciences, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B21 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
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Developing markers for multilocus phylogenetics in non-model organisms: A test case with turtles. Mol Phylogenet Evol 2008; 49:514-25. [PMID: 18761096 DOI: 10.1016/j.ympev.2008.08.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Revised: 08/01/2008] [Accepted: 08/05/2008] [Indexed: 11/21/2022]
Abstract
We present a strategy for phylogenetic marker development in non-model systems. Rather than using the traditional approach of comparing distantly related taxa to develop conserved primers for unknown species, we explore an alternative strategy that builds primers directly from a single, relatively well characterized species and applies those primers to increasingly distantly related taxa. We develop and test our protocol with turtles. Using a single BAC end-sequence library consisting of 3461 sequences totaling 2.43 million base pairs of data, we outline a procedure to flag repeat elements, followed by a BLAST approach to categorize sequences into high, low, and no similarity compartments compared to GenBank sequences. We developed and tested a panel of 96 primer pairs with a set of turtle tissues that forms a series of increasingly distantly related taxa with respect to the BAC reference species. Finally, we sequenced 11 of these newly discovered markers across a diverse set of 18 turtle species that spans the 210 million years of chelonian crown-group history and that includes representatives of most of the major clades of extant turtles. Our results indicate that large numbers of new, phylogenetically informative markers can be developed quickly and inexpensively from a single BAC, EST, or similar genomic resource, and that those markers provide reliable phylogenetic information across both shallow and deep levels of phylogenetic history. Our results also highlight the importance of screening for and managing repetitive elements found in randomly sequenced DNA fragments. We presume that our strategy should work well across any similarly divergent clade, suggesting that many-marker datasets can be developed quickly and efficiently for phylogenetic analysis.
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Amniote phylogenomics: testing evolutionary hypotheses with BAC library scanning and targeted clone analysis of large-scale DNA sequences from reptiles. Methods Mol Biol 2008; 422:91-117. [PMID: 18629663 DOI: 10.1007/978-1-59745-581-7_7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Phylogenomics research integrating established principles of systematic biology and taking advantage of the wealth of DNA sequences being generated by genome science holds promise for answering long-standing evolutionary questions with orders of magnitude more primary data than in the past. Although it is unrealistic to expect whole-genome initiatives to proceed rapidly for commercially unimportant species such as reptiles, practical approaches utilizing genomic libraries of large-insert clones pave the way for a phylogenomics of species that are nevertheless essential for testing evolutionary hypotheses within a phylogenetic framework. This chapter reviews the case for adopting genome-enabled approaches to evolutionary studies and outlines a program for using bacterial artificial chromosome (BAC) libraries or plasmid libraries as a basis for completing "genome scans" of reptiles. We have used BACs to close a critical gap in the genome database for Reptilia, the sister group of mammals, and present the methodological approaches taken to achieve this as a guideline for designing similar comparative studies. In addition, we provide a detailed step-by-step protocol for BAC-library screening and shotgun sequencing of specific clones containing target genes of evolutionary interest. Taken together, the genome scanning and shotgun sequencing techniques offer complementary diagnostic potential and can substantially increase the scale and power of analyses aimed at testing evolutionary hypotheses for nonmodel species.
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Organ CL, Moreno RG, Edwards SV. Three tiers of genome evolution in reptiles. Integr Comp Biol 2008; 48:494-504. [PMID: 21669810 DOI: 10.1093/icb/icn046] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Characterization of reptilian genomes is essential for understanding the overall diversity and evolution of amniote genomes, because reptiles, which include birds, constitute a major fraction of the amniote evolutionary tree. To better understand the evolution and diversity of genomic characteristics in Reptilia, we conducted comparative analyses of online sequence data from Alligator mississippiensis (alligator) and Sphenodon punctatus (tuatara) as well as genome size and karyological data from a wide range of reptilian species. At the whole-genome and chromosomal tiers of organization, we find that reptilian genome size distribution is consistent with a model of continuous gradual evolution while genomic compartmentalization, as manifested in the number of microchromosomes and macrochromosomes, appears to have undergone early rapid change. At the sequence level, the third genomic tier, we find that exon size in Alligator is distributed in a pattern matching that of exons in Gallus (chicken), especially in the 101-200 bp size class. A small spike in the fraction of exons in the 301 bp-1 kb size class is also observed for Alligator, but more so for Sphenodon. For introns, we find that members of Reptilia have a larger fraction of introns within the 101 bp-2 kb size class and a lower fraction of introns within the 5-30 kb size class than do mammals. These findings suggest that the mode of reptilian genome evolution varies across three hierarchical levels of the genome, a pattern consistent with a mosaic model of genomic evolution.
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Affiliation(s)
- Chris L Organ
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138, USA
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38
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Organ CL, Shedlock AM, Meade A, Pagel M, Edwards SV. Origin of avian genome size and structure in non-avian dinosaurs. Nature 2007; 446:180-4. [PMID: 17344851 DOI: 10.1038/nature05621] [Citation(s) in RCA: 185] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2006] [Accepted: 01/25/2007] [Indexed: 11/10/2022]
Abstract
Avian genomes are small and streamlined compared with those of other amniotes by virtue of having fewer repetitive elements and less non-coding DNA. This condition has been suggested to represent a key adaptation for flight in birds, by reducing the metabolic costs associated with having large genome and cell sizes. However, the evolution of genome architecture in birds, or any other lineage, is difficult to study because genomic information is often absent for long-extinct relatives. Here we use a novel bayesian comparative method to show that bone-cell size correlates well with genome size in extant vertebrates, and hence use this relationship to estimate the genome sizes of 31 species of extinct dinosaur, including several species of extinct birds. Our results indicate that the small genomes typically associated with avian flight evolved in the saurischian dinosaur lineage between 230 and 250 million years ago, long before this lineage gave rise to the first birds. By comparison, ornithischian dinosaurs are inferred to have had much larger genomes, which were probably typical for ancestral Dinosauria. Using comparative genomic data, we estimate that genome-wide interspersed mobile elements, a class of repetitive DNA, comprised 5-12% of the total genome size in the saurischian dinosaur lineage, but was 7-19% of total genome size in ornithischian dinosaurs, suggesting that repetitive elements became less active in the saurischian lineage. These genomic characteristics should be added to the list of attributes previously considered avian but now thought to have arisen in non-avian dinosaurs, such as feathers, pulmonary innovations, and parental care and nesting.
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Affiliation(s)
- Chris L Organ
- Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, Massachusetts 02138, USA.
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Wang Z, Miyake T, Edwards SV, Amemiya CT. Tuatara (Sphenodon) Genomics: BAC Library Construction, Sequence Survey, and Application to the DMRT Gene Family. J Hered 2006; 97:541-8. [PMID: 17135461 DOI: 10.1093/jhered/esl040] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The tuatara (Sphenodon punctatus) is of "extraordinary biological interest" as the most distinctive surviving reptilian lineage (Rhyncocephalia) in the world. To provide a genomic resource for an understanding of genome evolution in reptiles, and as part of a larger project to produce genomic resources for various reptiles (evogen.jgi.doe.gov/second_levels/BACs/our_libraries.html), a large-insert bacterial artificial chromosome (BAC) library from a male tuatara was constructed. The library consists of 215 424 individual clones whose average insert size was empirically determined to be 145 kb, yielding a genomic coverage of approximately 6.3x. A BAC-end sequencing analysis of 121 420 bp of sequence revealed a genomic GC content of 46.8%, among the highest observed thus far for vertebrates, and identified several short interspersed repetitive elements (mammalian interspersed repeat-type repeats) and long interspersed repetitive elements, including chicken repeat 1 element. Finally, as a quality control measure the arrayed library was screened with probes corresponding to 2 conserved noncoding regions of the candidate sex-determining gene DMRT1 and the DM domain of the related DMRT2 gene. A deep coverage contig spanning nearly 300 kb was generated, supporting the deep coverage and utility of the library for exploring tuatara genomics.
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Affiliation(s)
- Zhenshan Wang
- Department of Biology, University of Washington, Seattle, WA 98195, USA.
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