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Insights into the genomic evolution of insects from cricket genomes. Commun Biol 2021; 4:733. [PMID: 34127782 PMCID: PMC8203789 DOI: 10.1038/s42003-021-02197-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 04/16/2021] [Indexed: 12/14/2022] Open
Abstract
Most of our knowledge of insect genomes comes from Holometabolous species, which undergo complete metamorphosis and have genomes typically under 2 Gb with little signs of DNA methylation. In contrast, Hemimetabolous insects undergo the presumed ancestral process of incomplete metamorphosis, and have larger genomes with high levels of DNA methylation. Hemimetabolous species from the Orthopteran order (grasshoppers and crickets) have some of the largest known insect genomes. What drives the evolution of these unusual insect genome sizes, remains unknown. Here we report the sequencing, assembly and annotation of the 1.66-Gb genome of the Mediterranean field cricket Gryllus bimaculatus, and the annotation of the 1.60-Gb genome of the Hawaiian cricket Laupala kohalensis. We compare these two cricket genomes with those of 14 additional insects and find evidence that hemimetabolous genomes expanded due to transposable element activity. Based on the ratio of observed to expected CpG sites, we find higher conservation and stronger purifying selection of methylated genes than non-methylated genes. Finally, our analysis suggests an expansion of the pickpocket class V gene family in crickets, which we speculate might play a role in the evolution of cricket courtship, including their characteristic chirping. Ylla, Extavour et al. use genomic data from crickets to investigate the evolution of large genome sizes and DNA methylation events in insects. Their findings indicate that transposable element activity drove genome expansion in hemimetabolous insects, such as crickets and grasshoppers, and that DNA methylation is predominant in conserved genes.
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Li Y, Leveau A, Zhao Q, Feng Q, Lu H, Miao J, Xue Z, Martin AC, Wegel E, Wang J, Orme A, Rey MD, Karafiátová M, Vrána J, Steuernagel B, Joynson R, Owen C, Reed J, Louveau T, Stephenson MJ, Zhang L, Huang X, Huang T, Fan D, Zhou C, Tian Q, Li W, Lu Y, Chen J, Zhao Y, Lu Y, Zhu C, Liu Z, Polturak G, Casson R, Hill L, Moore G, Melton R, Hall N, Wulff BBH, Doležel J, Langdon T, Han B, Osbourn A. Subtelomeric assembly of a multi-gene pathway for antimicrobial defense compounds in cereals. Nat Commun 2021; 12:2563. [PMID: 33963185 PMCID: PMC8105312 DOI: 10.1038/s41467-021-22920-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 04/07/2021] [Indexed: 02/06/2023] Open
Abstract
Non-random gene organization in eukaryotes plays a significant role in genome evolution. Here, we investigate the origin of a biosynthetic gene cluster for production of defence compounds in oat-the avenacin cluster. We elucidate the structure and organisation of this 12-gene cluster, characterise the last two missing pathway steps, and reconstitute the entire pathway in tobacco by transient expression. We show that the cluster has formed de novo since the divergence of oats in a subtelomeric region of the genome that lacks homology with other grasses, and that gene order is approximately colinear with the biosynthetic pathway. We speculate that the positioning of the late pathway genes furthest away from the telomere may mitigate against a 'self-poisoning' scenario in which toxic intermediates accumulate as a result of telomeric gene deletions. Our investigations reveal a striking example of adaptive evolution underpinned by remarkable genome plasticity.
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Affiliation(s)
- Yan Li
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | | | - Qiang Zhao
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Qi Feng
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Hengyun Lu
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Jiashun Miao
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Zheyong Xue
- John Innes Centre, Norwich Research Park, Norwich, UK
| | | | - Eva Wegel
- John Innes Centre, Norwich Research Park, Norwich, UK
| | - Jing Wang
- John Innes Centre, Norwich Research Park, Norwich, UK
| | | | | | - Miroslava Karafiátová
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, Olomouc, Czech Republic
| | - Jan Vrána
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, Olomouc, Czech Republic
| | | | - Ryan Joynson
- Earlham Institute, Norwich Research Park, Norwich, UK
| | | | - James Reed
- John Innes Centre, Norwich Research Park, Norwich, UK
| | | | | | - Lei Zhang
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Xuehui Huang
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Tao Huang
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Danling Fan
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Congcong Zhou
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Qilin Tian
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Wenjun Li
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Yiqi Lu
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Jiaying Chen
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Yan Zhao
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Ying Lu
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Chuanrang Zhu
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Zhenhua Liu
- Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Guy Polturak
- John Innes Centre, Norwich Research Park, Norwich, UK
| | | | - Lionel Hill
- John Innes Centre, Norwich Research Park, Norwich, UK
| | - Graham Moore
- John Innes Centre, Norwich Research Park, Norwich, UK
| | - Rachel Melton
- John Innes Centre, Norwich Research Park, Norwich, UK
| | - Neil Hall
- Earlham Institute, Norwich Research Park, Norwich, UK
| | | | - Jaroslav Doležel
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, Olomouc, Czech Republic
| | - Tim Langdon
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Gogerddan, Aberystwyth, Ceredigion, SY23 3EE, UK
| | - Bin Han
- National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China.
| | - Anne Osbourn
- John Innes Centre, Norwich Research Park, Norwich, UK.
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Miao J, Feng Q, Li Y, Zhao Q, Zhou C, Lu H, Fan D, Yan J, Lu Y, Tian Q, Li W, Weng Q, Zhang L, Zhao Y, Huang T, Li L, Huang X, Sang T, Han B. Chromosome-scale assembly and analysis of biomass crop Miscanthus lutarioriparius genome. Nat Commun 2021; 12:2458. [PMID: 33911077 PMCID: PMC8080599 DOI: 10.1038/s41467-021-22738-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 03/12/2021] [Indexed: 11/09/2022] Open
Abstract
Miscanthus, a rhizomatous perennial plant, has great potential for bioenergy production for its high biomass and stress tolerance. We report a chromosome-scale assembly of Miscanthus lutarioriparius genome by combining Oxford Nanopore sequencing and Hi-C technologies. The 2.07-Gb assembly covers 96.64% of the genome, with contig N50 of 1.71 Mb. The centromere and telomere sequences are assembled for all 19 chromosomes and chromosome 10, respectively. Allotetraploid origin of the M. lutarioriparius is confirmed using centromeric satellite repeats. The tetraploid genome structure and several chromosomal rearrangements relative to sorghum are clearly demonstrated. Tandem duplicate genes of M. lutarioriparius are functional enriched not only in terms related to stress response, but cell wall biosynthesis. Gene families related to disease resistance, cell wall biosynthesis and metal ion transport are greatly expanded and evolved. The expansion of these families may be an important genomic basis for the enhancement of remarkable traits of M. lutarioriparius.
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Affiliation(s)
- Jiashun Miao
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qi Feng
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Yan Li
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Qiang Zhao
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Congcong Zhou
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Hengyun Lu
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Danlin Fan
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Juan Yan
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
| | - Yiqi Lu
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Qilin Tian
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Wenjun Li
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Qijun Weng
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Lei Zhang
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Yan Zhao
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Tao Huang
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Laigeng Li
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Xuehui Huang
- College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Tao Sang
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
| | - Bin Han
- National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center of Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China.
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Matar S, Melzer S. A 598-bp InDel Variation in the Promoter Region of Bna.SOC1.A05 Is Predominantly Present in Winter Type Rapeseeds. FRONTIERS IN PLANT SCIENCE 2021; 12:640163. [PMID: 33927737 PMCID: PMC8078208 DOI: 10.3389/fpls.2021.640163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 03/11/2021] [Indexed: 06/12/2023]
Abstract
During rapeseed domestication and breeding, genetic diversity allowed to adapt it to different eco-geographical regions and to shape its useful traits. Structural variations (SVs), including presence/absence variations (PAVs), are thought to play a major role in the genetic diversity and phenotypic plasticity of rapeseed. In this study, we detected a 598-bp PAV within the promoter region of an Arabidopsis ortholog of a major flowering time gene and a downstream target of FLC, SOC1, which is one of the first genes that are upregulated in rapeseed during vernalization. Further analysis showed that the insertion is present predominantly in winter types while absent in spring types. The 589-bp sequence is present only in the A sub-genome indicating that it originated from Brassica rapa. Since the genomic region around Bna.SOC1.A05 showed a strong reduction in nucleotide diversity, the insertion might represent a larger selected sweep for rapeseed adaptation. Cis-element analysis showed that the insertion contains an ACGTG box, which is the strongest binding motif for the HY5 transcription factor in Arabidopsis. In addition, expression analyses showed that mRNA levels of Bna.SOC1.A05 were lower in accessions carrying the insertion compared to the ones that had no insertion.
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Affiliation(s)
| | - Siegbert Melzer
- Plant Breeding Institute, Christian-Albrechts-University of Kiel, Kiel, Germany
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55
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Wang X, Chen S, Ma X, Yssel AEJ, Chaluvadi SR, Johnson MS, Gangashetty P, Hamidou F, Sanogo MD, Zwaenepoel A, Wallace J, Van de Peer Y, Bennetzen JL, Van Deynze A. Genome sequence and genetic diversity analysis of an under-domesticated orphan crop, white fonio (Digitaria exilis). Gigascience 2021; 10:6168810. [PMID: 33710327 PMCID: PMC7953496 DOI: 10.1093/gigascience/giab013] [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: 07/10/2020] [Revised: 12/14/2020] [Accepted: 02/10/2021] [Indexed: 01/05/2023] Open
Abstract
Background Digitaria exilis, white fonio, is a minor but vital crop of West Africa that is valued for its resilience in hot, dry, and low-fertility environments and for the exceptional quality of its grain for human nutrition. Its success is hindered, however, by a low degree of plant breeding and improvement. Findings We sequenced the fonio genome with long-read SMRT-cell technology, yielding a ∼761 Mb assembly in 3,329 contigs (N50, 1.73 Mb; L50, 126). The assembly approaches a high level of completion, with a BUSCO score of >99%. The fonio genome was found to be a tetraploid, with most of the genome retained as homoeologous duplications that differ overall by ∼4.3%, neglecting indels. The 2 genomes within fonio were found to have begun their independent divergence ∼3.1 million years ago. The repeat content (>49%) is fairly standard for a grass genome of this size, but the ratio of Gypsy to Copia long terminal repeat retrotransposons (∼6.7) was found to be exceptionally high. Several genes related to future improvement of the crop were identified including shattering, plant height, and grain size. Analysis of fonio population genetics, primarily in Mali, indicated that the crop has extensive genetic diversity that is largely partitioned across a north-south gradient coinciding with the Sahel and Sudan grassland domains. Conclusions We provide a high-quality assembly, annotation, and diversity analysis for a vital African crop. The availability of this information should empower future research into further domestication and improvement of fonio.
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Affiliation(s)
- Xuewen Wang
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Shiyu Chen
- Department of Plant Sciences, Seed Biotechnology Center, University of California, 1 Shields Ave. Davis, CA 95616, USA
| | - Xiao Ma
- Bioinformatics & Systems Biology, VIB / Ghent University, Technologiepark 71, 9052 Zwijnaarde, Belgium
| | - Anna E J Yssel
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0028, South Africa.,Centre for Bioinformatics and Computational Biology, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0028, South Africa
| | | | - Matthew S Johnson
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, 111 Riverbend Rd, Athens, GA 30602, USA
| | - Prakash Gangashetty
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), BP 12404, Niamey, Niger
| | - Falalou Hamidou
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), BP 12404, Niamey, Niger
| | - Moussa D Sanogo
- Institut d'Economie Rurale, Ministere de l'Agriculture, Cinzana, BP 214, Ségou, Mali
| | - Arthur Zwaenepoel
- Bioinformatics & Systems Biology, VIB / Ghent University, Technologiepark 71, 9052 Zwijnaarde, Belgium
| | - Jason Wallace
- Department of Crop and Soil Sciences, University of Georgia, 3111 Carlton St Bldg, Athens, GA 30602, USA
| | - Yves Van de Peer
- Bioinformatics & Systems Biology, VIB / Ghent University, Technologiepark 71, 9052 Zwijnaarde, Belgium.,Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0028, South Africa.,College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | | | - Allen Van Deynze
- Department of Plant Sciences, Seed Biotechnology Center, University of California, 1 Shields Ave. Davis, CA 95616, USA
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56
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Evolutionary Dynamics of the Pericentromeric Heterochromatin in Drosophila virilis and Related Species. Genes (Basel) 2021; 12:genes12020175. [PMID: 33513919 PMCID: PMC7911463 DOI: 10.3390/genes12020175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/21/2021] [Accepted: 01/23/2021] [Indexed: 12/19/2022] Open
Abstract
Pericentromeric heterochromatin in Drosophila generally consists of repetitive DNA, forming the environment associated with gene silencing. Despite the expanding knowledge of the impact of transposable elements (TEs) on the host genome, little is known about the evolution of pericentromeric heterochromatin, its structural composition, and age. During the evolution of the Drosophilidae, hundreds of genes have become embedded within pericentromeric regions yet retained activity. We investigated a pericentromeric heterochromatin fragment found in D. virilis and related species, describing the evolution of genes in this region and the age of TE invasion. Regardless of the heterochromatic environment, the amino acid composition of the genes is under purifying selection. However, the selective pressure affects parts of genes in varying degrees, resulting in expansion of gene introns due to TEs invasion. According to the divergence of TEs, the pericentromeric heterochromatin of the species of virilis group began to form more than 20 million years ago by invasions of retroelements, miniature inverted repeat transposable elements (MITEs), and Helitrons. Importantly, invasions into the heterochromatin continue to occur by TEs that fall under the scope of piRNA silencing. Thus, the pericentromeric heterochromatin, in spite of its ability to induce silencing, has the means for being dynamic, incorporating the regions of active transcription.
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57
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de Los Ríos-Pérez L, Nguinkal JA, Verleih M, Rebl A, Brunner RM, Klosa J, Schäfer N, Stüeken M, Goldammer T, Wittenburg D. An ultra-high density SNP-based linkage map for enhancing the pikeperch (Sander lucioperca) genome assembly to chromosome-scale. Sci Rep 2020; 10:22335. [PMID: 33339898 PMCID: PMC7749136 DOI: 10.1038/s41598-020-79358-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 12/04/2020] [Indexed: 02/08/2023] Open
Abstract
Pikeperch (Sander lucioperca) is a fish species with growing economic significance in the aquaculture industry. However, successful positioning of pikeperch in large-scale aquaculture requires advances in our understanding of its genome organization. In this study, an ultra-high density linkage map for pikeperch comprising 24 linkage groups and 1,023,625 single nucleotide polymorphisms markers was constructed after genotyping whole-genome sequencing data from 11 broodstock and 363 progeny, belonging to 6 full-sib families. The sex-specific linkage maps spanned a total of 2985.16 cM in females and 2540.47 cM in males with an average inter-marker distance of 0.0030 and 0.0026 cM, respectively. The sex-averaged map spanned a total of 2725.53 cM with an average inter-marker distance of 0.0028 cM. Furthermore, the sex-averaged map was used for improving the contiguity and accuracy of the current pikeperch genome assembly. Based on 723,360 markers, 706 contigs were anchored and oriented into 24 pseudomolecules, covering a total of 896.48 Mb and accounting for 99.47% of the assembled genome size. The overall contiguity of the assembly improved with a scaffold N50 length of 41.06 Mb. Finally, an updated annotation of protein-coding genes and repetitive elements of the enhanced genome assembly is provided at NCBI.
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Affiliation(s)
- Lidia de Los Ríos-Pérez
- Institute of Genetics and Biometry, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Julien A Nguinkal
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Marieke Verleih
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Alexander Rebl
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Ronald M Brunner
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Jan Klosa
- Institute of Genetics and Biometry, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Nadine Schäfer
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Marcus Stüeken
- Mecklenburg-Vorpommern Research Centre for Agriculture and Fisheries, Malchower Chaussee 1, 17194, Hohen Wangelin, Germany
| | - Tom Goldammer
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany. .,Molecular Biology and Fish Genetics, Faculty of Agriculture and Environmental Sciences, University of Rostock, 18059, Rostock, Germany.
| | - Dörte Wittenburg
- Institute of Genetics and Biometry, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany.
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58
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KLAI K, CHÉNAIS B, ZIDI M, DJEBBI S, CARUSO A, DENIS F, CONFAIS J, BADAWI M, CASSE N, MEZGHANI KHEMAKHEM M. Screening of Helicoverpa armigera Mobilome Revealed Transposable Element Insertions in Insecticide Resistance Genes. INSECTS 2020; 11:insects11120879. [PMID: 33322432 PMCID: PMC7764229 DOI: 10.3390/insects11120879] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/08/2020] [Accepted: 12/08/2020] [Indexed: 12/14/2022]
Abstract
Simple Summary Transposable elements (TEs) are mobile DNA sequences that can copy themselves within a host genome. TE-mediated changes in regulation can lead to massive and rapid changes in expression, responses that are potentially highly adaptive when an organism is faced with a mortality agent in the environment, such as an insecticide. Helicoverpa armigera shows a hight number of reported cases of insecticide resistance worldwide, having evolved resistance against pyrethroids, organophosphates, carbamates, organochlorines, and recently to macrocyclic lactone spinosad and several Bacillus thuringiensis toxins. In the present study, we conducted a TE annotation using combined approaches, and the results revealed a total of 8521 TEs, representing 236,132 copies, covering 12.86% of the H. armigera genome. In addition, we underlined TE insertions in defensome genes and we successfully identified nine TE insertions belonging to the RTE, R2, CACTA, Mariner and hAT superfamilies. Abstract The cotton bollworm Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) is an important pest of many crops that has developed resistance to almost all groups of insecticides used for its management. Insecticide resistance was often related to Transposable Element (TE) insertions near specific genes. In the present study, we deeply retrieve and annotate TEs in the H. armigera genome using the Pipeline to Retrieve and Annotate Transposable Elements, PiRATE. The results have shown that the TE library consists of 8521 sequences representing 236,132 TE copies, including 3133 Full-Length Copies (FLC), covering 12.86% of the H. armigera genome. These TEs were classified as 46.71% Class I and 53.29% Class II elements. Among Class I elements, Short and Long Interspersed Nuclear Elements (SINEs and LINEs) are the main families, representing 21.13% and 19.49% of the total TEs, respectively. Long Terminal Repeat (LTR) and Dictyostelium transposable element (DIRS) are less represented, with 5.55% and 0.53%, respectively. Class II elements are mainly Miniature Inverted Transposable Elements (MITEs) (49.11%), then Terminal Inverted Repeats (TIRs) (4.09%). Superfamilies of Class II elements, i.e., Transib, P elements, CACTA, Mutator, PIF-harbinger, Helitron, Maverick, Crypton and Merlin, were less represented, accounting for only 1.96% of total TEs. In addition, we highlighted TE insertions in insecticide resistance genes and we successfully identified nine TE insertions belonging to RTE, R2, CACTA, Mariner and hAT superfamilies. These insertions are hosted in genes encoding cytochrome P450 (CyP450), glutathione S-transferase (GST), and ATP-binding cassette (ABC) transporter belonging to the G and C1 family members. These insertions could therefore be involved in insecticide resistance observed in this pest.
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Affiliation(s)
- Khouloud KLAI
- Laboratory of Biochemistry and Biotechnology (LR01ES05), Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis 1068, Tunisia; (K.K.); (M.Z.); (S.D.)
- EA2160 Mer Molécules Santé, Le Mans Université, 72085 Le Mans, France; (B.C.); (A.C.); (F.D.); (M.B.)
| | - Benoît CHÉNAIS
- EA2160 Mer Molécules Santé, Le Mans Université, 72085 Le Mans, France; (B.C.); (A.C.); (F.D.); (M.B.)
| | - Marwa ZIDI
- Laboratory of Biochemistry and Biotechnology (LR01ES05), Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis 1068, Tunisia; (K.K.); (M.Z.); (S.D.)
| | - Salma DJEBBI
- Laboratory of Biochemistry and Biotechnology (LR01ES05), Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis 1068, Tunisia; (K.K.); (M.Z.); (S.D.)
| | - Aurore CARUSO
- EA2160 Mer Molécules Santé, Le Mans Université, 72085 Le Mans, France; (B.C.); (A.C.); (F.D.); (M.B.)
| | - Françoise DENIS
- EA2160 Mer Molécules Santé, Le Mans Université, 72085 Le Mans, France; (B.C.); (A.C.); (F.D.); (M.B.)
| | - Johann CONFAIS
- URGI, INRAE, Université Paris-Saclay, 78026 Versailles, France;
- Plant Bioinformatics Facility, BioinfOmics, INRAE, Université Paris-Saclay, 78026 Versailles, France
| | - Myriam BADAWI
- EA2160 Mer Molécules Santé, Le Mans Université, 72085 Le Mans, France; (B.C.); (A.C.); (F.D.); (M.B.)
| | - Nathalie CASSE
- EA2160 Mer Molécules Santé, Le Mans Université, 72085 Le Mans, France; (B.C.); (A.C.); (F.D.); (M.B.)
- Correspondence: (N.C.); (M.M.K.)
| | - Maha MEZGHANI KHEMAKHEM
- Laboratory of Biochemistry and Biotechnology (LR01ES05), Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis 1068, Tunisia; (K.K.); (M.Z.); (S.D.)
- Correspondence: (N.C.); (M.M.K.)
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Karageorgiou C, Tarrío R, Rodríguez-Trelles F. The Cyclically Seasonal Drosophila subobscura Inversion O 7 Originated From Fragile Genomic Sites and Relocated Immunity and Metabolic Genes. Front Genet 2020; 11:565836. [PMID: 33193649 PMCID: PMC7584159 DOI: 10.3389/fgene.2020.565836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 09/09/2020] [Indexed: 11/28/2022] Open
Abstract
Chromosome inversions are important contributors to standing genetic variation in Drosophila subobscura. Presently, the species is experiencing a rapid replacement of high-latitude by low-latitude inversions associated with global warming. Yet not all low-latitude inversions are correlated with the ongoing warming trend. This is particularly unexpected in the case of O7 because it shows a regular seasonal cycle that peaks in summer and rose with a heatwave. The inconsistent behavior of O7 across components of the ambient temperature suggests that is causally more complex than simply due to temperature alone. In order to understand the dynamics of O7, high-quality genomic data are needed to determine both the breakpoints and the genetic content. To fill this gap, here we generated a PacBio long read-based chromosome-scale genome assembly, from a highly homozygous line made isogenic for an O3 + 4 + 7 chromosome. Then we isolated the complete continuous sequence of O7 by conserved synteny analysis with the available reference genome. Main findings include the following: (i) the assembled O7 inversion stretches 9.936 Mb, containing > 1,000 annotated genes; (ii) O7 had a complex origin, involving multiple breaks associated with non-B DNA-forming motifs, formation of a microinversion, and ectopic repair in trans with the two homologous chromosomes; (iii) the O7 breakpoints carry a pre-inversion record of fragility, including a sequence insertion, and transposition with later inverted duplication of an Attacin immunity gene; and (iv) the O7 inversion relocated the major insulin signaling forkhead box subgroup O (foxo) gene in tight linkage with its antagonistic regulatory partner serine/threonine-protein kinase B (Akt1) and disrupted concerted evolution of the two inverted Attacin duplicates, reattaching them to dFOXO metabolic enhancers. Our findings suggest that O7 exerts antagonistic pleiotropic effects on reproduction and immunity, setting a framework to understand its relationship with climate change. Furthermore, they are relevant for fragility in genome rearrangement evolution and for current views on the contribution of breakage versus repair in shaping inversion-breakpoint junctions.
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Affiliation(s)
- Charikleia Karageorgiou
- Grup de Genòmica, Bioinformàtica i Biologia Evolutiva (GGBE), Departament de Genètica i de Microbiologia, Universitat Autonòma de Barcelona, Barcelona, Spain
| | - Rosa Tarrío
- Grup de Genòmica, Bioinformàtica i Biologia Evolutiva (GGBE), Departament de Genètica i de Microbiologia, Universitat Autonòma de Barcelona, Barcelona, Spain
| | - Francisco Rodríguez-Trelles
- Grup de Genòmica, Bioinformàtica i Biologia Evolutiva (GGBE), Departament de Genètica i de Microbiologia, Universitat Autonòma de Barcelona, Barcelona, Spain
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Zavallo D, Crescente JM, Gantuz M, Leone M, Vanzetti LS, Masuelli RW, Asurmendi S. Genomic re-assessment of the transposable element landscape of the potato genome. PLANT CELL REPORTS 2020; 39:1161-1174. [PMID: 32435866 DOI: 10.1007/s00299-020-02554-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/07/2020] [Indexed: 05/14/2023]
Abstract
We provide a comprehensive and reliable potato TE landscape, based on a wide variety of identification tools and integrative approaches, producing clear and ready-to-use outputs for the scientific community. Transposable elements (TEs) are DNA sequences with the ability to autoreplicate and move throughout the host genome. TEs are major drivers in stress response and genome evolution. Given their significance, the development of clear and efficient TE annotation pipelines has become essential for many species. The latest de novo TE discovery tools, along with available TEs from Repbase and sRNA-seq data, allowed us to perform a reliable potato TEs detection, classification and annotation through an open-source and freely available pipeline ( https://github.com/DiegoZavallo/TE_Discovery ). Using a variety of tools, approaches and rules, we were able to provide a clearly annotated of characterized TEs landscape. Additionally, we described the distribution of the different types of TEs across the genome, where LTRs and MITEs present a clear clustering pattern in pericentromeric and subtelomeric/telomeric regions respectively. Finally, we analyzed the insertion age and distribution of LTR retrotransposon families which display a distinct pattern between the two major superfamilies. While older Gypsy elements concentrated around heterochromatic regions, younger Copia elements located predominantly on euchromatic regions. Overall, we delivered not only a reliable, ready-to-use potato TE annotation files, but also all the necessary steps to perform de novo detection for other species.
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Affiliation(s)
- Diego Zavallo
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Los Reseros y Nicolas Repeto, Hurlingham, Argentina.
| | - Juan Manuel Crescente
- Grupo Biotecnologia y Recursos Genéticos, EEA INTA Marcos Juárez, Ruta 12 Km 3, 2580, Marcos Juárez, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Magdalena Gantuz
- Instituto de Biología Agrícola de Mendoza (IBAM), Facultad de Ciencias Agrarias (FCA), CONICET-UNCuyo, Almirante Brown 500, M5528AHB, Chacras de Coria, Mendoza, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Melisa Leone
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Los Reseros y Nicolas Repeto, Hurlingham, Argentina
- Agencia Nacional de Promocion Científica y Tecnológica (ANPCyT), Buenos Aires, Argentina
| | - Leonardo Sebastian Vanzetti
- Grupo Biotecnologia y Recursos Genéticos, EEA INTA Marcos Juárez, Ruta 12 Km 3, 2580, Marcos Juárez, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Ricardo Williams Masuelli
- Instituto de Biología Agrícola de Mendoza (IBAM), Facultad de Ciencias Agrarias (FCA), CONICET-UNCuyo, Almirante Brown 500, M5528AHB, Chacras de Coria, Mendoza, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Sebastian Asurmendi
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Los Reseros y Nicolas Repeto, Hurlingham, Argentina.
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Mikkelsen EK, Weir JT. The genome of the Xingu scale-backed antbird (Willisornis vidua nigrigula) reveals lineage-specific adaptations. Genomics 2020; 112:4552-4560. [PMID: 32771623 DOI: 10.1016/j.ygeno.2020.07.047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/08/2020] [Accepted: 07/30/2020] [Indexed: 12/23/2022]
Abstract
Antbirds (Thamnophilidae) are a large neotropical family of passerine bird renowned for the ant-following foraging strategies of several members of this clade. The high diversity of antbirds provides ample opportunity for speciation studies, however these studies can be hindered by the lack of an annotated antbird reference genome. In this study, we produced a high-quality annotated reference genome for the Xingu Scale-backed Antbird (Willisornis vidua nigrigula) using 10X Genomics Chromium linked-reads technology. The assembly is 1.09 Gb, with a scaffold N50 of 12.1 Mb and 17,475 annotated protein coding genes. We compare the proteome of W. v. nigrigula to several other passerines, and produce annotations for two additional antbird genomes in order to identify genes under lineage-specific positive selection and gene families with evidence for significant expansions in antbirds. Several of these genes have functions potentially related to the lineage-specific traits of antbirds, including adaptations for thermoregulation in a humid tropical environment.
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Affiliation(s)
- Else K Mikkelsen
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto M5S 3B2, ON, Canada.
| | - Jason T Weir
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto M5S 3B2, ON, Canada; Department of Biological Sciences, University of Toronto Scarborough, Toronto M1C 1A4, ON, Canada; Department of Ornithology, Royal Ontario Museum, Toronto, Canada
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The evolutionary history of mariner elements in stalk-eyed flies reveals the horizontal transfer of transposons from insects into the genome of the cnidarian Hydra vulgaris. PLoS One 2020; 15:e0235984. [PMID: 32658920 PMCID: PMC7357744 DOI: 10.1371/journal.pone.0235984] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/25/2020] [Indexed: 11/19/2022] Open
Abstract
The stalk-eyed flies (Diopsidae, Diptera) are a family of approximately 100 species of calypterate dipterans, characterised by extended head capsules. Species within the family have previously been shown to possess six subfamilies of mariner transposons, with nucleotide substitution patterns suggesting that at least two subfamilies are currently active. The vertumnana subfamily has been shown to have been involved in a horizontal transfer event involving Diopsidae and a second dipteran family in the Tephritidae. Presented here are cloned and sequenced mariner elements from three further diopsid species, in addition to a bioinformatic analysis of mariner elements identified in transcriptomic and genomic data from the genus Teleopsis. The newly identified mariner elements predominantly fall into previously recognised subfamilies, however the publicly available Teleopsis data also revealed a novel subfamily. Three of the seven identified subfamilies are shown to have undergone horizontal transfer, two of which appear to involve diopsid donor species. One recipient group of a diopsid mariner is the Bactrocera genus of tephritid flies, the transfer of which was previously proposed in an earlier study of diopsid mariner elements. The second horizontal transfer, of the mauritiana subfamily, can be traced from the Teleopsis genus to the cnidarian Hydra vulgaris. The mauritiana elements are shown to be active in the recipient H. vulgaris and transposase expression is observed in all body tissues examined in both species. The increased diversity of diopsid mariner elements points to a minimum of four subfamilies being present in the ancestral genome. Both vertical inheritance and stochastic loss of TEs have subsequently occurred within the diopsid radiation. The TE complement of H. vulgaris contains at least two mariner subfamilies of insect origin. Despite the phylogenetic distance between donor and recipient species, both subfamilies are shown to be active and proliferating within H. vulgaris.
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de Albuquerque NRM, Ebert D, Haag KL. Transposable element abundance correlates with mode of transmission in microsporidian parasites. Mob DNA 2020; 11:19. [PMID: 32587636 PMCID: PMC7313128 DOI: 10.1186/s13100-020-00218-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 06/18/2020] [Indexed: 01/16/2023] Open
Abstract
The extreme genome reduction and physiological simplicity of some microsporidia has been attributed to their intracellular, obligate parasitic lifestyle. Although not all microsporidian genomes are small (size range from about 2 to 50 MB), it is suggested that the size of their genomes has been streamlined by natural selection. We explore the hypothesis that vertical transmission in microsporidia produces population bottlenecks, and thus reduces the effectiveness of natural selection. Here we compare the transposable element (TE) content of 47 microsporidian genomes, and show that genome size is positively correlated with the amount of TEs, and that species that experience vertical transmission have larger genomes with higher proportion of TEs. Our findings are consistent with earlier studies inferring that nonadaptive processes play an important role in microsporidian evolution.
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Affiliation(s)
- Nathalia Rammé Medeiros de Albuquerque
- Department of Genetics and Post-Graduation Program of Genetics and Molecular Biology, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, Porto Alegre, RS 91501-970 Brazil
| | - Dieter Ebert
- Department of Environmental Sciences, Zoology, Basel University, Vesalgasse 1, 4051 Basel, Switzerland
| | - Karen Luisa Haag
- Department of Genetics and Post-Graduation Program of Genetics and Molecular Biology, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, Porto Alegre, RS 91501-970 Brazil
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Yan H, Bombarely A, Li S. DeepTE: a computational method for de novo classification of transposons with convolutional neural network. Bioinformatics 2020; 36:4269-4275. [DOI: 10.1093/bioinformatics/btaa519] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 04/12/2020] [Accepted: 05/12/2020] [Indexed: 01/23/2023] Open
Abstract
Abstract
Motivation
Transposable elements (TEs) classification is an essential step to decode their roles in genome evolution. With a large number of genomes from non-model species becoming available, accurate and efficient TE classification has emerged as a new challenge in genomic sequence analysis.
Results
We developed a novel tool, DeepTE, which classifies unknown TEs using convolutional neural networks (CNNs). DeepTE transferred sequences into input vectors based on k-mer counts. A tree structured classification process was used where eight models were trained to classify TEs into super families and orders. DeepTE also detected domains inside TEs to correct false classification. An additional model was trained to distinguish between non-TEs and TEs in plants. Given unclassified TEs of different species, DeepTE can classify TEs into seven orders, which include 15, 24 and 16 super families in plants, metazoans and fungi, respectively. In several benchmarking tests, DeepTE outperformed other existing tools for TE classification. In conclusion, DeepTE successfully leverages CNN for TE classification, and can be used to precisely classify TEs in newly sequenced eukaryotic genomes.
Availability and implementation
DeepTE is accessible at https://github.com/LiLabAtVT/DeepTE.
Supplementary information
Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Haidong Yan
- School of Plant and Environmental Sciences (SPES), Virginia Tech, Blacksburg, VA 24061, USA
| | - Aureliano Bombarely
- School of Plant and Environmental Sciences (SPES), Virginia Tech, Blacksburg, VA 24061, USA
- Department of Life Sciences, University of Milan, Milan 20122, Italy
| | - Song Li
- School of Plant and Environmental Sciences (SPES), Virginia Tech, Blacksburg, VA 24061, USA
- Graduate Program in Genetics, Bioinformatics and Computational Biology (GBCB), Virginia Tech, Blacksburg, VA 24061, USA
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65
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Miniature inverted-repeat transposable elements (MITEs), derived insertional polymorphism as a tool of marker systems for molecular plant breeding. Mol Biol Rep 2020; 47:3155-3167. [PMID: 32162128 DOI: 10.1007/s11033-020-05365-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 02/29/2020] [Indexed: 12/20/2022]
Abstract
Plant molecular breeding is expected to give significant gains in cultivar development through development and utilization of suitable molecular marker systems for genetic diversity analysis, rapid DNA fingerprinting, identification of true hybrids, trait mapping and marker-assisted selection. Transposable elements (TEs) are the most abundant component in a genome and being used as genetic markers in the plant molecular breeding. Here, we review on the high copious transposable element belonging to class-II DNA TEs called "miniature inverted-repeat transposable elements" (MITEs). MITEs are ubiquitous, short and non-autonomous DNA transposable elements which have a tendency to insert into genes and genic regions have paved a way for the development of functional DNA marker systems in plant genomes. This review summarises the characteristics of MITEs, principles and methodologies for development of MITEs based DNA markers, bioinformatics tools and resources for plant MITE discovery and their utilization in crop improvement.
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66
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VanBuren R, Man Wai C, Wang X, Pardo J, Yocca AE, Wang H, Chaluvadi SR, Han G, Bryant D, Edger PP, Messing J, Sorrells ME, Mockler TC, Bennetzen JL, Michael TP. Exceptional subgenome stability and functional divergence in the allotetraploid Ethiopian cereal teff. Nat Commun 2020; 11:884. [PMID: 32060277 PMCID: PMC7021729 DOI: 10.1038/s41467-020-14724-z] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 01/30/2020] [Indexed: 12/22/2022] Open
Abstract
Teff (Eragrostis tef) is a cornerstone of food security in the Horn of Africa, where it is prized for stress resilience, grain nutrition, and market value. Here, we report a chromosome-scale assembly of allotetraploid teff (variety Dabbi) and patterns of subgenome dynamics. The teff genome contains two complete sets of homoeologous chromosomes, with most genes maintaining as syntenic gene pairs. TE analysis allows us to estimate that the teff polyploidy event occurred ~1.1 million years ago (mya) and that the two subgenomes diverged ~5.0 mya. Despite this divergence, we detect no large-scale structural rearrangements, homoeologous exchanges, or biased gene loss, in contrast to many other allopolyploids. The two teff subgenomes have partitioned their ancestral functions based on divergent expression across a diverse expression atlas. Together, these genomic resources will be useful for accelerating breeding of this underutilized grain crop and for fundamental insights into polyploid genome evolution.
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Affiliation(s)
- Robert VanBuren
- Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA.
- Plant Resilience Institute, Michigan State University, East Lansing, MI, 48824, USA.
| | - Ching Man Wai
- Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA
- Plant Resilience Institute, Michigan State University, East Lansing, MI, 48824, USA
| | - Xuewen Wang
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
| | - Jeremy Pardo
- Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA
- Plant Resilience Institute, Michigan State University, East Lansing, MI, 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Alan E Yocca
- Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Hao Wang
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
| | | | - Guomin Han
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
| | - Douglas Bryant
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | - Patrick P Edger
- Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA
| | - Joachim Messing
- Waksman Institute of Microbiology, Rutgers University, Springfield, USA
| | - Mark E Sorrells
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY, USA
| | - Todd C Mockler
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
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Badet T, Oggenfuss U, Abraham L, McDonald BA, Croll D. A 19-isolate reference-quality global pangenome for the fungal wheat pathogen Zymoseptoria tritici. BMC Biol 2020; 18:12. [PMID: 32046716 PMCID: PMC7014611 DOI: 10.1186/s12915-020-0744-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/27/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The gene content of a species largely governs its ecological interactions and adaptive potential. A species is therefore defined by both core genes shared between all individuals and accessory genes segregating presence-absence variation. There is growing evidence that eukaryotes, similar to bacteria, show intra-specific variability in gene content. However, it remains largely unknown how functionally relevant such a pangenome structure is for eukaryotes and what mechanisms underlie the emergence of highly polymorphic genome structures. RESULTS Here, we establish a reference-quality pangenome of a fungal pathogen of wheat based on 19 complete genomes from isolates sampled across six continents. Zymoseptoria tritici causes substantial worldwide losses to wheat production due to rapidly evolved tolerance to fungicides and evasion of host resistance. We performed transcriptome-assisted annotations of each genome to construct a global pangenome. Major chromosomal rearrangements are segregating within the species and underlie extensive gene presence-absence variation. Conserved orthogroups account for only ~ 60% of the species pangenome. Investigating gene functions, we find that the accessory genome is enriched for pathogenesis-related functions and encodes genes involved in metabolite production, host tissue degradation and manipulation of the immune system. De novo transposon annotation of the 19 complete genomes shows that the highly diverse chromosomal structure is tightly associated with transposable element content. Furthermore, transposable element expansions likely underlie recent genome expansions within the species. CONCLUSIONS Taken together, our work establishes a highly complex eukaryotic pangenome providing an unprecedented toolbox to study how pangenome structure impacts crop-pathogen interactions.
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Affiliation(s)
- Thomas Badet
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Ursula Oggenfuss
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Leen Abraham
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Bruce A McDonald
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.
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68
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Badet T, Oggenfuss U, Abraham L, McDonald BA, Croll D. A 19-isolate reference-quality global pangenome for the fungal wheat pathogen Zymoseptoria tritici. BMC Biol 2020; 18:12. [PMID: 32046716 DOI: 10.1101/803098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/27/2020] [Indexed: 05/26/2023] Open
Abstract
BACKGROUND The gene content of a species largely governs its ecological interactions and adaptive potential. A species is therefore defined by both core genes shared between all individuals and accessory genes segregating presence-absence variation. There is growing evidence that eukaryotes, similar to bacteria, show intra-specific variability in gene content. However, it remains largely unknown how functionally relevant such a pangenome structure is for eukaryotes and what mechanisms underlie the emergence of highly polymorphic genome structures. RESULTS Here, we establish a reference-quality pangenome of a fungal pathogen of wheat based on 19 complete genomes from isolates sampled across six continents. Zymoseptoria tritici causes substantial worldwide losses to wheat production due to rapidly evolved tolerance to fungicides and evasion of host resistance. We performed transcriptome-assisted annotations of each genome to construct a global pangenome. Major chromosomal rearrangements are segregating within the species and underlie extensive gene presence-absence variation. Conserved orthogroups account for only ~ 60% of the species pangenome. Investigating gene functions, we find that the accessory genome is enriched for pathogenesis-related functions and encodes genes involved in metabolite production, host tissue degradation and manipulation of the immune system. De novo transposon annotation of the 19 complete genomes shows that the highly diverse chromosomal structure is tightly associated with transposable element content. Furthermore, transposable element expansions likely underlie recent genome expansions within the species. CONCLUSIONS Taken together, our work establishes a highly complex eukaryotic pangenome providing an unprecedented toolbox to study how pangenome structure impacts crop-pathogen interactions.
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Affiliation(s)
- Thomas Badet
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Ursula Oggenfuss
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Leen Abraham
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Bruce A McDonald
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.
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Fouché S, Badet T, Oggenfuss U, Plissonneau C, Francisco CS, Croll D. Stress-Driven Transposable Element De-repression Dynamics and Virulence Evolution in a Fungal Pathogen. Mol Biol Evol 2020; 37:221-239. [PMID: 31553475 DOI: 10.1093/molbev/msz216] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Transposable elements (TEs) are drivers of genome evolution and affect the expression landscape of the host genome. Stress is a major factor inducing TE activity; however, the regulatory mechanisms underlying de-repression are poorly understood. Plant pathogens are excellent models to dissect the impact of stress on TEs. The process of plant infection induces stress for the pathogen, and virulence factors (i.e., effectors) located in TE-rich regions become expressed. To dissect TE de-repression dynamics and contributions to virulence, we analyzed the TE expression landscape of four strains of the major wheat pathogen Zymoseptoria tritici. We experimentally exposed strains to nutrient starvation and host infection stress. Contrary to expectations, we show that the two distinct conditions induce the expression of different sets of TEs. In particular, the most highly expressed TEs, including miniature inverted-repeat transposable element and long terminal repeat-Gypsy element, show highly distinct de-repression across stress conditions. Both the genomic context of TEs and the genetic background stress (i.e., different strains harboring the same TEs) were major predictors of de-repression under stress. Gene expression profiles under stress varied significantly depending on the proximity to the closest TEs and genomic defenses against TEs were largely ineffective to prevent de-repression. Next, we analyzed the locus encoding the Avr3D1 effector. We show that the insertion and subsequent silencing of TEs in close proximity likely contributed to reduced expression and virulence on a specific wheat cultivar. The complexity of TE responsiveness to stress across genetic backgrounds and genomic locations demonstrates substantial intraspecific genetic variation to control TEs with consequences for virulence.
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Affiliation(s)
- Simone Fouché
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland.,Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Thomas Badet
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Ursula Oggenfuss
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Clémence Plissonneau
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland
| | | | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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Ou S, Su W, Liao Y, Chougule K, Agda JRA, Hellinga AJ, Lugo CSB, Elliott TA, Ware D, Peterson T, Jiang N, Hirsch CN, Hufford MB. Benchmarking transposable element annotation methods for creation of a streamlined, comprehensive pipeline. Genome Biol 2019. [PMID: 31843001 DOI: 10.1101/657890v1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023] Open
Abstract
BACKGROUND Sequencing technology and assembly algorithms have matured to the point that high-quality de novo assembly is possible for large, repetitive genomes. Current assemblies traverse transposable elements (TEs) and provide an opportunity for comprehensive annotation of TEs. Numerous methods exist for annotation of each class of TEs, but their relative performances have not been systematically compared. Moreover, a comprehensive pipeline is needed to produce a non-redundant library of TEs for species lacking this resource to generate whole-genome TE annotations. RESULTS We benchmark existing programs based on a carefully curated library of rice TEs. We evaluate the performance of methods annotating long terminal repeat (LTR) retrotransposons, terminal inverted repeat (TIR) transposons, short TIR transposons known as miniature inverted transposable elements (MITEs), and Helitrons. Performance metrics include sensitivity, specificity, accuracy, precision, FDR, and F1. Using the most robust programs, we create a comprehensive pipeline called Extensive de-novo TE Annotator (EDTA) that produces a filtered non-redundant TE library for annotation of structurally intact and fragmented elements. EDTA also deconvolutes nested TE insertions frequently found in highly repetitive genomic regions. Using other model species with curated TE libraries (maize and Drosophila), EDTA is shown to be robust across both plant and animal species. CONCLUSIONS The benchmarking results and pipeline developed here will greatly facilitate TE annotation in eukaryotic genomes. These annotations will promote a much more in-depth understanding of the diversity and evolution of TEs at both intra- and inter-species levels. EDTA is open-source and freely available: https://github.com/oushujun/EDTA.
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Affiliation(s)
- Shujun Ou
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, 50011, USA
| | - Weija Su
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, 50011, USA
| | - Yi Liao
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, 92697, USA
| | - Kapeel Chougule
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Jireh R A Agda
- Centre for Biodiversity Genomics, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Adam J Hellinga
- Centre for Biodiversity Genomics, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | | | - Tyler A Elliott
- Centre for Biodiversity Genomics, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Doreen Ware
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
- USDA-ARS NEA Robert W. Holley Center for Agriculture and Health, Cornell University, Ithaca, NY, 14853, USA
| | - Thomas Peterson
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, 50011, USA
| | - Ning Jiang
- Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA.
| | - Candice N Hirsch
- Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA.
| | - Matthew B Hufford
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, 50011, USA.
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Ou S, Su W, Liao Y, Chougule K, Agda JRA, Hellinga AJ, Lugo CSB, Elliott TA, Ware D, Peterson T, Jiang N, Hirsch CN, Hufford MB. Benchmarking transposable element annotation methods for creation of a streamlined, comprehensive pipeline. Genome Biol 2019; 20:275. [PMID: 31843001 PMCID: PMC6913007 DOI: 10.1186/s13059-019-1905-y] [Citation(s) in RCA: 491] [Impact Index Per Article: 98.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 11/28/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sequencing technology and assembly algorithms have matured to the point that high-quality de novo assembly is possible for large, repetitive genomes. Current assemblies traverse transposable elements (TEs) and provide an opportunity for comprehensive annotation of TEs. Numerous methods exist for annotation of each class of TEs, but their relative performances have not been systematically compared. Moreover, a comprehensive pipeline is needed to produce a non-redundant library of TEs for species lacking this resource to generate whole-genome TE annotations. RESULTS We benchmark existing programs based on a carefully curated library of rice TEs. We evaluate the performance of methods annotating long terminal repeat (LTR) retrotransposons, terminal inverted repeat (TIR) transposons, short TIR transposons known as miniature inverted transposable elements (MITEs), and Helitrons. Performance metrics include sensitivity, specificity, accuracy, precision, FDR, and F1. Using the most robust programs, we create a comprehensive pipeline called Extensive de-novo TE Annotator (EDTA) that produces a filtered non-redundant TE library for annotation of structurally intact and fragmented elements. EDTA also deconvolutes nested TE insertions frequently found in highly repetitive genomic regions. Using other model species with curated TE libraries (maize and Drosophila), EDTA is shown to be robust across both plant and animal species. CONCLUSIONS The benchmarking results and pipeline developed here will greatly facilitate TE annotation in eukaryotic genomes. These annotations will promote a much more in-depth understanding of the diversity and evolution of TEs at both intra- and inter-species levels. EDTA is open-source and freely available: https://github.com/oushujun/EDTA.
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Affiliation(s)
- Shujun Ou
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011 USA
| | - Weija Su
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA 50011 USA
| | - Yi Liao
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697 USA
| | - Kapeel Chougule
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724 USA
| | - Jireh R. A. Agda
- Centre for Biodiversity Genomics, University of Guelph, Guelph, Ontario N1G 2W1 Canada
| | - Adam J. Hellinga
- Centre for Biodiversity Genomics, University of Guelph, Guelph, Ontario N1G 2W1 Canada
| | | | - Tyler A. Elliott
- Centre for Biodiversity Genomics, University of Guelph, Guelph, Ontario N1G 2W1 Canada
| | - Doreen Ware
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724 USA
- USDA-ARS NEA Robert W. Holley Center for Agriculture and Health, Cornell University, Ithaca, NY 14853 USA
| | - Thomas Peterson
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA 50011 USA
| | - Ning Jiang
- Department of Horticulture, Michigan State University, East Lansing, MI 48824 USA
| | - Candice N. Hirsch
- Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN 55108 USA
| | - Matthew B. Hufford
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011 USA
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Southworth J, Grace CA, Marron AO, Fatima N, Carr M. A genomic survey of transposable elements in the choanoflagellate Salpingoeca rosetta reveals selection on codon usage. Mob DNA 2019; 10:44. [PMID: 31788034 PMCID: PMC6875170 DOI: 10.1186/s13100-019-0189-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 11/13/2019] [Indexed: 12/04/2022] Open
Abstract
Background Unicellular species make up the majority of eukaryotic diversity, however most studies on transposable elements (TEs) have centred on multicellular host species. Such studies may have therefore provided a limited picture of how transposable elements evolve across eukaryotes. The choanoflagellates, as the sister group to Metazoa, are an important study group for investigating unicellular to multicellular transitions. A previous survey of the choanoflagellate Monosiga brevicollis revealed the presence of only three families of LTR retrotransposons, all of which appeared to be active. Salpingoeca rosetta is the second choanoflagellate to have its whole genome sequenced and provides further insight into the evolution and population biology of transposable elements in the closest relative of metazoans. Results Screening the genome revealed the presence of a minimum of 20 TE families. Seven of the annotated families are DNA transposons and the remaining 13 families are LTR retrotransposons. Evidence for two putative non-LTR retrotransposons was also uncovered, but full-length sequences could not be determined. Superfamily phylogenetic trees indicate that vertical inheritance and, in the case of one family, horizontal transfer have been involved in the evolution of the choanoflagellates TEs. Phylogenetic analyses of individual families highlight recent element activity in the genome, however six families did not show evidence of current transposition. The majority of families possess young insertions and the expression levels of TE genes vary by four orders of magnitude across families. In contrast to previous studies on TEs, the families present in S. rosetta show the signature of selection on codon usage, with families favouring codons that are adapted to the host translational machinery. Selection is stronger in LTR retrotransposons than DNA transposons, with highly expressed families showing stronger codon usage bias. Mutation pressure towards guanosine and cytosine also appears to contribute to TE codon usage. Conclusions S. rosetta increases the known diversity of choanoflagellate TEs and the complement further highlights the role of horizontal gene transfer from prey species in choanoflagellate genome evolution. Unlike previously studied TEs, the S. rosetta families show evidence for selection on their codon usage, which is shown to act via translational efficiency and translational accuracy.
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Affiliation(s)
- Jade Southworth
- 1Department of Biological & Geographical Sciences, University of Huddersfield, Huddersfield, HD1 3DH UK
| | - C Alastair Grace
- 1Department of Biological & Geographical Sciences, University of Huddersfield, Huddersfield, HD1 3DH UK
| | - Alan O Marron
- 2Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA UK
| | - Nazeefa Fatima
- 3Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Martin Carr
- 1Department of Biological & Geographical Sciences, University of Huddersfield, Huddersfield, HD1 3DH UK
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73
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Nguinkal JA, Brunner RM, Verleih M, Rebl A, de Los Ríos-Pérez L, Schäfer N, Hadlich F, Stüeken M, Wittenburg D, Goldammer T. The First Highly Contiguous Genome Assembly of Pikeperch ( Sander lucioperca), an Emerging Aquaculture Species in Europe. Genes (Basel) 2019; 10:E708. [PMID: 31540274 PMCID: PMC6770990 DOI: 10.3390/genes10090708] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/27/2019] [Accepted: 09/08/2019] [Indexed: 01/14/2023] Open
Abstract
The pikeperch (Sander lucioperca) is a fresh and brackish water Percid fish natively inhabiting the northern hemisphere. This species is emerging as a promising candidate for intensive aquaculture production in Europe. Specific traits like cannibalism, growth rate and meat quality require genomics based understanding, for an optimal husbandry and domestication process. Still, the aquaculture community is lacking an annotated genome sequence to facilitate genome-wide studies on pikeperch. Here, we report the first highly contiguous draft genome assembly of Sander lucioperca. In total, 413 and 66 giga base pairs of DNA sequencing raw data were generated with the Illumina platform and PacBio Sequel System, respectively. The PacBio data were assembled into a final assembly size of ~900 Mb covering 89% of the 1,014 Mb estimated genome size. The draft genome consisted of 1966 contigs ordered into 1,313 scaffolds. The contig and scaffold N50 lengths are 3.0 Mb and 4.9 Mb, respectively. The identified repetitive structures accounted for 39% of the genome. We utilized homologies to other ray-finned fishes, and ab initio gene prediction methods to predict 21,249 protein-coding genes in the Sander lucioperca genome, of which 88% were functionally annotated by either sequence homology or protein domains and signatures search. The assembled genome spans 97.6% and 96.3% of Vertebrate and Actinopterygii single-copy orthologs, respectively. The outstanding mapping rate (99.9%) of genomic PE-reads on the assembly suggests an accurate and nearly complete genome reconstruction. This draft genome sequence is the first genomic resource for this promising aquaculture species. It will provide an impetus for genomic-based breeding studies targeting phenotypic and performance traits of captive pikeperch.
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Affiliation(s)
- Julien Alban Nguinkal
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
| | - Ronald Marco Brunner
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
| | - Marieke Verleih
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
| | - Alexander Rebl
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
| | - Lidia de Los Ríos-Pérez
- Institute of Genetics and Biometry, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
| | - Nadine Schäfer
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
| | - Frieder Hadlich
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
| | - Marcus Stüeken
- State Research Center of Agriculture and Fisheries M-V, 17194 Hohen Wangelin, Germany.
| | - Dörte Wittenburg
- Institute of Genetics and Biometry, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
| | - Tom Goldammer
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
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Valencia JD, Girgis HZ. LtrDetector: A tool-suite for detecting long terminal repeat retrotransposons de-novo. BMC Genomics 2019; 20:450. [PMID: 31159720 PMCID: PMC6547461 DOI: 10.1186/s12864-019-5796-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 05/14/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Long terminal repeat retrotransposons are the most abundant transposons in plants. They play important roles in alternative splicing, recombination, gene regulation, and defense mechanisms. Large-scale sequencing projects for plant genomes are currently underway. Software tools are important for annotating long terminal repeat retrotransposons in these newly available genomes. However, the available tools are not very sensitive to known elements and perform inconsistently on different genomes. Some are hard to install or obsolete. They may struggle to process large plant genomes. None can be executed in parallel out of the box and very few have features to support visual review of new elements. To overcome these limitations, we developed LtrDetector, which uses techniques inspired by signal-processing. RESULTS We compared LtrDetector to LTR_Finder and LTRharvest, the two most successful predecessor tools, on six plant genomes. For each organism, we constructed a ground truth data set based on queries from a consensus sequence database. According to this evaluation, LtrDetector was the most sensitive tool, achieving 16-23% improvement in sensitivity over LTRharvest and 21% improvement over LTR_Finder. All three tools had low false positive rates, with LtrDetector achieving 98.2% precision, in between its two competitors. Overall, LtrDetector provides the best compromise between high sensitivity and low false positive rate while requiring moderate time and utilizing memory available on personal computers. CONCLUSIONS LtrDetector uses a novel methodology revolving around k-mer distributions, which allows it to produce high-quality results using relatively lightweight procedures. It is easy to install and use. It is not species specific, performing well using its default parameters on genomes of varying size and repeat content. It is automatically configured for parallel execution and runs efficiently on an ordinary personal computer. It includes a k-mer scores visualization tool to facilitate manual review of the identified elements. These features make LtrDetector an attractive tool for future annotation projects involving long terminal repeat retrotransposons.
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Affiliation(s)
- Joseph D Valencia
- The Bioinformatics Toolsmith Laboratory, Tandy School of Computer Science, University of Tulsa, 800 South Tucker Drive, Tulsa, 74104, OK, USA
| | - Hani Z Girgis
- The Bioinformatics Toolsmith Laboratory, Tandy School of Computer Science, University of Tulsa, 800 South Tucker Drive, Tulsa, 74104, OK, USA.
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