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Majid M, Khan H, Liu X, Shaheer M, Huang Y. Evolutionary Dynamics of Satellite DNA Repeats across the Tettigoniidae Family: Insights from Genomic Analysis. Biomolecules 2024; 14:915. [PMID: 39199303 DOI: 10.3390/biom14080915] [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: 05/17/2024] [Revised: 07/23/2024] [Accepted: 07/26/2024] [Indexed: 09/01/2024] Open
Abstract
Satellite DNA repeats are repetitive DNA sequences found in eukaryotic genomes, typically consisting of short DNA motifs repeated in tandem arrays. Despite the vast body of literature on satellite DNA repeats in other taxa, investigations specifically targeting Tettigoniidae remain conspicuously absent. Our study aims to fill a critical gap in our understanding of satellitome evolutionary processes shaping Tettigoniidae genomes. Repeatome analysis revealed that the Meconema thalassinum genome comprises 92%, and Phryganogryllacris superangulata had the lowest value of 34%, with an average of 67% in other Tettigoniidae species. The analysis reveals significant variation in the number of satellite DNA repeats across species of the Tettigoniidae family, with M. thalassinum exhibiting the highest count, 246, reported in insects to date and the lowest count, 10, in Pholidoptera griseoptera. Ruspolia dubia and Ruspolia yunnana, which are congeneric species, showcase distinct counts of 104 and 84 families, respectively. Satellite DNA repeats in R. dubia exhibit the highest abundance, constituting 17.2% of the total genome, while the lowest abundance was reported in P. griseoptera, at 5.65%. The genome size correlates weakly with the satellite DNA family count (rs = 0.42, p = 0.29), but a strong correlation exists between satellite abundance and family number (rs = 0.73, p = 0.03). Moreover, the analysis of satellite DNA gain and loss patterns provides insights into the amplification and homogenization of satellite DNA families within the genome, with species-specific repeats exhibiting a positive trend toward amplification. The chromosomal distribution in M. thalassinum displayed that the highest accumulation was observed on Chr12, Chr01, and Chr04, constituting 17.79%, 17.4%, and 17.22% of the total chromosome size, respectively. The chromosome-specific propagation of satellite DNA families was evident, with MthSat01 solely on chromosome 1 and MthSat170 on chromosome 2, sharing 1.64% and 2.33%. The observed conservation and variations in satellite DNA number and abundances, along with distinct patterns of gain and loss, indicate the influence of potentially diverse evolutionary processes shaping the genomic landscape of these insects, which requires further investigation. Furthermore, the differential accumulation of satellite DNA on specific chromosomes implies that potential chromosome-specific functions or structural features influence the retention and proliferation of satellite sequences.
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Affiliation(s)
- Muhammad Majid
- College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
| | - Hashim Khan
- College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
| | - Xuanzeng Liu
- College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
| | - Muhammad Shaheer
- Department of Entomology, MNS Agriculture University, Multan 66000, Pakistan
| | - Yuan Huang
- College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
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Nie Y, Liu X, Zhao L, Huang Y. Repetitive element expansions contribute to genome size gigantism in Pamphagidae: A comparative study (Orthoptera, Acridoidea). Genomics 2024; 116:110896. [PMID: 39025318 DOI: 10.1016/j.ygeno.2024.110896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 07/10/2024] [Accepted: 07/15/2024] [Indexed: 07/20/2024]
Abstract
Pamphagidae is a family of Acridoidea that inhabits the desert steppes of Eurasia and Africa. This study employed flow cytometry to estimate the genome size of eight species in the Pamphagidae. The results indicate that the genome size of the eight species ranged from 13.88 pg to 14.66 pg, with an average of 14.26 pg. This is the largest average genome size recorded for the Orthoptera families, as well as for the entire Insecta. Furthermore, the study explored the role of repetitive sequences in the genome, including their evolutionary dynamics and activity, using low-coverage next-generation sequencing data. The genome is composed of 14 different types of repetitive sequences, which collectively make up between 59.9% and 68.17% of the total genome. The Pamphagidae family displays high levels of transposable element (TE) activity, with the number of TEs increasing and accumulating since the family's emergence. The study found that the types of repetitive sequences contributing to the TE outburst events are similar across species. Additionally, the study identified unique repetitive elements for each species. The differences in repetitive sequences among the eight Pamphagidae species correspond to their phylogenetic relationships. The study sheds new light on genome gigantism in the Pamphagidae and provides insight into the correlation between genome size and repetitive sequences within the family.
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Affiliation(s)
- Yimeng Nie
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Xuanzeng Liu
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Lina Zhao
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Yuan Huang
- College of Life Sciences, Shaanxi Normal University, Xi'an, China.
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Khan H, Yuan H, Liu X, Nie Y, Majid M. Comprehensive analysis of the Xya riparia genome uncovers the dominance of DNA transposons, LTR/Gypsy elements, and their evolutionary dynamics. BMC Genomics 2024; 25:687. [PMID: 38997681 PMCID: PMC11245825 DOI: 10.1186/s12864-024-10596-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 07/04/2024] [Indexed: 07/14/2024] Open
Abstract
Transposable elements (TEs) are DNA sequences that can move or replicate within a genome, and their study has become increasingly important in understanding genome evolution and function. The Tridactylidae family, including Xya riparia (pygmy mole cricket), harbors a variety of transposable elements (TEs) that have been insufficiently investigated. Further research is required to fully understand their diversity and evolutionary characteristics. Hence, we conducted a comprehensive repeatome analysis of X. riparia species using the chromosome-level assembled genome. The study aimed to comprehensively analyze the abundance, distribution, and age of transposable elements (TEs) in the genome. The results indicated that the genome was 1.67 Gb, with 731.63 Mb of repetitive sequences, comprising 27% of Class II (443.25 Mb), 16% of Class I (268.45 Mb), and 1% of unknown TEs (19.92 Mb). The study found that DNA transposons dominate the genome, accounting for approximately 60% of the total repeat size, with retrotransposons and unknown elements accounting for 37% and 3% of the genome, respectively. The members of the Gypsy superfamily were the most abundant amongst retrotransposons, accounting for 63% of them. The transposable superfamilies (LTR/Gypsy, DNA/nMITE, DNA/hAT, and DNA/Helitron) collectively constituted almost 70% of the total repeat size of all six chromosomes. The study further unveiled a significant linear correlation (Pearson correlation: r = 0.99, p-value = 0.00003) between the size of the chromosomes and the repetitive sequences. The average age of DNA transposon and retrotransposon insertions ranges from 25 My (million years) to 5 My. The satellitome analysis discovered 13 satellite DNA families that comprise about 0.15% of the entire genome. In addition, the transcriptional analysis of TEs found that DNA transposons were more transcriptionally active than retrotransposons. Overall, the study suggests that the genome of X. riparia is complex, characterized by a substantial portion of repetitive elements. These findings not only enhance our understanding of TE evolution within the Tridactylidae family but also provide a foundation for future investigations into the genomic intricacies of related species.
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Affiliation(s)
- Hashim Khan
- College of Life Sciences, Shaanxi Normal University, Xian, China
| | - Huang Yuan
- College of Life Sciences, Shaanxi Normal University, Xian, China
| | - Xuanzeng Liu
- College of Life Sciences, Shaanxi Normal University, Xian, China
| | - Yimeng Nie
- College of Life Sciences, Shaanxi Normal University, Xian, China
| | - Muhammad Majid
- College of Life Sciences, Shaanxi Normal University, Xian, China.
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Fourreau CJL, Kise H, Santander MD, Pirro S, Maronna MM, Poliseno A, Santos ME, Reimer JD. Genome sizes and repeatome evolution in zoantharians (Cnidaria: Hexacorallia: Zoantharia). PeerJ 2023; 11:e16188. [PMID: 37868064 PMCID: PMC10586311 DOI: 10.7717/peerj.16188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 09/06/2023] [Indexed: 10/24/2023] Open
Abstract
Across eukaryotes, large variations of genome sizes have been observed even between closely related species. Transposable elements as part of the repeated DNA have been proposed and confirmed as one of the most important contributors to genome size variation. However, the evolutionary implications of genome size variation and transposable element dynamics are not well understood. Together with phenotypic traits, they are commonly referred to as the "C-value enigma". The order Zoantharia are benthic cnidarians found from intertidal zones to the deep sea, and some species are particularly abundant in coral reefs. Despite their high ecological relevance, zoantharians have yet to be largely studied from the genomic point of view. This study aims at investigating the role of the repeatome (total content of repeated elements) in genome size variations across the order Zoantharia. To this end, whole-genomes of 32 zoantharian species representing five families were sequenced. Genome sizes were estimated and the abundances of different repeat classes were assessed. In addition, the repeat overlap between species was assessed by a sequence clustering method. The genome sizes in the dataset varied up to 2.4 fold magnitude. Significant correlations between genome size, repeated DNA content and transposable elements, respectively (Pearson's correlation test R2 = 0.47, p = 0.0016; R2 = 0.22, p = 0.05) were found, suggesting their involvement in the dynamics of genome expansion and reduction. In all species, long interspersed nuclear elements and DNA transposons were the most abundant identified elements. These transposable elements also appeared to have had a recent expansion event. This was in contrast to the comparative clustering analysis which revealed species-specific patterns of satellite elements' amplification. In summary, the genome sizes of zoantharians likely result from the complex dynamics of repeated elements. Finally, the majority of repeated elements (up to 70%) could not be annotated to a known repeat class, highlighting the need to further investigate non-model cnidarian genomes. More research is needed to understand how repeated DNA dynamics relate to zoantharian evolution and their biology.
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Affiliation(s)
- Chloé Julie Loïs Fourreau
- Molecular Invertebrate Systematics and Ecology (MISE) Lab, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Hiroki Kise
- Molecular Invertebrate Systematics and Ecology (MISE) Lab, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa, Japan
- AIST Tsukuba Central, Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan
| | - Mylena Daiana Santander
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Stacy Pirro
- Iridian Genomes, Bethesda, United States of America
| | - Maximiliano M. Maronna
- Molecular Invertebrate Systematics and Ecology (MISE) Lab, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa, Japan
- Faculdade de Ciências, Universidade Estadual Paulista (UNESP), Bauru, Brazil
| | - Angelo Poliseno
- Molecular Invertebrate Systematics and Ecology (MISE) Lab, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Maria E.A. Santos
- Molecular Invertebrate Systematics and Ecology (MISE) Lab, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa, Japan
- Okinawa Institute of Science and Technology, Onna, Okinawa, Japan
| | - James Davis Reimer
- Molecular Invertebrate Systematics and Ecology (MISE) Lab, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa, Japan
- Tropical Biosphere Research Center, University of the Ryukyus, Nishihara, Okinawa, United States of America
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Shin NR, Okamura Y, Kirsch R, Pauchet Y. Genome sequencing provides insights into the evolution of gene families encoding plant cell wall-degrading enzymes in longhorned beetles. INSECT MOLECULAR BIOLOGY 2023; 32:469-483. [PMID: 37119017 DOI: 10.1111/imb.12844] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 04/17/2023] [Indexed: 06/19/2023]
Abstract
With more than 36,000 species, the longhorned beetles (family Cerambycidae) are a mega-diverse lineage of mostly xylophagous insects, all of which are represented by the sole sequenced genome of the Asian longhorned beetle (Anoplophora glabripennis; Lamiinae). Their successful radiation has been linked to their ability to degrade plant cell wall components using a range of so-called plant cell wall-degrading enzymes (PCWDEs). Our previous analysis of larval gut transcriptomes demonstrated that cerambycid beetles horizontally acquired genes encoding PCWDEs from various microbial donors; these genes evolved through multiple duplication events to form gene families. To gain further insights into the evolution of these gene families during the Cerambycidae radiation, we assembled draft genomes for four beetle species belonging to three subfamilies using long-read nanopore sequencing. All the PCWDE-encoding genes we annotated from the corresponding larval gut transcriptomes were present in these draft genomes. We confirmed that the newly discovered horizontally acquired glycoside hydrolase family 7 (GH7), subfamily 26 of GH43 (GH43_26), and GH53 (all of which are absent from the A. glabripennis genome) were indeed encoded by these beetles' genome. Most of the PCWDE-encoding genes of bacterial origin gained introns after their transfer into the beetle genome. Altogether, we show that draft genome assemblies generated from nanopore long-reads offer meaningful information to the study of the evolution of gene families in insects. We anticipate that our data will support studies aiming to better understand the biology of the Cerambycidae and other beetles in general.
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Affiliation(s)
- Na Ra Shin
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Yu Okamura
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Roy Kirsch
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Yannick Pauchet
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany
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Abalde S, Tellgren-Roth C, Heintz J, Vinnere Pettersson O, Jondelius U. The draft genome of the microscopic Nemertoderma westbladi sheds light on the evolution of Acoelomorpha genomes. Front Genet 2023; 14:1244493. [PMID: 37829276 PMCID: PMC10565955 DOI: 10.3389/fgene.2023.1244493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/12/2023] [Indexed: 10/14/2023] Open
Abstract
Background: Xenacoelomorpha is a marine clade of microscopic worms that is an important model system for understanding the evolution of key bilaterian novelties, such as the excretory system. Nevertheless, Xenacoelomorpha genomics has been restricted to a few species that either can be cultured in the lab or are centimetres long. Thus far, no genomes are available for Nemertodermatida, one of the group's main clades and whose origin has been dated more than 400 million years ago. Methods: DNA was extracted from a single specimen and sequenced with HiFi following the PacBio Ultra-Low DNA Input protocol. After genome assembly, decontamination, and annotation, the genome quality was benchmarked using two acoel genomes and one Illumina genome as reference. The gene content of three cnidarians, three acoelomorphs, four deuterostomes, and eight protostomes was clustered in orthogroups to make inferences of gene content evolution. Finally, we focused on the genes related to the ultrafiltration excretory system to compare patterns of presence/absence and gene architecture among these clades. Results: We present the first nemertodermatid genome sequenced from a single specimen of Nemertoderma westbladi. Although genome contiguity remains challenging (N50: 60 kb), it is very complete (BUSCO: 80.2%, Metazoa; 88.6%, Eukaryota) and the quality of the annotation allows fine-detail analyses of genome evolution. Acoelomorph genomes seem to be relatively conserved in terms of the percentage of repeats, number of genes, number of exons per gene and intron size. In addition, a high fraction of genes present in both protostomes and deuterostomes are absent in Acoelomorpha. Interestingly, we show that all genes related to the excretory system are present in Xenacoelomorpha except Osr, a key element in the development of these organs and whose acquisition seems to be interconnected with the origin of the specialised excretory system. Conclusion: Overall, these analyses highlight the potential of the Ultra-Low Input DNA protocol and HiFi to generate high-quality genomes from single animals, even for relatively large genomes, making it a feasible option for sequencing challenging taxa, which will be an exciting resource for comparative genomics analyses.
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Affiliation(s)
- Samuel Abalde
- Department of Zoology, Swedish Museum of Natural History, Stockholm, Sweden
| | - Christian Tellgren-Roth
- Department of Immunology, Genetics and Pathology, SciLifeLab, Uppsala University, Uppsala, Sweden
| | - Julia Heintz
- Department of Immunology, Genetics and Pathology, SciLifeLab, Uppsala University, Uppsala, Sweden
| | - Olga Vinnere Pettersson
- Department of Immunology, Genetics and Pathology, SciLifeLab, Uppsala University, Uppsala, Sweden
| | - Ulf Jondelius
- Department of Zoology, Swedish Museum of Natural History, Stockholm, Sweden
- Department of Zoology, Stockholm University, Stockholm, Sweden
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Hundsdoerfer AK, Schell T, Patzold F, Wright CJ, Yoshido A, Marec F, Daneck H, Winkler S, Greve C, Podsiadlowski L, Hiller M, Pippel M. High-quality haploid genomes corroborate 29 chromosomes and highly conserved synteny of genes in Hyles hawkmoths (Lepidoptera: Sphingidae). BMC Genomics 2023; 24:443. [PMID: 37550607 PMCID: PMC10405479 DOI: 10.1186/s12864-023-09506-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 07/05/2023] [Indexed: 08/09/2023] Open
Abstract
BACKGROUND Morphological and traditional genetic studies of the young Pliocene genus Hyles have led to the understanding that despite its importance for taxonomy, phenotypic similarity of wing patterns does not correlate with phylogenetic relationship. To gain insights into various aspects of speciation in the Spurge Hawkmoth (Hyles euphorbiae), we assembled a chromosome-level genome and investigated some of its characteristics. RESULTS The genome of a male H. euphorbiae was sequenced using PacBio and Hi-C data, yielding a 504 Mb assembly (scaffold N50 of 18.2 Mb) with 99.9% of data represented by the 29 largest scaffolds forming the haploid chromosome set. Consistent with this, FISH analysis of the karyotype revealed n = 29 chromosomes and a WZ/ZZ (female/male) sex chromosome system. Estimates of chromosome length based on the karyotype image provided an additional quality metric of assembled chromosome size. Rescaffolding the published male H. vespertilio genome resulted in a high-quality assembly (651 Mb, scaffold N50 of 22 Mb) with 98% of sequence data in the 29 chromosomes. The larger genome size of H. vespertilio (average 1C DNA value of 562 Mb) was accompanied by a proportional increase in repeats from 45% in H. euphorbiae (measured as 472 Mb) to almost 55% in H. vespertilio. Several wing pattern genes were found on the same chromosomes in the two species, with varying amounts and positions of repetitive elements and inversions possibly corrupting their function. CONCLUSIONS Our two-fold comparative genomics approach revealed high gene synteny of the Hyles genomes to other Sphingidae and high correspondence to intact Merian elements, the ancestral linkage groups of Lepidoptera, with the exception of three simple fusion events. We propose a standardized approach for genome taxonomy using nucleotide homology via scaffold chaining as the primary tool combined with Oxford plots based on Merian elements to infer and visualize directionality of chromosomal rearrangements. The identification of wing pattern genes promises future understanding of the evolution of forewing patterns in the genus Hyles, although further sequencing data from more individuals are needed. The genomic data obtained provide additional reliable references for further comparative studies in hawkmoths (Sphingidae).
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Affiliation(s)
- Anna K Hundsdoerfer
- Senckenberg Natural History Collections Dresden, Königsbrücker Landstr. 159, 01109, Dresden, Germany.
| | - Tilman Schell
- LOEWE-Centre for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt Am Main, Germany
| | - Franziska Patzold
- Senckenberg Natural History Collections Dresden, Königsbrücker Landstr. 159, 01109, Dresden, Germany
| | | | - Atsuo Yoshido
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - František Marec
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Hana Daneck
- Senckenberg Natural History Collections Dresden, Königsbrücker Landstr. 159, 01109, Dresden, Germany
| | - Sylke Winkler
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307, Dresden, Germany
| | - Carola Greve
- LOEWE-Centre for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt Am Main, Germany
| | - Lars Podsiadlowski
- Centre for Molecular Biodiversity Research, Leibniz Institute for the Analysis of Biodiversity Change, Adenauerallee 127, 53113, Bonn, Germany
| | - Michael Hiller
- LOEWE-Centre for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt Am Main, Germany
| | - Martin Pippel
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307, Dresden, Germany
- Center for Systems Biology Dresden, Pfotenhauerstr. 108, 01307, Dresden, Germany
- Department of Cell and Molecular Biology, Uppsala University, Husargatan 3, Uppsala, 751 23, Sweden
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Šatović-Vukšić E, Plohl M. Satellite DNAs-From Localized to Highly Dispersed Genome Components. Genes (Basel) 2023; 14:genes14030742. [PMID: 36981013 PMCID: PMC10048060 DOI: 10.3390/genes14030742] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/15/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
According to the established classical view, satellite DNAs are defined as abundant non-coding DNA sequences repeated in tandem that build long arrays located in heterochromatin. Advances in sequencing methodologies and development of specialized bioinformatics tools enabled defining a collection of all repetitive DNAs and satellite DNAs in a genome, the repeatome and the satellitome, respectively, as well as their reliable annotation on sequenced genomes. Supported by various non-model species included in recent studies, the patterns of satellite DNAs and satellitomes as a whole showed much more diversity and complexity than initially thought. Differences are not only in number and abundance of satellite DNAs but also in their distribution across the genome, array length, interspersion patterns, association with transposable elements, localization in heterochromatin and/or in euchromatin. In this review, we compare characteristic organizational features of satellite DNAs and satellitomes across different animal and plant species in order to summarize organizational forms and evolutionary processes that may lead to satellitomes' diversity and revisit some basic notions regarding repetitive DNA landscapes in genomes.
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Affiliation(s)
- Eva Šatović-Vukšić
- Division of Molecular Biology, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Miroslav Plohl
- Division of Molecular Biology, Ruđer Bošković Institute, 10000 Zagreb, Croatia
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Lu W, Ma S, Sun L, Zhang T, Wang X, Feng M, Wang A, Shi R, Jia L, Xia Q. Combined CRISPR toolkits reveal the domestication landscape and function of the ultra-long and highly repetitive silk genes. Acta Biomater 2023; 158:190-202. [PMID: 36603730 DOI: 10.1016/j.actbio.2022.12.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 12/23/2022] [Accepted: 12/27/2022] [Indexed: 01/04/2023]
Abstract
Highly repetitive sequences play a major structural and function role in the genome. In the present study, we developed Cas9-assisted cloning and SMRT sequencing of long repetitive sequences (CACS) to sequence and manipulate highly repetitive genes from eukaryotic genomes. CACS combined Cas9-mediated cleavage of a target segment from an intact genome, Gibson assembly cloning, and PacBio SMRT sequencing. Applying CACS, we directly cloned and sequenced the complete sequences of fibroin heavy chain (FibH) genes from 17 domesticated (Bombyx mori) and 7 wild (Bombyx mandarina) silkworms. Our analysis revealed the unique fine structure organization, genetic variations, and domestication dynamics of FibH. We also demonstrated that the length of the repetitive regions determined the mechanical properties of silk fiber, which was further confirmed by Cas9 editing of FibH. CACS is a simple, robust, and efficient approach, providing affordable accessibility to highly repetitive regions of a genome. STATEMENT OF SIGNIFICANCE: Silkworm silk is the earliest and most widely used animal fiber, and its excellent performance mainly depends on the fibroin heavy chain (FibH) protein. The FibH gene is the main breakthrough in understanding the formation mechanism and improvement of silk fiber. In the study, we developed a CACS method for characterizing the fine structure and domestication landscape of 24 silkworm FibH genes. We used CRISPR/Cas9 to edit the repetitive sequence of FibH genes, revealing the relationship between FibH genes and mechanical properties of silkworm silk. Our study is helpful in modifying silk genes to manipulate other valuable highly repetitive sequences, and provides insight for silkworm breeding.
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Affiliation(s)
- Wei Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Biological Science Research Center, Southwest University, Chongqing 400715, China
| | - Sanyuan Ma
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Biological Science Research Center, Southwest University, Chongqing 400715, China.
| | - Le Sun
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Biological Science Research Center, Southwest University, Chongqing 400715, China
| | - Tong Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Biological Science Research Center, Southwest University, Chongqing 400715, China
| | - Xiaogang Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Biological Science Research Center, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory of Chinese Medicine & Health Science, Chongqing Academy of Chinese Materia Medica, Chongqing 400065, China
| | - Min Feng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China
| | - Aoming Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Biological Science Research Center, Southwest University, Chongqing 400715, China
| | - Run Shi
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Biological Science Research Center, Southwest University, Chongqing 400715, China
| | - Ling Jia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Biological Science Research Center, Southwest University, Chongqing 400715, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Biological Science Research Center, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory of Sericulture, Southwest University, Chongqing 400715, China.
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Abstract
The detection and quantification of transposable elements (TE) are notoriously challenging despite their relevance in evolutionary genomics and molecular ecology. The main hurdle is caused by the dependence of numerous tools on genome assemblies, whose level of completion directly affects the comparability of the results across species or populations. dnaPipeTE, whose use is demonstrated here, tackles this issue by directly performing TE detection, classification, and quantification from unassembled short reads. This chapter details all the required steps to perform a comparative analysis of the TE content between two related species, starting from the installation of a recently containerized version of the program to the post-processing of the outputs.
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Affiliation(s)
- Clément Goubert
- Canadian Centre for Computational Genomics, McGill University, Montreal, QC, Canada.
- McGill Genome Centre, Montreal, QC, Canada.
- Human Genetics, McGill University, Montreal, QC, Canada.
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11
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Hawlitschek O, Sadílek D, Dey LS, Buchholz K, Noori S, Baez IL, Wehrt T, Brozio J, Trávníček P, Seidel M, Husemann M. New estimates of genome size in Orthoptera and their evolutionary implications. PLoS One 2023; 18:e0275551. [PMID: 36920952 PMCID: PMC10016648 DOI: 10.1371/journal.pone.0275551] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 02/24/2023] [Indexed: 03/16/2023] Open
Abstract
Animal genomes vary widely in size, and much of their architecture and content remains poorly understood. Even among related groups, such as orders of insects, genomes may vary in size by orders of magnitude-for reasons unknown. The largest known insect genomes were repeatedly found in Orthoptera, e.g., Podisma pedestris (1C = 16.93 pg), Stethophyma grossum (1C = 18.48 pg) and Bryodemella holdereri (1C = 18.64 pg). While all these species belong to the suborder of Caelifera, the ensiferan Deracantha onos (1C = 19.60 pg) was recently found to have the largest genome. Here, we present new genome size estimates of 50 further species of Ensifera (superfamilies Gryllidea, Tettigoniidea) and Caelifera (Acrididae, Tetrigidae) based on flow cytometric measurements. We found that Bryodemella tuberculata (Caelifera: Acrididae) has the so far largest measured genome of all insects with 1C = 21.96 pg (21.48 gBp). Species of Orthoptera with 2n = 16 and 2n = 22 chromosomes have significantly larger genomes than species with other chromosome counts. Gryllidea genomes vary between 1C = 0.95 and 2.88 pg, and Tetrigidae between 1C = 2.18 and 2.41, while the genomes of all other studied Orthoptera range in size from 1C = 1.37 to 21.96 pg. Reconstructing ancestral genome sizes based on a phylogenetic tree of mitochondrial genomic data, we found genome size values of >15.84 pg only for the nodes of Bryodemella holdereri / B. tuberculata and Chrysochraon dispar / Euthystira brachyptera. The predicted values of ancestral genome sizes are 6.19 pg for Orthoptera, 5.37 pg for Ensifera, and 7.28 pg for Caelifera. The reasons for the large genomes in Orthoptera remain largely unknown, but a duplication or polyploidization seems unlikely as chromosome numbers do not differ much. Sequence-based genomic studies may shed light on the underlying evolutionary mechanisms.
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Affiliation(s)
- Oliver Hawlitschek
- Leibniz Institute for the Analysis of Biodiversity Change (LIB), Museum of Nature, Hamburg, Germany
- * E-mail:
| | - David Sadílek
- Institute of Medical Biochemistry and Laboratory Diagnostics, Centre of Oncocytogenomics, General University Hospital in Prague, Prague, Czech Republic
| | - Lara-Sophie Dey
- Leibniz Institute for the Analysis of Biodiversity Change (LIB), Museum of Nature, Hamburg, Germany
| | - Katharina Buchholz
- Leibniz Institute for the Analysis of Biodiversity Change (LIB), Museum of Nature, Hamburg, Germany
- Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Sajad Noori
- Leibniz Institute for the Analysis of Biodiversity Change (LIB), Museum of Nature, Hamburg, Germany
- Staatliches Museum für Naturkunde Stuttgart, Stuttgart, Germany
| | - Inci Livia Baez
- Leibniz Institute for the Analysis of Biodiversity Change (LIB), Museum of Nature, Hamburg, Germany
- Leibniz Institute for the Analysis of Biodiversity Change (LIB), Museum Koenig, Bonn, Germany
| | - Timo Wehrt
- Leibniz Institute for the Analysis of Biodiversity Change (LIB), Museum of Nature, Hamburg, Germany
| | - Jason Brozio
- Zoologische Staatssammlung München (ZSM-SNSB), München, Germany
| | - Pavel Trávníček
- Czech Academy of Sciences, Institute of Botany, Průhonice, Czech Republic
| | | | - Martin Husemann
- Leibniz Institute for the Analysis of Biodiversity Change (LIB), Museum of Nature, Hamburg, Germany
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12
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Cong Y, Ye X, Mei Y, He K, Li F. Transposons and Non-coding Regions Drive the Intrafamily Differences of Genome Size in Insects. iScience 2022; 25:104873. [PMID: 36039293 PMCID: PMC9418806 DOI: 10.1016/j.isci.2022.104873] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 06/24/2022] [Accepted: 07/29/2022] [Indexed: 11/02/2022] Open
Abstract
Genome size (GS) can vary considerably between phylogenetically close species, but the landscape of GS changes in insects remain largely unclear. To better understand the specific evolutionary factors that determine GS in insects, we examined flow cytometry-based published GS data from 1,326 insect species, spanning 700 genera, 155 families, and 21 orders. Model fitting showed that GS generally followed an Ornstein–Uhlenbeck adaptive evolutionary model in Insecta overall. Ancestral reconstruction indicated a likely GS of 1,069 Mb, suggesting that most insect clades appeared to undergo massive genome expansions or contractions. Quantification of genomic components in 56 species from nine families in four insect orders revealed that the proliferation of transposable elements contributed to high variation in GS between close species, such as within Coleoptera. This study sheds lights on the pattern of GS variation in insects and provides a better understanding of insect GS evolution. The most comprehensive variation pattern of insects genome size (GS) to date GS evolution of the Insecta was reflected by the adaptive Ornstein–Uhlenbeck model Ancestral state of insect GS was estimated to be ∼1 Gb Intrafamily GS variations were driven by recent transpositions and non-coding regions
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13
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Myriapod genomes reveal ancestral horizontal gene transfer and hormonal gene loss in millipedes. Nat Commun 2022; 13:3010. [PMID: 35637228 PMCID: PMC9151784 DOI: 10.1038/s41467-022-30690-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 05/12/2022] [Indexed: 01/08/2023] Open
Abstract
Animals display a fascinating diversity of body plans. Correspondingly, genomic analyses have revealed dynamic evolution of gene gains and losses among animal lineages. Here we sequence six new myriapod genomes (three millipedes, three centipedes) at key phylogenetic positions within this major but understudied arthropod lineage. We combine these with existing genomic resources to conduct a comparative analysis across all available myriapod genomes. We find that millipedes generally have considerably smaller genomes than centipedes, with the repeatome being a major contributor to genome size, driven by independent large gains of transposons in three centipede species. In contrast to millipedes, centipedes gained a large number of gene families after the subphyla diverged, with gains contributing to sensory and locomotory adaptations that facilitated their ecological shift to predation. We identify distinct horizontal gene transfer (HGT) events from bacteria to millipedes and centipedes, with no identifiable HGTs shared among all myriapods. Loss of juvenile hormone O-methyltransferase, a key enzyme in catalysing sesquiterpenoid hormone production in arthropods, was also revealed in all millipede lineages. Our findings suggest that the rapid evolution of distinct genomic pathways in centipede and millipede lineages following their divergence from the myriapod ancestor, was shaped by differing ecological pressures. Myriapods play an important ecological role in soil and forest ecosystems. Here the authors analyse nine myriapod genomes, showing rapid evolution of distinct genomic pathways in centipede and millipede lineages, shaped by differing ecological pressures.
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Haq IU, Muhammad M, Yuan H, Ali S, Abbasi A, Asad M, Ashraf HJ, Khurshid A, Zhang K, Zhang Q, Liu C. Satellitome Analysis and Transposable Elements Comparison in Geographically Distant Populations of Spodoptera frugiperda. Life (Basel) 2022; 12:521. [PMID: 35455012 PMCID: PMC9026859 DOI: 10.3390/life12040521] [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: 02/28/2022] [Revised: 03/25/2022] [Accepted: 03/28/2022] [Indexed: 11/29/2022] Open
Abstract
Spodoptera frugiperda (fall armyworm) is a member of the superfamily Noctuoidea that accounts for more than a third of all Lepidoptera and includes a considerable number of agricultural and forest pest species. Spodoptera frugiperda is a polyphagous species that is a significant agricultural pest worldwide, emphasizing its economic importance. Spodoptera frugiperda's genome size, assembly, phylogenetic classification, and transcriptome analysis have all been previously described. However, the different studies reported different compositions of repeated DNA sequences that occupied the whole assembled genome, and the Spodoptera frugiperda genome also lacks the comprehensive study of dynamic satellite DNA. We conducted a comparative analysis of repetitive DNA across geographically distant populations of Spodoptera frugiperda, particularly satellite DNA, using publicly accessible raw genome data from eight different geographical regions. Our results showed that most transposable elements (TEs) were commonly shared across all geographically distant samples, except for the Maverick and PIF/Harbinger elements, which have divergent repeat copies. The TEs age analysis revealed that most TEs families consist of young copies 1-15 million years old; however, PIF/Harbinger has some older/degenerated copies of 30-35 million years old. A total of seven satellite DNA families were discovered, accounting for approximately 0.65% of the entire genome of the Spodoptera frugiperda fall armyworm. The repeat profiling analysis of satellite DNA families revealed differential read depth coverage or copy numbers. The satellite DNA families range in size from the lowest 108 bp SfrSat06-108 families to the largest (1824 bp) SfrSat07-1824 family. We did not observe a statistically significant correlation between monomer length and K2P divergence, copy number, or abundance of each satellite family. Our findings suggest that the satellite DNA families identified in Spodoptera frugiperda account for a considerable proportion of the genome's repetitive fraction. The satellite DNA families' repeat profiling revealed a point mutation along the reference sequences. Limited TEs differentiation exists among geographically distant populations of Spodoptera frugiperda.
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Affiliation(s)
- Inzamam Ul Haq
- College of Plant Protection, Gansu Agricultural University, No. 1 Yingmen Village, Anning District, Lanzhou 730070, China; (I.U.H.); (A.K.); (K.Z.); (Q.Z.)
| | - Majid Muhammad
- College of Life Sciences, Shaanxi Normal University, Xi’an 710100, China; (M.M.); (H.Y.)
| | - Huang Yuan
- College of Life Sciences, Shaanxi Normal University, Xi’an 710100, China; (M.M.); (H.Y.)
| | - Shahbaz Ali
- Department of Agricultural Engineering, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan 64200, Pakistan;
| | - Asim Abbasi
- Department of Zoology, Bahawalpur Campus, University of Central Punjab, Bahawalpur 63100, Pakistan;
| | - Muhammad Asad
- College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China;
| | - Hafiza Javaria Ashraf
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China;
| | - Aroosa Khurshid
- College of Plant Protection, Gansu Agricultural University, No. 1 Yingmen Village, Anning District, Lanzhou 730070, China; (I.U.H.); (A.K.); (K.Z.); (Q.Z.)
| | - Kexin Zhang
- College of Plant Protection, Gansu Agricultural University, No. 1 Yingmen Village, Anning District, Lanzhou 730070, China; (I.U.H.); (A.K.); (K.Z.); (Q.Z.)
| | - Qiangyan Zhang
- College of Plant Protection, Gansu Agricultural University, No. 1 Yingmen Village, Anning District, Lanzhou 730070, China; (I.U.H.); (A.K.); (K.Z.); (Q.Z.)
| | - Changzhong Liu
- College of Plant Protection, Gansu Agricultural University, No. 1 Yingmen Village, Anning District, Lanzhou 730070, China; (I.U.H.); (A.K.); (K.Z.); (Q.Z.)
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15
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Comparative Analysis of Transposable Elements in Genus Calliptamus Grasshoppers Revealed That Satellite DNA Contributes to Genome Size Variation. INSECTS 2021; 12:insects12090837. [PMID: 34564277 PMCID: PMC8466570 DOI: 10.3390/insects12090837] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/01/2021] [Accepted: 09/14/2021] [Indexed: 12/15/2022]
Abstract
Simple Summary Calliptamus is a genus of grasshoppers belonging to the family Acrididae. The genus Calliptamus includes approximately 17 recognized species. Calliptamus abbreviatus, Calliptamus italicus, and Calliptamus barbarus are three species that are widely found in northern China. These species are polyphagous, feeding on a variety of wild plants as well as crops, particularly legumes. The genome sizes, phylogenetic position, and transcriptome analysis of the genus Calliptamus were already known previous to this research. The repeatome analysis of these species was missing, which is directly linked to the larger genome sizes of the grasshoppers. Here, we classified repetitive DNA sequences at the level of superfamilies and sub-families, and found that LINE, TcMar-Tc1 and Ty3-gypsy LTR retrotransposons dominated the repeatomes of all genomes, accounting for 16–34% of the total genomes of these species. Satellite DNA dynamic evolutionary changes in all three genomes played a role in genome size evolution. This study would be a valuable source for future genome assemblies. Abstract Transposable elements (TEs) play a significant role in both eukaryotes and prokaryotes genome size evolution, structural changes, duplication, and functional variabilities. However, the large number of different repetitive DNA has hindered the process of assembling reference genomes, and the genus level TEs diversification of the grasshopper massive genomes is still under investigation. The genus Calliptamus diverged from Peripolus around 17 mya and its species divergence dated back about 8.5 mya, but their genome size shows rather large differences. Here, we used low-coverage Illumina unassembled short reads to investigate the effects of evolutionary dynamics of satDNAs and TEs on genome size variations. The Repeatexplorer2 analysis with 0.5X data resulted in 52%, 56%, and 55% as repetitive elements in the genomes of Calliptamus barbarus, Calliptamus italicus, and Calliptamus abbreviatus, respectively. The LINE and Ty3-gypsy LTR retrotransposons and TcMar-Tc1 dominated the repeatomes of all genomes, accounting for 16–35% of the total genomes of these species. Comparative analysis unveiled that most of the transposable elements (TEs) except satDNAs were highly conserved across three genomes in the genus Calliptamus grasshoppers. Out of a total of 20 satDNA families, 17 satDNA families were commonly shared with minor variations in abundance and divergence between three genomes, and 3 were Calliptamus barbarus specific. Our findings suggest that there is a significant amplification or contraction of satDNAs at genus phylogeny which is the main cause that made genome size different.
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Stelzer CP, Blommaert J, Waldvogel AM, Pichler M, Hecox-Lea B, Mark Welch DB. Comparative analysis reveals within-population genome size variation in a rotifer is driven by large genomic elements with highly abundant satellite DNA repeat elements. BMC Biol 2021; 19:206. [PMID: 34530817 PMCID: PMC8447722 DOI: 10.1186/s12915-021-01134-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 08/27/2021] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Eukaryotic genomes are known to display an enormous variation in size, but the evolutionary causes of this phenomenon are still poorly understood. To obtain mechanistic insights into such variation, previous studies have often employed comparative genomics approaches involving closely related species or geographically isolated populations within a species. Genome comparisons among individuals of the same population remained so far understudied-despite their great potential in providing a microevolutionary perspective to genome size evolution. The rotifer Brachionus asplanchnoidis represents one of the most extreme cases of within-population genome size variation among eukaryotes, displaying almost twofold variation within a geographic population. RESULTS Here, we used a whole-genome sequencing approach to identify the underlying DNA sequence differences by assembling a high-quality reference genome draft for one individual of the population and aligning short reads of 15 individuals from the same geographic population including the reference individual. We identified several large, contiguous copy number variable regions (CNVs), up to megabases in size, which exhibited striking coverage differences among individuals, and whose coverage overall scaled with genome size. CNVs were of remarkably low complexity, being mainly composed of tandemly repeated satellite DNA with only a few interspersed genes or other sequences, and were characterized by a significantly elevated GC-content. CNV patterns in offspring of two parents with divergent genome size and CNV patterns in several individuals from an inbred line differing in genome size demonstrated inheritance and accumulation of CNVs across generations. CONCLUSIONS By identifying the exact genomic elements that cause within-population genome size variation, our study paves the way for studying genome size evolution in contemporary populations rather than inferring patterns and processes a posteriori from species comparisons.
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Affiliation(s)
- C P Stelzer
- Research Department for Limnology, University of Innsbruck, Mondsee, Austria.
| | - J Blommaert
- Research Department for Limnology, University of Innsbruck, Mondsee, Austria
- Department of Organismal Biology, Uppsala University, Uppsala, Sweden
| | - A M Waldvogel
- Institute of Zoology, University of Cologne, Cologne, Germany
| | - M Pichler
- Research Department for Limnology, University of Innsbruck, Mondsee, Austria
| | - B Hecox-Lea
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA, USA
| | - D B Mark Welch
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA, USA
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17
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Skern-Mauritzen R, Malde K, Eichner C, Dondrup M, Furmanek T, Besnier F, Komisarczuk AZ, Nuhn M, Dalvin S, Edvardsen RB, Klages S, Huettel B, Stueber K, Grotmol S, Karlsbakk E, Kersey P, Leong JS, Glover KA, Reinhardt R, Lien S, Jonassen I, Koop BF, Nilsen F. The salmon louse genome: Copepod features and parasitic adaptations. Genomics 2021; 113:3666-3680. [PMID: 34403763 DOI: 10.1016/j.ygeno.2021.08.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 07/06/2021] [Accepted: 08/03/2021] [Indexed: 12/13/2022]
Abstract
Copepods encompass numerous ecological roles including parasites, detrivores and phytoplankton grazers. Nonetheless, copepod genome assemblies remain scarce. Lepeophtheirus salmonis is an economically and ecologically important ectoparasitic copepod found on salmonid fish. We present the 695.4 Mbp L. salmonis genome assembly containing ≈60% repetitive regions and 13,081 annotated protein-coding genes. The genome comprises 14 autosomes and a ZZ-ZW sex chromosome system. Assembly assessment identified 92.4% of the expected arthropod genes. Transcriptomics supported annotation and indicated a marked shift in gene expression after host attachment, including apparent downregulation of genes related to circadian rhythm coinciding with abandoning diurnal migration. The genome shows evolutionary signatures including loss of genes needed for peroxisome biogenesis, presence of numerous FNII domains, and an incomplete heme homeostasis pathway suggesting heme proteins to be obtained from the host. Despite repeated development of resistance against chemical treatments L. salmonis exhibits low numbers of many genes involved in detoxification.
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Affiliation(s)
| | - Ketil Malde
- Institute of Marine Research, Postboks 1870 Nordnes, 5817 Bergen, Norway; Sea Lice Research Centre. Department of Biological Sciences, University of Bergen, Thormøhlens Gate 53, 5006 Bergen, Norway
| | - Christiane Eichner
- Sea Lice Research Centre. Department of Biological Sciences, University of Bergen, Thormøhlens Gate 53, 5006 Bergen, Norway
| | - Michael Dondrup
- Computational Biology Unit, Department of Informatics, University of Bergen, Thormøhlens Gate 55, 5008 Bergen, Norway
| | - Tomasz Furmanek
- Institute of Marine Research, Postboks 1870 Nordnes, 5817 Bergen, Norway
| | - Francois Besnier
- Institute of Marine Research, Postboks 1870 Nordnes, 5817 Bergen, Norway
| | - Anna Zofia Komisarczuk
- Sea Lice Research Centre. Department of Biological Sciences, University of Bergen, Thormøhlens Gate 53, 5006 Bergen, Norway
| | - Michael Nuhn
- EMBL-The European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, CB10 1SD, UK
| | - Sussie Dalvin
- Institute of Marine Research, Postboks 1870 Nordnes, 5817 Bergen, Norway
| | - Rolf B Edvardsen
- Institute of Marine Research, Postboks 1870 Nordnes, 5817 Bergen, Norway
| | - Sven Klages
- Sequencing Core Facility, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Bruno Huettel
- Max Planck Genome Centre Cologne, Carl von Linné Weg 10, D-50829 Köln, Germany
| | - Kurt Stueber
- Max Planck Genome Centre Cologne, Carl von Linné Weg 10, D-50829 Köln, Germany
| | - Sindre Grotmol
- Sea Lice Research Centre. Department of Biological Sciences, University of Bergen, Thormøhlens Gate 53, 5006 Bergen, Norway
| | - Egil Karlsbakk
- Sea Lice Research Centre. Department of Biological Sciences, University of Bergen, Thormøhlens Gate 53, 5006 Bergen, Norway
| | - Paul Kersey
- EMBL-The European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, CB10 1SD, UK; Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AE, UK
| | - Jong S Leong
- Department of Biology, University of Victoria, Victoria, British Columbia V8W 3N5, Canada
| | - Kevin A Glover
- Institute of Marine Research, Postboks 1870 Nordnes, 5817 Bergen, Norway; Sea Lice Research Centre. Department of Biological Sciences, University of Bergen, Thormøhlens Gate 53, 5006 Bergen, Norway
| | - Richard Reinhardt
- Max Planck Genome Centre Cologne, Carl von Linné Weg 10, D-50829 Köln, Germany
| | - Sigbjørn Lien
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Oluf Thesens vei 6, 1433 Ås, Norway
| | - Inge Jonassen
- Computational Biology Unit, Department of Informatics, University of Bergen, Thormøhlens Gate 55, 5008 Bergen, Norway
| | - Ben F Koop
- Department of Biology, University of Victoria, Victoria, British Columbia V8W 3N5, Canada
| | - Frank Nilsen
- Institute of Marine Research, Postboks 1870 Nordnes, 5817 Bergen, Norway; Sea Lice Research Centre. Department of Biological Sciences, University of Bergen, Thormøhlens Gate 53, 5006 Bergen, Norway.
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18
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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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Simple inheritance of color and pattern polymorphism in the steppe grasshopper Chorthippus dorsatus. Heredity (Edinb) 2021; 127:66-78. [PMID: 33864010 PMCID: PMC8249487 DOI: 10.1038/s41437-021-00433-w] [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: 01/25/2021] [Revised: 03/31/2021] [Accepted: 03/31/2021] [Indexed: 02/02/2023] Open
Abstract
The green-brown polymorphism of grasshoppers and bush-crickets represents one of the most penetrant polymorphisms in any group of organisms. This poses the question of why the polymorphism is shared across species and how it is maintained. There is mixed evidence for whether and in which species it is environmentally or genetically determined in Orthoptera. We report breeding experiments with the steppe grasshopper Chorthippus dorsatus, a polymorphic species for the presence and distribution of green body parts. Morph ratios did not differ between sexes, and we find no evidence that the rearing environment (crowding and habitat complexity) affected the polymorphism. However, we find strong evidence for genetic determination for the presence/absence of green and its distribution. Results are most parsimoniously explained by three autosomal loci with two alleles each and simple dominance effects: one locus influencing the ability to show green color, with a dominant allele for green; a locus with a recessive allele suppressing green on the dorsal side; and a locus with a recessive allele suppressing green on the lateral side. Our results contribute to the emerging contrast between the simple genetic inheritance of green-brown polymorphisms in the subfamily Gomphocerinae and environmental determination in other subfamilies of grasshoppers. In three out of four species of Gomphocerinae studied so far, the results suggest one or a few loci with a dominance of alleles allowing the occurrence of green. This supports the idea that brown individuals differ from green individuals by homozygosity for loss-of-function alleles preventing green pigment production or deposition.
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20
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Yuan H, Huang Y, Mao Y, Zhang N, Nie Y, Zhang X, Zhou Y, Mao S. The Evolutionary Patterns of Genome Size in Ensifera (Insecta: Orthoptera). Front Genet 2021; 12:693541. [PMID: 34249107 PMCID: PMC8261143 DOI: 10.3389/fgene.2021.693541] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 05/25/2021] [Indexed: 11/13/2022] Open
Abstract
Genomic size variation has long been a focus for biologists. However, due to the lack of genome size data, the mechanisms behind this variation and the biological significance of insect genome size are rarely studied systematically. The detailed taxonomy and phylogeny of the Ensifera, as well as the extensive documentation concerning their morphological, ecological, behavioral, and distributional characteristics, make them a strong model for studying the important scientific problem of genome size variation. However, data on the genome size of Ensifera are rather sparse. In our study, we used flow cytometry to determine the genome size of 32 species of Ensifera, the smallest one being only 1C = 0.952 pg with the largest species up to 1C = 19.135 pg, representing a 20-fold range. This provides a broader blueprint for the genome size variation of Orthoptera than was previously available. We also completed the assembly of nine mitochondrial genomes and combined mitochondrial genome data from public databases to construct phylogenetic trees containing 32 species of Ensifera and three outgroups. Based on these inferred phylogenetic trees, we detected the phylogenetic signal of genome size variation in Ensifera and found that it was strong in both males and females. Phylogenetic comparative analyses revealed that there were no correlations between genome size and body size or flight ability in Tettigoniidae. Reconstruction of ancestral genome size revealed that the genome size of Ensifera evolved in a complex pattern, in which the genome size of the grylloid clade tended to decrease while that of the non-grylloid clade expanded significantly albeit with fluctuations. However, the evolutionary mechanisms underlying variation of genome size in Ensifera are still unknown.
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Affiliation(s)
- Hao Yuan
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Yuan Huang
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Ying Mao
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Nan Zhang
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Yimeng Nie
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Xue Zhang
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Yafu Zhou
- Xi'an Botanical Garden of Shaanxi Province/Institute of Botany of Shaanxi Province, Shaanxi Engineering Research Centre for Conservation and Utilization of Botanical Resources, Xi'an, China
| | - Shaoli Mao
- Xi'an Botanical Garden of Shaanxi Province/Institute of Botany of Shaanxi Province, Shaanxi Engineering Research Centre for Conservation and Utilization of Botanical Resources, Xi'an, China
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