1
|
Haber DA, Arien Y, Lamdan LB, Alcalay Y, Zecharia C, Krsticevic F, Yonah ES, Avraham RD, Krzywinska E, Krzywinski J, Marois E, Windbichler N, Papathanos PA. Targeting mosquito X-chromosomes reveals complex transmission dynamics of sex ratio distorting gene drives. Nat Commun 2024; 15:4983. [PMID: 38862555 PMCID: PMC11166636 DOI: 10.1038/s41467-024-49387-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 06/04/2024] [Indexed: 06/13/2024] Open
Abstract
Engineered sex ratio distorters (SRDs) have been proposed as a powerful component of genetic control strategies designed to suppress harmful insect pests. Two types of CRISPR-based SRD mechanisms have been proposed: X-shredding, which eliminates X-bearing sperm, and X-poisoning, which eliminates females inheriting disrupted X-chromosomes. These differences can have a profound impact on the population dynamics of SRDs when linked to the Y-chromosome: an X-shredder is invasive, constituting a classical meiotic Y-drive, whereas X-poisoning is self-limiting, unable to invade but also insulated from selection. Here, we establish X-poisoning strains in the malaria vector Anopheles gambiae targeting three X-linked genes during spermatogenesis, resulting in male bias. We find that sex distortion is primarily driven by a loss of X-bearing sperm, with limited evidence for postzygotic lethality of female progeny. By leveraging a Drosophila melanogaster model, we show unambiguously that engineered SRD traits can operate differently in these two insects. Unlike X-shredding, X-poisoning could theoretically operate at early stages of spermatogenesis. We therefore explore premeiotic Cas9 expression to target the mosquito X-chromosome. We find that, by pre-empting the onset of meiotic sex chromosome inactivation, this approach may enable the development of Y-linked SRDs if mutagenesis of spermatogenesis-essential genes is functionally balanced.
Collapse
Affiliation(s)
- Daniella An Haber
- Department of Entomology, Institute of Environmental Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Yael Arien
- Department of Entomology, Institute of Environmental Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Lee Benjamin Lamdan
- Department of Entomology, Institute of Environmental Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Yehonathan Alcalay
- Department of Entomology, Institute of Environmental Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Chen Zecharia
- Department of Entomology, Institute of Environmental Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Flavia Krsticevic
- Department of Entomology, Institute of Environmental Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Elad Shmuel Yonah
- Department of Entomology, Institute of Environmental Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Rotem Daniel Avraham
- Department of Entomology, Institute of Environmental Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Elzbieta Krzywinska
- The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK
- Forest Research, Alice Holt Lodge, Farnham, Surrey, GU10 4LH, UK
| | - Jaroslaw Krzywinski
- The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK
- Genetics and Ecology Research Centre, Polo d'Innovazione di Genomica Genetica e Biologia, Via Mazzieri, 05100, Terni, Italy
| | - Eric Marois
- Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, INSERM, CNRS, Strasbourg, France
| | | | - Philippos Aris Papathanos
- Department of Entomology, Institute of Environmental Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 7610001, Israel.
| |
Collapse
|
2
|
Habtewold T, Wagah M, Tambwe MM, Moore S, Windbichler N, Christophides G, Johnson H, Heaton H, Collins J, Krasheninnikova K, Pelan SE, Pointon DLB, Sims Y, Torrance JW, Tracey A, Uliano Da Silva M, Wood JMD, von Wyschetzki K, McCarthy SA, Neafsey DE, Makunin A, Lawniczak MK, Lawniczak M. A chromosomal reference genome sequence for the malaria mosquito, Anopheles gambiae, Giles, 1902, Ifakara strain. Wellcome Open Res 2024; 8:74. [PMID: 37424773 PMCID: PMC10326452 DOI: 10.12688/wellcomeopenres.18854.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2024] [Indexed: 04/01/2024] Open
Abstract
We present a genome assembly from an individual female Anopheles gambiae (the malaria mosquito; Arthropoda; Insecta; Diptera; Culicidae), Ifakara strain. The genome sequence is 264 megabases in span. Most of the assembly is scaffolded into three chromosomal pseudomolecules with the X sex chromosome assembled. The complete mitochondrial genome was also assembled and is 15.4 kilobases in length.
Collapse
Affiliation(s)
- Tibebu Habtewold
- Department of Life Sciences, Imperial College London, London, UK
| | - Martin Wagah
- Tree of Life, Wellcome Sanger Institute, Hinxton, UK
| | - Mgeni Mohamed Tambwe
- Vector Control Product Testing Unit, Ifakara Health institute, Bagamoyo, Tanzania
| | - Sarah Moore
- Vector Control Product Testing Unit, Ifakara Health institute, Bagamoyo, Tanzania
- Vector Biology Unit, Swiss Tropical and Public Health Institute, Bagamoyo, Tanzania
| | | | | | - Harriet Johnson
- Scientific Operations, Wellcome Sanger Institute, Hinxton, UK
| | | | | | | | | | | | - Ying Sims
- Tree of Life, Wellcome Sanger Institute, Hinxton, UK
| | | | - Alan Tracey
- Tree of Life, Wellcome Sanger Institute, Hinxton, UK
| | | | | | | | - Wellcome Sanger Institute Scientific Operations: DNA Pipelines collective
- Department of Life Sciences, Imperial College London, London, UK
- Tree of Life, Wellcome Sanger Institute, Hinxton, UK
- Vector Control Product Testing Unit, Ifakara Health institute, Bagamoyo, Tanzania
- Vector Biology Unit, Swiss Tropical and Public Health Institute, Bagamoyo, Tanzania
- Scientific Operations, Wellcome Sanger Institute, Hinxton, UK
- CSSE, Auburn University, Auburn, Alabama, USA
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | | | - Daniel E. Neafsey
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Alex Makunin
- Tree of Life, Wellcome Sanger Institute, Hinxton, UK
| | | | | |
Collapse
|
3
|
Zamyatin A, Avdeyev P, Liang J, Sharma A, Chen C, Lukyanchikova V, Alexeev N, Tu Z, Alekseyev MA, Sharakhov IV. Chromosome-level genome assemblies of the malaria vectors Anopheles coluzzii and Anopheles arabiensis. Gigascience 2021; 10:giab017. [PMID: 33718948 PMCID: PMC7957348 DOI: 10.1093/gigascience/giab017] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/01/2021] [Accepted: 01/23/2021] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Anopheles coluzzii and Anopheles arabiensis belong to the Anopheles gambiae complex and are among the major malaria vectors in sub-Saharan Africa. However, chromosome-level reference genome assemblies are still lacking for these medically important mosquito species. FINDINGS In this study, we produced de novo chromosome-level genome assemblies for A. coluzzii and A. arabiensis using the long-read Oxford Nanopore sequencing technology and the Hi-C scaffolding approach. We obtained 273.4 and 256.8 Mb of the total assemblies for A. coluzzii and A. arabiensis, respectively. Each assembly consists of 3 chromosome-scale scaffolds (X, 2, 3), complete mitochondrion, and unordered contigs identified as autosomal pericentromeric DNA, X pericentromeric DNA, and Y sequences. Comparison of these assemblies with the existing assemblies for these species demonstrated that we obtained improved reference-quality genomes. The new assemblies allowed us to identify genomic coordinates for the breakpoint regions of fixed and polymorphic chromosomal inversions in A. coluzzii and A. arabiensis. CONCLUSION The new chromosome-level assemblies will facilitate functional and population genomic studies in A. coluzzii and A. arabiensis. The presented assembly pipeline will accelerate progress toward creating high-quality genome references for other disease vectors.
Collapse
Affiliation(s)
- Anton Zamyatin
- Computer Technologies Laboratory, ITMO University, Kronverkskiy Prospekt 49-A, Saint Petersburg 197101, Russia
| | - Pavel Avdeyev
- Department of Mathematics, The George Washington University, 801 22nd Street NW, Washington, DC 20052, USA
- Computational Biology Institute, Milken Institute School of Public Health, The George Washington University, 800 22nd Street NW, Washington, DC 20052, USA
| | - Jiangtao Liang
- Department of Entomology, Virginia Polytechnic Institute and State University, 170 Drillfield Drive, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Polytechnic Institute and State University, 360 West Campus Drive, Blacksburg, VA 24061, USA
| | - Atashi Sharma
- Fralin Life Sciences Institute, Virginia Polytechnic Institute and State University, 360 West Campus Drive, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Chujia Chen
- Fralin Life Sciences Institute, Virginia Polytechnic Institute and State University, 360 West Campus Drive, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Varvara Lukyanchikova
- Department of Entomology, Virginia Polytechnic Institute and State University, 170 Drillfield Drive, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Polytechnic Institute and State University, 360 West Campus Drive, Blacksburg, VA 24061, USA
- Institute of Cytology and Genetics the Siberian Division of the Russian Academy of Sciences, Prospekt Lavrentyeva 10, Novosibirsk 630090, Russia
| | - Nikita Alexeev
- Computer Technologies Laboratory, ITMO University, Kronverkskiy Prospekt 49-A, Saint Petersburg 197101, Russia
| | - Zhijian Tu
- Fralin Life Sciences Institute, Virginia Polytechnic Institute and State University, 360 West Campus Drive, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Max A Alekseyev
- Department of Mathematics, The George Washington University, 801 22nd Street NW, Washington, DC 20052, USA
- Computational Biology Institute, Milken Institute School of Public Health, The George Washington University, 800 22nd Street NW, Washington, DC 20052, USA
| | - Igor V Sharakhov
- Department of Entomology, Virginia Polytechnic Institute and State University, 170 Drillfield Drive, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Polytechnic Institute and State University, 360 West Campus Drive, Blacksburg, VA 24061, USA
| |
Collapse
|
4
|
Sharma A, Kinney NA, Timoshevskiy VA, Sharakhova MV, Sharakhov IV. Structural Variation of the X Chromosome Heterochromatin in the Anopheles gambiae Complex. Genes (Basel) 2020; 11:E327. [PMID: 32204543 PMCID: PMC7140835 DOI: 10.3390/genes11030327] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 12/31/2022] Open
Abstract
Heterochromatin is identified as a potential factor driving diversification of species. To understand the magnitude of heterochromatin variation within the Anopheles gambiae complex of malaria mosquitoes, we analyzed metaphase chromosomes in An. arabiensis, An. coluzzii, An. gambiae, An. merus, and An. quadriannulatus. Using fluorescence in situ hybridization (FISH) with ribosomal DNA (rDNA), a highly repetitive fraction of DNA, and heterochromatic Bacterial Artificial Chromosome (BAC) clones, we established the correspondence of pericentric heterochromatin between the metaphase and polytene X chromosomes of An. gambiae. We then developed chromosome idiograms and demonstrated that the X chromosomes exhibit qualitative differences in their pattern of heterochromatic bands and position of satellite DNA (satDNA) repeats among the sibling species with postzygotic isolation, An. arabiensis, An. merus, An. quadriannulatus, and An. coluzzii or An. gambiae. The identified differences in the size and structure of the X chromosome heterochromatin point to a possible role of repetitive DNA in speciation of mosquitoes. We found that An. coluzzii and An. gambiae, incipient species with prezygotic isolation, share variations in the relative positions of the satDNA repeats and the proximal heterochromatin band on the X chromosomes. This previously unknown genetic polymorphism in malaria mosquitoes may be caused by a differential amplification of DNA repeats or an inversion in the sex chromosome heterochromatin.
Collapse
Affiliation(s)
- Atashi Sharma
- Department of Entomology, Virginia Polytechnic and State University, Blacksburg, VA 24061, USA; (A.S.); (V.A.T.); (M.V.S.)
| | - Nicholas A. Kinney
- Genomics Bioinformatics and Computational Biology, Virginia Polytechnic and State University, Blacksburg, VA 24061, USA;
| | - Vladimir A. Timoshevskiy
- Department of Entomology, Virginia Polytechnic and State University, Blacksburg, VA 24061, USA; (A.S.); (V.A.T.); (M.V.S.)
| | - Maria V. Sharakhova
- Department of Entomology, Virginia Polytechnic and State University, Blacksburg, VA 24061, USA; (A.S.); (V.A.T.); (M.V.S.)
- Laboratory of Evolutionary Genomics of Insects, the Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Laboratory of Ecology, Genetics and Environmental Protection, Tomsk State University, 634050 Tomsk, Russia
| | - Igor V. Sharakhov
- Department of Entomology, Virginia Polytechnic and State University, Blacksburg, VA 24061, USA; (A.S.); (V.A.T.); (M.V.S.)
- Genomics Bioinformatics and Computational Biology, Virginia Polytechnic and State University, Blacksburg, VA 24061, USA;
- Laboratory of Evolutionary Genomics of Insects, the Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Department of Cytology and Genetics, Tomsk State University, 634050 Tomsk, Russia
| |
Collapse
|
5
|
Jedlicka P, Lexa M, Kejnovsky E. What Can Long Terminal Repeats Tell Us About the Age of LTR Retrotransposons, Gene Conversion and Ectopic Recombination? FRONTIERS IN PLANT SCIENCE 2020; 11:644. [PMID: 32508870 PMCID: PMC7251063 DOI: 10.3389/fpls.2020.00644] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 04/27/2020] [Indexed: 05/10/2023]
Abstract
LTR retrotransposons constitute a significant part of plant genomes and their evolutionary dynamics play an important role in genome size changes. Current methods of LTR retrotransposon age estimation are based only on LTR (long terminal repeat) divergence. This has prompted us to analyze sequence similarity of LTRs in 25,144 LTR retrotransposons from fifteen plant species as well as formation of solo LTRs. We found that approximately one fourth of nested retrotransposons showed a higher LTR divergence than the pre-existing retrotransposons into which they had been inserted. Moreover, LTR similarity was correlated with LTR length. We propose that gene conversion can contribute to this phenomenon. Gene conversion prediction in LTRs showed potential converted regions in 25% of LTR pairs. Gene conversion was higher in species with smaller genomes while the proportion of solo LTRs did not change with genome size in analyzed species. The negative correlation between the extent of gene conversion and the abundance of solo LTRs suggests interference between gene conversion and ectopic recombination. Since such phenomena limit the traditional methods of LTR retrotransposon age estimation, we recommend an improved approach based on the exclusion of regions affected by gene conversion.
Collapse
Affiliation(s)
- Pavel Jedlicka
- Department of Plant Developmental Genetics, Institute of Biophysics of the Czech Academy of Sciences, Brno, Czechia
| | - Matej Lexa
- Faculty of Informatics, Masaryk University, Brno, Czechia
| | - Eduard Kejnovsky
- Department of Plant Developmental Genetics, Institute of Biophysics of the Czech Academy of Sciences, Brno, Czechia
- *Correspondence: Eduard Kejnovsky,
| |
Collapse
|
6
|
Papathanos PA, Windbichler N. Redkmer: An Assembly-Free Pipeline for the Identification of Abundant and Specific X-Chromosome Target Sequences for X-Shredding by CRISPR Endonucleases. CRISPR J 2018; 1:88-98. [PMID: 30627701 PMCID: PMC6319322 DOI: 10.1089/crispr.2017.0012] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
CRISPR-based synthetic sex ratio distorters, which operate by shredding the X-chromosome during male meiosis, are promising tools for the area-wide control of harmful insect pest or disease vector species. X-shredders have been proposed as tools to suppress insect populations by biasing the sex ratio of the wild population toward males, thus reducing its natural reproductive potential. However, to build synthetic X-shredders based on CRISPR, the selection of gRNA targets, in the form of high-copy sequence repeats on the X chromosome of a given species, is difficult, since such repeats are not accurately resolved in genome assemblies and cannot be assigned to chromosomes with confidence. We have therefore developed the redkmer computational pipeline, designed to identify short and highly abundant sequence elements occurring uniquely on the X chromosome. Redkmer was designed to use as input minimally processed whole genome sequence data from males and females. We tested redkmer with short- and long-read whole genome sequence data of Anopheles gambiae, the major vector of human malaria, in which the X-shredding paradigm was originally developed. Redkmer established long reads as chromosomal proxies with excellent correlation to the genome assembly and used them to rank X-candidate kmers for their level of X-specificity and abundance. Among these, a high-confidence set of 25-mers was identified, many belonging to previously known X-chromosome repeats of Anopheles gambiae, including the ribosomal gene array and the selfish elements harbored within it. Data from a control strain, in which these repeats are shared with the Y chromosome, confirmed the elimination of these kmers during filtering. Finally, we show that redkmer output can be linked directly to gRNA selection and off-target prediction. In addition, the output of redkmer, including the prediction of chromosomal origin of single-molecule long reads and chromosome specific kmers, could also be used for the characterization of other biologically relevant sex chromosome sequences, a task that is frequently hampered by the repetitiveness of sex chromosome sequence content.
Collapse
Affiliation(s)
- Philippos Aris Papathanos
- Department of Experimental Medicine, Section of Genomics and Genetics, University of Perugia, Perugia, Italy
| | - Nikolai Windbichler
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, South Kensington Campus, London, United Kingdom
| |
Collapse
|
7
|
Impact of Repetitive Elements on the Y Chromosome Formation in Plants. Genes (Basel) 2017; 8:genes8110302. [PMID: 29104214 PMCID: PMC5704215 DOI: 10.3390/genes8110302] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/19/2017] [Accepted: 10/26/2017] [Indexed: 12/21/2022] Open
Abstract
In contrast to animals, separate sexes and sex chromosomes in plants are very rare. Although the evolution of sex chromosomes has been the subject of numerous studies, the impact of repetitive sequences on sex chromosome architecture is not fully understood. New genomic approaches shed light on the role of satellites and transposable elements in the process of Y chromosome evolution. We discuss the impact of repetitive sequences on the structure and dynamics of sex chromosomes with specific focus on Rumex acetosa and Silene latifolia. Recent papers showed that both the expansion and shrinkage of the Y chromosome is influenced by sex-specific regulation of repetitive DNA spread. We present a view that the dynamics of Y chromosome formation is an interplay of genetic and epigenetic processes.
Collapse
|
8
|
Satović E, Vojvoda Zeljko T, Luchetti A, Mantovani B, Plohl M. Adjacent sequences disclose potential for intra-genomic dispersal of satellite DNA repeats and suggest a complex network with transposable elements. BMC Genomics 2016; 17:997. [PMID: 27919246 PMCID: PMC5139131 DOI: 10.1186/s12864-016-3347-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/25/2016] [Indexed: 11/14/2022] Open
Abstract
Background Satellite DNA (satDNA) sequences are typically arranged as arrays of tandemly repeated monomers. Due to the similarity among monomers, their organizational pattern and abundance, satDNAs are hardly accessible to structural and functional studies and still represent the most obscure genome component. Although many satDNA arrays of diverse length and even single monomers exist in the genome, surprisingly little is known about transition from satDNAs to other sequences. Studying satDNA monomers at junctions and identifying DNA sequences adjacent to them can help to understand the processes that (re)distribute satDNAs and significance that evolution of these sequence elements might have in creating the genomic landscape. Results We explored sets of randomly selected satDNA-harboring genomic fragments in four mollusc species to examine satDNA transition sites, and the nature of adjacent sequences. All examined junctions are characterized by abrupt transitions from satDNAs to other sequences. Among them, junctions of only one examined satDNA mapped non-randomly (within the palindrome), indicating that well-defined sequence feature is not a necessary prerequisite in the junction formation. In the studied sample, satDNA flanking sequences can be roughly classified into two groups. The first group is composed of anonymous DNA sequences which occasionally include short segments of transposable elements (TEs) as well as segments of other satDNA sequences. In the second group, satDNA repeats and the array flanking sequences are identified as parts of TEs of the Helitron superfamily. There, some array flanking regions hold fragmented satDNA monomers alternating with anonymous sequences of comparable length as missing monomer parts, suggesting a process of sequence reorganization by a mechanism able to excise short monomer parts and replace them with unrelated sequences. Conclusions The observed architecture of satDNA transition sites can be explained as a result of insertion and/or recombination events involving short arrays of satDNA monomers and TEs, in combination with hypothetical transposition-related ability of satDNA monomers to be shuffled independently in the genome. We conclude that satDNAs and TEs can form a complex network of sequences which essentially share the propagation mechanisms and in synergy shape the genome. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3347-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Eva Satović
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | | | - Andrea Luchetti
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali-Università di Bologna, Bologna, Italy
| | - Barbara Mantovani
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali-Università di Bologna, Bologna, Italy
| | - Miroslav Plohl
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia.
| |
Collapse
|
9
|
Krzywinska E, Dennison NJ, Lycett GJ, Krzywinski J. A maleness gene in the malaria mosquito Anopheles gambiae. Science 2016; 353:67-9. [PMID: 27365445 DOI: 10.1126/science.aaf5605] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 06/01/2016] [Indexed: 12/22/2022]
Abstract
The molecular pathways controlling gender are highly variable and have been identified in only a few nonmammalian model species. In many insects, maleness is conferred by a Y chromosome-linked M factor of unknown nature. We have isolated and characterized a gene, Yob, for the M factor in the malaria mosquito Anopheles gambiae Yob, activated at the beginning of zygotic transcription and expressed throughout a male's life, controls male-specific splicing of the doublesex gene. Silencing embryonic Yob expression is male-lethal, whereas ectopic embryonic delivery of Yob transcripts yields male-only broods. This female-killing property may be an invaluable tool for creation of conditional male-only transgenic Anopheles strains for malaria control programs.
Collapse
Affiliation(s)
| | - Nathan J Dennison
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK. Department of Life Sciences, Imperial College, South Kensington Campus, London SW7 2AZ, UK
| | - Gareth J Lycett
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Jaroslaw Krzywinski
- The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK. Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
| |
Collapse
|
10
|
Hall AB, Papathanos PA, Sharma A, Cheng C, Akbari OS, Assour L, Bergman NH, Cagnetti A, Crisanti A, Dottorini T, Fiorentini E, Galizi R, Hnath J, Jiang X, Koren S, Nolan T, Radune D, Sharakhova MV, Steele A, Timoshevskiy VA, Windbichler N, Zhang S, Hahn MW, Phillippy AM, Emrich SJ, Sharakhov IV, Tu ZJ, Besansky NJ. Radical remodeling of the Y chromosome in a recent radiation of malaria mosquitoes. Proc Natl Acad Sci U S A 2016; 113:E2114-23. [PMID: 27035980 PMCID: PMC4839409 DOI: 10.1073/pnas.1525164113] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Y chromosomes control essential male functions in many species, including sex determination and fertility. However, because of obstacles posed by repeat-rich heterochromatin, knowledge of Y chromosome sequences is limited to a handful of model organisms, constraining our understanding of Y biology across the tree of life. Here, we leverage long single-molecule sequencing to determine the content and structure of the nonrecombining Y chromosome of the primary African malaria mosquito, Anopheles gambiae We find that the An. gambiae Y consists almost entirely of a few massively amplified, tandemly arrayed repeats, some of which can recombine with similar repeats on the X chromosome. Sex-specific genome resequencing in a recent species radiation, the An. gambiae complex, revealed rapid sequence turnover within An. gambiae and among species. Exploiting 52 sex-specific An. gambiae RNA-Seq datasets representing all developmental stages, we identified a small repertoire of Y-linked genes that lack X gametologs and are not Y-linked in any other species except An. gambiae, with the notable exception of YG2, a candidate male-determining gene. YG2 is the only gene conserved and exclusive to the Y in all species examined, yet sequence similarity to YG2 is not detectable in the genome of a more distant mosquito relative, suggesting rapid evolution of Y chromosome genes in this highly dynamic genus of malaria vectors. The extensive characterization of the An. gambiae Y provides a long-awaited foundation for studying male mosquito biology, and will inform novel mosquito control strategies based on the manipulation of Y chromosomes.
Collapse
Affiliation(s)
- Andrew Brantley Hall
- The Interdisciplinary PhD Program in Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Philippos-Aris Papathanos
- Section of Genomics and Genetics, Department of Experimental Medicine, University of Perugia, 06132 Perugia, Italy; Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Atashi Sharma
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Changde Cheng
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556; Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
| | - Omar S Akbari
- Department of Entomology, Riverside Center for Disease Vector Research, Institute for Integrative Genome Biology, University of California, Riverside, CA 92521
| | - Lauren Assour
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, IN 46556
| | - Nicholas H Bergman
- National Biodefense Analysis and Countermeasures Center, Frederick, MD 21702
| | - Alessia Cagnetti
- Section of Genomics and Genetics, Department of Experimental Medicine, University of Perugia, 06132 Perugia, Italy
| | - Andrea Crisanti
- Section of Genomics and Genetics, Department of Experimental Medicine, University of Perugia, 06132 Perugia, Italy; Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Tania Dottorini
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Elisa Fiorentini
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Roberto Galizi
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Jonathan Hnath
- National Biodefense Analysis and Countermeasures Center, Frederick, MD 21702
| | - Xiaofang Jiang
- The Interdisciplinary PhD Program in Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Sergey Koren
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892
| | - Tony Nolan
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Diane Radune
- National Biodefense Analysis and Countermeasures Center, Frederick, MD 21702
| | - Maria V Sharakhova
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061; Laboratory of Evolutionary Cytogenetics, Tomsk State University, Tomsk 634050, Russia
| | - Aaron Steele
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, IN 46556
| | - Vladimir A Timoshevskiy
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Nikolai Windbichler
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Simo Zhang
- School of Informatics and Computing, Indiana University, Bloomington, IN 47405
| | - Matthew W Hahn
- School of Informatics and Computing, Indiana University, Bloomington, IN 47405; Department of Biology, Indiana University, Bloomington, IN 47405
| | - Adam M Phillippy
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892
| | - Scott J Emrich
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556; Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, IN 46556
| | - Igor V Sharakhov
- The Interdisciplinary PhD Program in Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061; Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061; Laboratory of Evolutionary Cytogenetics, Tomsk State University, Tomsk 634050, Russia;
| | - Zhijian Jake Tu
- The Interdisciplinary PhD Program in Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061; Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Nora J Besansky
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556; Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556;
| |
Collapse
|
11
|
Tsoumani KT, Drosopoulou E, Bourtzis K, Gariou-Papalexiou A, Mavragani-Tsipidou P, Zacharopoulou A, Mathiopoulos KD. Achilles, a New Family of Transcriptionally Active Retrotransposons from the Olive Fruit Fly, with Y Chromosome Preferential Distribution. PLoS One 2015; 10:e0137050. [PMID: 26398504 PMCID: PMC4580426 DOI: 10.1371/journal.pone.0137050] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 08/13/2015] [Indexed: 11/19/2022] Open
Abstract
Sex chromosomes have many unusual features relative to autosomes. The in depth exploration of their structure will improve our understanding of their origin and divergence (degeneration) as well as the evolution of genetic sex determination pathways which, most often are attributed to them. In Tephritids, the structure of Y chromosome, where the male-determining factor M is localized, is largely unexplored and limited data concerning its sequence content and evolution are available. In order to get insight into the structure and organization of the Y chromosome of the major olive insect pest, the olive fly Bactrocera oleae, we characterized sequences from a Pulse Field Gel Electrophoresis (PFGE)-isolated Y chromosome. Here, we report the discovery of the first olive fly LTR retrotransposon with increased presence on the Y chromosome. The element belongs to the BEL-Pao superfamily, however, its sequence comparison with the other members of the superfamily suggests that it constitutes a new family that we termed Achilles. Its ~7.5 kb sequence consists of the 5'LTR, the 5'non-coding sequence and the open reading frame (ORF), which encodes the polyprotein Gag-Pol. In situ hybridization to the B. oleae polytene chromosomes showed that Achilles is distributed in discrete bands dispersed on all five autosomes, in all centromeric regions and in the granular heterochromatic network corresponding to the mitotic sex chromosomes. The between sexes comparison revealed a variation in Achilles copy number, with male flies possessing 5-10 copies more than female (CI range: 18-38 and 12-33 copies respectively per genome). The examination of its transcriptional activity demonstrated the presence of at least one intact active copy in the genome, showing a differential level of expression between sexes as well as during embryonic development. The higher expression was detected in male germline tissues (testes). Moreover, the presence of Achilles-like elements in different species of the Tephritidae family suggests an ancient origin of this element.
Collapse
Affiliation(s)
| | - Elena Drosopoulou
- Department of Genetics, Development and Molecular Biology, Aristotle University of Thessaloniki (AUTH), Thessaloniki, Greece
| | - Kostas Bourtzis
- Insect Molecular Genetics Group, IMBB, Vassilika Vouton, 71110 Heraklion, Crete, PO Box 1527, Greece
- Department of Environmental and Natural Resources Management, University of Patras, Agrinio, Greece
- Insect Pest Control Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Vienna, Austria
| | - Aggeliki Gariou-Papalexiou
- Department of Biology, Division of Genetics, Cell and Developmental Biology, University of Patras, Patras, Greece
| | - Penelope Mavragani-Tsipidou
- Department of Genetics, Development and Molecular Biology, Aristotle University of Thessaloniki (AUTH), Thessaloniki, Greece
| | - Antigone Zacharopoulou
- Department of Biology, Division of Genetics, Cell and Developmental Biology, University of Patras, Patras, Greece
| | | |
Collapse
|
12
|
Bardella VB, da Rosa JA, Vanzela ALL. Origin and distribution of AT-rich repetitive DNA families in Triatoma infestans (Heteroptera). INFECTION GENETICS AND EVOLUTION 2014; 23:106-14. [PMID: 24524986 DOI: 10.1016/j.meegid.2014.01.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 01/26/2014] [Accepted: 01/29/2014] [Indexed: 11/17/2022]
Abstract
Triatoma infestans, one of the most important vectors of Trypanosoma cruzi, is very interesting model, because it shows large interpopulation variation in the amount and distribution of heterochromatin. This polymorphism involved the three large pairs up to almost all autosomal pairs, including the sex chromosomes. To understand the dynamics of heterochromatin variation in T. infestans, we isolated the AT-rich satDNA portion of this insect using reassociation kinetics (C0t), followed by cloning, sequencing and FISH. After chromosome localization, immunolabeling with anti-5-methylcytosine, anti-H4K5ac and anti-H3K9me2 antibodies was performed to determine the functional characteristics of heterochromatin. The results allowed us to reorganize the karyotype of T. infestans in accordance with the distribution of the families of repetitive DNA using seven different markers. We found that two arrays with lengths of 79 and 33bp have a strong relationship with transposable element sequences, suggesting that these two families of satDNA probably originated from Polintons. The results also allowed us to identify at least four chromosome rearrangements involved in the amplification/dispersion of AT-rich satDNA of T. infestans. These data should be very useful in new studies including those examining the cytogenomic and population aspects of this very important species of insect.
Collapse
Affiliation(s)
- Vanessa Bellini Bardella
- Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, IBILCE/UNESP, 15054-000 São José do Rio Preto, São Paulo, Brazil.
| | - João Aristeu da Rosa
- Departamento de Ciências Biológicas, Faculdade de Ciências Famacêuticas de Araraquara, FCFAR/UNESP, 14801-902 Araraquara, São Paulo, Brazil.
| | - André Luís Laforga Vanzela
- Departamento de Biologia Geral, CCB, Universidade Estadual de Londrina, 86051-990 Londrina, Paraná, Brazil.
| |
Collapse
|
13
|
Matyášek R, Renny-Byfield S, Fulneček J, Macas J, Grandbastien MA, Nichols R, Leitch A, Kovařík A. Next generation sequencing analysis reveals a relationship between rDNA unit diversity and locus number in Nicotiana diploids. BMC Genomics 2012; 13:722. [PMID: 23259460 PMCID: PMC3563450 DOI: 10.1186/1471-2164-13-722] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 12/13/2012] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Tandemly arranged nuclear ribosomal DNA (rDNA), encoding 18S, 5.8S and 26S ribosomal RNA (rRNA), exhibit concerted evolution, a pattern thought to result from the homogenisation of rDNA arrays. However rDNA homogeneity at the single nucleotide polymorphism (SNP) level has not been detailed in organisms with more than a few hundred copies of the rDNA unit. Here we study rDNA complexity in species with arrays consisting of thousands of units. METHODS We examined homogeneity of genic (18S) and non-coding internally transcribed spacer (ITS1) regions of rDNA using Roche 454 and/or Illumina platforms in four angiosperm species, Nicotiana sylvestris, N. tomentosiformis, N. otophora and N. kawakamii. We compared the data with Southern blot hybridisation revealing the structure of intergenic spacer (IGS) sequences and with the number and distribution of rDNA loci. RESULTS AND CONCLUSIONS In all four species the intragenomic homogeneity of the 18S gene was high; a single ribotype makes up over 90% of the genes. However greater variation was observed in the ITS1 region, particularly in species with two or more rDNA loci, where >55% of rDNA units were a single ribotype, with the second most abundant variant accounted for >18% of units. IGS heterogeneity was high in all species. The increased number of ribotypes in ITS1 compared with 18S sequences may reflect rounds of incomplete homogenisation with strong selection for functional genic regions and relaxed selection on ITS1 variants. The relationship between the number of ITS1 ribotypes and the number of rDNA loci leads us to propose that rDNA evolution and complexity is influenced by locus number and/or amplification of orphaned rDNA units at new chromosomal locations.
Collapse
Affiliation(s)
- Roman Matyášek
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i, Královopolská 135, Brno, CZ-612 65, Czech Republic
| | - Simon Renny-Byfield
- Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road, London, E1 4NS, UK
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Jaroslav Fulneček
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i, Královopolská 135, Brno, CZ-612 65, Czech Republic
| | - Jiří Macas
- Biology Centre, Academy of Sciences of the Czech Republic, Institute of Plant Molecular Biology, Branišovská 31, České Budějovice, CZ-370 05, Czech Republic
| | - Marie-Angele Grandbastien
- Institut Jean-Pierre Bourgin, Laboratoire de Biologie Cellulaire, INRA-Centre de Versailles, Versailles Cedex, F-780 26, France
| | - Richard Nichols
- Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road, London, E1 4NS, UK
| | - Andrew Leitch
- Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road, London, E1 4NS, UK
| | - Aleš Kovařík
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i, Královopolská 135, Brno, CZ-612 65, Czech Republic
| |
Collapse
|
14
|
Sharakhova MV, Sharakhov IV. Organization and evolution of heterochromatin in malaria mosquitoes. RUSS J GENET+ 2010. [DOI: 10.1134/s1022795410100273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
15
|
Sharakhova MV, George P, Brusentsova IV, Leman SC, Bailey JA, Smith CD, Sharakhov IV. Genome mapping and characterization of the Anopheles gambiae heterochromatin. BMC Genomics 2010; 11:459. [PMID: 20684766 PMCID: PMC3091655 DOI: 10.1186/1471-2164-11-459] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Accepted: 08/04/2010] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Heterochromatin plays an important role in chromosome function and gene regulation. Despite the availability of polytene chromosomes and genome sequence, the heterochromatin of the major malaria vector Anopheles gambiae has not been mapped and characterized. RESULTS To determine the extent of heterochromatin within the An. gambiae genome, genes were physically mapped to the euchromatin-heterochromatin transition zone of polytene chromosomes. The study found that a minimum of 232 genes reside in 16.6 Mb of mapped heterochromatin. Gene ontology analysis revealed that heterochromatin is enriched in genes with DNA-binding and regulatory activities. Immunostaining of the An. gambiae chromosomes with antibodies against Drosophila melanogaster heterochromatin protein 1 (HP1) and the nuclear envelope protein lamin Dm0 identified the major invariable sites of the proteins' localization in all regions of pericentric heterochromatin, diffuse intercalary heterochromatin, and euchromatic region 9C of the 2R arm, but not in the compact intercalary heterochromatin. To better understand the molecular differences among chromatin types, novel Bayesian statistical models were developed to analyze genome features. The study found that heterochromatin and euchromatin differ in gene density and the coverage of retroelements and segmental duplications. The pericentric heterochromatin had the highest coverage of retroelements and tandem repeats, while intercalary heterochromatin was enriched with segmental duplications. We also provide evidence that the diffuse intercalary heterochromatin has a higher coverage of DNA transposable elements, minisatellites, and satellites than does the compact intercalary heterochromatin. The investigation of 42-Mb assembly of unmapped genomic scaffolds showed that it has molecular characteristics similar to cytologically mapped heterochromatin. CONCLUSIONS Our results demonstrate that Anopheles polytene chromosomes and whole-genome shotgun assembly render the mapping and characterization of a significant part of heterochromatic scaffolds a possibility. These results reveal the strong association between characteristics of the genome features and morphological types of chromatin. Initial analysis of the An. gambiae heterochromatin provides a framework for its functional characterization and comparative genomic analyses with other organisms.
Collapse
|
16
|
Contrasting evolutionary dynamics between angiosperm and mammalian genomes. Trends Ecol Evol 2009; 24:572-82. [PMID: 19665255 DOI: 10.1016/j.tree.2009.04.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Revised: 04/06/2009] [Accepted: 04/22/2009] [Indexed: 12/23/2022]
Abstract
Continuing advances in genomics are revealing substantial differences between genomes of major eukaryotic lineages. Because most data (in terms of depth and phylogenetic breadth) are available for angiosperms and mammals, we explore differences between these groups and show that angiosperms have less highly compartmentalized and more diverse genomes than mammals. In considering the causes of these differences, four mechanisms are highlighted: polyploidy, recombination, retrotransposition and genome silencing, which have different modes and time scales of activity. Angiosperm genomes are evolutionarily more dynamic and labile, whereas mammalian genomes are more stable at both the sequence and chromosome level. We suggest that fundamentally different life strategies and development feedback on the genome exist, influencing dynamics and evolutionary trajectories at all levels from the gene to the genome.
Collapse
|
17
|
The role of repetitive DNA in structure and evolution of sex chromosomes in plants. Heredity (Edinb) 2009; 102:533-41. [PMID: 19277056 DOI: 10.1038/hdy.2009.17] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Eukaryotic genomes contain a large proportion of repetitive DNA sequences, mostly transposable elements (TEs) and tandem repeats. These repetitive sequences often colonize specific chromosomal (Y or W chromosomes, B chromosomes) or subchromosomal (telomeres, centromeres) niches. Sex chromosomes, especially non-recombining regions of the Y chromosome, are subject to different evolutionary forces compared with autosomes. In non-recombining regions of the Y chromosome repetitive DNA sequences are accumulated, representing a dominant and early process forming the Y chromosome, probably before genes start to degenerate. Here we review the occurrence and role of repetitive DNA in Y chromosome evolution in various species with a focus on dioecious plants. We also discuss the potential link between recombination and transposition in shaping genomes.
Collapse
|
18
|
Evolutionary dynamics and sites of illegitimate recombination revealed in the interspersion and sequence junctions of two nonhomologous satellite DNAs in cactophilic Drosophila species. Heredity (Edinb) 2009; 102:453-64. [PMID: 19259119 DOI: 10.1038/hdy.2009.9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Satellite DNA (satDNA) is a major component of genomes but relatively little is known about the fine-scale organization of unrelated satDNAs residing at the same chromosome location, and the sequence structure and dynamics of satDNA junctions. We studied the organization and sequence junctions of two nonhomologous satDNAs, pBuM and DBC-150, in three species from the neotropical Drosophila buzzatii cluster (repleta group). In situ hybridization to microchromosomes, interphase nuclei and extended DNA fibers showed frequent interspersion of the two satellites in D. gouveai, D. antonietae and, to a lesser extent, D. seriema. We isolated by PCR six pBuM x DBC-150 junctions: four are exclusive to D. gouveai and two are exclusive to D. antonietae. The six junction breakpoints occur at different positions within monomers, suggesting independent origin. Four junctions showed abrupt transitions between the two satellites, whereas two junctions showed a distinct 10 bp tandem duplication before the junction. Unlike pBuM, DBC-150 junction repeats are more variable than randomly cloned monomers and showed diagnostic features in common to a 3-monomer higher-order repeat seen in the sister species D. serido. The high levels of interspersion between pBuM and DBC-150 repeats suggest extensive rearrangements between the two satellites, maybe favored by specific features of the microchromosomes. Our interpretation is that the junctions evolved by multiples events of illegitimate recombination between nonhomologous satDNA repeats, with subsequent rounds of unequal crossing-over expanding the copy number of some of the junctions.
Collapse
|
19
|
Xia A, Sharakhova MV, Sharakhov IV. Reconstructing ancestral autosomal arrangements in the Anopheles gambiae complex. J Comput Biol 2008; 15:965-80. [PMID: 18774905 DOI: 10.1089/cmb.2008.0076] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Members of the Anopheles gambiae complex have remarkably distinct ecological adaptations, behaviors, and degrees of vectorial capacity. Inferring phylogenetic relationships in the complex is crucial for identifying the genomic changes associated with the origin and loss of epidemiologically important traits. However, the high level of sequence similarity, genetic introgression, and shared molecular ancestral polymorphisms makes reconstruction of the A. gambiae complex phylogeny difficult. Phylogenetic relationships among the members of species complexes can be inferred from the distribution of fixed chromosomal inversions if outgroup arrangements are known. The aim of this work is to test a possibility of determining ancestral autosomal arrangements in the A. gambiae complex using outgroup chromosomes and a combination of bioinformatic and cytogenetic approaches. The minimum number of inversions between members of the A. gambiae complex and the outgroup species A. funestus and A. stephensi was calculated using the Multiple Genome Rearrangements (MGR) and Sorting Permutation by Reversals and block-INterchanGes (SPRING) programs. The physical mapping of A. merus chromosomes identified molecular coordinates of the proximal 2Ro+ inversion breakpoint in A. gambiae. DNA probes from 2La+ and 2Ro+ inversion breakpoints of the A. gambiae were mapped to the A. stephensi chromosomes. Assuming monophyletic origin of the inversions, this study concludes that physical mapping of ingroup and outgroup species can be used for identifying inversion breakpoints and ancestral autosomal arrangements within species complexes. Molecular characterization of the breakpoints in both ingroup and outgroup species will provide a solid basis for reconstructing the inversion history in the A. gambiae complex.
Collapse
Affiliation(s)
- Ai Xia
- Department of Entomology, Virginia Tech, Blacksburg, VA 24061, USA
| | | | | |
Collapse
|
20
|
Abstract
The study of insect satellite DNAs (satDNAs) indicates the evolutionary conservation of certain features despite their sequence heterogeneity. Such features can include total length, monomer length, motifs, particular regions and/or secondary and tertiary structures. satDNAs may act as protein-binding sites, structural domains or sites for epigenetic modifications. The selective constraints in the evolution of satDNAs may be due to the satDNA sequence interaction with specific proteins important in heterochromatin formation and possible a role in controlling gene expression. The transcription of satDNA has been described in vertebrates, invertebrates and plants. In insects, differential satDNA expression has been observed in different cells, developmental stages, sex and caste of the individuals. These transcription differences may suggest their involvement in gene-regulation processes. In addition, the satDNA or its transcripts appear to be involved in heterochromatin formation and in chromatin-elimination processes. The importance of transposable elements to insect satDNA is shown by their presence as a constituent of satDNA in several species of insects (including possible active elements). In addition, they may be involved in the formation of centromeres and telomeres and in the homogenization and expansion of satDNA.
Collapse
Affiliation(s)
- T Palomeque
- Departamento de Biología Experimental, Area de Genética, Universidad de Jaén, Jaén, Spain.
| | | |
Collapse
|
21
|
Wilkins EE, Howell PI, Benedict MQ. X and Y chromosome inheritance and mixtures of rDNA intergenic spacer regions in Anopheles gambiae. INSECT MOLECULAR BIOLOGY 2007; 16:735-741. [PMID: 18093002 DOI: 10.1111/j.1365-2583.2007.00769.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We observed Anopheles gambiae sensu stricto stocks that contained both Mopti (M) and Savanna (S) rDNA intergenic spacers (IGS). ASEMBO1 male IGS sequences consistently had a mixture. A diagnostic M and S Hha I restriction enzyme site in these fragments was concordant with two SNPs associated with M and S. Standard M and S stocks demonstrated X-chromosome-only inheritance of the rDNA form, but the ASEMBO1 males showed X and Y chromosome linkage of mixed rDNA. The metaphase Y chromosomes of ASEMBO1 contained a significantly larger amount of DNA relative to the X than a standard S stock. Analysis of wild A. gambiae males from the putative location of origin of the ASEMBO1 stock did not detect the same pattern of polymorphism observed in the laboratory stock but did detect heterogeneous arrays including some missing a diagnostic Hha I restriction site. These results demonstrate that M and S IGS types can occur within the rDNA arrays of a chromatid in laboratory A. gambiae stocks, and some A. gambiae s.s. have rDNA on the Y chromosome.
Collapse
Affiliation(s)
- E E Wilkins
- Centers for Disease Control and Prevention (CDC) and Atlanta Research and Education Foundation, Atlanta, GA, USA
| | | | | |
Collapse
|
22
|
Mravinac B, Plohl M. Satellite DNA junctions identify the potential origin of new repetitive elements in the beetle Tribolium madens. Gene 2007; 394:45-52. [PMID: 17379457 DOI: 10.1016/j.gene.2007.01.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 01/24/2007] [Accepted: 01/26/2007] [Indexed: 11/25/2022]
Abstract
Two related satellite DNA families (satellite I and satellite II) with complex higher-order repeat (HOR) monomers represent major DNA components equilocated in the pericentromeric heterochromatin of all Tribolium madens chromosomes. Fragments obtained upon genomic DNA restriction revealed two subfamilies of satellite II monomers, and also identified regions of transition between satellite I and satellite II sequences. The two subfamilies differ not only in diagnostic nucleotides, but also in flipped orientation of constituent subunits. Hybrid genomic fragments comprise directly linked satellite I and satellite II monomers that cannot be distinguished from randomly cloned monomers of corresponding families. An exception is the most proximal satellite I monomer in the hybrid fragment named TMADhinf, which shows sequence divergence typical for repeats evolving at array ends, in zones of low homogenization efficiency. This pattern points to the extensive rearrangement processes generating abrupt transitions between satellite arrays combined with array maintenance by unequal crossover. Switching points between adjacent satellites as well as the edges of flipped subunits are localized within a short sequence segment, indicating a preferential site of recombination within satellite subunits. Multiple copies of TMADhinf junction fragment support the hypothesis that sites of evolutionary origin of novel satellite repeat (sub)families can be localized at array ends, in regions of enhanced sequence divergence.
Collapse
Affiliation(s)
- Brankica Mravinac
- Department of Molecular Biology, Ruder Bosković Institute, Bijenicka 54, HR-10002 Zagreb, Croatia
| | | |
Collapse
|
23
|
Sharakhova MV, Hammond MP, Lobo NF, Krzywinski J, Unger MF, Hillenmeyer ME, Bruggner RV, Birney E, Collins FH. Update of the Anopheles gambiae PEST genome assembly. Genome Biol 2007; 8:R5. [PMID: 17210077 PMCID: PMC1839121 DOI: 10.1186/gb-2007-8-1-r5] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 10/24/2006] [Accepted: 01/08/2007] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND The genome of Anopheles gambiae, the major vector of malaria, was sequenced and assembled in 2002. This initial genome assembly and analysis made available to the scientific community was complicated by the presence of assembly issues, such as scaffolds with no chromosomal location, no sequence data for the Y chromosome, haplotype polymorphisms resulting in two different genome assemblies in limited regions and contaminating bacterial DNA. RESULTS Polytene chromosome in situ hybridization with cDNA clones was used to place 15 unmapped scaffolds (sizes totaling 5.34 Mbp) in the pericentromeric regions of the chromosomes and oriented a further 9 scaffolds. Additional analysis by in situ hybridization of bacterial artificial chromosome (BAC) clones placed 1.32 Mbp (5 scaffolds) in the physical gaps between scaffolds on euchromatic parts of the chromosomes. The Y chromosome sequence information (0.18 Mbp) remains highly incomplete and fragmented among 55 short scaffolds. Analysis of BAC end sequences showed that 22 inter-scaffold gaps were spanned by BAC clones. Unmapped scaffolds were also aligned to the chromosome assemblies in silico, identifying regions totaling 8.18 Mbp (144 scaffolds) that are probably represented in the genome project by two alternative assemblies. An additional 3.53 Mbp of alternative assembly was identified within mapped scaffolds. Scaffolds comprising 1.97 Mbp (679 small scaffolds) were identified as probably derived from contaminating bacterial DNA. In total, about 33% of previously unmapped sequences were placed on the chromosomes. CONCLUSION This study has used new approaches to improve the physical map and assembly of the A. gambiae genome.
Collapse
Affiliation(s)
- Maria V Sharakhova
- Center for Global Health and Infectious Diseases, University of Notre Dame, Galvin Life Sciences Building, Notre Dame, IN 46556-0369, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Cywinska A, Hunter FF, Hebert PDN. Identifying Canadian mosquito species through DNA barcodes. MEDICAL AND VETERINARY ENTOMOLOGY 2006; 20:413-24. [PMID: 17199753 DOI: 10.1111/j.1365-2915.2006.00653.x] [Citation(s) in RCA: 189] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A short fragment of mt DNA from the cytochrome c oxidase 1 (CO1) region was used to provide the first CO1 barcodes for 37 species of Canadian mosquitoes (Diptera: Culicidae) from the provinces Ontario and New Brunswick. Sequence variation was analysed in a 617-bp fragment from the 5' end of the CO1 region. Sequences of each mosquito species formed barcode clusters with tight cohesion that were usually clearly distinct from those of allied species. CO1 sequence divergences were, on average, nearly 20 times higher for congeneric species than for members of a species; divergences between congeneric species averaged 10.4% (range 0.2-17.2%), whereas those for conspecific individuals averaged 0.5% (range 0.0-3.9%).
Collapse
Affiliation(s)
- A Cywinska
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada.
| | | | | |
Collapse
|
25
|
Kejnovsky E, Hobza R, Kubat Z, Widmer A, Marais GAB, Vyskot B. High intrachromosomal similarity of retrotransposon long terminal repeats: evidence for homogenization by gene conversion on plant sex chromosomes? Gene 2006; 390:92-7. [PMID: 17134852 DOI: 10.1016/j.gene.2006.10.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Revised: 10/03/2006] [Accepted: 10/03/2006] [Indexed: 11/25/2022]
Abstract
Retrotransposons are ubiquitous in the plant genomes and are responsible for their plasticity. Recently, we described a novel family of gypsy-like retrotransposons, named Retand, in the dioecious plant Silene latifolia possessing evolutionary young sex chromosomes of the mammalian type (XY). Here we have analyzed long terminal repeats (LTRs) of Retand that were amplified from laser microdissected X and Y sex chromosomes and autosomes of S. latifolia. A majority of X and Y-derived LTRs formed a few separate clades in phylogenetic analysis reflecting their high intrachromosomal similarity. Moreover, the LTRs localized on the Y chromosome were less divergent than the X chromosome-derived or autosomal LTRs. These data can be explained by a homogenization process, such as gene conversion, working more intensively on the Y chromosome.
Collapse
Affiliation(s)
- Eduard Kejnovsky
- Laboratory of Plant Developmental Genetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, CZ-612 65 Brno, Czech Republic.
| | | | | | | | | | | |
Collapse
|
26
|
Krzywinski J, Chrystal MA, Besansky NJ. Gene finding on the Y: fruitful strategy in Drosophila does not deliver in Anopheles. Genetica 2006; 126:369-75. [PMID: 16636930 DOI: 10.1007/s10709-005-1985-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Accepted: 08/07/2005] [Indexed: 10/24/2022]
Abstract
The Anopheles gambiae genome project yielded almost complete sequences for the autosomes and for a large part of the X chromosome, however, no information for the Y chromosome was obtained. Yet, by design, fragmented Y chromosome sequences should be present in the resulting assembly. Here we report the search for Anopheles Y chromosome genes using a strategy successfully applied for identification of Y genes in Drosophila. A complete set of the unmapped scaffolds was targeted in a broad TBLASTN search using both A. gambiae predicted genes and all proteins from nr database as query sequences. After filtering of the BLAST report, we selected 181 scaffolds possibly containing fragments of Y chromosome genes to experimentally test their Y-linkage. Surprisingly, none of the tested sequences appeared to originate from the Y chromosome. Several factors could account for the failure to detect Y genes, including their different organization in A. gambiae compared to Drosophila and the suboptimal quality of the assembly and annotation of the Anopheles genome. Regardless of the cause, our results illuminate problems associated with the genome analysis of outbred organisms.
Collapse
Affiliation(s)
- Jaroslaw Krzywinski
- Center for Tropical Disease Research and Training, Department of Biology, University of Notre Dame, 46556, Notre Dame, Indiana, USA
| | | | | |
Collapse
|