1
|
Analyses of the Updated "Animal rDNA Loci Database" with an Emphasis on Its New Features. Int J Mol Sci 2021; 22:ijms222111403. [PMID: 34768834 PMCID: PMC8584138 DOI: 10.3390/ijms222111403] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/17/2021] [Accepted: 10/20/2021] [Indexed: 11/17/2022] Open
Abstract
We report on a major update to the animal rDNA loci database, which now contains cytogenetic information for 45S and 5S rDNA loci in more than 2600 and 1000 species, respectively. The data analyses show the following: (i) A high variability in 5S and 45S loci numbers, with both showing 50-fold or higher variability. However, karyotypes with an extremely high number of loci were rare, and medians generally converged to two 5S sites and two 45S rDNA sites per diploid genome. No relationship was observed between the number of 5S and 45S loci. (ii) The position of 45S rDNA on sex chromosomes was relatively frequent in some groups, particularly in arthropods (14% of karyotypes). Furthermore, 45S rDNA was almost exclusively located in microchromosomes when these were present (in birds and reptiles). (iii) The proportion of active NORs (positively stained with silver staining methods) progressively decreased with an increasing number of 45S rDNA loci, and karyotypes with more than 12 loci showed, on average, less than 40% of active loci. In conclusion, the updated version of the database provides some new insights into the organization of rRNA genes in chromosomes. We expect that its updated content will be useful for taxonomists, comparative cytogeneticists, and evolutionary biologists.
Collapse
|
2
|
Li Y, Zhang B, Moran NA. The Aphid X Chromosome Is a Dangerous Place for Functionally Important Genes: Diverse Evolution of Hemipteran Genomes Based on Chromosome-Level Assemblies. Mol Biol Evol 2021; 37:2357-2368. [PMID: 32289166 PMCID: PMC7403619 DOI: 10.1093/molbev/msaa095] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Different evolutionary forces shape gene content and sequence evolution on autosomes versus sex chromosomes. Location on a sex chromosome can favor male-beneficial or female-beneficial mutations depending on the sex determination system and selective pressure on different sexual morphs. An X0 sex determination can lead to autosomal enrichment of male-biased genes, as observed in some hemipteran insect species. Aphids share X0 sex determination; however, models predict the opposite pattern, due to their unusual life cycles, which alternate between all-female asexual generations and a single sexual generation. Predictions include enrichment of female-biased genes on autosomes and of male-biased genes on the X, in contrast to expectations for obligately sexual species. Robust tests of these models require chromosome-level genome assemblies for aphids and related hemipterans with X0 sex determination and obligate sexual reproduction. In this study, we built the first chromosome-level assembly of a psyllid, an aphid relative with X0 sex determination and obligate sexuality, and compared it with recently resolved chromosome-level assemblies of aphid genomes. Aphid and psyllid X chromosomes differ strikingly. In aphids, female-biased genes are strongly enriched on autosomes and male-biased genes are enriched on the X. In psyllids, male-biased genes are enriched on autosomes. Furthermore, functionally important gene categories of aphids are enriched on autosomes. Aphid X-linked genes and male-biased genes are under relaxed purifying selection, but gene content and order on the X is highly conserved, possibly reflecting constraints imposed by unique chromosomal mechanisms associated with the unusual aphid life cycle.
Collapse
Affiliation(s)
- Yiyuan Li
- Department of Integrative Biology, University of Texas at Austin, Austin, TX
| | - Bo Zhang
- Department of Integrative Biology, University of Texas at Austin, Austin, TX.,Laboratory of Predatory Mites, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| | - Nancy A Moran
- Department of Integrative Biology, University of Texas at Austin, Austin, TX
| |
Collapse
|
3
|
Kuznetsova V, Grozeva S, Gokhman V. Telomere structure in insects: A review. J ZOOL SYST EVOL RES 2019. [DOI: 10.1111/jzs.12332] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Valentina Kuznetsova
- Department of Karyosystematics, Zoological Institute Russian Academy of Sciences St. Petersburg Russia
| | - Snejana Grozeva
- Cytotaxonomy and Evolution Research Group, Institute of Biodiversity and Ecosystem Research Bulgarian Academy of Sciences Sofia Bulgaria
| | | |
Collapse
|
4
|
Mandrioli M, Melchiori G, Panini M, Chiesa O, Giordano R, Mazzoni E, Manicardi GC. Analysis of the extent of synteny and conservation in the gene order in aphids: A first glimpse from the Aphis glycines genome. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 113:103228. [PMID: 31446034 DOI: 10.1016/j.ibmb.2019.103228] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 07/03/2019] [Accepted: 08/21/2019] [Indexed: 06/10/2023]
Abstract
In the last decade several insect genomes have been sequenced, but for most the chromosomal mapping of the identified scaffolds/annotated genes is not available. The lack of this information makes it difficult to analyse various genetic aspects, including the presence of genome rearrangements and the extent of synteny within and across species. We mapped five multigenic DNA families (major and minor rDNAs, histone gene cluster, esterases and carotenoid desaturases) and seven scaffolds corresponding to 9 Mb of the soybean aphid, Aphis glycines, genome and identified loci spanning the four soybean aphid chromosomes. A comparative analysis of the localization of the annotated A. glycines genes with respect to the peach potato aphid, Myzus persicae, and the fly, Drosophila melanogaster, evidenced a lower degree of synteny between the two aphid species than in the aphid-fly comparison. Only 1.4 genes per syntenic block were observed in aphids in contrast to 2.3 genes per block in flies. This higher chromosomal rearrangement rate in aphids could be explained considering that they possess holocentric chromosomes that can favour the stabilization and inheritance of chromosomal rearrangements. Lastly, our experiments did not detect the presence of chimeric assemblies in the newly available A. glycines biotype 1 genome, differently from what reported in assembled genome of other aphid species, suggesting that chromosomal mapping can be used to ascertain the quality of assembled genomes.
Collapse
Affiliation(s)
- Mauro Mandrioli
- Dipartimento di Scienze della Vita, Università di Modena e Reggio Emilia, Via Campi 213/D, 41125, Modena, Italy.
| | - Giulia Melchiori
- Dipartimento di Scienze della Vita, Università di Modena e Reggio Emilia, Via Campi 213/D, 41125, Modena, Italy
| | - Michela Panini
- Dipartimento di Scienze delle produzioni vegetali sostenibili, Università Cattolica del Sacro Cuore, Piacenza, Italy
| | - Olga Chiesa
- Dipartimento di Scienze delle produzioni vegetali sostenibili, Università Cattolica del Sacro Cuore, Piacenza, Italy
| | - Rosanna Giordano
- Puerto Rico Science, Technology & Research Trust, San Juan, PR, USA; Know Your Bee, Inc., San Juan, PR, USA
| | - Emanuele Mazzoni
- Dipartimento di Scienze delle produzioni vegetali sostenibili, Università Cattolica del Sacro Cuore, Piacenza, Italy
| | - Gian Carlo Manicardi
- Dipartimento di Scienze della Vita, Università di Modena e Reggio Emilia, Via Campi 213/D, 41125, Modena, Italy
| |
Collapse
|
5
|
Mandrioli M, Zambonini G, Manicardi GC. Comparative Gene Mapping as a Tool to Understand the Evolution of Pest Crop Insect Chromosomes. Int J Mol Sci 2017; 18:ijms18091919. [PMID: 28880213 PMCID: PMC5618568 DOI: 10.3390/ijms18091919] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 08/31/2017] [Accepted: 09/05/2017] [Indexed: 11/22/2022] Open
Abstract
The extent of the conservation of synteny and gene order in aphids has been previously investigated only by comparing a small subset of linkage groups between the pea aphid Acyrthosiphon pisum and a few other aphid species. Here we compared the localization of eight A. pisum scaffolds (covering more than 5 Mb and 83 genes) in respect to the Drosophila melanogaster Muller elements identifying orthologous loci spanning all the four A. pisum chromosomes. Comparison of the genetic maps revealed a conserved synteny across different loci suggesting that the study of the fruit fly Muller elements could favour the identification of chromosomal markers useful for the study of chromosomal rearrangements in aphids. A. pisum is the first aphid species to have its genome sequenced and the finding that there are several chromosomal regions in synteny between Diptera and Hemiptera indicates that the genomic tools developed in A. pisum will be broadly useful not only for the study of other aphids but also for other insect species.
Collapse
Affiliation(s)
- Mauro Mandrioli
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena 41125, Italy.
| | - Giada Zambonini
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena 41125, Italy.
| | - Gian Carlo Manicardi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena 41125, Italy.
| |
Collapse
|
6
|
Chirino MG, Dalíková M, Marec FR, Bressa MJ. Chromosomal distribution of interstitial telomeric sequences as signs of evolution through chromosome fusion in six species of the giant water bugs (Hemiptera, Belostoma). Ecol Evol 2017; 7:5227-5235. [PMID: 28770061 PMCID: PMC5528210 DOI: 10.1002/ece3.3098] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 04/26/2017] [Accepted: 04/27/2017] [Indexed: 11/11/2022] Open
Abstract
Tandem arrays of TTAGG repeats show a highly conserved location at the telomeres across the phylogenetic tree of arthropods. In giant water bugs Belostoma, the chromosome number changed during speciation by fragmentation of the single ancestral X chromosome, resulting in a multiple sex chromosome system. Several autosome–autosome fusions and a fusion between the sex chromosome pair and an autosome pair resulted in the reduced number in several species. We mapped the distribution of telomeric sequences and interstitial telomeric sequences (ITSs) in Belostoma candidulum (2n = 12 + XY/XX; male/female), B. dentatum (2n = 26 + X1X2Y/X1X1X2X2), B. elegans (2n = 26 + X1X2Y/X1X1X2X2), B. elongatum (2n = 26 + X1X2Y/X1X1X2X2), B. micantulum (2n = 14 + XY/XX), and B. oxyurum (2n = 6 + XY/XX) by FISH with the (TTAGG)n probes. Hybridization signals confirmed the presence of TTAGG repeats in the telomeres of all species examined. The three species with reduced chromosome numbers showed additional hybridization signals in interstitial positions, indicating the occurrence of ITS. From the comparison of all species here analyzed, we observed inverse relationships between chromosome number and chromosome size, and between presence/absence of ITS and chromosome number. The ITS distribution between these closely related species supports the hypothesis that several telomere–telomere fusions of the chromosomes from an ancestral diploid chromosome number 2n = 26 + XY/XX played a major role in the karyotype evolution of Belostoma. Consequently, our study provide valuable features that can be used to understand the karyotype evolution, may contribute to a better understanding of taxonomic relationships, and also elucidate the high plasticity of nuclear genomes at the chromosomal level during the speciation processes.
Collapse
Affiliation(s)
- Mónica G Chirino
- Grupo de Citogenética de Insectos Instituto de Ecología, Genética y Evolución de Buenos Aires Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires Ciudad Autónoma de Buenos Aires Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas Ciudad Autónoma de Buenos Aires Argentina
| | - Martina Dalíková
- Laboratory of Molecular Cytogenetics Institute of Entomology Biology Centre ASCR České Budějovice Czech Republic
| | - František R Marec
- Laboratory of Molecular Cytogenetics Institute of Entomology Biology Centre ASCR České Budějovice Czech Republic
| | - María J Bressa
- Grupo de Citogenética de Insectos Instituto de Ecología, Genética y Evolución de Buenos Aires Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires Ciudad Autónoma de Buenos Aires Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas Ciudad Autónoma de Buenos Aires Argentina
| |
Collapse
|
7
|
Gavrilov-Zimin IA, Stekolshchikov AV, Gautam D. General trends of chromosomal evolution in Aphidococca (Insecta, Homoptera, Aphidinea + Coccinea). COMPARATIVE CYTOGENETICS 2015; 9:335-422. [PMID: 26312130 PMCID: PMC4547034 DOI: 10.3897/compcytogen.v9i3.4930] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 05/14/2015] [Indexed: 05/08/2023]
Abstract
Parallel trends of chromosomal evolution in Aphidococca are discussed, based on the catalogue of chromosomal numbers and genetic systems of scale insects by Gavrilov (2007) and the new catalogue for aphids provided in the present paper. To date chromosome numbers have been reported for 482 species of scale insects and for 1039 species of aphids, thus respectively comprising about 6% and 24% of the total number of species. Such characters as low modal numbers of chromosomes, heterochromatinization of part of chromosomes, production of only two sperm instead of four from each primary spermatocyte, physiological sex determination, "larval" meiosis, wide distribution of parthenogenesis and chromosomal races are considered as a result of homologous parallel changes of the initial genotype of Aphidococca ancestors. From a cytogenetic point of view, these characters separate Aphidococca from all other groups of Paraneoptera insects and in this sense can be considered as additional taxonomic characters. In contrast to available paleontological data the authors doubt that Coccinea with their very diverse (and partly primitive) genetic systems may have originated later then Aphidinea with their very specialised and unified genetic system.
Collapse
Affiliation(s)
- Ilya A. Gavrilov-Zimin
- Zoological Institute, Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia
| | - Andrey V. Stekolshchikov
- Zoological Institute, Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia
| | - D.C. Gautam
- Department of Bio-Sciences, Himachal Pradesh University, Shimla, India
| |
Collapse
|
8
|
Manicardi GC, Mandrioli M, Blackman RL. The cytogenetic architecture of the aphid genome. Biol Rev Camb Philos Soc 2014; 90:112-25. [PMID: 24593177 DOI: 10.1111/brv.12096] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 02/04/2014] [Accepted: 02/07/2014] [Indexed: 12/28/2022]
Abstract
In recent years aphids, with their well-defined polyphenism, have become favoured as model organisms for the study of epigenetic processes. The availability of the pea aphid (Acyrthosiphon pisum) genome sequence has engendered much research aimed at elucidating the mechanisms by which the phenotypic plasticity of aphids is inherited and controlled. Yet so far this research effort has paid little attention to the cytogenetic processes that play a vital part in the organisation, expression and inheritance of the aphid genome. Aphids have holocentric chromosomes, which have very different properties from the chromosomes with localised centromeres that are found in most other organisms. Here we review the diverse forms of aphid chromosome behaviour that occur during sex determination and male and female meiosis, often in response to environmental changes and mediated by endocrine factors. Remarkable differences occur, even between related species, that could have significant effects on the inheritance of all or parts of the genome. In relation to this, we review the particular features of the distribution of heterochromatin, rDNA genes and other repetitive DNA in aphid chromosomes, and discuss the part that these may play in the epigenetic modification of chromatin structure and function.
Collapse
Affiliation(s)
- Gian Carlo Manicardi
- Department of Life Sciences, University of Modena and Reggio Emilia, Besta Building, via Amendola 2, 42122, Reggio Emilia, Italy
| | | | | |
Collapse
|
9
|
Bellavia D, Dimarco E, Naselli F, Caradonna F. DNA-methylation dependent regulation of embryo-specific 5S ribosomal DNA cluster transcription in adult tissues of sea urchin Paracentrotus lividus. Genomics 2013; 102:397-402. [PMID: 23933480 DOI: 10.1016/j.ygeno.2013.08.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 07/25/2013] [Accepted: 08/01/2013] [Indexed: 11/26/2022]
Abstract
We have previously reported a molecular and cytogenetic characterization of three different 5S rDNA clusters in the sea urchin Paracentrotus lividus and recently, demonstrated the presence of high heterogeneity in functional 5S rRNA. In this paper, we show some important distinctive data on 5S rRNA transcription for this organism. Using single strand conformation polymorphism (SSCP) analysis, we demonstrate the existence of two classes of 5S rRNA, one which is embryo-specific and encoded by the smallest (700 bp) cluster and the other which is expressed at every stage and encoded by longer clusters (900 and 950 bp). We also demonstrate that the embryo-specific class of 5S rRNA is expressed in oocytes and embryonic stages and is silenced in adult tissue and that this phenomenon appears to be due exclusively to DNA methylation, as indicated by sensitivity to 5-azacytidine, unlike Xenopus where this mechanism is necessary but not sufficient to maintain the silenced status.
Collapse
Affiliation(s)
- Daniele Bellavia
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), Sezione di Biologia Cellulare, Ed. 16, Università degli Studi di Palermo, V.le delle Scienze, 90128 Palermo, Italy; Istituto Ortopedico Rizzoli, c/o Dipartimento di Biopatologia e Biotecnologie Mediche e Forensi (DIBIMEF), Università degli Studi di Palermo, Via Divisi 81, 90133 Palermo, Italy.
| | | | | | | |
Collapse
|
10
|
Bickel RD, Dunham JP, Brisson JA. Widespread selection across coding and noncoding DNA in the pea aphid genome. G3 (BETHESDA, MD.) 2013; 3:993-1001. [PMID: 23589520 PMCID: PMC3689810 DOI: 10.1534/g3.113.005793] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 04/08/2013] [Indexed: 12/03/2022]
Abstract
Genome-wide patterns of diversity and selection are critical measures for understanding how evolution has shaped the genome. Yet, these population genomic estimates are available for only a limited number of model organisms. Here we focus on the population genomics of the pea aphid (Acyrthosiphon pisum). The pea aphid is an emerging model system that exhibits a range of intriguing biological traits not present in classic model systems. We performed low-coverage genome resequencing of 21 clonal pea aphid lines collected from alfalfa host plants in North America to characterize genome-wide patterns of diversity and selection. We observed an excess of low-frequency polymorphisms throughout coding and noncoding DNA, which we suggest is the result of a founding event and subsequent population expansion in North America. Most gene regions showed lower levels of Tajima's D than synonymous sites, suggesting that the majority of the genome is not evolving neutrally but rather exhibits significant constraint. Furthermore, we used the pea aphid's unique manner of X-chromosome inheritance to assign genomic scaffolds to either autosomes or the X chromosome. Comparing autosomal vs. X-linked sequence variation, we discovered that autosomal genes show an excess of low frequency variants indicating that purifying selection acts more efficiently on the X chromosome. Overall, our results provide a critical first step in characterizing the genetic diversity and evolutionary pressures on an aphid genome.
Collapse
Affiliation(s)
- Ryan D Bickel
- University of Nebraska, School of Biological Sciences, Lincoln, Nebraska 68588, USA.
| | | | | |
Collapse
|
11
|
Monti V, Serafini C, Manicardi GC, Mandrioli M. Characterization of Non-LTR Retrotransposable TRAS Elements in the Aphids Acyrthosiphon pisum and Myzus persicae (Aphididae, Hemiptera). J Hered 2013; 104:547-53. [DOI: 10.1093/jhered/est017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
12
|
Panzera Y, Pita S, Ferreiro MJ, Ferrandis I, Lages C, Pérez R, Silva AE, Guerra M, Panzera F. High Dynamics of rDNA Cluster Location in Kissing Bug Holocentric Chromosomes (Triatominae, Heteroptera). Cytogenet Genome Res 2012; 138:56-67. [PMID: 22907389 DOI: 10.1159/000341888] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2012] [Indexed: 11/19/2022] Open
Affiliation(s)
- Y Panzera
- Sección Genética Evolutiva, Instituto de Biología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Monti V, Giusti M, Bizzaro D, Manicardi GC, Mandrioli M. Presence of a functional (TTAGG)(n) telomere-telomerase system in aphids. Chromosome Res 2011; 19:625-33. [PMID: 21667174 DOI: 10.1007/s10577-011-9222-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/18/2011] [Accepted: 05/20/2011] [Indexed: 11/28/2022]
Abstract
The structure of the telomeres of four aphid species (Acyrthosiphon pisum, Megoura viciae, Myzus persicae and Rhopalosiphum padi) was evaluated by Southern blotting and fluorescent in situ hybridization, revealing that each chromosomal end consists of a (TTAGG)(n) repeat. The presence of a telomerase coding gene has been verified successively in the A. pisum genome, revealing that aphid telomerase shares sequence identity ranging from 12% to 18% with invertebrate and vertebrate homologues, and possesses the two main domains involved in telomerase activity. Interestingly, telomerase expression has been verified in different somatic tissues suggesting that, in aphids, telomerase activity is not as restricted as in human cells. The study of telomeres in a M. persicae strain with a variable chromosome number showed that aphid telomerase can initiate the de novo synthesis of telomere sequences at internal breakpoints, resulting in the stabilization of chromosomal fragments.
Collapse
Affiliation(s)
- Valentina Monti
- Dipartimento di Biologia, Università di Modena e Reggio Emilia, Via Campi 213/D, 41125 Modena, Italy
| | | | | | | | | |
Collapse
|
14
|
Heckmann S, Schroeder-Reiter E, Kumke K, Ma L, Nagaki K, Murata M, Wanner G, Houben A. Holocentric Chromosomes of Luzula elegans Are Characterized by a Longitudinal Centromere Groove, Chromosome Bending, and a Terminal Nucleolus Organizer Region. Cytogenet Genome Res 2011; 134:220-8. [DOI: 10.1159/000327713] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2011] [Indexed: 11/19/2022] Open
|
15
|
Novotná J, Havelka J, Starý P, Koutecký P, Vítková M. Karyotype analysis of the Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae) reveals a large X chromosome with rRNA and histone gene families. Genetica 2011; 139:281-9. [DOI: 10.1007/s10709-011-9546-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 01/03/2011] [Indexed: 11/28/2022]
|
16
|
Mandrioli M, Azzoni P, Lombardo G, Manicardi GC. Composition and epigenetic markers of heterochromatin in the aphid Aphis nerii (Hemiptera: Aphididae). Cytogenet Genome Res 2011; 133:67-77. [PMID: 21273762 DOI: 10.1159/000323510] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2010] [Indexed: 11/19/2022] Open
Abstract
A detailed karyotype analysis of the oleander aphid Aphis nerii focusing on the distribution, molecular composition and epigenetic modifications of heterochromatin was done in order to better understand the structure and evolution of holocentric/holokinetic chromosomes in aphids. The female karyotype (2n = 8) consisted of 3 pairs of autosomes and a pair of X chromosomes that were the longest elements in the karyotype and carried a single, terminally located nucleolar organizer region. Males showed 2n = 7 chromosomes due to the presence of a single X chromosome. Heterochromatin was located in the X chromosomes only and consisted of 4 satellite DNAs that have been identified. A. nerii constitutive heterochromatin was enriched in mono-, di- and tri-methylated H3 histones and HP1 proteins but, interestingly, it lacked DNA methylation that was widespread in euchromatic chromosomal regions. These results suggest that aphid heterochromatin is assembled and condensed without any involvement of DNA methylation.
Collapse
Affiliation(s)
- M Mandrioli
- Dipartimento di Biologia, Università di Modena e Reggio Emilia, Modena, Italia.
| | | | | | | |
Collapse
|
17
|
Monti V, Manicardi GC, Mandrioli M. Cytogenetic and molecular analysis of the holocentric chromosomes of the potato aphid Macrosiphum euphorbiae (Thomas, 1878). COMPARATIVE CYTOGENETICS 2011; 5:163-72. [PMID: 24260627 PMCID: PMC3833776 DOI: 10.3897/compcytogen.v5i3.1724] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 07/19/2011] [Indexed: 05/08/2023]
Abstract
Cytogenetic and molecular investigations on the holocentric chromosomes of the aphid Macrosiphum euphorbiae (Thomas, 1878)have been carried out using silver staining and C-banding (followed by chromomycin A3 and DAPI staining) in order to improve our knowledge about the structure of aphid chromosomes. The C-banding pattern is peculiar since only the two X chromosomes and a single pair of autosomes presented heterochromatic bands. Silver staining and FISH with the 28S rDNA probe localized the rDNA genes on one telomere of each X chromosome that were also brightly fluorescent after chromomycin A3 staining of C-banded chromosomes, whereas all other heterochromatic bands were DAPI positive. Interestingly, a remarkable nucleolar organizing region (NOR) heteromorphism was present making the two X chromosomes easily distinguishable. Southern blotting and FISH assessed the presence of the (TTAGG)n repeat at the ends of all the Macrosiphum euphorbiae chromosomes. Karyotype analysis showed that all males possessed the X chromosome with the larger amount of rDNA suggesting a non-Mendelian inheritance of the two X chromosomes.
Collapse
Affiliation(s)
- Valentina Monti
- Dipartimento di Biologia, Università di Modena e Reggio Emilia, Via Campi 213/D, 41125 Modena, Italy
- Dipartimento di Scienze Agrarie e degli Alimenti, Università di Modena e Reggio Emilia, Via Amendola 2, 42100 Reggio Emilia, Italy
| | - Gian Carlo Manicardi
- Dipartimento di Scienze Agrarie e degli Alimenti, Università di Modena e Reggio Emilia, Via Amendola 2, 42100 Reggio Emilia, Italy
| | - Mauro Mandrioli
- Dipartimento di Biologia, Università di Modena e Reggio Emilia, Via Campi 213/D, 41125 Modena, Italy
| |
Collapse
|
18
|
Mandrioli M, Borsatti F. Analysis of heterochromatic epigenetic markers in the holocentric chromosomes of the aphid Acyrthosiphon pisum. Chromosome Res 2007; 15:1015-22. [PMID: 18004669 DOI: 10.1007/s10577-007-1176-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2007] [Revised: 09/07/2007] [Accepted: 09/07/2007] [Indexed: 11/28/2022]
Abstract
Monomethylated-K9 H3 histones (Me9H3) and heterochromatin protein 1 (HP1) are reported as heterochromatin markers in several eukaryotes possessing monocentric chromosomes. In order to confirm that these epigenetic markers are evolutionarily conserved, we sequenced the HP1 cDNA and verified the distribution of Me9H3 histones and HP1 in the holocentric chromosomes of the aphid Acyrthosiphon pisum. Sequencing indicates that A. pisum HP1 cDNA (called ApHP1) is 1623 bp long, including a 170 bp long 5'UTR and a 688 bp long 3'UTR. The ApHP1 protein consists of 254 amino acidic residues, has a predicted molecular mass of 28 kDa and a net negative charge. At the structural level, it shows an N terminal chromo domain and a chromo shadow domain at the C terminus linked by a short hinge region. At the cytogenetic level, ApHP1 is located exclusively in the heterochromatic regions of the chromosomes. The same heterochromatic regions were labelled after immuno-staining with antibodies against Me9H3 histones, confirming that Hp1 and Me9H3 co-localize at heterochromatic chromosomal areas. Surprisingly, aphid heterochromatin lacks DNA methylation and methylated cytosine residues were mainly spread at euchromatic regions. Finally, the absence of DNA methylation is observed also in aphid rDNA genes that have been repeatedly described as mosaic of methylated and unmethylated units in vertebrates.
Collapse
Affiliation(s)
- Mauro Mandrioli
- Dipartimento di Biologia Animale, Università di Modena e Reggio Emilia, Via Campi 213/D, 41100 Modena, Italy.
| | | |
Collapse
|
19
|
Braendle C, Caillaud MC, Stern DL. Genetic mapping of aphicarus -- a sex-linked locus controlling a wing polymorphism in the pea aphid (Acyrthosiphon pisum). Heredity (Edinb) 2005; 94:435-42. [PMID: 15674387 DOI: 10.1038/sj.hdy.6800633] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
We have initiated research to determine the genetic basis of a male wing polymorphism in the pea aphid Acyrthosiphon pisum (Hemiptera: Aphididae). Previous studies showed that this polymorphism is controlled by a single biallelic locus, which we name aphicarus (api), on the X chromosome. Our objectives were to confirm that api segregates as a polymorphism of a single gene on the X chromosome, and to obtain molecular markers flanking api that can be used as a starting point for high-resolution genetic and physical mapping of the target region, which will ultimately allow the cloning of api. We have established an F2 population segregating for api and have generated X-linked AFLP markers. The segregation pattern of api in the F2 population shows that the male wing polymorphism segregates as a polymorphism of a single gene, or set of closely linked genes on the X chromosome. Using a subset of 78 F2 males, we have constructed a linkage map of the chromosomal region encompassing api using seven AFLP markers. The map spans 74.1 cM and we have mapped api to an interval of 10 cM. In addition, we confirmed X linkage of our AFLP markers and api by using one X-linked marker developed in an earlier study. Our study presents the first mapping of a gene with known function in aphids, and the results indicate that target gene mapping in aphids is feasible.
Collapse
Affiliation(s)
- C Braendle
- Laboratory for Development and Evolution, University Museum of Zoology, Cambridge CB2 3EJ, UK.
| | | | | |
Collapse
|
20
|
Ribeiro LDFC, Fernandez MA. Molecular characterization of the 5S ribosomal gene of the Bradysia hygida(Diptera:Sciaridae). Genetica 2004; 122:253-60. [PMID: 15609548 DOI: 10.1007/s10709-004-1704-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The rRNA genes are amongst the most extensively studied eukaryotic genes. They contain both highly conserved and rapidly evolving regions. The aim of this work was to clone and to sequence the Bradysia hygida 5S rDNA gene. A positive clone was sequenced and its 346 bp sequence was analyzed against the GenBank database. Sequence analysis revealed that the B. hygida 5S (Bh5S) rDNA gene is 120 bp long and is 87% identical to the aphid Acyrthosiphon magnoliae 5S rDNA gene. The Bh5S rDNA gene presents two unusual features: a GG pair at the 5' end of the gene sequence and the localization of the polyT signal immediately after the 3' end of the gene. In situ hybridization experiments revealed that the Bh5S rDNA gene is localized in the autosomal A chromosome.
Collapse
|
21
|
Frydrychová R, Grossmann P, Trubac P, Vítková M, Marec F. Phylogenetic distribution of TTAGG telomeric repeats in insects. Genome 2004; 47:163-78. [PMID: 15060613 DOI: 10.1139/g03-100] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We examined the presence of TTAGG telomeric repeats in 22 species from 20 insect orders with no or inconclusive information on the telomere composition by single-primer polymerase chain reaction with (TTAGG)6 primers, Southern hybridization of genomic DNAs, and fluorescence in situ hybridization of chromosomes with (TTAGG)n probes. The (TTAGG)n sequence was present in 15 species and absent in 7 species. In a compilation of new and published data, we combined the distribution of (TTAGG)n telomere motif with the insect phylogenetic tree. The pattern of phylogenetic distribution of the TTAGG repeats clearly supported a hypothesis that the sequence was an ancestral motif of insect telomeres but was lost repeatedly during insect evolution. The motif was conserved in the "primitive" apterous insect orders, the Archaeognatha and Zygentoma, in the "lower" Neoptera (Plecoptera, Phasmida, Orthoptera, Blattaria, Mantodea, and Isoptera) with the exception of Dermaptera, and in Paraneoptera (Psocoptera, Thysanoptera, Auchenorrhyncha, and Sternorrhyncha) with the exception of Heteroptera. Surprisingly, the (TTAGG)n motif was not found in the "primitive" pterygotes, the Palaeoptera (Ephemeroptera and Odonata). The Endopterygota were heterogeneous for the occurrence of TTAGG repeats. The motif was conserved in Hymenoptera, Lepidoptera, and Trichoptera but was lost in one clade formed by Diptera, Siphonaptera, and Mecoptera. It was also lost in Raphidioptera, whereas it was present in Megaloptera. In contrast with previous authors, we did not find the motif in Neuroptera. Finally, both TTAGG-positive and TTAGG-negative species were reported in Coleoptera. The repeated losses of TTAGG in different branches of the insect phylogenetic tree and, in particular, in the most successful lineage of insect evolution, the Endopterygota, suggest a backup mechanism in the genome of insects that enabled them frequent evolutionary changes in telomere composition.
Collapse
|
22
|
d'Alençon E, Piffanelli P, Volkoff AN, Sabau X, Gimenez S, Rocher J, Cérutti P, Fournier P. A genomic BAC library and a new BAC-GFP vector to study the holocentric pest Spodoptera frugiperda. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2004; 34:331-341. [PMID: 15041017 DOI: 10.1016/j.ibmb.2003.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2003] [Revised: 12/04/2003] [Accepted: 12/16/2003] [Indexed: 05/24/2023]
Abstract
Two genomic tools for the study of Lepidoptera and the holocentric structure of their chromosomes are presented in this paper. A bacterial artificial chromosome (BAC) library was constructed using nuclear DNA partially digested with HindIII from eggs of Spodoptera frugiperda. The library contains a total of 36,864 clones with an average insert size of 125 kb, which corresponds to approximately 11.5 genome equivalents. Hybridization screening of the library was performed with eight single-copy genes, giving an average hit of 10 clones per marker gene. Colinearity between the genome and BACs was demonstrated at the triose phosphate isomerase (tpi) locus. Probing of the library with a PCR fragment internal to the 18S ribosomal gene allowed an estimation of the rDNA locus size close to 115 repeats per haploid genome. A new vector (pBAC3.6eGFP) for transient transfection into S. frugiperda cell lines has been constructed. It is based on the BAC vector, pBAC3.6e, in which a gene encoding GFP was inserted under the control of the densovirus P9 promoter. This vector has the advantage to accommodate large genomic inserts and to be transfected in a large lepidopteran host range. It was used to construct a second BAC library from Sf9 cell nuclear DNA in order to allow a comparison between somatic and cell line genome organization.
Collapse
Affiliation(s)
- Emmanuelle d'Alençon
- Laboratoire de Pathologie Comparée, Institut National de la Recherche Agronomique (INRA) UMR 1231, Centre National de la recherche Scientifique (CNRS) FRE 2689, Univ. Montpellier II, 30380 Saint Christol-les-Alès, France.
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Rego A, Marec F. Telomeric and interstitial telomeric sequences in holokinetic chromosomes of Lepidoptera: telomeric DNA mediates association between postpachytene bivalents in achiasmatic meiosis of females. Chromosome Res 2003; 11:681-94. [PMID: 14606630 DOI: 10.1023/a:1025937808382] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Telomeres, besides their main role in the protection and maintenance of chromosome ends, have several other vital functions in the cell cycle. We studied their role in the achiasmatic meiosis of female Lepidoptera, insects with holokinetic chromosomes. By fluorescence in-situ hybridization (FISH) with the insect telomeric probe, (TTAGG)n, we mapped the distribution of telomeric and interstitial telomeric sequences (ITS) in female meiotic chromosomes of two species, Orgyia antiqua with a reduced chromosome number (2n = 28) and Ephestia kuehniella mutants, possessing a radiation-induced chromosome fusion in the genome (2n = 59). In addition to the strong typical telomeric signals, O. antiqua displayed weaker hybridization signals in interstitial sites of pachytene bivalents. The observed ITS most probably reflect remnants of chromosomal rearrangements and support the hypothesis that the Orgyia karyotype had arisen by multiple fusions of ancestral chromosomes. On the other hand, the absence of ITS in the chromosome fusion of Ephestia indicated the loss of telomeres before the two original chromosomes fused. When the telomeric probe was amplified by enzymatic reaction with tyramid, the number of ITS observed increased in Orgyia, and a few ITS were also observed in several chromosomes of Ephestia but not in the fused chromosome. This suggests that the genomes of both species also contain ITS other than those originating from chromosome fusions. The analysis of female meiotic prophase I revealed non-homologous associations of postpachytene bivalents mediated by telomeric DNA, which were not observed in the pachytene stage. Surprisingly, in early postpachytene nuclei the telomeric associations also involved ITS, whereas later postpachytene nuclei displayed chains of bivalents interconnected only by true telomeres. This finding favours a hypothesis that telomeric associations between bivalents play a role in chromosome segregation in the achiasmatic meiosis of female Lepidoptera.
Collapse
Affiliation(s)
- Alena Rego
- Department of Genetics, Institute of Entomology ASCR, Branisovská 31, CZ-370 05 Ceské Budĕjovice, Czech Republic
| | | |
Collapse
|