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Antigone Zacharopoulou - One of the best experts on this subject based on the ideXlab platform.
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the bactrocera dorsalis species complex comparative cytogenetic analysis in support of sterile insect technique applications
BMC Genetics, 2014Co-Authors: Penelope Mavraganitsipidou, Antonios A Augustinos, Elena Drosopoulou, Kostas Bourtzis, Aggeliki Garioupapalexiou, Antigone ZacharopoulouAbstract:The Bactrocera dorsalis species complex currently harbors approximately 90 different members. The species complex has undergone many revisions in the past decades, and there is still an ongoing debate about the species limits. The availability of a variety of tools and approaches, such as molecular-genomic and cytogenetic analyses, are expected to shed light on the rather complicated issues of species complexes and incipient speciation. The clarification of genetic relationships among the different members of this complex is a prerequisite for the rational application of sterile insect technique (SIT) approaches for population control. Colonies established in the Insect Pest Control Laboratory (IPCL) (Seibersdorf, Vienna), representing five of the main economic important members of the Bactrocera dorsalis complex were cytologically characterized. The taxa under study were B. dorsalis s.s., B. philippinensis, B. papayae, B. invadens and B. carambolae. Mitotic and Polytene Chromosome analyses did not reveal any chromosomal characteristics that could be used to distinguish between the investigated members of the B. dorsalis complex. Therefore, their Polytene Chromosomes can be regarded as homosequential with the reference maps of B. dorsalis s.s.. In situ hybridization of six genes further supported the proposed homosequentiallity of the Chromosomes of these specific members of the complex. The present analysis supports that the Polytene Chromosomes of the five taxa under study are homosequential. Therefore, the use of the available Polytene Chromosome maps for B. dorsalis s.s. as reference maps for all these five biological entities is proposed. Present data provide important insight in the genetic relationships among the different members of the B. dorsalis complex, and, along with other studies in the field, can facilitate SIT applications targeting this complex. Moreover, the availability of 'universal' reference Polytene Chromosome maps for members of the complex, along with the documented application of in situ hybridization, can facilitate ongoing and future genome projects in this complex.
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mitotic and Polytene Chromosomes analysis of the oriental fruit fly bactrocera dorsalis hendel diptera tephritidae
Genetica, 2011Co-Authors: Antigone Zacharopoulou, Antonios A Augustinos, A S Robinson, W. A. A. Sayed, Gerald FranzAbstract:The Oriental fruit fly, Batrocera dorsalis s.s. (Hendel) is one of the most destructive agricultural pests, belonging to a large group of difficult to distinguish morphologically species, referred as the B. dorsalis complex. We report here a cytogenetic analysis of two laboratory strains of the species and provide a photographic Polytene Chromosome map from larval salivary glands. The mitotic complement consists of six Chromosome pairs including a heteromorphic sex (XX/XY) Chromosome pair. Analysis of the Polytene complement has shown a total of five Polytene Chromosomes (10 Polytene arms) that correspond to the five autosomes. The most important landmarks of each Polytene Chromosome and characteristic asynapsis at a specific chromosomal region are presented and discussed. Chromosomal homology between B. dorsalis and Ceratitis capitata has been determined by comparing Chromosome banding patterns. The detection of Chromosome inversions in both B. dorsalis strains is shown and discussed. Our results show that the Polytene maps presented here are suitable for cytogenetic analysis of this species and can be used for comparative studies among species of the Tephritidae family. They also provide a diagnostic tool that could accelerate species identification within the B. dorsalis complex and could shed light on the ongoing speciation in this complex. Polytene Chromosome maps can facilitate the development of biological control methods and support the genome mapping project of the species that is currently in progress.
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mitotic and Polytene Chromosome analysis in the mexican fruit fly anastrepha ludens loew diptera tephritidae
Genome, 2009Co-Authors: E Hernandezortiz, C S Zepetacisneros, A S Robinson, Antigone Zacharopoulou, Virginia GarciamartinezAbstract:The present study constitutes the first attempt to construct a Polytene Chromosome map of an Anastrepha species, Anastrepha ludens (Loew), a major agricultural pest. The mitotic karyotype has a diploid complement of 12 acrocentric Chromosomes, including five pairs of autosomes and an XX/XY sex Chromosome pair. The analysis of salivary gland Polytene Chromosomes has shown a total number of five Polytene elements that correspond to the five autosomes. The characteristic features and the most prominent landmarks of each Chromosome are described. By comparing Chromosome banding patterns, the possible chromosomal homology between A. ludens and Ceratitis capitata (Wiedemann) is presented. This work shows that Polytene maps of A. ludens are suitable for cytogenetic studies in this species and may be used as reference for other Anastrepha species, most of which are also serious agricultural pests.
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mitotic and Polytene Chromosome analysis in the mexican fruit fly anastrepha ludens loew diptera tephritidae v garcia martinez e hernandez ortiz c s zepeta cisneros a s robinson a zacharopoulou and g franz
2009Co-Authors: Antigone ZacharopoulouAbstract:The present study constitutes the first attempt to construct a Polytene Chromosome map of an Anastrepha spe- cies, Anastrepha ludens (Loew), a major agricultural pest. The mitotic karyotype has a diploid complement of 12 acrocen- tric Chromosomes, including five pairs of autosomes and an XX/XY sex Chromosome pair. The analysis of salivary gland Polytene Chromosomes has shown a total number of five Polytene elements that correspond to the five autosomes. The characteristic features and the most prominent landmarks of each Chromosome are described. By comparing Chromosome banding patterns, the possible chromosomal homology between A. ludens and Ceratitis capitata (Wiedemann) is presented. This work shows that Polytene maps of A. ludens are suitable for cytogenetic studies in this species and may be used as reference for other Anastrepha species, most of which are also serious agricultural pests.
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photographic Polytene Chromosome maps for glossina morsitans submorsitans diptera glossinidae cytogenetic analysis of a colony with sex ratio distortion
Genome, 2002Co-Authors: Angeliki Garioupapalexiou, Antigone Zacharopoulou, George Yannopoulos, R H GoodingAbstract:Photographic Polytene Chromosome maps from trichogen cells of pharate adult Glossina morsitans submorsitans were constructed. Using the standard system employed to map Polytene Chromosomes of Drosophila, the characteristic landmarks were described for the X Chromosome and the two autosomes (L1 and L2). Sex-ratio distortion, which is expressed in male G. m. submorsitans, was found to be associated with an X Chromosome (XB) that contains three inversions in each arm. Preliminary data indicate no differences in the fecundity of XAXA and XAXB females, but there are indications that G. m. submorsitans in colonies originating from Burkina Faso and Nigeria have genes on the autosomes and (or) the Y Chromosome that suppress expression of sex-ratio distortion.Key words: tsetse, Glossina morsitans submorsitans, Polytene Chromosome maps, inversions, sex-ratio distortion.
Igor F. Zhimulev - One of the best experts on this subject based on the ideXlab platform.
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Architecture of Promoters of House-Keeping Genes in Polytene Chromosome Interbands of Drosophila melanogaster
Doklady Biochemistry and Biophysics, 2019Co-Authors: T. Yu. Zykova, V. G. Levitsky, Igor F. ZhimulevAbstract:This is the first study to investigate the molecular-genetic organization of Polytene Chromosome interbands located on both molecular and cytological maps of Drosophila genome. The majority of the studied interbands contained one gene with a single transcription initiation site; the remaining interbands contained one gene with several alternative promoters, two or more unidirectional genes, and “head-to-head” arranged genes. In addition, intricately arranged interbands containing three or more genes in both unidirectional and bidirectional orientation were found. Insulator proteins, ORC, P -insertions, DNase I hypersensitive sites, and other open chromatin structures were situated in the promoter region of the genes located in the interbands. This area is critical for the formation of the interband, an open chromatin region in which gene transcription and replication are combined.
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genetic organization of open chromatin domains situated in Polytene Chromosome interbands in drosophila
Doklady Biochemistry and Biophysics, 2018Co-Authors: Yu T Zykova, V A Khoroshko, Igor F. Zhimulev, O O Popova, Victor G Levitsky, Sergey LavrovAbstract:New data on the organization of genes entirely located in the open domains for chromatin transcription and occupying only one Chromosome structure (interband) were obtained. The characteristic features of these genes are the small size (on average, 1-2 kb), depletion of the replicative complex proteins in the regulatory region, and the presence of specific motifs for binding transcription factors, as compared to the genes occupying two structures (interband and gray band). The biological function of these genes is associated primarily with the processes of gene expression and RNA metabolism.
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Localization of Polytene Chromosomes’ black bands on the Drosophila genome map could be predicted by means of data on the distribution of interband-specific chromatin proteins in cell cultures: Region 43F-46B of Polytene Chromosome 2R as an example.
2018Co-Authors: Tatyana D. Kolesnikova, Fedor P Goncharov, Igor F. ZhimulevAbstract:(A) Distribution of four chromatin types [4]. Ruby chromatin (depicted in magenta) is devoid of active chromatin markers. Aquamarine chromatin (depicted in cyan) is enriched with all the proteins that are typical of Polytene Chromosome interbands (see text). (B) Locations of condensed bands in Polytene Chromosomes as predicted from the distribution of ruby chromatin and aquamarine chromatin (each of these bands appears as an interval between aquamarine segments that include ruby chromatin) (see A). (C) A distribution of nine chromatin states in S2 cells (top) and Bg3 cells (bottom) [22]. The red color corresponds to chromatin type enriched with active promoters. The presence of this chromatin type in both cell cultures at once is one of the markers of Polytene Chromosome interbands. (D) Enrichment peaks of CHRIZ, the most typical interband protein, in the Chromosomes of four cell lines (top to bottom: Bg3, Kc, S2, and Cl8) (modENCODE data). (E) Localization of the predicted positions of compacted bands within the framework of the 4-state model combined with the interband criterion filtering (see C, D). (F) FlyBase CytoMap locations of compacted bands corresponding to rb-bands (see G) (http://flybase.org). (G) Localization of the predicted positions of compacted bands after all correction steps (rb-bands, see text). Bands were assigned names according to mapping data in FlyBase (see text) and Bridges’ detailed map ([47], see J). (H–J) Locations of compacted bands in Polytene Chromosomes from salivary glands (H, J) and pseudonurse cells of otu11 mutants (H, reprinted from [11] under a CC BY license, with permission from Springer Nature: Chromosome Research, original copyright [1995]) in comparison and their correspondence to the bands predicted by the analysis of protein distribution in the cell cultures (G). Compacted black bands as visualized by aceto-orcein staining (H, I) and according to Bridges’ detailed map [47] (J).
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Genetic Organization of Interphase Chromosome Bands and Interbands in Drosophila melanogaster
2016Co-Authors: Igor F. Zhimulev, Tatyana Yu Zykova, Fedor P Goncharov, V A Khoroshko, Olga V Demakova, Lidiya V Boldyreva, Darya S Demidova, Galina V. Pokholkova, Valeriy F Semeshin, Vladimir N BabenkoAbstract:Drosophila melanogaster Polytene Chromosomes display specific banding pattern; the underlying genetic organization of this pattern has remained elusive for many years. In the present paper, we analyze 32 cytology-mapped Polytene Chromosome interbands. We estimated molecular locations of these interbands, described their molecular and genetic organization and demonstrate that Polytene Chromosome interbands contain the 59 ends of housekeeping genes. As a rule, interbands display preferential ‘‘head-to-head’ ’ orientation of genes. They are enriched for ‘‘broad’ ’ class promoters characteristic of housekeeping genes and associate with open chromatin proteins and Origin Recognition Complex (ORC) components. In two regions, 10A and 100B, coding sequences of genes whose 59-ends reside in interbands map to constantly loosely compacted, early-replicating, so-called ‘‘grey’ ’ bands. Comparison of expression patterns of genes mapping to late-replicating dense bands vs genes whose promoter regions map to interbands shows that the former are generally tissue-specific, whereas the latter are represented by ubiquitously active genes. Analysis of RNA-seq data (modENCODE-FlyBase) indicates that transcripts from interband-mapping genes are present in most tissues and cell lines studied, across most developmental stages and upon various treatment conditions. We developed a special algorithm to computationally process protein localization data generated by the modENCODE project and show that Drosophila genom
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Drosophila Polytene Chromosome bands formed by gene introns
Doklady Biochemistry and Biophysics, 2016Co-Authors: Igor F. Zhimulev, Tatyana Yu Zykova, V A Khoroshko, Olga V Demakova, Lidiya V Boldyreva, Poholkova Gv, S. A. Lavrov, Elena S. BelyaevaAbstract:Genetic organization of bands and interbands in Polytene Chromosomes has long remained a puzzle for geneticists. It has been recently demonstrated that interbands typically correspond to the 5’-ends of house-keeping genes, whereas adjacent loose bands tend to be composed of coding sequences of the genes. In the present work, we made one important step further and mapped two large introns of ubiquitously active genes on the Polytene Chromosome map. We show that alternative promoter regions of these genes map to interbands, whereas introns and coding sequences found between those promoters correspond to loose grey bands. Thus, a gene having its long intron “sandwiched” between to alternative promoters and a common coding sequence may occupy two interbands and one band in the context of Polytene Chromosomes. Loose, partially decompacted bands appear to host large introns.
Antonios A Augustinos - One of the best experts on this subject based on the ideXlab platform.
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cytogenetic analysis of the south american fruit fly anastrepha fraterculus diptera tephritidae species complex construction of detailed photographic Polytene Chromosome maps of the argentinian af sp 1 member
PLOS ONE, 2016Co-Authors: Angeliki Garioupapalexiou, Antonios A Augustinos, Elena Drosopoulou, Maria Cecilia Giardini, Silvia Beatriz Lanzavecchia, Jorge Luis Cladera, Carlos Caceres, Kostas Bourtzis, Penelope MavraganitsipidouAbstract:Genetic and cytogenetic studies constitute a significant basis for understanding the biology of insect pests and the design and the construction of genetic tools for biological control strategies. Anastrepha fraterculus is an important pest of the Tephritidae family. It is distributed from southern Texas through eastern Mexico, Central America and South America causing significant crop damage and economic losses. Currently it is considered as a species complex; until now seven members have been described based on multidisciplinary approaches. Here we report the cytogenetic analysis of an Argentinian population characterized as Af. sp.1 member of the Anastrepha fraterculus species complex. The mitotic karyotype and the first detailed photographic maps of the salivary gland Polytene Chromosomes are presented. The mitotic metaphase complement consists of six (6) pairs of Chromosomes, including one pair of heteromorphic sex Chromosomes, with the male being the heterogametic sex. The analysis of the salivary gland Polytene complement shows a total number of five long Chromosomes that correspond to the five autosomes of the mitotic karyotype and a heterochromatic network corresponding to the sex Chromosomes. Comparison of the Polytene Chromosome maps between this species and Anastrepha ludens shows significant similarity. The Polytene maps presented here are suitable for cytogenetic studies that could shed light on the species limits within this species complex and support the development of genetic tools for sterile insect technique (SIT) applications.
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the bactrocera dorsalis species complex comparative cytogenetic analysis in support of sterile insect technique applications
BMC Genetics, 2014Co-Authors: Penelope Mavraganitsipidou, Antonios A Augustinos, Elena Drosopoulou, Kostas Bourtzis, Aggeliki Garioupapalexiou, Antigone ZacharopoulouAbstract:The Bactrocera dorsalis species complex currently harbors approximately 90 different members. The species complex has undergone many revisions in the past decades, and there is still an ongoing debate about the species limits. The availability of a variety of tools and approaches, such as molecular-genomic and cytogenetic analyses, are expected to shed light on the rather complicated issues of species complexes and incipient speciation. The clarification of genetic relationships among the different members of this complex is a prerequisite for the rational application of sterile insect technique (SIT) approaches for population control. Colonies established in the Insect Pest Control Laboratory (IPCL) (Seibersdorf, Vienna), representing five of the main economic important members of the Bactrocera dorsalis complex were cytologically characterized. The taxa under study were B. dorsalis s.s., B. philippinensis, B. papayae, B. invadens and B. carambolae. Mitotic and Polytene Chromosome analyses did not reveal any chromosomal characteristics that could be used to distinguish between the investigated members of the B. dorsalis complex. Therefore, their Polytene Chromosomes can be regarded as homosequential with the reference maps of B. dorsalis s.s.. In situ hybridization of six genes further supported the proposed homosequentiallity of the Chromosomes of these specific members of the complex. The present analysis supports that the Polytene Chromosomes of the five taxa under study are homosequential. Therefore, the use of the available Polytene Chromosome maps for B. dorsalis s.s. as reference maps for all these five biological entities is proposed. Present data provide important insight in the genetic relationships among the different members of the B. dorsalis complex, and, along with other studies in the field, can facilitate SIT applications targeting this complex. Moreover, the availability of 'universal' reference Polytene Chromosome maps for members of the complex, along with the documented application of in situ hybridization, can facilitate ongoing and future genome projects in this complex.
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analysis of mitotic and Polytene Chromosomes and photographic Polytene Chromosome maps in bactrocera cucurbitae diptera tephritidae
Annals of The Entomological Society of America, 2011Co-Authors: W. A. A. Sayed, Antonios A Augustinos, Farzana Yesmin, A S Robinson, Gerald FranzAbstract:ABSTRACT We report here a cytogenetic analysis of the melon fly, Bactrocera Cucurbitae, Coquillett (Diptera: Tephritidae), a species of significant agricultural importance. The mitotic karyotype and detailed photographic maps of the larval salivary gland Polytene Chromosomes of the species are presented. The mitotic karyotype consists of six pairs of Chromosomes including one pair of heteromorphic sex (XX/XY) Chromosomes. The heterogametic sex is ascribed to the male. The analysis of Polytene Chromosomes has shown a total number of five long Polytene elements (10 Polytene arms) that correspond to the five autosomes. The characteristic features and the most prominent landmarks of each Polytene Chromosome are presented. The proposed chromosomal homology between B. Cucurbitae and Mediterranean fruit fly, Ceratitis capitata (Wiedemann), was determined by comparing Chromosome banding patterns. The detection of heterozygous Chromosome inversions in two strains is shown and discussed. The current study provides ...
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mitotic and Polytene Chromosomes analysis of the oriental fruit fly bactrocera dorsalis hendel diptera tephritidae
Genetica, 2011Co-Authors: Antigone Zacharopoulou, Antonios A Augustinos, A S Robinson, W. A. A. Sayed, Gerald FranzAbstract:The Oriental fruit fly, Batrocera dorsalis s.s. (Hendel) is one of the most destructive agricultural pests, belonging to a large group of difficult to distinguish morphologically species, referred as the B. dorsalis complex. We report here a cytogenetic analysis of two laboratory strains of the species and provide a photographic Polytene Chromosome map from larval salivary glands. The mitotic complement consists of six Chromosome pairs including a heteromorphic sex (XX/XY) Chromosome pair. Analysis of the Polytene complement has shown a total of five Polytene Chromosomes (10 Polytene arms) that correspond to the five autosomes. The most important landmarks of each Polytene Chromosome and characteristic asynapsis at a specific chromosomal region are presented and discussed. Chromosomal homology between B. dorsalis and Ceratitis capitata has been determined by comparing Chromosome banding patterns. The detection of Chromosome inversions in both B. dorsalis strains is shown and discussed. Our results show that the Polytene maps presented here are suitable for cytogenetic analysis of this species and can be used for comparative studies among species of the Tephritidae family. They also provide a diagnostic tool that could accelerate species identification within the B. dorsalis complex and could shed light on the ongoing speciation in this complex. Polytene Chromosome maps can facilitate the development of biological control methods and support the genome mapping project of the species that is currently in progress.
Penelope Mavraganitsipidou - One of the best experts on this subject based on the ideXlab platform.
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cytogenetic analysis of the south american fruit fly anastrepha fraterculus diptera tephritidae species complex construction of detailed photographic Polytene Chromosome maps of the argentinian af sp 1 member
PLOS ONE, 2016Co-Authors: Angeliki Garioupapalexiou, Antonios A Augustinos, Elena Drosopoulou, Maria Cecilia Giardini, Silvia Beatriz Lanzavecchia, Jorge Luis Cladera, Carlos Caceres, Kostas Bourtzis, Penelope MavraganitsipidouAbstract:Genetic and cytogenetic studies constitute a significant basis for understanding the biology of insect pests and the design and the construction of genetic tools for biological control strategies. Anastrepha fraterculus is an important pest of the Tephritidae family. It is distributed from southern Texas through eastern Mexico, Central America and South America causing significant crop damage and economic losses. Currently it is considered as a species complex; until now seven members have been described based on multidisciplinary approaches. Here we report the cytogenetic analysis of an Argentinian population characterized as Af. sp.1 member of the Anastrepha fraterculus species complex. The mitotic karyotype and the first detailed photographic maps of the salivary gland Polytene Chromosomes are presented. The mitotic metaphase complement consists of six (6) pairs of Chromosomes, including one pair of heteromorphic sex Chromosomes, with the male being the heterogametic sex. The analysis of the salivary gland Polytene complement shows a total number of five long Chromosomes that correspond to the five autosomes of the mitotic karyotype and a heterochromatic network corresponding to the sex Chromosomes. Comparison of the Polytene Chromosome maps between this species and Anastrepha ludens shows significant similarity. The Polytene maps presented here are suitable for cytogenetic studies that could shed light on the species limits within this species complex and support the development of genetic tools for sterile insect technique (SIT) applications.
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the bactrocera dorsalis species complex comparative cytogenetic analysis in support of sterile insect technique applications
BMC Genetics, 2014Co-Authors: Penelope Mavraganitsipidou, Antonios A Augustinos, Elena Drosopoulou, Kostas Bourtzis, Aggeliki Garioupapalexiou, Antigone ZacharopoulouAbstract:The Bactrocera dorsalis species complex currently harbors approximately 90 different members. The species complex has undergone many revisions in the past decades, and there is still an ongoing debate about the species limits. The availability of a variety of tools and approaches, such as molecular-genomic and cytogenetic analyses, are expected to shed light on the rather complicated issues of species complexes and incipient speciation. The clarification of genetic relationships among the different members of this complex is a prerequisite for the rational application of sterile insect technique (SIT) approaches for population control. Colonies established in the Insect Pest Control Laboratory (IPCL) (Seibersdorf, Vienna), representing five of the main economic important members of the Bactrocera dorsalis complex were cytologically characterized. The taxa under study were B. dorsalis s.s., B. philippinensis, B. papayae, B. invadens and B. carambolae. Mitotic and Polytene Chromosome analyses did not reveal any chromosomal characteristics that could be used to distinguish between the investigated members of the B. dorsalis complex. Therefore, their Polytene Chromosomes can be regarded as homosequential with the reference maps of B. dorsalis s.s.. In situ hybridization of six genes further supported the proposed homosequentiallity of the Chromosomes of these specific members of the complex. The present analysis supports that the Polytene Chromosomes of the five taxa under study are homosequential. Therefore, the use of the available Polytene Chromosome maps for B. dorsalis s.s. as reference maps for all these five biological entities is proposed. Present data provide important insight in the genetic relationships among the different members of the B. dorsalis complex, and, along with other studies in the field, can facilitate SIT applications targeting this complex. Moreover, the availability of 'universal' reference Polytene Chromosome maps for members of the complex, along with the documented application of in situ hybridization, can facilitate ongoing and future genome projects in this complex.
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sex Chromosomes and associated rdna form a heterochromatic network in the Polytene nuclei of bactrocera oleae diptera tephritidae
Genetica, 2012Co-Authors: Elena Drosopoulou, Ifigeneia Nakou, Jindra Sichova, Svatava Kubickova, Frantisek Marec, Penelope MavraganitsipidouAbstract:The olive fruit fly, Bactrocera oleae, has a diploid set of 2n = 12 Chromosomes including a pair of sex Chromosomes, XX in females and XY in males, but Polytene nuclei show only five Polytene Chromosomes, obviously formed by five autosome pairs. Here we examined the fate of the sex Chromosomes in the Polytene complements of this species using fluorescence in situ hybridization (FISH) with the X and Y Chromosome-derived probes, prepared by laser microdissection of the respective Chromosomes from mitotic metaphases. Specificity of the probes was verified by FISH in preparations of mitotic Chromosomes. In Polytene nuclei, both probes hybridized strongly to a granular heterochromatic network, indicating thus underreplication of the sex Chromosomes. The X Chromosome probe (in both female and male nuclei) highlighted most of the granular mass, whereas the Y Chromosome probe (in male nuclei) identified a small compact body of this heterochromatic network. Additional hybridization signals of the X probe were observed in the centromeric region of Polytene Chromosome II and in the telomeres of six Polytene arms. We also examined distribution of the major ribosomal DNA (rDNA) using FISH with an 18S rDNA probe in both mitotic and Polytene Chromosome complements of B. oleae. In mitotic metaphases, the probe hybridized exclusively to the sex Chromosomes. The probe signals localized a discrete rDNA site at the end of the short arm of the X Chromosome, whereas they appeared dispersed over the entire dot-like Y Chromosome. In Polytene nuclei, the rDNA was found associated with the heterochromatic network representing the sex Chromosomes. Only in nuclei with preserved nucleolar structure, the probe signals were scattered in the restricted area of the nucleolus. Thus, our study clearly shows that the granular heterochromatic network of Polytene nuclei in B. oleae is formed by the underreplicated sex Chromosomes and associated rDNA.
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cytogenetic analysis of malpighian tubule and salivary gland Polytene Chromosomes of bactrocera oleae dacus oleae diptera tephritidae
Genome, 1995Co-Authors: Anna Zambetaki, Kleanthis Kleanthous, Penelope MavraganitsipidouAbstract:Photomaps of the Malpighian tubule and the salivary gland Polytene Chromosomes of Bactrocera oleae (Dacus oleae) are presented and compared with those of the fat body. Five Polytene Chromosomes (10 Polytene arms) corresponding to the five autosomes of the mitotic nuclei, as well as a heterochromatic mass corresponding to the sex Chromosomes, are observed in the nuclei of the three somatic tissues. The most prominent features of each Polytene Chromosome, the reverse tandem duplications, as well as the rather unusual ectopic pairing of the telomeric regions of different Chromosome arms, are described. The constancy of the banding pattern based on the analysis of the three larval tissues is discussed.Key words: Bactrocera oleae (Dacus oleae), Polytene Chromosomes, salivary gland, Malpighian tubule, banding pattern.
James A. Kennison - One of the best experts on this subject based on the ideXlab platform.
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molecular genetic analyses of Polytene Chromosome region 72a d in drosophila melanogaster reveal a gene desert in 72d
PLOS ONE, 2011Co-Authors: Monica T. Cooper, James A. KennisonAbstract:We have investigated a region of ∼310 kb of genomic DNA within Polytene Chromosome subdivisions 72A to 72D of Drosophila melanogaster. This region includes 57 predicted protein-coding genes. Seventeen of these genes are in six clusters that appear to have arisen by tandem duplication. Within this region we found 23 complementation groups that are essential for zygotic viability, and we have identified the transcription units for 18 of the 23. We also found a 55 kb region in 72D that is nonessential. Flies deficient for this region are viable and fertile. Within this nonessential region are 48 DNA sequences of 12 to 33 base pairs that are completely conserved among 12 distantly related Drosophila species. These sequences do not have the evolutionary signature of conserved protein-coding DNA sequences, nor do they appear to encode microRNAs, however, the strong selection suggests functions in wild populations that are not apparent in laboratory cultures. This region resembles dispensable gene deserts previously characterized in the mouse genome.
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Molecular genetic analysis of Chd3 and Polytene Chromosome region 76B-D in Drosophila melanogaster.
Genetics, 2010Co-Authors: Monica T. Cooper, Alex Conant, James A. KennisonAbstract:The Drosophila melanogaster Chd3 gene encodes a member of the CHD group of SNF2/RAD54 ATPases. CHD proteins are conserved from yeast to man and many are subunits of chromatin-remodeling complexes that facilitate transcription. Drosophila CHD3 proteins are not found in protein complexes, but as monomers that remodel chromatin in vitro. CHD3 colocalize with elongating RNA polymerase II on salivary gland Polytene Chromosomes. Since the role of Chd3 in development was unknown, we isolated and characterized the essential genes within the 640-kb region of the third Chromosome (Polytene Chromosome region 76B-D) that includes Chd3. We recovered mutations in 24 genes that are essential for zygotic viability. We found that transposon-insertion mutants for 46% of the essential genes are included in the Drosophila Gene Disruption Project collection. None of the essential genes that we identified are in a 200-kb region that includes Chd3. We generated a deletion of Chd3 by targeted gene replacement. This deletion had no effect on either viability or fertility.
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Dissection of Larval Salivary Glands and Polytene Chromosome Preparation
CSH Protocols, 2008Co-Authors: James A. KennisonAbstract:INTRODUCTIONAlthough the large Polytene Chromosomes of diptera were originally described in the late 1880s, it was not until the early 1930s that their significance to the study of the genome of Drosophila was realized. Polytene Chromosomes are found in several larval and adult tissues, but preparations are usually made of the Chromosomes in the larval salivary glands, because the glands are easily dissected and the Polytene Chromosomes are large.
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genetic analysis of the brahma gene of drosophila melanogaster and Polytene Chromosome subdivisions 72ab
Genetics, 1994Co-Authors: B J Brizuela, Lisa K Elfring, J Ballard, J W Tamkun, James A. KennisonAbstract:The brahma gene is required for activation of the homeotic genes of the Antennapedia and bithorax complexes in Drosophila. We have isolated and characterized 21 mutations in brahma. We show that both maternal and zygotic functions of brahma are required during embryogenesis. In addition, the severe abnormalities caused by loss of maternal brahma expression show that the homeotic genes are not the only targets for brahma activation. The complex pattern of interallelic complementation for the 21 brahma alleles suggests that brahama may act as a multimer. In addition to mutations in brahma, we have isolated mutations in four other essential genes within Polytene Chromosome subdivisions 72AB. Based on a compilation of similar studies that include about 24% of the genome, we estimate that about 3600 genes in Drosophila can mutate to cause recessive lethality, with fewer than 900 additional genes essential only for gametogenesis. We have identified three times more transcripts than lethal complementation groups in 72AB. One transcript in 72AB is the product of the essential arf-like gene and encodes a member of the ARF subfamily of small GTP-binding proteins. Two other transcripts are probably the products of a single gene whose protein products are similar to the catalytic subunits of cAMP-dependent protein kinases.
