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Karyotype characterization reveals an up and down of 45S and 5S rDNA sites in Crotalaria (Leguminosae-Papilionoideae) species of the section Hedriocarpae subsection Macrostachyae

Morales, A. G.; Perecin, Margarida Lopes Rodrigues de Aguiar; Mondin, M.
Fonte: SPRINGER; DORDRECHT Publicador: SPRINGER; DORDRECHT
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
35.8%
The genus Crotalaria is one of the largest within the family Leguminosae-Papilionoideae, with more than 600 species. However, few karyotypes have been described. In the present paper, five species belonging to the section Hedriocarpae were studied (subsection Machrostachyae), in order to better understand chromosomal evolution in Crotalaria. The results reveals that all species presented 2n = 2x = 16 with symmetrical karyotypes, and slight differences in the chromosome morphology. A secondary constriction was identified at short arm of the pair 1. The 45S rDNA was mapped in the secondary constriction and adjacent heterochromatin (NOR-heterochromatin) and a minor site was identified in C. ochroleuca. The 5S rDNA was mapped linked to 45S rDNA at chromosome 1 short arm in all species. Additional sites for 5S rDNA were identified in C. pallida, C. striata and C. mucronata. Heterochromatin blocks around the centromeres are not CMA(+) neither DAPI(+). The karyotypes of the subsection Macrostachyae are characterized by an inversion at chromosome pair one in relation to previous specialized floral species analyzed. Additional sites of 45S and 5S rDNA were assumed to be a result of transposition events by different ways. The results suggest heterochromatin differentiation and the position of ribosomal genes indicates chromosomal rearrangements during evolution. Karyotype characteristics corroborate the morphological infrageneric classification.; Coordenacao de Aperfeicoamento de Pessoal de Nivel Supeior (CAPES); Coordenacao de Aperfeicoamento de Pessoal de Nivel Supeior (CAPES); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq); PRODOC/CAPES; PRODOC/CAPES; Fundacao de Apoio a Pesquisa do Estado de Sao Paulo (FAPESP); Fundacao de Apoio a Pesquisa do Estado de Sao Paulo (FAPESP) [Proc. 98/01170-5]

The karyotype of Nothoscordum arenarium Herter (Gilliesioideae, Alliaceae) : a populational and cytomolecular analysis

Souza, Luiz G. R.; Crosa, Orfeo; Winge, Helga; Guerra, Marcelo
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
56.36%
The genus Nothoscordum Kunth comprises approximately 20 species native to South America. Karyologically, the genus is remarkable for its large chromosomes and Robertsonian translocations. Variation in chromosome number has been recorded in a few polyploid species and it is unknown among diploids. This study presents the chromosome number and morphology of 53 individuals of seven populations of N. arenarium Herter (2n = 10). In addition, karyotype analyses after C-banding, staining with CMA and DAPI, and in situ hybridization with 5S and 45S rDNA probes were performed in six individuals from one population. All individuals exhibited 2n = 10 (6M + 4A), except for one tetraploid (2n = 20, 12M + 8A) and one triploid (2n = 15, 9M + 6A) plant. C-banding revealed the presence of CMA+/DAPI- heterochromatin in the short arm and in the proximal region of the long arm of all acrocentric chromosomes. The 45S rDNA sites co-localized with the CMA+ regions of the acrocentrics short arms, while the 5S rDNA probe only hybridized with the subterminal region of a pair of metacentric chromosomes. A change in the pattern of CMA bands and rDNA sites was observed in only one individual bearing a reciprocal translocation involving the long arm of a metacentric and the long arm of an acrocentric chromosome. These data suggest that...

Meiosis aspects and nucleolar activity in Triatoma vitticeps (Triatominae, Heteroptera)

Severi-Aguiar, GDC; Lourenco, L. B.; Bicudo, HEMC; Oliveira, Maria Tercília Vilela de Azeredo
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica Formato: 141-151
ENG
Relevância na Pesquisa
36.12%
Some aspects of both the nucleolar organizer activity and meiosis were studied in the testes of Triatoma vitticeps (Heteroptera, Triatominae). The techniques used included squashing followed by lacto-acetic orcein staining, silver-ion impregnation, fluorescent banding (CMA(3), Quinacrine mustard and DAPI) and fluorescent in situ hybridization (FISH). A close relationship between heterochromatin and nucleolus in testicular cells was observed. During meiosis, the silver-ion impregnation pattern varied. At metaphase plate, a small body appeared apart from the chromosomes. In the spermatids this small body was seen in preparations stained with orcein and silver- ion impregnation but not with fluorochromes or FISH. These characteristics combined suggest that these corpuscles represent a source of ribonucleoproteins (RNP) - RNA and specific nucleolar proteins. Silver-ion impregnation and (FISH) revealed nucleolar organizer activity in two metaphase sex chromosomes (X). These results indicate that, in these species, nucleolar organizer regions (NORs) are located in the sex chromosomes, X chromosomes were were CMA(3)(+) and Y chromosome was DAPI(+).

High Diversity in CMA(3)/DAPI-Banding Patterns in Heteropterans

Bardella, V. B.; Grazia, J.; Fernandes, J. A. M.; Vanzela, A. L. L.
Fonte: Karger Publicador: Karger
Tipo: Artigo de Revista Científica Formato: 46-53
ENG
Relevância na Pesquisa
66.39%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Heteroptera is the most numerous and diverse suborder of Hemiptera, with about 38,000 species. This diversity also involves cytogenetic features, including chromosome number and a sex determining system. Information about heterochromatin occurrence and distribution is scarce in heteropterans, but still, there is some evidence of variability. We determined the chromosome number and CMA(3)/DAPI-banding pattern of 179 individuals of 25 heteropteran species from Brazil. Eight species of Pentatomidae exhibited a constant chromosome number (2n = 12 + XY), but in Coreidae (12 species), Largidae (1 species), Rhopalidae (1 species), and Pyrrhocoridae (3 species), the numbers ranged from 2n = 10 + 2m + X0 to 2n = 24 + 2m + X0. Although there were no large differences in the chromosome size between species, the CMA(3)/DAPI-banding patterns differed markedly. Among the genera, species of Edessa, Spartocera, Hypselonotus, Phtia, Holhymenia and Euryophthalmus showed a large accumulation of heterochromatin, while the other species exhibited few or no heterochromatic bands. In general, when heterochromatin was more accumulated...

Caracteização cariotipica de especies de Vermonia Schreb (Asteraceae: Vernonieae) com tecnicas de diferencial longitudinal de cromossomos (bandamentos e hibridação de DNA in situ); Cytotaxonomic studies in species of genus Vernonia Schreb (Asteraceae: Vernonieae)

Vanessa Mancuso de Oliveira
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 07/07/2008 PT
Relevância na Pesquisa
26.47%
O gênero Vernonia é o maior da tribo Vernonieae (Asteraceae), possuindo mais de 1.000 espécies. O Brasil é o maior centro de diversidade das espécies do Novo Mundo deste gênero. As subdivisões de Vernonia têm sido de difícil circunscrição devido ao seu tamanho, que acomoda muitas variações e paralelismos. Recentemente, este gênero foi segregado em outros 22, e o mesmo ficou restrito apenas aos representantes da América do Norte. Entretanto, essa mudança não foi aceita por alguns autores. O objetivo deste trabalho foi subsidiar a proposta sobre a segregação de Vernonia em gêneros menores (sensu ROBINSON) ou da manutenção de sua integridade (sensu BAKER) mediante a comparação de cariótipo. No total, foram estudadas 14 espécies de Vernonia. Oito delas, pertencentes à seção Lepidaploa, correspondentes às subseções Axilliflorae, Macrocephalae, Oligocephalae, Paniculatae e Scorpioideae foram estudadas através da técnica de Giemsa. As espécies foram coletadas em áreas de cerrado e de campo rupestre e em ambiente perturbado, nos Estados de São Paulo, Minas Gerais e Goiás. Foram realizadas contagens cromossômicas nestas mesma espécies, que variaram de 2n=20 a 2n=60 e, elaborados cariótipos, verificando-se o predomínio de cromossomos metacêntricos...

Citotaxonia e aspectos evolutivos de especies de Hoffmannsegella H.G.Jones (Orchidaceae)

Julia Yamagishi Costa
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 09/06/2006 PT
Relevância na Pesquisa
26.61%
Dentro da família Orchidaceae, composta por cerca de 25.000 espécies, o gênero Hoffmannseggella (antiga seção Parviflorae do gênero Laelia Lindl.) é composto por espécies rupícolas, endêmicas da Cadeia do Espinhaço/MG. Estudos sugerem uma evolução rápida para o gênero, com a transição do hábito epifítico para o rupícola, mudança de polinizadores e eventos de hibridização e poliploidia como os principais mecanismos evolutivos envolvidos na origem das espécies de Hoffmannseggella. Estudos cromossômicos prévios haviam sugerido o número básico de x=20 para o gênero, com alta incidência de poliplóides. No presente trabalho, foram obtidas contagens cromossômicas para dez espécies: H. angereri n=20/2n=40, H. bradei n=20-21/2n=40, H. briegeri 2n=80, H. caulescens 2n=80, H. cinnabarina 2n=40, H. crispata n=20, H. fournieri n=20/2n=40, H. liliputana 2n=40/60, H. rupestris n=40/2n=80 e 2n=40 e H. viridiflora 2n=44. Foi observada aneussomatia em células de meristema radicular em H. briegeri (2n=80) e H. rupestris (2n=80), ocorrência de citótipos em H. rupestris (2n=40/80) e anormalidades meióticas em várias espécies, com presença de monovalentes, disjunção adiantada de bivalentes e possíveis tetravalentes nas espécies poliplóides. Por ocorrerem em sincronopatria...

Karyotype characterization of two populations of Vernonia geminata (Asteraceae, Vernonieae) using banding and FISH techniques

Oliveira, V. M.; Mansanares, M. E.; Semir, J.; Forni-Martins, E. R.
Fonte: Funpec-Editora; Ribeirao Preto Publicador: Funpec-Editora; Ribeirao Preto
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.08%
In order to extend our knowledge concerning karyotypes of the genus Vernonia, we applied various techniques of chromosome banding, including AgNOR and triple staining with the fluorochromes CMA/DA/DAPI (CDD), and of fluorescent in situ hybridization (FISH) for the 45S rDNA probe to specimens of two populations of Vernonia geminata collected from an open-pasture area, in southern Brazil. B chromosomes were observed in one of the populations. Both populations of V. geminata presented a pair of CMA(3)(+) terminal bands and one pair of chromosomes with terminal AgNOR banding. The FISH evidenced, in one population, two pairs of small sites of 45S rDNA; these being two small terminal sites and two centromeric sites. In the other population, there was only one pair of small terminal sites and two sites in two B chromosomes, one in each chromosome. There was coincidence of localization between CMA(+) and NOR bands with one of the small terminal sites of 45S rDNA of one chromosome of the normal complement, but not in B chromosomes.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The karyotype of Nothoscordum arenarium Herter (Gilliesioideae, Alliaceae): a populational and cytomolecular analysis

Souza,Luiz G.R.; Crosa,Orfeo; Winge,Helga; Guerra,Marcelo
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2009 EN
Relevância na Pesquisa
56.36%
The genus Nothoscordum Kunth comprises approximately 20 species native to South America. Karyologically, the genus is remarkable for its large chromosomes and Robertsonian translocations. Variation in chromosome number has been recorded in a few polyploid species and it is unknown among diploids. This study presents the chromosome number and morphology of 53 individuals of seven populations of N. arenarium Herter (2n = 10). In addition, karyotype analyses after C-banding, staining with CMA and DAPI, and in situ hybridization with 5S and 45S rDNA probes were performed in six individuals from one population. All individuals exhibited 2n = 10 (6M + 4A), except for one tetraploid (2n = 20, 12M + 8A) and one triploid (2n = 15, 9M + 6A) plant. C-banding revealed the presence of CMA+/DAPI- heterochromatin in the short arm and in the proximal region of the long arm of all acrocentric chromosomes. The 45S rDNA sites co-localized with the CMA+ regions of the acrocentrics short arms, while the 5S rDNA probe only hybridized with the subterminal region of a pair of metacentric chromosomes. A change in the pattern of CMA bands and rDNA sites was observed in only one individual bearing a reciprocal translocation involving the long arm of a metacentric and the long arm of an acrocentric chromosome. These data suggest that...

Karyotype differentiation of four Cestrum species (Solanaceae) revealed by fluorescent chromosome banding and FISH

Fernandes,Thiago; Rego,Letícia do Nascimento Andrade de Almeida; Nardy,Mariana; Yuyama,Priscila Mary; Vanzela,André Luís Laforga
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2009 EN
Relevância na Pesquisa
36.28%
The karyotypes of four South American species of Cestrum (C. capsulare, C. corymbosum, C. laevigatum and C. megalophylum) were studied using conventional staining, C-CMA/DAPI chromosome banding and FISH with 45S and 5S rDNA probes. The karyotypes showed a chromosome number of 2n = 2x = 16, with metacentric chromosomes, except for the eighth submeta- to acrocentric pair. Several types of heterochromatin were detected, which varied in size, number, distribution and base composition. The C-CMA+ bands and 45S rDNA were located predominantly in terminal regions. The C-CMA+/DAPI+ bands appeared in interstitial and terminal regions, and the C-DAPI+ bands were found in all chromosome regions. The 5S rDNA sites were observed on the long arm of pair 8 in all species except C. capsulare, where they were found in the paracentromeric region of the long arm of pair 4. The differences in band patterns among the species studied here, along with data from other nine species reported in the literature, suggest that the bands are dispersed in an equilocal and non-equilocal manner and that structural rearrangements can be responsible for internal karyotype diversification. However, it is important to point out that the structural changes involving repetitive segments did not culminate in substantial changes in the general karyotype structure concerning chromosome size and morphology.

Genome re-assignment of Arachis trinitensis (Sect. Arachis, Leguminosae) and its implications for the genetic origin of cultivated peanut

Robledo,Germán; Lavia,Graciela I.; Seijo,Guillermo
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 EN
Relevância na Pesquisa
36.12%
The karyotype structure of Arachis trinitensis was studied by conventional Feulgen staining, CMA/DAPI banding and rDNA loci detection by fluorescence in situ hybridization (FISH) in order to establish its genome status and test the hypothesis that this species is a genome donor of cultivated peanut. Conventional staining revealed that the karyotype lacked the small "A chromosomes" characteristic of the A genome. In agreement with this, chromosomal banding showed that none of the chromosomes had the large centromeric bands expected for A chromosomes. FISH revealed one pair each of 5S and 45S rDNA loci, located in different medium-sized metacentric chromosomes. Collectively, these results suggest that A. trinitensis should be removed from the A genome and be considered as a B or non-A genome species. The pattern of heterochromatic bands and rDNA loci of A. trinitensis differ markedly from any of the complements of A. hypogaea, suggesting that the former species is unlikely to be one of the wild diploid progenitors of the latter.

Intra- and interspecific chromosome polymorphisms in cultivated Cichorium L. species (Asteraceae)

Bernardes,Ebenézer C.S.; Benko-Iseppon,Ana M.; Vasconcelos,Santelmo; Carvalho,Reginaldo; Brasileiro-Vidal,Ana C.
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
56.36%
Endive (Cichorium endivia L.) and chicory (C. intybus L.) both have 2n = 18, but until now, there has been no detailed karyomorphological characterization. The present work evaluated five accessions of each species using FISH with rDNA probes and fluorochrome staining with CMA and DAPI. Both species presented distinct banding patterns after fluorochrome staining: while endive had proximal CMA++/DAPI- bands in the short arms of pairs 1, 2 and 3, chicory had proximal CMA-positive bands in chromosomes 1 and 3 and interstitial in the short arm of chromosome 8. Among endive accessions, FISH procedures revealed conserved position and number of 5S and 45S rDNA sites (two and three pairs, respectively), associated with the CMA-positive bands. Notwithstanding, polymorphisms were detected within chicory accessions regarding the number and the distribution of rDNA sites in relation to the most frequent karyotype (two pairs with 45S and one with 5S rDNA). The karyological markers developed allowed karyotypic differentiation between both species, uncovering peculiarities in the number and position of rDNA sites, which suggest chromosome rearrangements, such as translocations in chicory cultivars. The interspecific and intraspecific polymorphisms observed emphasize the potential of karyomorphological evaluations...

The karyotype of Nothoscordum arenarium Herter (Gilliesioideae, Alliaceae): A populational and cytomolecular analysis

Souza, Luiz G. R.; Crosa, Orfeo; Winge, Helga; Guerra, Marcelo
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.25%
The genus Nothoscordum Kunth comprises approximately 20 species native to South America. Karyologically, the genus is remarkable for its large chromosomes and Robertsonian translocations. Variation in chromosome number has been recorded in a few polyploid species and it is unknown among diploids. This study presents the chromosome number and morphology of 53 individuals of seven populations of N. arenarium Herter (2n = 10). In addition, karyotype analyses after C-banding, staining with CMA and DAPI, and in situ hybridization with 5S and 45S rDNA probes were performed in six individuals from one population. All individuals exhibited 2n = 10 (6M + 4A), except for one tetraploid (2n = 20, 12M + 8A) and one triploid (2n = 15, 9M + 6A) plant. C-banding revealed the presence of CMA+ /DAPI - heterochromatin in the short arm and in the proximal region of the long arm of all acrocentric chromosomes. The 45S rDNA sites co-localized with the CMA + regions of the acrocentrics short arms, while the 5S rDNA probe only hybridized with the subterminal region of a pair of metacentric chromosomes. A change in the pattern of CMA bands and rDNA sites was observed in only one individual bearing a reciprocal translocation involving the long arm of a metacentric and the long arm of an acrocentric chromosome. These data suggest that...

Intra- and interspecific chromosome polymorphisms in cultivated Cichorium L. species (Asteraceae)

Bernardes, Ebenézer C.S.; Benko-Iseppon, Ana M.; Vasconcelos, Santelmo; Carvalho, Reginaldo; Brasileiro-Vidal, Ana C.
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.24%
Endive (Cichorium endivia L.) and chicory (C. intybus L.) both have 2n = 18, but until now, there has been no detailed karyomorphological characterization. The present work evaluated five accessions of each species using FISH with rDNA probes and fluorochrome staining with CMA and DAPI. Both species presented distinct banding patterns after fluorochrome staining: while endive had proximal CMA++/DAPI− bands in the short arms of pairs 1, 2 and 3, chicory had proximal CMA-positive bands in chromosomes 1 and 3 and interstitial in the short arm of chromosome 8. Among endive accessions, FISH procedures revealed conserved position and number of 5S and 45S rDNA sites (two and three pairs, respectively), associated with the CMA-positive bands. Notwithstanding, polymorphisms were detected within chicory accessions regarding the number and the distribution of rDNA sites in relation to the most frequent karyotype (two pairs with 45S and one with 5S rDNA). The karyological markers developed allowed karyotypic differentiation between both species, uncovering peculiarities in the number and position of rDNA sites, which suggest chromosome rearrangements, such as translocations in chicory cultivars. The interspecific and intraspecific polymorphisms observed emphasize the potential of karyomorphological evaluations...

The Diversity of Karyotypes and Genomes within Section Syllinum of the Genus Linum (Linaceae) Revealed by Molecular Cytogenetic Markers and RAPD Analysis

Bolsheva, Nadezhda L.; Zelenin, Alexander V.; Nosova, Inna V.; Amosova, Alexandra V.; Samatadze, Tatiana E.; Yurkevich, Olga Yu.; Melnikova, Nataliya V.; Zelenina, Daria A.; Volkov, Alexander A.; Muravenko, Olga V.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 02/04/2015 EN
Relevância na Pesquisa
36.05%
The wide variation in chromosome number found in species of the genus Linum (2n = 16, 18, 20, 26, 28, 30, 32, 36, 42, 72, 84) indicates that chromosomal mutations have played an important role in the speciation of this taxon. To contribute to a better understanding of the genetic diversity and species relationships in this genus, comparative studies of karyotypes and genomes of species within section Syllinum Griseb. (2n = 26, 28) were carried out. Elongated with 9-aminoacridine chromosomes of 10 species of section Syllinum were investigated by C- and DAPI/С-banding, CMA and Ag-NOR-staining, FISH with probes of rDNA and of telomere repeats. RAPD analysis was also performed. All the chromosome pairs in karyotypes of the studied species were identified. Chromosome DAPI/C-banding patterns of 28-chromosomal species were highly similar. Two of the species differed from the others in chromosomal location of rDNA sites. B chromosomes were revealed in all the 28-chromosomal species. Chromosomes of Linum nodiflorum L. (2n = 26) and the 28-chromosomal species were similar in DAPI/C-banding pattern and localization of several rDNA sites, but they differed in chromosomal size and number. The karyotype of L. nodiflorum was characterized by an intercalary site of telomere repeat...

Brief communication. XY chromosome sex systems in the neogastropods Fasciolaria lignaria and Pisania striata (Mollusca: Prosobranchia)

Vitturi, R; Colomba, MS; Caputo, V; Pandolfo, A
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica Formato: text/html
EN
Relevância na Pesquisa
35.8%
The mitotic and meiotic chromosomes of the neogastropods Fasciolaria lignaria (L. 1758) (Fasciolaridae) and Pisania striata (Gmelin 1791) (Buccinidae) have been analyzed. Both species display 70 chromosomes in spermatogonial mitoses and 35 bivalents in the corresponding spermatocytes. In both F. lignaria and P. striata pair 35 was found to be heteromorphic in the males and homomorphic in the females thus suggesting that an XY(male)/XX(female) mechanism of chromosomal sex determination is operating. Data obtained from combined C-banding and chromomycin A3 (CMA3), mithramycin (MM), and DAPI staining suggest that the differentiated Y chromosome of F. lignaria does not possess heterogeneous DNA. The possible origins of XY chromosomes in these neogastropods are discussed in the light of the current views of sex chromosome evolution.

Chromosomal evolution in Pleurothallidinae (Orchidaceae: Epidendroideae) with an emphasis on the genus Acianthera: chromosome numbers and heterochromatin

Oliveira, Irenice Gomes de; Moraes, Ana Paula; Almeida, Erton Mendonça de; Assis, Felipe Nollet Medeiros de; Cabral, Juliano Sarmento; Barros, Fabio de; Felix, Leonardo Pessoa
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 102-120
ENG
Relevância na Pesquisa
36.12%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 2011/22215-3; In this study, we analysed chromosome number variation and chromomycin A(3)/4,6-diamidino-2-phenylindole (CMA/DAPI) banding patterns in 48 species belonging to 12 genera of subtribe Pleurothallidinae (Orchidaceae) in order to understand the chromosome evolution based on recent phylogenetic hypotheses and taxonomic treatments. All species had small chromosomes, with numbers ranging from 2n=20 in two Specklinia spp. to 2n=80 in an unidentified Octomeria sp. In Acianthera, the most highly represented genus in this study, a great diversity of chromosome number and pattern of fluorescent bands was observed, showing heterochromatin accumulation in Acianthera section Sicariae subsection Pectinatae. Interspecific ascending and, mainly, descending dysploidy were the main mechanisms of chromosome number evolution in subtribe Pleurothallidinae. For Pleurothallidinae, x=20 is suggested as the basic chromosome number, the same suggested for the related subtribe Laeliinae and for the whole tribe Epidendreae. The Brazilian species of the mega-genus Stelis had chromosomes with small amounts of heterochromatin and chromosome numbers based on x(2)=16. These are generally divergent from those reported for Andean and Meso-American species...

Molecular cytogenetic analysis of the crucian carp, Carassius carassius (Linnaeus, 1758) (Teleostei, Cyprinidae), using chromosome staining and fluorescence in situ hybridisation with rDNA probes

Spoz, Aneta; Boron, Alicja; Porycka, Katarzyna; Karolewska, Monika; Ito, Daisuke; Abe, Syuiti; Kirtiklis, Lech; Juchno, Dorota
Fonte: Pensosoft Publishers Publicador: Pensosoft Publishers
Tipo: Artigo de Revista Científica
Publicado em 18/08/2014 ENG
Relevância na Pesquisa
35.96%
The crucian carp Carassius carassius (Linnaeus, 1758) is a species with restricted and decreasing distribution in Europe. Six males and six females of the species from the Baltic Sea basin in Poland were examined to show sequentially CMA3/AgNO3 staining pattern, DAPI staining, and, for the first time in literature, molecular cytogenetic analysis using double-colour fluorescence in situ hybridisation (FISH) with 28S and 5S rDNA probes. The karyotype consisted of 20 m, 36 sm and 44 sta chromosomes, NF=156. The AgNO3 stained NORs were most frequently located terminally in the short arms of two sm and two sta elements, and CMA3-positive sites were also observed suggesting abundant GC-rich repetitive DNA in the regions. Other CMA3-positive sites in the short arms of six to ten sm and sta chromosomes were detected. The results based on 28S rDNA FISH confirmed the location of rDNA sites. DAPI-negative staining of NORs suggested the scarcity of AT-rich DNA in the regions. FISH with 5S rDNA probe revealed 8-14 loci (ten and 12 in respectively 49 and 29% of metaphases). They were located in two sm and eight to ten sta chromosomes and six of them were larger than others. Simultaneously, mapping of the two rDNA families on the chromosomes of C. carassius revealed that both 28S and 5S rDNA probes were located in different chromosomes. Molecular cytogenetic data of C. carassius presented here for the first time give an important insight into the structure of chromosomes of this polyploid and declining species and may be useful in its systematics.; State Committee for Scientific Research KBN grant: (2P04C 08229)...

Heterochromatin diversity and its co-localization with 5S and 45S rDNA sites in chromosomes of four Maxillaria species (Orchidaceae)

Cabral,Juliano S.; Felix,Leonardo P.; Guerra,Marcelo
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2006 EN
Relevância na Pesquisa
76.42%
We investigated four orchids of the genus Maxillaria (M. discolor, M. acicularis, M. notylioglossa and M. desvauxiana) in regard to the position of heterochromatin blocks as revealed using chromomycin A3 (CMA) and 4'-6-diamidino-2-phenylindole (DAPI) fluorochrome staining and 5S and 45S rDNA sites using fluorescence in situ hybridization (FISH). The species showed differences in chromosome number and a diversified pattern of CMA+ and DAPI+ bands, including heteromorphism for CMA+ bands. The 5S and 45S rDNA sites also varied in number and most of them were co-localized with CMA+ bands. The relationship between 5S rDNA sites and CMA+ bands was more evident in M. notylioglossa, in which the brighter CMA+ bands were associated with large 5S rDNA sites. However, not all 5S and 45S rDNA sites were co-localized with CMA+ bands, probably due to technical constraints. We compare these results to banding data from other species and suggest that not all blocks of tandemly repetitive sequences, such as 5S rDNA sites, can be observed as heterochromatin blocks.

Estudios citogenéticos en especies de Passiflora subgénero Passiflora (Passifloraceae); Cytogenetic studies in species of Passiflora subgenus Passiflora (Passifloraceae)

Chiapero, Ana Laura; Las Peñas, Maria Laura; Amela Garcia, Maria Teresa; Bernardello, Gabriel Luis Mario
Fonte: Sociedad Argentina de Botánica Publicador: Sociedad Argentina de Botánica
Tipo: info:eu-repo/semantics/article; info:ar-repo/semantics/artículo; info:eu-repo/semantics/publishedVersion Formato: application/pdf
SPA
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Passiflora comprende alrededor de 525 especies con x = 9 ó 6. Se realizó un estudio citogenético de cuatro especies del subgénero Passiflora que crecen en la Argentina. Se utilizaron las técnicas de Giemsa, bandeo cromosómico fluorescente CMA/DAPI y FISH (sonda 18-5,8-26S y 5S) en cromosomas mitóticos. P. caerulea, P. tucumanensis y P. cincinnata resultaron diploides (2n = 18) mientras que P. mooreana, tetraploide (2n=36). Los cariotipos fueron altamente simétricos con la fórmula 8 m + 1 sm, duplicada en P. mooreana. Con CMA/DAPI, todos los diploides presentaron dos o tres pares de bandas terminales CMA+ /DAPI- , mientras que la especie tetraploide presentó cinco pares, asociadas a NOR. Con FISH, los loci 18-5,8-26S coincidieron en número y posición con las bandas CMA+ /DAPI- . En cada especie, el número de sitios para los genes de 5S ADNr concordaron con el nivel de ploidía. Los datos de P. tucumanensis y P. mooreana se reportan por primera vez, siendo esta última el primer tetraploide conocido para el subgénero Passiflora. Los patrones de FISH y las bandas heterocrómaticas variaron entre las especies de Passiflora estudiadas, principalmente en el número y distribución de las señales.; Cytogenetic studies in species of Passiflora subgenus Passiflora (Passifloraceae). Passiflora has nearly 525 spp. with x = 9 or 6. A cytogenetic study of four species from subgenus Passiflora that
grow in Argentina was performed. Giemsa technique...

Genome size and karyotype diversity in Solanum sect. Acanthophora (Solanaceae)

Chiarini, Franco Ezequiel; Santiñaque, F. F.; Urdampilleta, Juan Domingo; Las Peñas, Maria Laura
Fonte: Springer Wien Publicador: Springer Wien
Tipo: info:eu-repo/semantics/article; info:ar-repo/semantics/artículo; info:eu-repo/semantics/publishedVersion Formato: application/pdf
ENG
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Abstract In order to study the evolution of different cytogenetic characters in species of Solanum sect. Acanthophora in relationship to the known phylogeny for this group, the following techniques were used: CMA/DAPI chromosome banding; fluorescent in situ hybridization with probes for the 18-5.8-26S and the 5S rDNA genes in mitotic chromosomes; nuclear DNA quantification by flow cytometry. Depending on the species, 2?6 of the 12 basic chromosome pairs were identified. The heterochromatic banding patterns were shown to be species-specific. All species presented one chromosome pair bearing a 18-5.8-26S signal and one pair (rarely two) with a 5S signal, the two rDNA sites being non-syntenic. The techniques employed allowed us to stablish two species groups within sect. Acanthophora: one with small, symmetric chromosomes, little heterochromatin and lower DNA content, and the other one with larger and more asymmetric chromosomes, more heterochromatin CMA+/DAPI- (associated with NOR or not) and a higher DNA content. An elevated karyotype asymmetry would be associated with a high amount of heterochromatin and a high DNA content. The trend within sect. Acanthophora would be towards a loss of heterochromatin, a reduction of chromosome size...