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Registros recuperados: 7
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Chromosomal variability in Brazilian species of Anthurium Schott (Araceae): Heterochromatin, polyploidy, and B chromosomes Genet. Mol. Biol.
Nascimento,Sarah do; Coelho,Marcus Alberto Nadruz; Cordeiro,Joel M. P.; Felix,Leonardo P..
Abstract The genus Anthurium has a Neotropical distribution, with karyotype predominance of x = 15, although some species show disploidy or polyploid variations. The karyotypes of seven species and different populations of Anthurium were analyzed using fluorochrome CMA and DAPI staining. The karyotypes were composed of meta- and submetacentric chromosomes, with numbers varying from 2n = 30 to 2n = 60. Supernumerary euchromatic chromosomes were observed in A. affine, and supernumerary heterochromatic chromosomes were observed in A. gladiifolium and A. petrophilum. Polyploidy was recurrent in the Anthurium species analyzed, with records of 2n = 30 and 60 in different A. pentaphyllum populations. Fluorochrome staining revealed different CMA+ banding...
Tipo: Info:eu-repo/semantics/article Palavras-chave: B chromosomes; CMA/DAPI; Cytotaxonomy; Neotropical Araceae.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572019000400635
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Cytogenetic characterization of Melipona rufiventris Lepeletier 1836 and Melipona mondury Smith 1863 (Hymenoptera, Apidae) by C banding and fluorochromes staining Genet. Mol. Biol.
Lopes,Denilce Meneses; Pompolo,Sílvia das Graças; Campos,Lúcio Antônio de Oliveira; Tavares,Mara Garcia.
The stingless bees Melipona rufiventris and M. mondury were analyzed cytogenetically by conventional staining with Giemsa, C-banding and sequential staining with the fluorochromes CMA3/DA/DAPI. Both species presented 2n = 18 and n = 9, except for one colony of M. rufiventris, in which some individuals had 2n = 19 due to the presence of a B chromosome. After Giemsa staining and C-banding the chromosomes appeared very condensed and presented a high heterochromatic content, making it difficult to localize the centromere and therefore to visualize the chromosomes morphology. The constitutive heterochromatin was located in interstitial chromosome regions covering most of the chromosomes extension and consisted mainly of AT, as shown by DAPI staining. The...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Melipona; Stingless bees; B chromosomes; Fluorochromes; C-banding.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000100010
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First report of a B chromosome in a natural population of Astyanax altiparanae (Characiformes, Characidae) Genet. Mol. Biol.
Hashimoto,Diogo Teruo; Gonçalves,Vanessa Regina; Bortolozzi,Jehud; Foresti,Fausto; Porto-Foresti,Fábio.
Several species of the genus Astyanax have already been genetically studied, and B-chromosomes have been considered to be an interesting feature in some species of this group. In the present paper we report, for the first time, the occurrence of a B microchromosome in a natural population of A. altiparanae. This additional genomic element was identified as an acrocentric chromosome, similar in size to the smallest chromosomal pairs of the standard karyotype. Analysis of the constitutive heterochromatin pattern by C-banding evidenced heterochromatic blocks located on centromeric, pericentromeric, and interstitial regions of some chromosomes, and also positive marks in a subtelocentric chromosomal pair that presented the short arms entirely heterochromatic....
Tipo: Info:eu-repo/semantics/article Palavras-chave: B chromosomes; Fish cytogenetics; Astyanax altiparanae.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200021
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Identification and description of distinct B chromosomes in Cyphocharax modestus (Characiformes, Curimatidae) Genet. Mol. Biol.
Santos,Lessandra Viviane De Rosa; Foresti,Fausto; Martins,Cesar; Oliveira,Claudio; Wasko,Adriane Pinto.
Cytogenetic analyses were performed in Cyphocharax modestus, collected at Paranapanema River and Tietê River (São Paulo State, Brazil). A karyotype with 2n = 54 chromosomes was observed in the animals from both Brazilian freshwater river systems. One to four B chromosomes were also detected in individuals from the Paranapanema River, which represents the probable first report of more than a single supernumerary element in a species of the Curimatidae group. C-banding revealed centromeric and telomeric heterochromatin blocks in several chromosomes of the normal karyotype complement of C. modestus. Moreover, while some B chromosomes were characterized by the complete absence of C-bands, others were totally heterochromatic. Although there was a prevalence of...
Tipo: Info:eu-repo/semantics/article Palavras-chave: B chromosomes; C-banding; Curimatidae; Cyphocharax modestus; Supernumerary chromosomes.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200019
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Intrapopulational chromosome number variation in Zephyranthes sylvatica Baker (Amaryllidaceae: Hippeastreae) from Northeast Brazil Rev. Bras. Bot.
Felix,Winston J. P.; Dutilh,Julie H. A.; Melo,Natoniel F. de; Fernandes,Andrea A.; Felix,Leonardo P..
Zephyranthes Herb. is a taxonomically complex and cytologically variable group, with about 65 species of Neotropical distribution. Chromosome number variability in 32 individuals of a Zephyranthes sylvatica population from Northeast Brazil was investigated. Three cytotypes were found: 2n = 12 (one metacentric, four submetacentric and one acrocentric pairs), in 24 individuals; 2n = 12 + 1B, in five and three individuals with 2n = 18, a triploid cytotype. All diploid individuals showed chromosomes with polymorphism in pair one and two, while in triploids this polymorphism was observed in all chromosome triplets, generally with two homomorphic chromosomes and a higher or lower heteromorphic chromosome. All individuals had reticulated interfasic nucleus and a...
Tipo: Info:eu-repo/semantics/report Palavras-chave: Amaryllidaceae; B chromosomes; Chromosome variability; Triploid; Zephyranthes.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042008000200020
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Occurrence of B chromosomes in Tetragonisca Latreille, 1811 (Hymenoptera, Apidae, Meliponini): a new contribution to the cytotaxonomy of the genus Genet. Mol. Biol.
Barth,Adriane; Fernandes,Anderson; Pompolo,Silvia das Graças; Costa,Marco Antônio.
Tetragonisca angustula and Tetragonisca fiebrigi have recently been listed as valid species. This study aimed to cytogenetically investigate both species, emphasizing the new registry of B chromosomes in the tribe Meliponini. We analyzed colonies of T. angustula and T. fiebrigi collected at Tangará da Serra, Mato Grosso, Brazil, through conventional Giemsa staining, C-banding, and base-specific fluorochrome staining (CMA3/DAPI). T. angustula showed 2n = 34 chromosomes in females and n = 17 in males, with karyotype formula 2K = 34A M. T. fiebrigi showed numeric variation, with chromosome number varying from 2n = 34 to 2n = 36 in females and from n = 17 to n=18in males, with karyotype formula 2K = 32A M+2A Mc and 2K = 32A M+2A Mc + 1 or 2 B-chromosomes. The...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Stingless bees; Cytogenetics; Interspecific differentiation; B chromosomes.
Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572011000100014
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Preferential accumulation of sex and Bs chromosomes in biarmed karyotypes by meiotic drive and rates of chromosomal changes in fishes Anais da ABC (AABC)
MOLINA,WAGNER F.; MARTINEZ,PABLO A.; BERTOLLO,LUIZ A.C.; BIDAU,CLAUDIO J..
Mechanisms of accumulation based on typical centromeric drive or of chromosomes carrying pericentric inversions are adjusted to the general karyotype differentiation in the principal Actinopterygii orders. Here, we show that meiotic drive in fish is also supported by preferential establishment of sex chromosome systems and B chromosomes in orders with predominantly bi-brachial chromosomes. The mosaic of trends acting at an infra-familiar level in fish could be explained as the interaction of the directional process of meiotic drive as background, modulated on a smaller scale by adaptive factors or specific karyotypic properties of each group, as proposed for the orthoselection model.
Tipo: Info:eu-repo/semantics/article Palavras-chave: Actinopterygii; B chromosomes; Centromeric drive; Chromosome evolution; Sex chromosomes.
Ano: 2014 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000401801
Registros recuperados: 7
Primeira ... 1 ... Última
 

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