Supernumerary Chromosomes
Mostrando 1-12 de 38 artigos, teses e dissertações.
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1. Chromosomal variability in Brazilian species of Anthurium Schott (Araceae): Heterochromatin, polyploidy, and B chromosomes
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, w
Genet. Mol. Biol.. Publicado em: 14/11/2019
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2. A case of intersex occurrence in Steindachneridion parahybae (Steindachner, 1877) (Siluriformes: Pimelodidae) under captivity condition: a cytogenetic and morphological study
ABSTRACT Little is known about reproductive biology of endangered Steindachneridion parahybae , a gonochoristic teleost species inhabiting the Paraíba do Sul River Basin, and herein is the first description of intersex in S. parahybae juvenile. The normal appearance of ovaries and testes in juvenile from the same lot of breeding were also described for comp
Neotrop. ichthyol.. Publicado em: 22/12/2016
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3. A comparative structural cytogenetic study in three allopatric populations of Astyanax scabripinnis (Teleostei: Characidae)
Individual samples from five populations of the characid fish Astyanax scabripinnis (Jenyns, 1842) from the Tietê and Paranapanema river basins (Brazil) were studied. All individuals analyzed presented 50 chromosomes but three different karyotypic forms were observed. Additionally, some individuals of one karyomorph presented a macro supernumerary chromosom
Zoologia (Curitiba). Publicado em: 2012-04
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4. Estudo citogenético em duas espécies da família Callichthyidae (Callichthyinae, Siluriformes) da bacia do Rio de Contas/Bahia
The family Callichthyidae is included in the order Siluriformes, is widely distributed by the Neotropical region and comprises 194 species and eight genera, distributed in two subfamilies, Corydoradinae and Callichthyinae. Aiming to expand the cytogenetics information of the ichthyofauna of the eastern Atlantic basins, this work was done in Callichthys calli
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/02/2011
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5. Intraspecific crosses resulting in the first occurrence of eight and nine B chromosomes in Prochilodus lineatus (Characiformes, Prochilodontidae)
B chromosomes are supernumerary elements present in about 15% of eukaryotic species and are most frequently heterochromatic, behave parasitically, show a transmission rate higher than standard (A) chromosomes, and can provoke harmful effects on carriers. In the current work, Prochilodus lineatus individuals carrying eight and nine B chromosomes were obtained
Genetics and Molecular Biology. Publicado em: 01/04/2011
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6. Cromossomic and molecular studies in Rhamdia (Pisces, Siluriformes, Heptapteridae): a relationship overview / Estudos cromossômicos e moleculares em Rhamdia (Pisces, Siluriformes, Heptapteridae): análise de relações evolutivas
The genus Rhamdia, popularly known as jundia, belongs to the family Heptapteridae, one of the greatest radiations within neotropical freshwater catfish. This group of middle-sized fish of opportunistic behavior is found in small rivers and streams. In the past, Rhamdia was considered one of the most specious genera of Siluriformes, comprising about 100 descr
Publicado em: 2009
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7. Identification and description of distinct B chromosomes in Cyphocharax modestus (Characiformes, Curimatidae)
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 p
Genetics and Molecular Biology. Publicado em: 2008
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8. B chromosomes in a population of Astyanax eigenmanniorum (Characiformes, Characidae) from the Araguari River Basin (Uberlândia, MG, Brazil)
A cytogenetic study was conducted on an Astyanax eigenmanniorum population from the Caetano Stream (18° 44' 56" S/ 048° 18' 39" W) - in Uberlândia, MG, Brazil - showing a modal diploid number of 48 chromosomes in the standard male and female karyotypes. However, in several specimens it was also possible to observe metaphases with one or two B chromosomes,
Genetics and Molecular Biology. Publicado em: 2008
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9. Supernumerary chromosomes in the pufferfish Sphoeroides spengleri: first occurrence in marine Teleostean Tetraodontiformes fish
Cytogenetic analyses carried out in eight specimens of Sphoeroides spengleri revealed the presence of 2n = 46 chromosomes (20 M/SM and 26 ST/A). Besides the standard karyotypical set, the presence of B microchromosomes was observed in two individuals, ranging from 0 to 2 microchromosomes per cell. A karyotype composed by 2n = 46 chromosomes with occurrence o
Genetics and Molecular Biology. Publicado em: 2008
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10. First report of a B chromosome in a natural population of Astyanax altiparanae (Characiformes, Characidae)
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 a
Genetics and Molecular Biology. Publicado em: 2008
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11. High levels of chromosomal differentiation in Euchroma gigantea L. 1735 (Coleoptera, Buprestidae)
Euchroma gigantea was karyotypically studied using conventional staining, C-banding, silver nitrate staining and ribosomal fluorescent in situ hybridization (rDNA FISH). Broad wide autosomal polymorphism and a complex sex determination system were found in this beetle. Karyotype complements ranging from 2n = 32, X1X2X3Y1Y2Y3 to 2n = 36,X1X2X3Y1Y2Y3 were dete
Genetics and Molecular Biology. Publicado em: 2008
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12. Molecular Cytogenetic Characterization of Supernumerary Marker Chromosomes / Caracterização citogenética molecular de cromossomos marcadores extranumerários
Rearranjos cromossômicos envolvendo a presença de cromossomos marcadores extranumerário são achados citogenéticos freqüentes em pacientes que apresentam deficiência mental, alterações de crescimento, dismorfias e/ou malformações. A presença desse material é responsável por trissomia ou tetrassomia parcial de determinadas regiões cromossômicas
Publicado em: 2008