Sex Chromosomes
Mostrando 1-12 de 288 artigos, teses e dissertações.
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1. Chromosomal characterization of Amazonian freshwater stingrays with evidence for new karyomorphs and XX/XY sex chromosomes
Abstract Cytogenetic studies in the subfamily Potamotrygoninae have provided valuable insights into the understanding of the evolution and diversification of its species. In the present study, the chromosomal features of seven nominal potamotrygonin species are provided: Plesiotrygon iwamae (2n=74, FN=120), Potamotrygon amazona (2n=66, FN=107), P. constellat
Genet. Mol. Biol.. Publicado em: 14/11/2019
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2. First chromosomal analysis of Gymnorhamphichthys britskii: the remarkable lowest diploid value within the family Rhamphichthyidae (Gymnotiformes)
RESUMO Gymnorhamphichthys britskii é um peixe neotropical da família Rhamphichthyidae descrita no sistema Paraná-Paraguai. Este estudo relata a primeira descrição cariotípica de G. britskii coletado na bacia do alto rio Paraná, que apresentou 2n = 38 cromossomos, cariótipo composto por 14 metacêntricos, 8 submetacêntricos, 2 subtelocêntricos e 14
Neotrop. ichthyol.. Publicado em: 30/09/2019
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3. Cytogenetics and DNA barcode reveal an undescribed Apareiodon species (Characiformes: Parodontidae)
Abstract Parodontidae is a small group of fish and some species are particularly difficult to identify due to the lack of sufficiently consistent morphological traits. Cytogenetically, the species possess 2n = 54 chromosomes and are either sex-homomorphic or sex-heteromorphic (regarding its chromosomes). We evaluated data on color, tooth morphology, cytogene
Genet. Mol. Biol.. Publicado em: 27/06/2019
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4. Dispersion of transposable elements and multigene families: Microstructural variation in Characidium (Characiformes: Crenuchidae) genomes
Abstract Eukaryotic genomes consist of several repetitive DNAs, including dispersed DNA sequences that move between chromosome sites, tandem repeats of DNA sequences, and multigene families. In this study, repeated sequences isolated from the genome of Characidium gomesi were analyzed and mapped to chromosomes in Characidium zebra and specimens from two popu
Genet. Mol. Biol.. Publicado em: 16/07/2018
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5. Comparative cytogenetic analysis in Erythrolamprus snakes (Serpentes: Dipsadidae) from Argentina
ABSTRACT We described the karyotypes of five snake taxa from Argentina: Erythrolamprus almadensis, E. ceii, E. poecilogyrus caesius, E. p. schotti and E. p. sublineatus, and also intergrading individuals between the last two subspecies by conventional staining, chromosome bandings and fluorescent in situ hybridization (FISH) with 28S ribosomal DNA probes. Er
An. Acad. Bras. Ciênc.. Publicado em: 2018-04
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6. 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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7. Heterochromatin base pair composition and diversification in holocentric chromosomes of kissing bugs (Hemiptera, Reduviidae)
The subfamily Triatominae (Hemiptera, Reduviidae) includes 150 species of blood-sucking insects, vectors of Chagas disease or American trypanosomiasis. Karyotypic information reveals a striking stability in the number of autosomes. However, this group shows substantial variability in genome size, the amount and distribution of C-heterochromatin, and the chro
Mem. Inst. Oswaldo Cruz. Publicado em: 2016-10
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8. X1X1X2X2/X1X2Y sex chromosome systems in the Neotropical Gymnotiformes electric fish of the genus Brachyhypopomus
Several types of sex chromosome systems have been recorded among Gymnotiformes, including male and female heterogamety, simple and multiple sex chromosomes, and different mechanisms of origin and evolution. The X1X1X2X2/X1X2Y systems identified in three species of this order are considered homoplasic for the group. In the genus Brachyhypopomus, only B. gaude
Genet. Mol. Biol.. Publicado em: 2015-06
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9. Karyotypic and morphological divergence between two cryptic species of Eigenmannia in the Amazon basin with a new occurrence of XX/XY sex chromosomes (Gymnotiformes: Sternopygidae)
Espécies de Eigenmannia estão amplamente distribuídas na região Neotropical, com oito espécies válidas atualmente reconhecidas. Populações de Eigenmannia de três localidades do leste da Amazônia foram investigadas usando técnicas citogenéticas e morfológicas, revelando dois táxons designados aqui como Eigenmannia sp. "A" e Eigenmannia sp. "B".
Neotrop. ichthyol.. Publicado em: 2015-06
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10. Preferential accumulation of sex and Bs chromosomes in biarmed karyotypes by meiotic drive and rates of chromosomal changes in fishes
Mecanismos de acúmulo baseados em deriva centromérica típica ou de cromossomos portadores de inversões pericêntricas mostram-se adequados à diferenciação cariotípica mais ampla nas principais ordens de Actinopterygii. Aqui nós mostramos que a deriva meiótica nos peixes é também apoiada pela fixação preferencial de sistemas de cromossomos sexua
An. Acad. Bras. Ciênc.. Publicado em: 2014-12
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11. Chromosomal divergence and evolutionary inferences in Rhodniini based on the chromosomal location of ribosomal genes
In this study, we used fluorescence in situ hybridisation to determine the chromosomal location of 45S rDNA clusters in 10 species of the tribe Rhodniini (Hemiptera: Reduviidae: Triatominae). The results showed striking inter and intraspecific variability, with the location of the rDNA clusters restricted to sex chromosomes with two patterns: either on one
Mem. Inst. Oswaldo Cruz. Publicado em: 2013-05
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12. Sex chromosome system ZZ/ZW in Apareiodon hasemani Eigenmann, 1916 (Characiformes, Parodontidae) and a derived chromosomal region
Parodontidae fish show few morphological characteristics for the identification of their representatives and chromosomal analyses have provided reliable features for determining the interrelationships in this family. In this study, the chromosomes of Apareiodon hasemani from the São Francisco River basin, Brazil, were analyzed and showed a karyotype with 2n
Genet. Mol. Biol.. Publicado em: 13/11/2012