Consulta: subjectFacets:"Sex chromosome system"
Registros recuperados: 3
Data/hora: 10/06/2024 04:30:47

Chromosomes of Theridiidae spiders (Entelegynae): interspecific karyotype diversity in Argyrodes and diploid number intraspecific variability in Nesticodes rufipes
Provedor de dados: 74
Autores: Stavale,Leila Miguel; Schneider,Marielle Cristina; Araujo,Douglas; Brescovit,Antonio Domingos; Cella,Doralice Maria.
Theridiidae is a derived family within the Araneoidea clade. In contrast to closely related groups, the 2n(male) = 20+X1X2 with acro/telocentric chromosomes is the most widespread karyotype among the theridiid spiders. In this work, the cytogenetic analysis of Argyrodes elevatus revealed original chromosome features different from those previously registered for Theridiidae, including the presence of 2n(male) = 20+X with meta/submetacentric chromosomes. Most individuals of Nesticodes rufipes showed family conserved karyotype characteristics. However, one individual had a 2n(male) = 24 due to the presence of an extra chromosome pair, which exhibited regular behavior and reductional segregation during meiosis. After silver staining, mitotic cells exhibited...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chromosome morphology; Cytogenetic; Meiosis; Nucleolar organizer region; Sex chromosome system.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000400012

Chromosome evolution in tiger beetles: Karyotypes and localization of 18S rDNA loci in Neotropical Megacephalini (Coleoptera, Cicindelidae)
Provedor de dados: 74
Autores: Proença,Sónia J.R.; Collares-Pereira,Maria João; Serrano,Artur R.M.
Four Neotropical tiger beetle species, three from the genus Megacephala and one from the genus Oxycheila, currently assigned to the tribe Megacephalini were examined cytogenetically. All three Megacephala species showed simple sex chromosome systems of the X0/XX type but different numbers of autosomal pairs (15 in M. cruciata, 14 in M. sobrina and 12 in M. rutilans), while Oxycheila tristis was inferred to have a multiple sex chromosome system with four X chromosomes (2n = 24 + X1X2X3X4Y/X1X1X2X2X3X3X4X4). Fluorescence in situ hybridization (FISH) using a PCR-amplified 18S rDNA fragment as a probe revealed the presence of rDNA clusters located exclusively on the autosomes in all the Megacephala species (five clusters in M. cruciata, eight in M. sobrina and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chromosome evolution; Cicindelidae; Megacephalini; Oxycheila; RDNA localization; Sex chromosome system.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000500012

Chromosomal analysis of Centromochlus heckelii (Siluriformes: Auchenipteridae), with a contribution to Centromochlus definition
Provedor de dados: 83
Autores: Kowalski,Samantha; Paiz,Leonardo Marcel; da Silva,Maelin; Machado,Amanda de Souza; Feldberg,Eliana; Traldi,Josiane Baccarin; Margarido,Vladimir Pavan; Lui,Roberto Laridondo.
ABSTRACT Historically, there are divergences in the species allocation between Centromochlus and Tatia. This study aimed to generate the first cytogenetic data about Centromochlus and, by analyzing a population of Centromochlus heckelii from the Amazon River basin, to contribute as evidence to a historical taxonomic dilemma. Diploid number of 46 chromosomes and a heteromorphic pair was found in the female karyotypes, thus characterizing a ZZ/ZW sex chromosome system. Pale blocks of heterochromatin were located in centromeric regions of some chromosomes; however, the exclusive female chromosome (W) is almost entirely heterochromatic. AgNORs were detected in terminal position on the short arms of one acrocentric pair in males and two chromosome pairs in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Centromochlinae; Cytogenetics; Sex chromosome system; Taxonomy; ZZ/ZW.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252020000300203