Data/hora: 17/06/2024 15:31:25

Provedor de dados: | 74
País: | Brazil
Título: | Cytogenetic analysis of Astylus antis (Perty, 1830) (Coleoptera, Melyridae): Karyotype, heterochromatin and location of ribosomal genes
Autores: | Mendes-Neto,Ernani de Oliveira; Vicari,Marcelo Ricardo; Campaner,Carlos; Nogaroto,Viviane; Artoni,Roberto Ferreira; Almeida,Mara Cristina.
Data: | 2010-01-01
Ano: | 2010
Palavras-chave: | Sex chromosomes; Meiosis; Metaphase; FISH; 18S rDNA.
Resumo: | Cytogenetic analysis of Astylus antis using mitotic and meiotic cells was performed to characterize the haploid and diploid numbers, sex determination system, chromosome morphology, constitutive heterochromatin distribution pattern and chromosomes carrying nucleolus organizer regions (NORs). Analysis of spermatogonial metaphase cells revealed the diploid number 2n = 18, with mostly metacentric chromosomes. Metaphase I cells exhibited 2n = 8II+Xyp and a parachute configuration of the sex chromosomes. Spermatogonial metaphase cells submitted to C-banding showed the presence of small dots of constitutive heterochromatin in the centromeric regions of nearly all the autosomes and on the short arm of the X chromosome (Xp), as well as an additional band on one of the arms of pair 1. Mitotic cells submitted to double staining with base-specific fluorochromes (DAPI-CMA3) revealed no regions rich in A+T or G+C sequences. Analysis of spermatogonial mitotic cells after sequential Giemsa/AgNO3 staining did not reveal any specific mark on the chromosomes. Meiotic metaphase I cells stained with silver nitrate revealed a strong impregnation associated to the sex chromosomes, and in situ hybridization with an 18S rDNA probe showed ribosomal cistrons in an autosomal bivalent.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000200007
Editor: | Sociedade Brasileira de Genética
Relação: | 10.1590/S1415-47572010005000050
Formato: | text/html
Fonte: | Genetics and Molecular Biology  v.33 n.2 2010
Fonte: | info:eu-repo/semantics/openAccess