Data/hora: 16/06/2024 03:16:33

Provedor de dados: | 74
País: | Brazil
Título: | High levels of chromosomal differentiation in Euchroma gigantea L. 1735 (Coleoptera, Buprestidae)
Autores: | Moura,Rita de Cássia de; Melo,Natoniel Franklin de; Souza,Maria José de.
Data: | 2008-01-01
Ano: | 2008
Palavras-chave: | Chromosome polymorphism; C-banding; Multiple sex system; NOR; RDNA.
Resumo: | 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 detected in the sample analyzed. Punctiform supernumerary chromosomes were present in the different karyotypes. The karyotypic evolution of Brazilian E. gigantea may have taken two directions, reduction in the diploid number of 2n = 36 to 24 through centric fusions or 2n = 24 to 36 due to chromosomal fissions. In addition, pericentric inversions were also involved. The complex multiple sex mechanism of this species seems to be old and well established since it is found in specimens from different populations. Small pericentromeric blocks of constitutive heterochromatin were located on the autosomes and terminal blocks were also found on some small pairs. The sex chromosomes showed larger constitutive heterochromatin blocks. Silver nitrate staining during prophase I of meiosis showed labeling of the sex chromosome chain. However, the rDNA sites could only be precisely determined by FISH, which permitted the identification of these ribosomal sites on chromosomes X1 and X2 of this species.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000300007
Editor: | Sociedade Brasileira de Genética
Relação: | 10.1590/S1415-47572008000300007
Formato: | text/html
Fonte: | Genetics and Molecular Biology  v.31 n.2 2008
Fonte: | info:eu-repo/semantics/openAccess