Karyotype differentiation of four Cestrum species (Solanaceae) revealed by fluorescent chromosome banding and FISH

Genetics and Molecular Biology

Thiago Fernandes¹  Letícia Do Nascimento Andrade De Almeida Rego¹  Mariana Nardy¹  Priscila Mary Yuyama¹  André Luís Laforga Vanzela¹ 

[1] ,Universidade Estadual de Londrina Centro de Ciências Biológicas Laboratório de Biodiversidade e Restauração de EcossistemasLondrina PR ,Brazil

关键词: Cestrum;    chromosome banding;    FISH;    heterochromatin;    physical maps;    45S and 5S rDNA;   

DOI  :  10.1590/S1415-47572009000200019

来源: SciELO

【 摘 要 】

The karyotypes of four South American species of Cestrum (C. capsulare, C. corymbosum, C. laevigatum and C. megalophylum) were studied using conventional staining, C-CMA/DAPI chromosome banding and FISH with 45S and 5S rDNA probes. The karyotypes showed a chromosome number of 2n = 2x = 16, with metacentric chromosomes, except for the eighth submeta- to acrocentric pair. Several types of heterochromatin were detected, which varied in size, number, distribution and base composition. The C-CMA+ bands and 45S rDNA were located predominantly in terminal regions. The C-CMA+/DAPI+ bands appeared in interstitial and terminal regions, and the C-DAPI+ bands were found in all chromosome regions. The 5S rDNA sites were observed on the long arm of pair 8 in all species except C. capsulare, where they were found in the paracentromeric region of the long arm of pair 4. The differences in band patterns among the species studied here, along with data from other nine species reported in the literature, suggest that the bands are dispersed in an equilocal and non-equilocal manner and that structural rearrangements can be responsible for internal karyotype diversification. However, it is important to point out that the structural changes involving repetitive segments did not culminate in substantial changes in the general karyotype structure concerning chromosome size and morphology.

【 授权许可】

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