FISH-aimed karyotype analysis in Aconitum subgen. Aconitum reveals excessive rDNA sites in tetraploid taxa

The location of 5S and 35S rDNA sequences in chromosomes of four Aconitum subsp. Aconitum species was analyzed after fluorescence in situ hybridization (FISH). Both in diploids (2n = 2x = 16; Aconitum variegatum, A. degenii) and tetraploids (2n = 4× = 32; A. firmum, A. plicatum), rDNA repeats were l...

Descripción completa

Detalles Bibliográficos
Autores principales: Joachimiak, Andrzej J., Hasterok, Robert, Sliwinska, Elwira, Musiał, Krystyna, Grabowska-Joachimiak, Aleksandra
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer Vienna 2018
Materias:
Original Article
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6133112/
https://www.ncbi.nlm.nih.gov/pubmed/29541843
http://dx.doi.org/10.1007/s00709-018-1238-9
Descripción
Sumario:The location of 5S and 35S rDNA sequences in chromosomes of four Aconitum subsp. Aconitum species was analyzed after fluorescence in situ hybridization (FISH). Both in diploids (2n = 2x = 16; Aconitum variegatum, A. degenii) and tetraploids (2n = 4× = 32; A. firmum, A. plicatum), rDNA repeats were localized exclusively on the shorter arms of chromosomes, in subterminal or pericentromeric sites. All analyzed species showed similar basal genome size (Cx = 5.31–5.71 pg). The most striking features of tetraploid karyotypes were the conservation of diploid rDNA loci and emergence of many additional 5S rDNA clusters. Chromosomal distribution of excessive ribosomal sites suggests their role in the secondary diploidization of tetraploid karyotypes.

Ejemplares similares