We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Wheat Neocentromeres Found in F1 Triticale x Tritordeum Hybrids (AABBRH<sup>ch</sup>) After 5-Azacytidine Treatment.
- Authors
Carvalho, A.; Guedes-Pinto, H.; Heslop-Harrison, J. S.; Lima-Brito, J.
- Abstract
The DNA hypomethylation effect of 5-azacytine (5-AC; a cytosine analog) is widely known. This agent has been used for rRNA gene expression studies of Triticeae amphiploids and hybrids regarding rye rRNA genes suppression caused by the wheat nucleolar dominance phenomenon. However, this situation is reverted by 5-AC treatment which activates rye rRNA gene expression as it has been intensively observed in triticale. For nucleo|ar dominance studies, we produced F1 multigeneric hybrids (AABBRHCh; 2n=6x=42) from crosses between the triticale cultivar 'Corgo' (AABBRR; 2u=6x=42) and the tritordeum cultivars HT9 and HT31 (AABBHchHch; 2n=6x=42). The hybrid seeds were germinated in a low concentration of 5-AC (treatment) and in distilled water (nontreated control plants). Silver nitrate staining performed in one 5-AC-treated F1 hybrid revealed a reduced number of interphase cells with seven nucleoli, metaphases with eight Ag-NORs, and neocentromeres in the long arm of three wheat chromosomes. Nontreated hybrids presented six Ag-NORs per mitotic metaphase cell and a maximum of six nucleoli per interphase because of the 1R Ag-NOR suppression. No neocentromere was found in the control F1 hybrid plants. Both treated and nontreated seedlings were subsequently evaluated by fluorescent in situ hybridization performed with genomic and repetitive DNA probes to identify Hch and rye genomes, to confirm Ag-NORs location, and to detect inactive rDNA loci. DAPI counterstaining was also helpful for the detection of neocentromeres in the lung arm of three wheat chromosomes. This study allowed us to suggest that 5-AC treatment specifically induced wheat neocentromeres in the F1 multigeneric triticale x tritordeum hybrids.
- Subjects
CENTROMERE; TRITICALE; WHEAT; GENE expression; FLUORESCENCE in situ hybridization
- Publication
Plant Molecular Biology Reporter, 2008, Vol 26, Issue 1, p46
- ISSN
0735-9640
- Publication type
Article
- DOI
10.1007/s11105-008-0021-z