Chromosomal distributions of oligo-Am1 and (TTG)(6) trinucleotide and their utilization in genome association analysis of sixteen Avena species

摘要

Fluorescence in situ hybridization was used to investigate the physical location of oligo-Am1 and (TTG)(6) trinucleotide repeats in the metaphase chromosomes of seven diploid species (AA or CC genomes), seven tetraploid species (AABB or AACC genomes), and two hexaploid species (AACCDD genomes) belonging to the genus Avena. The oligo-Am1 probe produced signals that were particularly enriched on almost whole C-genome chromosomes, whereas the (TTG)(6) probe was located in the pericentromeric (M), and, occasionally, their telomeric (T) chromosome regions, but showed low matching to C genome. All the species possessed (TTG)(6) loci in M regions, and the CC, AABB, and AACCDD species also possessed (TTG)(6) loci in T regions. The (TTG)(6) signal number is constant in both the AA and CC species but slightly differs in signal intensity, whereas the (TTG)(6) signal pattern shows wide diversity in the AABB, AACC and AACCDD species. The probe hybridization results provide key information that can be used in the physical assignment of genome sequences to chromosomes.