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Genome-Wide Distribution of Novel Ta-3A1 Mini-Satellite Repeats and Its Use for Chromosome Identification in Wheat and Related Species

Lang, Tao, Li, Guangrong, Yu, Zhihui, Ma, Jiwei, Chen, Qiheng, Yang, Ennian, Yang, Zujun
Agronomy 2019 v.9 no.2
DNA, Triticum, chromosome aberrations, chromosomes, fluorescence in situ hybridization, genome, germplasm, grasses, linkage groups, oligonucleotides, satellite DNA, sequence analysis, tandem repeat sequences, wheat
A large proportion of the genomes of grasses is comprised of tandem repeats (TRs), which include satellite DNA. A mini-satellite DNA sequence with a length of 44 bp, named Ta-3A1, was found to be highly accumulated in wheat genome, as revealed by a comprehensive sequence analysis. The physical distribution of Ta-3A1 in chromosomes 3A, 5A, 5B, 5D, and 7A of wheat was confirmed by nondenaturing fluorescence in situ hybridization (ND-FISH) after labeling the oligonucleotide probe. The analysis of monomer variants indicated that rapid sequence amplification of Ta-3A1 occurred first on chromosomes of linkage group 5, then groups 3 and 7. Comparative ND-FISH analysis suggested that rapid changes occurred in copy number and chromosomal locations of Ta-3A1 among the different species in the tribe Triticeae, which may have been associated with chromosomal rearrangements during speciation and polyploidization. The labeling and subsequent use of Ta-3A1 by ND-FISH may assist in the precise identification and documentation of novel wheat germplasm engineered by chromosome manipulation.