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Preferential elimination of repeated DNA sequences from the paternal, Nicotiana tomentosiformis genome donor of a synthetic, allotetraploid tobacco
Author(s) -
Skalická K.,
Lim K. Y.,
Matyasek R.,
Matzke M.,
Leitch A. R.,
Kovarik A.
Publication year - 2005
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2004.01297.x
Subject(s) - genome , biology , nicotiana , nicotiana tabacum , genetics , chromosome , genome evolution , gene , solanaceae
Summary• Nicotiana tabacum (tobacco, 2 n = 4 x = 48) is a natural allotetraploid combining two ancestral genomes closely related to modern Nicotiana sylvestris and Nicotiana tomentosiformis . Here we examine the immediate consequences of allopolyploidy on genome evolution using 20 S 4 ‐generation plants derived from a single synthetic, S 0 plant made by Burk in 1973 (Th37).• Using molecular and cytogenetic methods we analysed 14 middle and highly repetitive sequences that together total ≈ 4% of the genome.• Two repeats related to endogenous geminiviruses (GRD5) and pararetroviruses ( Nto EPRV), and two classes of satellite repeats (NTRS, A1/A2) were partially or completely eliminated at variable frequency (25–60%). These sequences are all from the N. tomentosiformis parent. Genomic in situ hybridization revealed additivity in chromosome numbers in two plants (2 n = 48), while a third was aneuploid for an N. tomentosiformis ‐origin chromosome (2 n = 49). Two plants had homozygous translocations between chromosomes of the S‐ and T‐genomes.• The data demonstrate that genetic changes in synthetic tobacco were fast, targeted to the paternal N. tomentosiformis ‐donated genome, and some of the changes showed concordance with changes that presumably occurred during evolution of natural tobacco.