J. Briza et al., DISTRIBUTION OF UNLINKED TRANSPOSITIONS OF A DS ELEMENT FROM A T-DNA LOCUS ON TOMATO CHROMOSOME-4, Genetics, 141(1), 1995, pp. 383-390
In maize, receptor sites for unlinked transpositions of Activator (Ac)
elements are not distributed randomly. To test whether the same is tr
ue in tomato, the receptor sites for a Dissociation (Ds) element deriv
ed from Ac, were mapped for 26 transpositions unlinked to a donor T-DN
A locus on chromosome 4. Four independent transposed Dss mapped to sit
es on chromosome 4 genetically unlinked to the donor T-DNA, consistent
with a preference for transposition to unlinked sites on the same chr
omosome as opposed to sites on other chromosomes. There was little pre
ference among the nondonor chromosomes, except perhaps for chromosome
2, which carried seven transposed Dss, but these could not be proven t
o be independent. However, these data, when combined with those from o
ther studies in tomato examining the distribution of transposed Acs or
Dss among nondonor chromosomes, suggest there may be absolute prefere
nces for transposition irrespective of the chromosomal location of the
donor site. If true, transposition to nondonor chromosomes in tomato
would differ from that in maize, where the preference seems to be dete
rmined by the spatial arrangement of chromosomes in the interphase nuc
leus. The tomato lines carrying Ds elements at known locations are ava
ilable for targeted transposon tagging experiments.