J. Royo et al., A RETROTRANSPOSON-LIKE SEQUENCE LINKED TO THE S-LOCUS OF NICOTIANA-ALATA IS EXPRESSED IN STYLES IN RESPONSE TO TOUCH, MGG. Molecular & general genetics, 250(2), 1996, pp. 180-188
We have identified a family of repetitive sequences in the genome of N
icotiana alata named Tna1 (Transposon of N. alata). The first element
we characterised was on a genomic clone for the N. alata S-6-ribonucle
ase (S-6-RNase), a gene required for self-incompatibility in this spec
ies. The DNA sequence of this element resembles the integrase domain o
f retrotransposons of the gypsy class and is most similar to a retrotr
ansposon from Lilium henryi. A transcript present in N. alata styles (
self-incompatibility genotype S6S6) hybridized to Tna1 and accumulated
in the style following either pollination or touching. This transcrip
t was cloned from a cDNA Library and was encoded by a second, partial
Tna1 element. Neither the transcribed sequence nor the original Tna1 e
lement contain an open reading frame or is likely to be able to transp
ose. The second element was mapped using a population of N. alata plan
ts segregating for alleles of the self-incompatibility locus and is cl
osely linked to the S-6-allele. The Tna1 element is present in a numbe
r of Nicotiana species and appears to have been active at least twice
during the evolution of this genus.