Dp. Matton et al., THE S-LOCUS OF NICOTIANA-ALATA - GENOMIC ORGANIZATION AND SEQUENCE-ANALYSIS OF 2 S-RNASE ALLELES, Plant molecular biology, 28(5), 1995, pp. 847-858
Genomic clones encoding the S-2- and S-6-RNases of Nicotiana alata Lin
k and Otto, which are the allelic stylar products of the self-incompat
ibility (S) locus, were isolated and sequenced. Analysis of genomic DN
A by pulsed-field gel electrophoresis and Southern blotting indicates
the presence of only a single S-RNase gene in the N. alata genome. The
sequences of the open-reading frames in the genomic and corresponding
cDNA clones were identical. The organization of the genes was similar
to that of other S-RNase genes from solanaceous plants. No sequence s
imilarity was found between the DNA flanking the S-2- and S-6-RNase ge
nes, despite extensive similarities between the coding regions. The DN
A flanking the S-6-RNase gene contained sequences that were moderately
abundant in the genome. These repeat sequences are also present in ot
her members of the Nicotianae.