Duplicated SP11 genes produce alternative transcripts in the S¹⁵ haplotype of Brassica oleracea

抄録

Self-incompatibility (SI) discriminating self and non-self pollen is regulated by S-locus genes in Brassica. In most S haplotypes, a set of three highly polymorphic genes, SLG, SRK, and SP11, is located at the S-locus region. In the present study, we found duplicated SP11 genes, S¹⁵-SP11a, S¹⁵-SP11b, and S¹⁵-SP11b’, in the self-incompatible S¹⁵ haplotype of B. oleracea. RNA gel blot and reverse transcription polymerase chain reaction (RT-PCR) analyses showed that two different sizes of SP11 transcripts were specifically detected in anther tissues: a 0.65-kb transcript corresponded to S¹⁵-SP11a (an exon-1 region of S¹⁵-SP11b was also co-transcribed in some cases), and a 1.4-kb transcript contained the duplicated three genes, S¹⁵-SP11a, S¹⁵-SP11b, and an exon-1 region of S¹⁵-SP11b’, all three of which were connected to intergenic spacer regions.