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Query: UMLS:C0277787 (stigma)
 13,352 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The self-incompatibility locus of Brassica consists of a coadapted gene complex that contains at least two genes required for the recognition and inhibition of pollen by the stigma when self-pollinated. Here, we report the identification of a third S locus-linked gene from the S2 haplotype of Brassica oleracea. This gene, which we designated SLA (for S Locus Anther), is a novel gene with an unusual structure. SLA is transcribed from two promoters to produce two complementary anther-specific transcripts, one spliced and the other unspliced, that accumulate in an antiparallel manner in developing microspores and anthers. The sequence of the spliced transcript showed the presence of two open reading frames that predict proteins of 10 and 7.5 kD. Neither transcript was produced in a self-compatible B. napus strain carrying an S2-like haplotype, indicating that the SLA gene in this strain is nonfunctional. Interestingly, sequences related to SLA were not detected in DNA or RNA from plants carrying S haplotypes other than S2. The haplotype specificity of SLA, its anther-specific expression, and its physical linkage to the S locus are properties expected for a gene that encodes a determinant of S2 specificity in pollen.
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PMID:An anther-specific gene encoded by an S locus haplotype of Brassica produces complementary and differentially regulated transcripts. 754 84

The self-incompatibility (SI) response in Brassica involves recognition of self-pollen by the papillar cells of the stigma and is mediated by the products of genes localized at the S (self-incompatibility) locus. Two S locus genes, SRK and SLG, are thought to encode components of a receptor complex present in the female partner. The putative gene product of SLA, a third S locus-linked gene that is expressed specifically in anthers, is a candidate for the male component of the SI recognition system. The identification of a mutant SLA allele, interrupted by a large insert resembling a retrotransposon, in self-compatible Brassica napus initially suggested that SLA played an essential role in the SI response. In this study, we have characterized an SLA allele from a self-compatible B. oleracea var acephala line and show that it too is interrupted by a large insert. However, analysis of seven B. oleracea var botrytis lines exhibiting both self-compatible and self-incompatible phenotypes showed that these lines carry an S allele very similar or identical to that of the B. oleracea var acephala line and that the SLA gene is interrupted by an insert in all seven lines. The insertion of the putative retrotransposon was shown to interfere with gene expression, with no SLA transcripts being detected by RNA gel blot analysis in a self-incompatible B. oleracea var botrytis line carrying an interrupted SLA gene. These data indicate that a functional SLA gene is not required for the SI response in Brassica.
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PMID:A functional S locus anther gene is not required for the self-incompatibility response in Brassica oleracea. 940 Nov 28