| Autor: |
Tantikanjana, Titima, Nasrallah, Mikhail E., Nasrallah, J. B. |
| Zdroj: |
Sexual Plant Reproduction; Mar1996, Vol. 9 Issue 2, p107-116, 10p |
| Abstrakt: |
The S gene family of higher plants includes secreted glycoprotein-encoding genes and transmembrane protein kinase-encoding genes all of which share sequence similarity to the S-locus genes of Brassica. In our continuing effort to understand the structural and functional diversification of this gene family in Brassica, we analyzed the S-locus-related SLR2 gene from B. oleracea and B. campestris. SLR2 is a flower-specific gene that exhibits a high degree of sequence similarity to the S-locus genes derived from the S self-incompatibility haplotype. We present data which suggest that the SLR2 gene encodes a secreted protein as predicted from its nucleotide sequence. However, unlike other secreted glycoprotein-encoding members of the S gene family, the gene contains a 591 base-pair intron at or near its 3′ terminus. Based on this structure, we propose that this gene arose prior to speciation by partial duplication of an ancestral gene similar in structure to the S-locus-linked SRK ( S Receptor Kinase) gene. The high degree of variability in SLR2 transcript levels noted in different Brassica strains was found to be correlated with the segregation of an SLR2 polymorphism, whereby a mutated SLR2 allele containing a duplication within the promoter region directs low expression. The implications of these findings for SLR2 gene function are discussed. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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