tailieunhanh - báo cáo khoa học: " Sequence analysis of two alleles reveals that intra-and intergenic recombination played a role in the evolution of the radish fertility restorer (Rfo)"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Sequence analysis of two alleles reveals that intra-and intergenic recombination played a role in the evolution of the radish fertility restorer (Rfo) | Hernandez Mora et al. BMC Plant Biology 2010 10 35 http 1471-2229 10 35 BMC Plant Biology RESEARCH ARTICLE Open Access Sequence analysis of two alleles reveals that intra-and intergenic recombination played a role in the evolution of the radish fertility restorer Rfo José R Hernandez Mora1 Eric Rivals2 Hakim Mireau1 Frangoise Budar1 Abstract Background Land plant genomes contain multiple members of a eukaryote-specific gene family encoding proteins with pentatricopeptide repeat PPR motifs. Some PPR proteins were shown to participate in post-transcriptional events involved in organellar gene expression and this type of function is now thought to be their main biological role. Among PPR genes restorers of fertility Rf of cytoplasmic male sterility systems constitute a peculiar subgroup that is thought to evolve in response to the presence of mitochondrial sterility-inducing genes. Rf genes encoding PPR proteins are associated with very close relatives on complex loci. Results We sequenced a non-restoring allele L7rfo of the Rfo radish locus whose restoring allele D81Rfo was previously described and compared the two alleles and their PPR genes. We identified a ca 13 kb long fragment likely originating from another part of the radish genome inserted into the L7rfo sequence. The L7rfo allele carries two genes PPR-1 and PPR-2 closely related to the three previously described PPR genes of the restorer D81Rfo allele PPR-A PPR-B and PPR-C . Our results indicate that alleles of the Rfo locus have experienced complex evolutionary events including recombination and insertion of extra-locus sequences since they diverged. Our analyses strongly suggest that present coding sequences of Rfo PPR genes result from intragenic recombination. We found that the 10 C-terminal PPR repeats in Rfo PPR gene encoded proteins result from the tandem duplication of a 5 PPR repeat block. Conclusions The Rfo locus appears to experience more complex evolution than its flanking