Cytoplasmic male sterility (CMS) is a widespread phenomenon in flowering plants caused by mitochondrial (mt) genes. CMS genes typically encode novel proteins that interfere with mt functions and can be silenced by nuclear fertility-restorer genes. Although the molecular basis of CMS is well established in a number of crop systems, our understanding of it in natural populations is far more limited. To identify CMS genes in a gynodioecious plant, Silene vulgaris, we constructed mt transcriptomes and compared transcript levels and RNA editing patterns in floral bud tissue from female and hermaphrodite full siblings. The transcriptomes from female and hermaphrodite individuals were very similar overall with respect to variation in levels of transcript abundance across the genome, the extent of RNA editing, and the order in which RNA editing and intron splicing events occurred. We found only a single genomic region that was highly overexpressed and differentially edited in females relative to hermaphrodites. This region is not located near any other transcribed elements and lacks an open-reading frame (ORF) of even moderate size. To our knowledge, this transcript would represent the first non-coding mt RNA associated with CMS in plants and is, therefore, an important target for future functional validation studies.

• Klíčová slova
• Cytoplasmic male sterility, Silene vulgaris, editing, mitochondrion, non-coding RNA, splicing, transcriptome.,
• MeSH
• editace RNA MeSH
• květy genetika   růst a vývoj   MeSH
• mitochondriální geny * MeSH
• nekódující RNA * MeSH
• neplodnost rostlin * MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• Silene genetika   fyziologie   MeSH
• transkriptom * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• nekódující RNA * MeSH
• rostlinné proteiny MeSH

An extraordinary variation in mitochondrial DNA sequence exists in angiosperm Silene vulgaris. The atp1 gene is flanked by very variable regions, as deduced from four completely sequenced mitochondrial genomes of this species. This diversity contributed to a highly variable transcript profile of this gene observed across S. vulgaris populations. We examined the atp1 transcript in the KOV mitochondrial genome and found three 5' ends, created most likely by the combination of transcription initiation and RNA processing. Most atp1 transcripts terminated about 70 bp upstream of the translation stop codon, which was present in only 10 % of them. Controlled crosses between a KOV mother and a geographically distant pollen donor (Krasnoyarsk, Russia) showed that nuclear background also affected atp1 transcription. The distant pollen donor introduced the factor(s) preventing the formation of a long 2,100 nt-transcript, because this long atp1 transcript reappeared in the progeny from self-crosses. The highly rearranged mitochondrial genomes with a variation in gene flanking regions make S. vulgaris an excellent model for the study of mitochondrial gene expression in plants.

• MeSH
• 5' nepřekládaná oblast genetika   MeSH
• buněčné jádro genetika   MeSH
• genetická transkripce * MeSH
• genom mitochondriální genetika   MeSH
• genom rostlinný genetika   MeSH
• genová přestavba genetika   MeSH
• křížení genetické MeSH
• messenger RNA genetika   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• northern blotting MeSH
• otevřené čtecí rámce genetika   MeSH
• pyl genetika   MeSH
• regulace genové exprese u rostlin MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• sekvence nukleotidů MeSH
• sekvenční seřazení MeSH
• Silene genetika   MeSH
• stanovení celkové genové exprese MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 5' nepřekládaná oblast MeSH
• messenger RNA MeSH
• rostlinné proteiny MeSH

Chimeric genes are significant sources of evolutionary innovation that are normally created when portions of two or more protein coding regions fuse to form a new open reading frame. In plant mitochondria astonishingly high numbers of different novel chimeric genes have been reported, where they are generated through processes of rearrangement and recombination. Nonetheless, because most studies do not find or report nucleotide variation within the same chimeric gene, evolution after the origination of these chimeric genes remains unstudied. Here we identify two alleles of a complex chimera in Silene vulgaris that are divergent in nucleotide sequence, genomic position relative to other mitochondrial genes, and expression patterns. Structural patterns suggest a history partially influenced by gene conversion between the chimeric gene and functional copies of subunit 1 of the mitochondrial ATP synthase gene (atp1). We identified small repeat structures within the chimeras that are likely recombination sites allowing generation of the chimera. These results establish the potential for chimeric gene divergence in different plant mitochondrial lineages within the same species. This result contrasts with the absence of diversity within mitochondrial chimeras found in crop species.

• MeSH
• alely MeSH
• DNA primery genetika   MeSH
• druhová specificita MeSH
• fylogeneze MeSH
• genetická transkripce MeSH
• genetická variace MeSH
• genom rostlinný MeSH
• kodon MeSH
• křížení genetické MeSH
• messenger RNA metabolismus   MeSH
• mitochondriální geny * MeSH
• modely genetické MeSH
• molekulární evoluce MeSH
• mozaicismus MeSH
• polymerázová řetězová reakce MeSH
• pravděpodobnostní funkce MeSH
• proteiny huseníčku genetika   MeSH
• protonové ATPasy genetika   MeSH
• regulace genové exprese MeSH
• rekombinace genetická MeSH
• rostlinné geny MeSH
• Silene genetika   MeSH
• Southernův blotting MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• ATP1 protein, Arabidopsis MeSH Prohlížeč
• DNA primery MeSH
• kodon MeSH
• messenger RNA MeSH
• proteiny huseníčku MeSH
• protonové ATPasy MeSH