Concerted evolution rapidly eliminates sequence variation in rDNA coding regions but not in intergenic spacers in Nicotiana tabacum allotetraploid

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081707%3A_____%2F17%3A00485527" target="_blank" >RIV/68081707:_____/17:00485527 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1007/s00606-017-1442-7" target="_blank" >http://dx.doi.org/10.1007/s00606-017-1442-7</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00606-017-1442-7" target="_blank" >10.1007/s00606-017-1442-7</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Concerted evolution rapidly eliminates sequence variation in rDNA coding regions but not in intergenic spacers in Nicotiana tabacum allotetraploid

Popis výsledku v původním jazyce

Nicotiana tabacum (tobacco) is a natural allotetraploid that formed from two diploid progenitors (N. sylvestris-S-genome, N. tomentosiformis-T-genome) within past 0.2 million years. Previous classical studies have shown that its 35S rDNA has been largely homogenised towards T-genome-like homeologs. However, the degree of conversion at single nucleotide resolution remains unknown. Here, we analysed intragenomic variation of rDNA at high resolution in natural tobacco, synthetic tobacco and the progenitors employing genomic, molecular and cytogenetic methods. In synthetic tobacco, we identified 13 highly (>= 10% units) polymorphic sites in the 18S-5.8S-26S coding region. In contrast, only a single polymorphic site was detected in natural tobacco, indicating that gene conversion has removed most of the polymorphisms over shallow evolutionary times. However, the non-coding 26S-18S intergenic spacer (IGS) was highly polymorphic in both natural (57 polymorphic sites) and synthetic tobacco (128 polymorphic sites). In natural tobacco, most (64%) IGS polymorphisms were inherited from the N. tomentosiformis progenitor, while 36% appeared de novo indicating rapid rates of sequence divergence of IGS. FISH revealed that the T-genome-like units (harbouring N. tomentosiformis-type IGS) occurred on all four loci in tobacco variety 095-55, including those loci derived from N. sylvestris progenitor, while the variety SR-1 retained 1-2 S-genome loci unconverted and transcriptionally silenced. We discuss potential caveats associated with experimental and in silico approaches used for determination of rDNA polymorphisms. We also hypothesise that polyploidy-associated gene conversion may eliminate mutated and non-functional genes that have accumulated in progenitor genomes, thereby contributing to success of polyploidy species.

Název v anglickém jazyce

Concerted evolution rapidly eliminates sequence variation in rDNA coding regions but not in intergenic spacers in Nicotiana tabacum allotetraploid

Popis výsledku anglicky

Nicotiana tabacum (tobacco) is a natural allotetraploid that formed from two diploid progenitors (N. sylvestris-S-genome, N. tomentosiformis-T-genome) within past 0.2 million years. Previous classical studies have shown that its 35S rDNA has been largely homogenised towards T-genome-like homeologs. However, the degree of conversion at single nucleotide resolution remains unknown. Here, we analysed intragenomic variation of rDNA at high resolution in natural tobacco, synthetic tobacco and the progenitors employing genomic, molecular and cytogenetic methods. In synthetic tobacco, we identified 13 highly (>= 10% units) polymorphic sites in the 18S-5.8S-26S coding region. In contrast, only a single polymorphic site was detected in natural tobacco, indicating that gene conversion has removed most of the polymorphisms over shallow evolutionary times. However, the non-coding 26S-18S intergenic spacer (IGS) was highly polymorphic in both natural (57 polymorphic sites) and synthetic tobacco (128 polymorphic sites). In natural tobacco, most (64%) IGS polymorphisms were inherited from the N. tomentosiformis progenitor, while 36% appeared de novo indicating rapid rates of sequence divergence of IGS. FISH revealed that the T-genome-like units (harbouring N. tomentosiformis-type IGS) occurred on all four loci in tobacco variety 095-55, including those loci derived from N. sylvestris progenitor, while the variety SR-1 retained 1-2 S-genome loci unconverted and transcriptionally silenced. We discuss potential caveats associated with experimental and in silico approaches used for determination of rDNA polymorphisms. We also hypothesise that polyploidy-associated gene conversion may eliminate mutated and non-functional genes that have accumulated in progenitor genomes, thereby contributing to success of polyploidy species.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10603 - Genetics and heredity (medical genetics to be 3)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Plant Systematics and Evolution

ISSN

0378-2697

e-ISSN

—

Svazek periodika

303

Číslo periodika v rámci svazku

8

Stát vydavatele periodika

AT - Rakouská republika

Počet stran výsledku

18

Strana od-do

1043-1060

Kód UT WoS článku

000412976200006

EID výsledku v databázi Scopus

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