Prospects and limitations of expansion microscopy in chromatin ultrastructure determination

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378050%3A_____%2F20%3A00538175" target="_blank" >RIV/68378050:_____/20:00538175 - isvavai.cz</a>

Výsledek na webu

<a href="https://link.springer.com/article/10.1007/s10577-020-09637-y" target="_blank" >https://link.springer.com/article/10.1007/s10577-020-09637-y</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s10577-020-09637-y" target="_blank" >10.1007/s10577-020-09637-y</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Prospects and limitations of expansion microscopy in chromatin ultrastructure determination

Popis výsledku v původním jazyce

Expansion microscopy (ExM) is a method to magnify physically a specimen with preserved ultrastructure. It has the potential to explore structural features beyond the diffraction limit of light. The procedure has been successfully used for different animal species, from isolated macromolecular complexes through cells to tissue slices. Expansion of plant-derived samples is still at the beginning, and little is known, whether the chromatin ultrastructure becomes altered by physical expansion. In this study, we expanded isolated barley nuclei and compared whether ExM can provide a structural view of chromatin comparable with super-resolution microscopy. Different fixation and denaturation/digestion conditions were tested to maintain the chromatin ultrastructure. We achieved up to similar to 4.2-times physically expanded nuclei corresponding to a maximal resolution of similar to 50-60 nm when imaged by wild-field (WF) microscopy. By applying structured illumination microscopy (SIM, super-resolution) doubling the WF resolution, the chromatin structures were observed at a resolution of similar to 25-35 nm. WF microscopy showed a preserved nucleus shape and nucleoli. Moreover, we were able to detect chromatin domains, invisible in unexpanded nuclei. However, by applying SIM, we observed that the preservation of the chromatin ultrastructure after the expansion was not complete and that the majority of the tested conditions failed to keep the ultrastructure. Nevertheless, using expanded nuclei, we localized successfully centromere repeats by fluorescence in situ hybridization (FISH) and the centromere-specific histone H3 variant CENH3 by indirect immunolabelling. However, although these repeats and proteins were localized at the correct position within the nuclei (indicating a Rabl orientation), their ultrastructural arrangement was impaired.

Název v anglickém jazyce

Prospects and limitations of expansion microscopy in chromatin ultrastructure determination

Popis výsledku anglicky

Expansion microscopy (ExM) is a method to magnify physically a specimen with preserved ultrastructure. It has the potential to explore structural features beyond the diffraction limit of light. The procedure has been successfully used for different animal species, from isolated macromolecular complexes through cells to tissue slices. Expansion of plant-derived samples is still at the beginning, and little is known, whether the chromatin ultrastructure becomes altered by physical expansion. In this study, we expanded isolated barley nuclei and compared whether ExM can provide a structural view of chromatin comparable with super-resolution microscopy. Different fixation and denaturation/digestion conditions were tested to maintain the chromatin ultrastructure. We achieved up to similar to 4.2-times physically expanded nuclei corresponding to a maximal resolution of similar to 50-60 nm when imaged by wild-field (WF) microscopy. By applying structured illumination microscopy (SIM, super-resolution) doubling the WF resolution, the chromatin structures were observed at a resolution of similar to 25-35 nm. WF microscopy showed a preserved nucleus shape and nucleoli. Moreover, we were able to detect chromatin domains, invisible in unexpanded nuclei. However, by applying SIM, we observed that the preservation of the chromatin ultrastructure after the expansion was not complete and that the majority of the tested conditions failed to keep the ultrastructure. Nevertheless, using expanded nuclei, we localized successfully centromere repeats by fluorescence in situ hybridization (FISH) and the centromere-specific histone H3 variant CENH3 by indirect immunolabelling. However, although these repeats and proteins were localized at the correct position within the nuclei (indicating a Rabl orientation), their ultrastructural arrangement was impaired.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

30102 - Immunology

Projekt

<a href="/cs/project/GJ17-20613Y" target="_blank" >GJ17-20613Y: Vzájemná regulace BBSomu a aktinu ve tvorbě cilia a imunologické synapse</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

Chromosome Research

ISSN

0967-3849

e-ISSN

—

Svazek periodika

28

Číslo periodika v rámci svazku

3-4

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

14

Strana od-do

355-368

Kód UT WoS článku

000571228600001

EID výsledku v databázi Scopus

—