Transcriptional Activation of Arabidopsis Zygotes Is Required for Initial Cell Divisions

Kao, Ping; Nodine, Michael D.

doi:10.1038/s41598-019-53704-2

Cited by 43 publications

(35 citation statements)

References 91 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5 a, c). Arabidopsis zygotes require de novo synthesis of gene products directly after fertilization [ 57 , 73 ], and genes involved in rRNA biogenesis produce high levels of transcripts in preglobular embryos relative to later stages [ 40 ]. In contrast to Arabidopsis, maternally donated proteins drive early embryogenesis in Xenopus and H1 dynamics mediate transcriptional activation of rRNA loci in oocytes and their silencing in somatic tissues [ 74 , 75 ].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Chromatin regulates expression of small RNAs to help maintain transposon methylome homeostasis in Arabidopsis

et al. 2020

Self Cite

View full text Add to dashboard Cite

Background Eukaryotic genomes are partitioned into euchromatic and heterochromatic domains to regulate gene expression and other fundamental cellular processes. However, chromatin is dynamic during growth and development and must be properly re-established after its decondensation. Small interfering RNAs (siRNAs) promote heterochromatin formation, but little is known about how chromatin regulates siRNA expression. Results We demonstrate that thousands of transposable elements (TEs) produce exceptionally high levels of siRNAs in Arabidopsis thaliana embryos. TEs generate siRNAs throughout embryogenesis according to two distinct patterns depending on whether they are located in euchromatic or heterochromatic regions of the genome. siRNA precursors are transcribed in embryos, and siRNAs are required to direct the re-establishment of DNA methylation on TEs from which they are derived in the new generation. Decondensed chromatin also permits the production of 24-nt siRNAs from heterochromatic TEs during post-embryogenesis, and siRNA production from bipartite-classified TEs is controlled by their chromatin states. Conclusions Decondensation of heterochromatin in response to developmental, and perhaps environmental, cues promotes the transcription and function of siRNAs in plants. Our results indicate that chromatin-mediated siRNA transcription provides a cell-autonomous homeostatic control mechanism to help reconstitute pre-existing chromatin states during growth and development including those that ensure silencing of TEs in the future germ line.

show abstract

Section: Discussionmentioning

confidence: 99%

“…The expansion microscopy technique [ 109 ] optimized for Arabidopsis seeds was conducted as previously described [ 73 ]. Anti-Fibrillarin antibody (ab4566, Abcam) and anti-alpha Tubulin antibody (ab89984, Abcam) were used in 1:500 dilution as primary antibodies.…”

Section: Methodsmentioning

confidence: 99%

Chromatin regulates expression of small RNAs to help maintain transposon methylome homeostasis in Arabidopsis

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Other protocols focus on preservation and isotropic expansion of ultrastructure (U-ExM) (Gambarotto et al, 2019) or on precise tuning of the expansion factor between 2 and 8 (ZOOM) (Park et al, 2019). Recently, ExM has been applied also to bacterial pathogens (Kunz et al, 2019) and to plants (Kao and Nodine, 2019), paving the way for new methodological approaches in these fields.…”

Section: Introductionmentioning

confidence: 99%

Expansion Microscopy for Cell Biology Analysis in Fungi

Götz¹,

Panzer²,

Trinks³

et al. 2020

Front. Microbiol.

View full text Add to dashboard Cite

Super-resolution microscopy has evolved as a powerful method for subdiffractionresolution fluorescence imaging of cells and cellular organelles, but requires sophisticated and expensive installations. Expansion microscopy (ExM), which is based on the physical expansion of the cellular structure of interest, provides a cheap alternative to bypass the diffraction limit and enable super-resolution imaging on a conventional fluorescence microscope. While ExM has shown impressive results for the magnified visualization of proteins and RNAs in cells and tissues, it has not yet been applied in fungi, mainly due to their complex cell wall. Here we developed a method that enables reliable isotropic expansion of ascomycetes and basidiomycetes upon treatment with cell wall degrading enzymes. Confocal laser scanning microscopy (CLSM) and structured illumination microscopy (SIM) images of 4.5-fold expanded sporidia of Ustilago maydis expressing fluorescent fungal rhodopsins and hyphae of Fusarium oxysporum or Aspergillus fumigatus expressing either histone H1-mCherry together with Lifeact-sGFP or mRFP targeted to mitochondria, revealed details of subcellular structures with an estimated spatial resolution of around 30 nm. ExM is thus well suited for cell biology studies in fungi on conventional fluorescence microscopes.

show abstract

“…On the other hand, several reports (Chozinski et al 2016;Cahoon et al 2017;Freifiled et al 217;Jiang et al 2018;Wang et al 2018b;Gambarotto et al 2019;Kao and Nodine 2019;Xu et al 2019;Zwettler et al 2020a, b) demonstrated the improved visualisation of target proteins after applying ExM. Thus, ExM can reveal the unaltered localization of target molecules, but preserving the chromatin ultrastructure of isolated nuclei is more challenging, and therefore, further improved ExM protocols have to be developed.…”

Section: Discussionmentioning

confidence: 99%

Prospects and limitations of expansion microscopy in chromatin ultrastructure determination

et al. 2020

View full text Add to dashboard Cite

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 ~4.2-times physically expanded nuclei corresponding to a maximal resolution of ~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 ~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.

show abstract

Transcriptional Activation of Arabidopsis Zygotes Is Required for Initial Cell Divisions

Cited by 43 publications

References 91 publications

Chromatin regulates expression of small RNAs to help maintain transposon methylome homeostasis in Arabidopsis

Chromatin regulates expression of small RNAs to help maintain transposon methylome homeostasis in Arabidopsis

Expansion Microscopy for Cell Biology Analysis in Fungi

Prospects and limitations of expansion microscopy in chromatin ultrastructure determination

Contact Info

Product

Resources

About