Polycomb-mediated repression of paternal chromosomes maintains haploid dosage in diploid embryos of Marchantia
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Austria
- Institute of Biology, University of Hohenheim, Germany
Figures
Figure 1 with 1 supplement
Embryonic transcription is maternally biased.
(A) Life cycle of Marchantia polymorpha. Haploid (1n) vegetative males and females produce male and female reproductive structures, which subsequently produce sperm and egg. The diploid (2n) embryo …
Figure 1—figure supplement 1
Maternally biased transcription in embryos.
(A) Distance matrix heatmap of RNA-seq replicates. Individual replicates indicated along the bottom axis and the sample stage is indicated along the right axis. daf (days after fertilization), an …
Figure 2 with 1 supplement
Levels of H3K27me3 enrichment are paternally biased.
(A) Heatmap of gene expression of Polycomb repressive complex 2 subunits across Marchantia development. Vegetative male (Tak-1) and female (Cam-2) tissues give rise to male and female sexual organs …
Figure 2—figure supplement 1
Paternally biased H3K27me3 in embryos.
(A) Venn diagram of upregulated genes in wild-type embryos compared to male (Tak-1) and female (Cam-2) parents. (B) Venn diagram of downregulated genes in wild-type embryos compared to male (Tak-1) …
Figure 3 with 1 supplement
Paternal autosomes are coated in H3K27me3 and partitioned in heterochromatic foci.
(A) Immunofluorescence of H3K27me3 in interphase wild-type embryonic and vegetative nuclei. DNA is stained with DAPI. Scale bar as indicated. (B) Immunofluorescence of H3K27me3 in mitotic wild-type …
Figure 3—figure supplement 1
Quantification of immunofluorescence experiments.
(A) Number of heterochromatic foci per nucleus in wild-type embryos. (B) Percentage of nuclear area covered by heterochromatic foci in wild-type embryos. (C) Percentage of immunofluorescence signal …
Figure 4 with 1 supplement
H3K27me3 is deposited in paternal pronuclei.
(A) Annotated confocal image of a Marchantia zygote 3 days after fertilization (daf) with surrounding vegetative mother tissue. The paternal pronucleus is visible in the vicinity of the maternal …
Figure 4—figure supplement 1
Immunofluorescence of pronuclei.
(A) Representative images of wild-type zygotes at 2 and 3 days after fertilization (daf) immunostained against H3K27me3 (red) and H3 (green). Paternal pronuclei are indicated with a cyan box and in …
Figure 5 with 2 supplements
Embryonic Polycomb repressive complex 2 (PRC2) deposits H3K27me3 and represses the paternal genome.
(A) Immunofluorescence of H3K27me3 in interphase wild-type (WT) and mutant embryonic nuclei. DNA is stained with DAPI. (B) Violin plots of maternal ratios for WT and mutant H3K27me3 and …
Figure 5—figure supplement 1
Chromatin phenotypes of e(z)2/e(z)3 mutants.
(A) Structure of E(z)2 and E(z)3 genes and the mutations generated in each. (B) Growth of Cam-2 e(z)2/e(z)3 mutants in the vegetative stage relative to Cam-2 wild type. Area of vegetative haploid …
Figure 5—figure supplement 2
Transcription phenotypes in mutant embryos.
(A) Percentage of measured genes within each category of maternal ratio (pm) of transcription in mutant embryos. Segments are for full paternal (pm ≤ 0.05), paternal bias (0.05 <pm ≤ 0.35), no bias …
Figure 6
Model of genomic imprinting in Marchantia.
Model of H3K27me3 deposition in wild-type (WT) paternal pronuclei and subsequent propagation throughout embryogenesis. Closed lollipops depict H3K27me3 on genes. Pink and blue circles depict …
Figure 7
Immunofluorescence image analysis.
(A) Nucleus segmentation. Top panel: A sequence of 20 segmentations created by thresholding. Bottom panel: Differences (d) between nucleus mask sizes (blue curve). Plateau identified by estimating a …
Videos
Video 1
Movie of the dissection of a representative Marchantia embryo from surrounding calyptra of maternal origin.
Additional files
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Supplementary file 1
List of Marchantia chromatin-related genes and their expression status in embryos relative to other tissues.
- https://cdn.elifesciences.org/articles/79258/elife-79258-supp1-v1.csv
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Supplementary file 2
Data for χ2 test.
List of all Marchantia genes and the presence or absence of H3K27me3 peaks in e(z)2/e(z)3 mutant embryos plus whether the genes were upregulated, downregulated, or unchanged in a differential gene expression analysis between wild-type and e(z)2/e(z)3 mutant embryos.
- https://cdn.elifesciences.org/articles/79258/elife-79258-supp2-v1.csv
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MDAR checklist
- https://cdn.elifesciences.org/articles/79258/elife-79258-mdarchecklist1-v1.pdf
