Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2021 Jan 19;34(3):108655. doi: 10.1016/j.celrep.2020.108655

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2021 The Authors

This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

PMC Copyright notice

Sequence of remodeling steps of epiblast and polar trophectoderm tissues upon implantation

(A) E4.5 implanting blastocyst and E5.0 early egg cylinder. Staining: DAPI (blue), F-actin (green), and Oct4 (red). Oct4 is expressed in the epiblast tissue. Zoom-in on the epiblast tissue highlights shapes of the epiblast upon implantation (oval) and post-implantation (cup).

(B) Schematic of the epiblast (pink) and polar TE (blue) lineages from implantation to egg-cylinder formation.

(C) Lineage staining of embryos fixed at sequential time points from implantation to egg-cylinder formation (E4.5–5.0). Top row: embryos stained for Gata6 (white) and Cdx2 (blue) to distinguish primitive endoderm and polar TE lineages, respectively. Staining: DAPI (red) and F-actin (green). This allows analysis of epiblast and polar TE tissue shapes. Bottom row: zoom-in on epiblast and polar TE lineages, with polar TE highlighted in blue and the epiblast in red.

(D) Schematic to illustrate measurements taken for quantitative analysis. Polar TE is indicated in blue, and epiblast is indicated in pink. Measurements were taken in plane of maximum tissue area for both lineages. Epiblast height (white) and width (green) were measured through the center of the epiblast. Epiblast area (green dotted line) was measured for the maximum area. Polar TE height (red) was measured at three points, and the average for each embryo was analyzed.

(E) Quantification of epiblast height (in microns) over time. Scatterplot, mean ± SEM. The epiblast height changes significantly over time. Stage I, n = 69; stage II, n = 81; stage III, n = 51; stage IV, n = 40; stage V, n = 43. Analysis, unpaired Student’s t test: stages I–II, p < 0.0001; II–III, p = 0.0020; III–IV, p = 0.3530; IV–V, p = 0.0059.

(F) Quantification of epiblast width over time. Scatterplot, mean ± SEM. Epiblast width increases slightly. Stage I, n = 68; stage II, n = 81; stage III, n = 51; stage IV, n = 40; stage V, n = 43. Analysis, unpaired Student’s t test: stages I–II, p = 0.6192; II–III, p = 0.1559; III–IV, p = 0.1523; IV–V, p = 0.2277; I–V, p < 0.0001.

(G) Quantification of epiblast area over time. Scatterplot, mean ± SEM. Area increases significantly over time. Stage I, n = 69; stage II, n = 81; stage III, n = 51; stage IV, n = 40; stage V, n = 44. Analysis, unpaired Student’s t test: stages I–II, p < 0.0001; II–III, p < 0.0001; III–IV, p = 0.0005; IV–V, p = 0.4385.

(H) Quantification of polar TE height over time. Scatterplot, mean ± SEM. Height of polar TE increases exponentially over time. Stage I, n = 69; stage II, n = 82; stage III, n = 51; stage IV, n = 40; stage V, n = 44. Analysis, unpaired Student’s t test: stages I–II, p < 0.0001; II–III, p < 0.0001; III–IV, p < 0.0001; IV–V, p < 0.0001. Scale bars, 20 μm.

(I) Analysis of epiblast and polar TE cell numbers over time. Stages I: black, II: red, III: yellow, IV: blue, V: green. The growth in cell numbers is highly correlated; Pearson r = 0.8884, p < 0.0001. Stage I, n = 62; stage II, n = 51; stage III, n = 16; stage IV, n = 17; stage V, n = 28.