XX, but Not XY, UGRs Induce Xi Reactivation in E9.5 and E11.5 XX PGCs

<div><p>A transwell system was used to study the X-chromosome reactivation in E9.5 and E11.5 <i>X^GFP</i> PGCs cultured for a period of 48 hours.</p><p>(A) The percentage of X-linked GFP-expressing XX E9.5 PGCs after culture. Hindgut and the surrounding mesentery were dissociated and cultured in the top compartment with the lower compartment containing: medium only (control), one dissociated XX E11.5 UGR pair (XX), or one dissociated XY E11.5 UGR pair (XY). Red bars depict the median, <i>n</i> is the total number of transwell filter membranes (each containing 1.5× embryo) analysed. *, <i>p</i> < 0.05.</p><p>(B) The percentage of X-linked GFP-expressing XX E11.5 PGCs after culture. FACS-sorted PGCs (SSEA1-positive) were cultured in the top compartment with FACS-sorted XX (XX) or XY (XY) E11.5 UGR somatic tissue (SSEA1-negative). Red bars depict the median, <i>n</i> is the total number of embryos analysed.</p><p>(C,D) GFP-positive (white arrow) and GFP-negative (asterisk) <i>Xp-X^GFP</i> E9.5 PGCs (SSEA1-positive) after culture.</p><p>(E–J) Representative dot-plots showing FACS-analysis of E13.5 genital ridges from individual <i>XX</i> (E,F), <i>X^GFPX</i> (G), <i>X^GFPX Sry</i> (H), <i>X^GFPY</i> (I), and <i>X^GFPY Sry</i> (J) embryos.</p><p>(K,L) The percentage of FACS-analysed GFP-expressing PGCs (K) and surrounding somatic tissue (L) in the genital ridges of individual <i>X^GFPX</i>, <i>X^GFPX Sry</i>, <i>X^GFPY</i>, and <i>X^GFPY Sry</i> E13.5 embryos. PGCs and somatic cells were respectively positive and negative for PECAM1. Red bars depict the median, <i>n</i> is the total number of embryos analysed.</p>