Fig. 6. High-level Nkx2-5GFP/lacZ or
Nkx2-5GFP/Y-A ES cell contribution to chimaeric embryos
perturbs heart development. (A,B)
Nkx2-5GFP/Y-A
wild-type chimaeras at 7.5 and 8.5 dpc
stained for lacZ. (C) Chimaera showing abnormal cardiac
development at 9.0 dpc with pericardial oedema (arrows). (D-I)
Comparison of heart morphology (upper panels) and histology (lower panels) in
9.0 dpc chimaeric embryos composed of indicated ES cell genotypes.
Nkx2-5lacZ/+
wild-type chimaeras (D,G) were
morphologically normal. Nkx2-5GFP/lacZ
wild-type
(E,H) and Nkx2-5GFP/Y-A
wild-type (F,I) chimaeras showed
arrested heart development and absence of ventricular trabeculation (arrows).
(J,K) High-level chimaera at E9.5 carrying
Nkx2-5Y-A:IRESlacZ/+ ES cells (stained for lacZ) and
section, showing relatively normal cardiac morphology. Abbreviations: CA,
common atrium; LV, left ventricle; OT, outflow tract; PV, primitive ventricle;
RA, right atrium.