Phenotype Image Detail

Image

Caption

Whole-mount embryos in their yolk sacs were stained for beta-gal activity. (A, B, E and F) Direct microscopic examiniation of the yolk sacs. (C, D, G, and H) Sagittal histological sections. At E9.0, the normal capillary plexus and initiation of branching are seen in the Eng^tm1Mle/Eng⁺ (End +/-) embryo (A and C). The Eng^tm1Mle/Eng^tm1Mle (End -/-) yolk sac also has a highly vascularized plexus, but no vessel branching is observed (B and D). At E9.5, a vitelline vessel (v) is readily detectable in the heterozygous yolk sac (E); this intact vessel is full of primitive red cells (G). The homozygous yolk sac shows a disorganized capillary plexus and no vitelline vessels (F); abnormally dilated blood islands are seen (H), which have ruptured, releasing primitive erythroblasts toward the amnion (arrowhead). (I and J) Unstained E9.5 embryos, with yolk sac and placenta still attached. Bleeding in the yolk sac cavity (arrowhead) and edematous pericardium (arrow) are observed in the homozygous embryo (J), compared with a littermate control (I). An unstained E9.0 heterozygous embryo (K), dissected away from the yolk sac, is compared with a homozygous embryo littermate (L), which shows internal bleeding (arrow). Sagittal sections stained for beta-gal demonstrate the presence of blood (arrow) in the peritoneal cavity of the homozygous embryo (N), which is absent from the heterozygous embryo (M). a, dorsal aorta; pc, peritoneal cavity; u, umbilical vein. Scal bar, 100um A-H; 500um I and J; 250um K-N.

Copyright

This image is from Bourdeau A, J Clin Invest 1999 Nov;104(10):1343-51 and is displayed with the permission of the American Society for Clinical Investigation who owns the Copyright. J:58502

Associated Alleles

Symbol	Name
Eng^tm1Mle	endoglin; targeted mutation 1, Michelle Letarte

Associated Genotypes

Allelic Composition	Genetic Background
Eng^tm1Mle/Eng^tm1Mle	involves: 129P2/OlaHsd * C57BL/6