Morphology, topology and dimensions of the heart and arteries of genetically normal and mutant mouse embryos at stages S21–S23

Figure 1. Heart of E14.5 mouse embryos. Bottom of all images is ventral. View is from cranial. (A–E) Virtually sectioned volume‐rendered heart models of genetically normal (A–C) and mutant (D,E) embryos of S21 and S23. Compared to the controls in (B and C), the mutant in (D) (Chtop−/−) shows double‐outlet right ventricle and the mutant in (E), (Atpa−/−), shows a perimembranous ventricular septal defect (arrow). Note that the perimembranous ventricular septal defect in the S22 embryo appears similar to the large interventricular communication and overriding aortic valve (arrow in A), which is normal for embryos of S21. (F) Atpa−/− mutant with a muscular septal defect (arrow), view from cranial in an axial high‐resolution episcopic microscopy (HREM) image. (G–J) Volume‐rendered models of the semilunar valves. The cusps (asterisk) of normal S22 embryos can still appear as solid tissue protrusions (G) as in earlier stages or show cavitations (H), as in later embryos. Note the bicuspid aortic valve (av) in a Camsap−/− mutant (I) and the common valve (cv) with still visible endocardial ridges (r) in an Ssr2−/− mutant (J). (K,L) Compact layer of the myocardium in axial HREM sections. Note the…

Figure 2. Arteries of E14.5 mouse embryos. (A–D) Combined volume‐rendered models of whole embryos and surface‐rendered models of large arteries at S21 (A,B) and S23 (C,D) from the right (A, C) and ventrally (B, D). (E–J) Axial high‐resolution episcopic microscopy (HREM) sections, view from cranial. Bottom of images is ventral. Compare (E) and (F) for the variable diameter of the posterior communicating artery, (G) and (H) for the variable appearance of the wall thickness of the descending aorta (dao), and the contralateral arteries in (I) and (J) for the variable appearance of the vertebral (va) and parasellar segments of the internal carotid arteries (ica). (K,L) Volume‐rendered models of the thorax and surface‐rendered models of the great intra‐thoracic arteries at S21 (K) and S23 (L) ventrally. Bottom of images is caudal. Note the position of the lvcs ( left vena cava superior) arteries in respect to the 1st rib (co1). Due to tissue maturation, rib material appears white at S21 and black at S23. (M–R) Surface‐rendered models of the great intra‐thoracic arteries ventrally, showing the origin of the left subclavian artery (lsa) with respect to the ductus arterious (da). View as in (I) and…

Figure 3. Head arteries of E14.5 mouse embryos. (A,B) Volume‐rendered models of the head and surface‐rendered models of its arteries at S21 (A) and S23 (B) from right. Bottom of panel is caudal. Frontal view in top left insert. Top right insert in (A) holds sagittal high‐resolution episcopic microscopy (HREM) section from right that demonstrates the position of the internal carotid artery (ica) with respect to cochlea (c), inferior vagus ganglion and vagus nerve (X) and superior cervical ganglion (s). (C–F) Axial HREM sections through the head. Bottom of image is medial, right of image is ventral. Compare (C) and (D) for the normal position of the stapedial artery (sa) running through the anlage of the stapes in genetically normal embryos and the absence of the sa in an Adcy9−/− mutant. Note the abnormal shape of the stapes in (D). A dorsal ophthalmic artery (oa) originates from the internal carotid artery (ica) in a Nsun2−/− mutant (F). (G,H) Surface‐rendered models of the head arteries above superimposed on HREM sections showing the circulus arteriosus and its tributaries cranially at S21 (G) and S23 (H). Bottom of image is ventral. (I,J) Axial HREM sections showing the formation and…

Figure 4. External carotid (A–C) and subclavian arteries (D–H) and branches. (A) Volume‐rendered model of the head and surface‐rendered model of the external carotid artery and branches in a S23‐ embryo from the right. Bottom of image is caudal. Insert shows an axial section through the tongue (t) with entering lingual arteries (lia). (B,C) Axial high‐resolution episcopic microscopy (HREM) sections showing the right sided external carotid artery (reca) and branches viewed from cranial. Right side of image is ventral. (D) Surface‐rendered model of the aortic arch and great intrathoracic arteries superimposed on an axial HREM section from ventro‐cranial. Bottom of image is ventral. Note the origin of the intrathoracic branches of the left (lsa) and right (rsa) subclavian arteries. (E) Coronally sectioned, volume‐rendered model of the thorax of a 4933434E20Rik−/− embryo from ventral. Bottom of image is caudal. Note the left subclavian artery (lsa) that originates from a right‐sided descending aorta and crosses dorsal to the oesophagus (E) towards the left 1st rib (left retroesophageal subclavian artery). (F) Course of the internal thoracic arteries (lti, rti) towards and along the 1st rib…

Figure 5. Arteries of the lower body of E14.5 mouse embryos. (A, B) Volume‐rendered models of the lower body and surface‐rendered models of its arteries at S21 (A) and S23 (B) from right. Insert to the right show a ventral and slightly cranial view. Inserts to the left show the entire embryo from anterolateral view. (C,D) Surface‐rendered models of the descending aorta (dao), coeliac trunk (tc) and superior mesenteric artery (sma) from the right in a genetically normal (C) and an H13−/− mutant (D). The coeliac trunk is missing in the mutant. (E) Right‐sided origin of the superior mesenteric artery (sma). Axial high‐resolution episcopic microscopy (HREM) section. Right side of image is ventral. Note the relation to the arteries to the paraaortic bodies (pab). Insert shows sma and vitelline vein (vi) in the covering of the umbilical hernia. Compare the diameters of the sma in (E) and the insert. (F–H) Umbilical arteries in axial HREM sections, cranial view. Bottom of image is ventral. Note the diameters of the left (lua) and right (rua) umblical arteries. (I) Ectatic vasa vasorum in the wall of the ascending aorta (aoa) in an axial HREM section, cranial view. Bottom of image is ventral. (J)…