Developmental Biology- Surgically induced cardia bifida in chicken embryos

Figure 1. First method of transferring the embryo directly from the shell to the culture dish; here, an opened shell with the embryo exposed, surrounded by a filter paper ring.

Figure 2. Second method of transfer; here, the intact yolk has been moved to a petri dish and the embryo isolated with a filter paper ring.

Figure 3. A stage 8 chick showing dark shadowy regions that indicate the bilateral heart primordia on either side of the notochord.

Figure 4. A glass taper (extending from top left corner) can be seen enlarging the surgical incision made in the anterior portion of the chick embryo.

Figure 5. A glass taper (extending from top left corner) can be seen enlarging the surgical incision made in the anterior portion of the chick embryo.

Figure 6. Surgery gone wrong: a two-headed embryo, presumably caused by an incision that bisected too much anterior tissue.

Figure 7. An embryo with two beating hearts, one on each side of the notochord.

Figure 8. This chicken embryo has an abnormal heart, probably due to late fusion of more fully developed heart primordia.

Figure 9. A stage 21 control chick with a functioning circulatory system – the heart is beating, which is noted in this photograph as a blue outline surrounding the moving tissue.

Figure 10. The steadily beating heart of a stage 23 control chicken embryo. The branching of the vascular system is more complex.