1. Embryonic
Development
(mosly mice and mammals)

2. Chapter 10

3. Cleavage
Cell division
without growth
First few divisions
are slow (24 hrs, then12 hrs)

5. Blastomeres
Products of cleavage

7. Compaction
Developing embryo
becomes more spherical.
Flattening of blastomeres
to form to maximize
intracellular contacts.

8. Microvilli
Cell membrane protrusions
and Gap Junctions
Cellular connections
joining cell cytoplasms
form

9. Microvilli
Porter, Fonte and Weiss, Cancer Research, 1974

10. Figure 20-22 Essential Cell Biology (© Garland Science 2010)

11. Gap Junctions
connexon proteins

12. Morula
Embryo from compaction
to about the 32-cell stage

13. Desmosomes
and tight junctions
form

14. Desmosomes
Localized, spot-like,
cell-to-cell adhesions

15. Figure 20-22 Essential Cell Biology (© Garland Science 2010)

17. Figure 17-2a Essential Cell Biology (© Garland Science 2010)

18. Figure 17-2b Essential Cell Biology (© Garland Science 2010)

19. Tight Junctions
Junctions sealing
neighboring cells together
so that water-soluble molecules
cannot easily leak between them

20. Figure 20-22 Essential Cell Biology (© Garland Science 2010)

21. Figure 20-23a, b Essential Cell Biology (© Garland Science 2010)

22. Figure 20-23c Essential Cell Biology (© Garland Science 2010)

23. Blastocoel
Fluid-filled cavity
begins to form, forming...

24. the Blastocyst
Mammalian embryo
after cavitation

26. the Blastocyst,
Mammalian embryo
after cavitation
consisting of the
Trophoectoderm, Blastocoel
and Inner Cell Mass

27. Trophoectoderm
The outer layer of the blastocyst,
which will form part of
the placenta

28. Inner Cell Mass
Will form the “embryo proper”
and the amnion

29. Amnion
Extraembryonic membrane
enclosing the embryo

30. Fig. 3.20
Principles of Development 4e Wolpert/Tickle Copyright © 2011 by Oxford University Press

31. ICM and trophoectoblast
cells become determined

32. Late Blastocyst
Formation of
distinct regions

33. Implantation
Emergence from the zona
Attachment to the uterine wall
Initial formation of the placenta

34. “Hatching”
Emergence from the zona;
trophoectoderm cells
opposite the ICM
secrete a protease
that digest the zona

35. Fig. 3.23
Principles of Development 4e Wolpert/Tickle Copyright © 2011 by Oxford University Press