1. Drosophila melanogaster

2. Dorsal
Anterior
Posterior
Ventral

4. Cleavage in the Drosophila Embryo

6. Embryo A P
Larva A P

7. P
2 hrs. A A
10 hrs. P

8. A P A P

10. Genetic
Hierarchy in
A-P Axis
Specification

11. Immunostaining
Dye-conjugated antibody
Protein

12. Mutant Phenotypes for Maternal-Effect Genes

14. Bicoid mRNA/Protein Distribution

15. Bicoid is Sufficient for Anterior
Structure Formation

16. Bicoid
Hunchback (hb)
Promoter

17. Gap Gene
Expression
Patterns

18. Bicoid Controls Hunchback (hb) Expression

21. Pair-rule Gene Expression Pattern in Syncytial/Cellular Blstoderm14 13 1 12 2 3 11 4 10 5 6 7 8 9
Parasegments
Eve = Blue
Ftz = Brown

22. Eve Gene regulation

23. Eve Stripe 2 (parasegment 3)
Regulatory Region

25. Segment Polarity

26. Segment Polarity Genes
Engrailed (en) Gene Expression

27. Wild Type
wg mutant
segment

28. Homeotic (Hox) Genes

29. Homeotic (Hox) Genes

30. Antennapedia

31. Homeodomain (Hox) Transcription Factors

33. Homeotic (Hox) Genes

34. Synpolydactyl Phenotype
HoxD13 mutation

35. Extra-embryonic
tissue
Dorsal ectoderm
(epidermis)
Ventral ectoderm
(nervous system)
Mesoderm

37. Nuclear Localization of Dorsal Protein

39. Neural Tube
Dorsal
Ventral

40. Neuron Specification
Shh = Sonic hedgegog (signal molecule)