Developmental cascade of morphogens Define Drosophila Body Plan
- 1. Developmental Cascade of Morphogens Drosophila melanogaster Development
- 2. Gene Expression is Regulated and Much Evolution is Based on Changes in Regulatory Genes
- 3. A Few Conserved Signaling Molecules are Used Over in Different Aspects of Development
- 4. Cascades of Induction Can Pattern an Entire Embryo or Embryonic Field
- 8. Drosophila Early Development is Syncytial
- 9. Anterior Posterior Segmentation is Mapped from Syncytial Blastoderm to Larva Hindgut & Internal organs Foregut & Internal organs Anatomical Gene Exp.
- 10. Drosophila Fate Map Gastrulation Movements
- 13. Only 1 gene inactive Only 1 gene active White area is controlled by Indicated gene Wt. Bicoid Nanos Torso None active
- 14. Morphogens Are laid Down Durring Oogenesis
- 16. The Egg Polarity Gradient Systems
- 17. Regulatory Hierarchy of Morphogens
- 18. The “Gap” Genes, “Pair Rule” and “Segment Polarity” Genes
- 19. Gap Gene Proteins Maintain Gradients By Mutual Inhibition Nos A) bcd and nos maternal transcripts are tightly localized at the anterior and posterior poles of the unfertilized egg Shortly after fertilization, bcd transcripts are translated, and the resulting protein diffuses posteriorly, generating a gradient; similarly, nos transcripts are thought to generate an opposing gradient of nos (B) The hb protein gradient then provides a series of concentration thresholds that independently dictate where the anterior Kr, kni, and gt boundaries, as well as the posterior Kr boundary
- 20. Regulation of Even Skipped by Gap Gene Products Gt & Kr define St 2 Giant and Kruppel Repressors and Knirps and Hunchback delimit expression borders of the even-skipped stripes 3,4, 6 and 7 (see Figure 2, panel C). Two corresponding regulatory regions, 4+6 and 3+7 enhancers encode all sufficient transcriptional information for these four stripes. The eve stripes 4 and 6 are formed in the embryo zones with lower concentration of hunchback and higher concentration of Knirps, conversely the eve stripes 3 and 7 are formed where hunchback concentration is greater than that of Knirps.
- 21. Regulation of Stripe 2 Promoter Stripe 2 Enhancer Eve expression Activators Bcd & Hb Inhibitors Gnt & Kr
- 22. Pair Rule and Segment Polarity Gene Expression Effects Structures in Adult Fly Expression of Segment Polarity Gene Engrailed
- 23. Bicoid is a Homeobox Transcription Factor
- 24. Dorsal Side is Determined by Absence of “Dorsal” Protein D Dorsal protein Concentrated in Cytoplasm Dorsal protein V Concentrated in nuclei Dorsal protein binds to regulatory DNA that turns on mesoderm and nervous system genes and turns off dorsal genes
- 25. Protostome vs.. Duterostome Body Plans Upside Down and Backwards
- 27. Presumptive Mesoderm Cells Express the Transcription Factor, Twist TTime