luokai0 Developmental Biology Expert
Before Starting
- Which model organism? (Drosophila, C. elegans, zebrafish, mouse, Xenopus)
- Which developmental process?
- Basic development or regenerative medicine focus?
Core Expertise Areas
Early Embryogenesis
Fertilization: acrosome reaction, cortical reaction, zygote formation. Cleavage: rapid cell division without growth, blastomere formation. Blastulation: blastocyst (mammals) or blastula (non-mammals), inner cell mass. Gastrulation: three germ layers — ectoderm, mesoderm, endoderm. Neurulation: neural plate, neural tube formation, neural crest migration.
Cell Fate and Patterning
Induction: one tissue instructing adjacent tissue to change fate. Morphogen gradients: Bicoid, Sonic Hedgehog, BMP, Wnt — concentration encodes position. French flag model: threshold concentrations specify different cell fates. Positional information: cells read their position and differentiate accordingly. Hox genes: homeotic genes specifying anterior-posterior body axis identity.
Signaling Pathways in Development
Wnt: anterior-posterior patterning, cell proliferation, stem cell maintenance. Notch: lateral inhibition, boundary formation, binary cell fate decisions. Hedgehog: limb development, left-right asymmetry, neural tube patterning. FGF: mesoderm induction, limb outgrowth, tissue maintenance. BMP: dorsal-ventral patterning, bone formation, apoptosis.
Stem Cells
Totipotent: can form entire organism including extraembryonic tissues. Pluripotent: can form all three germ layers (ESCs, iPSCs). Multipotent: restricted to specific lineages (HSCs, NSCs). iPSC reprogramming: Yamanaka factors (Oct4, Sox2, Klf4, c-Myc). Niche: microenvironment maintaining stem cell self-renewal.
Key Patterns
Best Practices
- Consider both cell-autonomous and non-autonomous mechanisms
- Use multiple model organisms to distinguish conserved from species-specific mechanisms
- Distinguish instructive from permissive inductions
- Validate morpholino knockdowns with rescue experiments or CRISPR
- Consider timing — same signal can have different effects at different stages
Common Pitfalls
| Pitfall | Fix |
|---|---|
| Confusing induction and competence | Both signal and receptive tissue required |
| Morpholino off-target effects | Always include p53 morpholino control |
| Oversimplifying stem cell potency | Potency is context and assay dependent |
| Ignoring extraembryonic tissues | Placenta and yolk sac profoundly influence embryo |
Related Skills
- cell-biology-expert
- molecular-biology-expert
- genetics-expert
- physiology-expert