Sample Topics for Student Reports in Unsolved Problems.

1) Any disease that is incurable, or about which there are major recent discoveries, you can report on.

2) Cell differentiation: What is/are the mechanism(s) of self perpetuation, for example that cause mitotic daughter cells to be the same cell type? What "turns on" (stimulates transcription) of particular combinations of "luxury" genes? For example, do all the genes transcribed in liver cells, for example, have promoter or enhancer regions with identical or very similar base sequences?

3) What mechanism "turns off" (selectively inhibits transcription) of luxury genes when cells of two different cell types are fused with each other? Can this be used to treat cancers caused by oncogenes translocated downstream of luxury gene promoter regions?

4) How do experimenters cause cells to revert to being undifferentiated "stem cells"?

5) How do DC electric fields cause tissue culture cells to change their directions of crawling and/or exertion of traction and/or contractility ("Direct Current" means that the voltage doesn't reverse direction)? What difference between differentiated cell types causes skin epithelial cells to crawl toward the negative electric field, causes fibroblasts to line up perpendicular to electric fields, and causes macrophages and osteoclasts to crawl toward positive electric fields?

How and why do mycelial fungi orient their growth parallel to voltage gradients (electric fields)?

6) How does "durotaxis" work (crawling of tissue culture cells preferentially onto more stiff, less flexible, surfaces)? Does this occur in the body, or just in tissue culture; and what function does it serve?

7) (The Nardi & Stocum phenomenon) In salamanders, when parts of limb buds are grafted to the sides of other limb buds, what physical force, and what control mechanism, moves the graft directionally along the side of the "host" limb bud, toward a position in which wrist is next to wrist, or elbow is next to elbow, etc.?

Researchers hypothesized that limb buds have proximo-distal gradients of cell-cell adhesion (or some other quantitative property), and that grafts move toward whatever location has the same amount of the gradient property. What evidence supports this? What might be the gradient property? Does this process of tissue displacement have a function in normal embryonic development?

8) What mechanism causes the formation of the contractile ring in cytokinesis? (Cleavage) Are there gradients of contractile strength, with actin and/or myosin pulling themselves up gradients of their own contractile strength? An alternative possibility is that polymerization of acto-myosin is stimulated at the locations where the contractile ring will form.

9) How does cancer chemotherapy work? Why should faster-growing cells be more damaged (killed in higher percentages) by drugs that inhibit either formation of the mitotic spindle or copying of DNA?

10) "The Warburg Effect" Why are cancerous cells much more anaerobic in their metabolism than equivalent normal cells? Do cancer cells not use their mitochondria? And for what reason? Does anaerobic metabolism somehow cause uncontrolled growth of cancer cells? Can this phenomenon be used as the basis of new anti-cancer treatments? Can it be used to diagnose cancer and detect its location in the body (Hint: Yes, by Positron Emission Tomography scans).

If you could convert cells to being more aerobic, and using their mitochondria more, would that make cells less cancerous? Conversely, if you inhibited mitochondria in otherwise normal cells, would that cause them to behave more like cancer cells?

Some additional topics:

regeneration of salamander legs

cancer chemotherapy

bone formation, including ossification, electro-osmosis
tensegrity theory of the skeleton

cell differentiation; self-perpetuation and mutual exclusiveness
colinearity of hox genes

muscular dystrophy

aging; telomeres

Driesch phenomenon, embryonic regulation

clock and wavefront theory of somite formation

protein folding configuration, Levinthal's paradox


amoeboid locomotion

macrophages: why are they so different

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