Signals, Development, Transposons

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Signals, Development, Transposons(?)
Nov. 15, 2005
Second Exam,One Week from Today
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Insecta, Diptera
Two wings, One pair
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Bilateral Symmetry of Embryowith dorsoventral
pattern modification
Normal Drosophila
Normal
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Diffusion to Structure
Embryoniccross section
Embryonic longitudinal section
Embryonic signal gradient initiated
Embryonic signal gradient developed
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Cell to cell dynamics of signal responses
(Note that cells must have receptors at their
membrane, which are generated from within the
cell in response to other signals.)
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Functional Similarity between Insect and
Mammalian Genes
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Embryonic Similarities
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Points to Ponder

• If transposons are common in eukaryotes, how
  might they affect cell functions that either
  cause abnormal developmental patterns, or are
  part of normal patterns?
• If developmental patterns are initiated by cell
  differentiation, how might one anticipate that
  there are signal systems involved?
• Postulate how transposons could be a common
  component in some differentiation patterns.
• Different kinds of zebras have more small or
  fewer wider strip patterns. Explain how these
  differences might be inherited.