You have discovered a new gene similar to an integrin. If you misexpress this gene in the wrong tissue early in development, what is a likely phenotype?

Question

A.  migration into the wrong area
B.  apoptosis
C.  homeotic transformation
D.  defects in anterior-posterior patterning

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
· What key words does the question contain and what do they mean?
 
Gather Content
· What do you already know about integrins?

  Consider Possibilities
· Consider the different answer options. Which can you rule out?

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
 
Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

A.  migration into the wrong area

Clarify Question
· What is the key concept addressed by the question?
        o This question addresses integrins.
· What type of thinking is required?
        o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer.
· What key words does the question contain and what do they mean?
        o Integrins are proteins that attach to the cytoskeleton and also reach out to bind things in the extracellular matrix.
 
Gather Content
· What do you already know about integrins?
        o Integrins are attached to actin filaments of the cytoskeleton and protrude out from the cell surface in pairs, like two hands. The “hands” grasp a specific component of the matrix, such as collagen or fibronectin, thus linking the cytoskeleton to the fibers of the matrix.
        o In addition to providing an anchor, this binding can initiate changes within the cell.
        o Cell migration is largely a matter of changing patterns of cell adhesion. As a migrating cell travels, it continually extends projections that probe the nature of its environment. Tugged this way and that by different tentative attachments, the cell literally feels its way toward its ultimate target site.

  Consider Possibilities
· Consider the different answer options. Which can you rule out?
       o Are integrins often associated with apoptosis? No, we learned about other genes in the apoptotic pathway, like Bcl-2 or the ced genes.
        o Are integrins often associated with homeotic transformation? No, we learned about other genes that cause homeotic transformation – the Hox genes.
        o Are integrins often associated with defects in anterior-posterior patterning? No, we learned about other genes that control AP patterning, like bicoid and nanos.  

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o Are integrins often associated with cell migration? Yes. We learned how blocking integrins could block cell migration. It makes sense that misexpression could lead cells to migrate to the wrong place.
 
Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o This question asked what might result from misexpression of integrins.
        o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer.
        o Did you recognize that misexpression of integrins might lead cells to migrate toward signals in the wrong place?