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Old 02-05-2013
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Default male development

a researcher come into conclusion that , a certain cells that make a very important structure( strucure labelled 8 in diagram) , play important role in male development , and can lead to female development in their asence even in situation where both X and Y chromosome are present . what is the correct sequence of genes interactions that lead to multiplication of these cells ?
a.) SOX9 --->> SRY--->>FGF9
b ) SOX9--->>FGF9--->>SRY
C) FGF9--->>SRY--->>SOX9
D) SRY--->>SOX9--->>FGF9
E) SRY--->>FGF9--->>SOX9

kEY : --->> = STIMULATION .
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Old 02-05-2013
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for me it seems SRY gene, but I don't understand following
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Old 02-05-2013
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Is it one of those WTF questions on the exam?
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Old 02-05-2013
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Totally guessed based on a weird logic but i think its D.

I would like to know the correct answer. Pls inbox me if you know or post it here later.
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Old 02-05-2013
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Quote:
Originally Posted by koyi View Post
a researcher come into conclusion that , a certain cells that make a very important structure( strucure labelled 8 in diagram) , play important role in male development , and can lead to female development in their asence even in situation where both X and Y chromosome are present . what is the correct sequence of genes interactions that lead to multiplication of these cells ?
a.) SOX9 --->> SRY--->>FGF9
b ) SOX9--->>FGF9--->>SRY
C) FGF9--->>SRY--->>SOX9
D) SRY--->>SOX9--->>FGF9
E) SRY--->>FGF9--->>SOX9

kEY : --->> = STIMULATION .


The answer is D. Here's why.

SRY of Y chromosome activates SOX 9. Next, SOX 9 activates FGF 9; which forms forward loops with FGF 9 and PGD 2. These loops are important for producing SOX 9; without these loops, SOX 9 would run out and the development of a female would almost certainly happen.

So the researcher was talking about SOX 9 gene in particular.
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Old 02-05-2013
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Quote:
Originally Posted by mdsoon View Post
Totally guessed based on a weird logic but i think its D.

I would like to know the correct answer. Pls inbox me if you know or post it here later.
relax Guys ) this is my own formulated WTF mimic question ))) well , from figure given , number 8 is tight junction (also called blood-testis barrier) made up of or maintained by SERTOLI CELLS (v/s astrocytes in Blood brain barrer ) (note similar figure as in FA 2011 page 480) SRY GENE is main start of the sequence in multiplication of these cells (FA 2011 page486) . WTF big time come now , wat next sequence ? then narrow out yar choices (by taking only where SRY is a beginner in sequence ) u remain with D and E . how to get most correct from these ? two option , if u knew it before is easy (SRY---SOX9....FGF9 , i.e choice D) if not then is big time of guessing and go on . so most correct answer is D .
conclusion : researcher was trying talk about SERTOLI CELLS @ doctor Ali (and not SOX9) . any interruption in sequence will lead to female development .
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