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Eduncle posted an MCQ
December 30, 2019 • 16:40 pm 0 points
  • CSIR NET
  • Life Sciences

 cAMP signalling plays a very important role in the development of Dictyostelium discoideum. Below are few statements related to it.

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    Eduncle Best Answer

    Throughout the aggregation stage cAMP synthesis is oscillatory with a period of about 6 min as the result of control of ACA activity by the PKA circuit. So option A is correct, while E is incorrect.
     RegA is an internal cAMP phosphodiesterase. So option D is incorrect.
     Mutants of acrA (ACB gene) show severe defects in terminal differentiation.
    They aggregate normally but they produce only about 10% of viable spores.
     Their fruiting bodies show abnormally long stalks and glassy spore heads due to the reduced number of spores - hence option B is correct.
       Expression of adenylyl cyclase G, encoded by the acgA gene, is induced after 12 hours of development in prespore cells and greatly increased during spore differentiation. AcG activity is regulated by osmolarity of the external media and this enzyme is required to avoid spore germination inside the sorus. - So option C is incorrect.

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