Decoding Oocyte Stages: An Essay on Labeling and Identification Methods

1.Why is PBS used throughout the dissection and staining procedure?



2.Circle the answer that correctly labels the stage 10 oocyte in the figure below.

(a)1. Nurse cells, 2. Pole cells, 3. Oocyte
(b)1. Stem cells, 2. Oocyte, 3. Pole cells
(c)1. Nurse cells, 2. Oocyte, 3. Yolk
(d)1. Nurse cells, 2. Oocyte, 3. Follicle cells


 
3.Based on your Lab 4 results (staining pattern of kinesin), how do you presume the microtubules are arranged in the oocyte?

(a)(-) end at X and (+) end at Z
(b)(-) end at X and (+) end at Y
(c)(-) end at Y and (+) end at X
(d)(-) end at Z and (+) end at Y

4.On the figure below, label the structures indicated on the embryo (1. and 2.) and its orientation (W, X, Y, Z).




5.Briefly describe an experiment that would allow you to test whether the posterior cytoplasm is responsible for the formation of germ cells?





6.How can kinesin and microtubules contribute to the formation of the germ cells?






7.What you would expect to observe if the following modifications to the Lab 4 protocol (see Part I) were made. Provide a brief explanation for your observation?

a)Colchicine, a microtubule-depolymerizing agent, was fed to adult female flies expressing the kinesin-ß-galactosidase fusion protein



b)A mutation was included in the conserved ATP-binding motif of the kinesin domain



Part II. Techniques for studying gene expression and DNA-protein interactions