Question

This image shows data from two regions of the body. One is mature brain from adult mice. The other is brain from embryonic mice. 75 a. Describe one way these researchers could have tested their cells for the presence of apoptosis. 25 0 P-Bcl-2 blb the bar graph if mature brain is shown in white, while embryonic brain is shown in Grey. Based on your knowledge of why cells undergo apoptosis why do you think their Bcl-2 results make sense? Cyto C (Mitofrac) Cyto C (Cyto. frac.) d. Based on this image, what is the effect of apoptosis on Bcl-2? Why is it important that they have both the BCL-2 gel and the P-Bcl2 gel rather then just showing P-Bcl2? In the next experiment they isolated a mitochondrial fraction from their cells (Mito. frac.) and a cytoplasmic fraction- lacking all mitochondria (Ctve frac.) They tested both of these fractions for Cytochrome C. Based on your understanding of apoptosis fill in the data that you would expect for this result and describe your reasoning for this result below. e. % Cell Death 50

Answer 1

a)Based on one of the main characteristics of an apoptotic cell, the caspase activity. Caspase is one of the main proteins which are activated once apoptotic signals affect the cellular function. Researchers can use fluorescent antibodies that recognize the activated form of caspases and observe the number of apoptotic cells in a culture using a fluorescent microscope.

b)Apoptosis is a programmed cell death mechanism important for embryonic development. As cells rapidly proliferate during development (in this case embryonic brain cells) some of these cells undergo apoptosis which is essentially important for neural development. For this reason you can observe a higher number of apoptotic cells of embryonic brain cells

d) The anti-apoptotic Bcl-2 protein is expressed in embryonic and mature brain cells. For this reason is important to show Bcl-2 in gel. When, bcl-2 is overexpressed, apoptosis in neural cells decreases resulting in increased number of cells. It’s important to show the phosphorylated Bcl2 (P-Bcl2) because this will show you if Bcle2 is activated or not in that particular situation.