Murder, Suicide, and Canibalism: the life of a cell

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In summary, the conversation discusses the concept of apoptosis, or programmed cell death, in multicellular organisms. This mechanism is essential for the survival of the organism as a whole, as it allows damaged or unnecessary cells to be eliminated without causing inflammation. Apoptosis can be triggered by various stimuli, such as DNA damage, and has multiple functions, including shaping limbs and regulating the immune system. The process is believed to have evolved as a general mechanism for cell disposal, rather than for one specific purpose.
  • #1
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The title sounds strange, but that is what the life of a cell will eventually experience.

Cells from multicellular organisms are specialized in performing suicide, it is actually a very important mechanisms of survival of the organisms as a whole. The reason is, that programmed cell death, or apoptosis (from greek: popping off) is a very clean way for a cell to die.

A normal cell that is murdered by toxins will swell by the influx of water (osmosis) since the cell membranes become leaky. This cell will eventually explode and spill its contents over neighbouring cells, potentially causing a dangerous inflamation reaction.

A cell that performs apoptosis, will shrink and collaps on itself, since it is breaking down its cytoskeleton and concentrates its cytoplasm. The cell will form pockets that budd of the cell, these cellular vesicles will be eaten up (phagocytised) by neighbouring cells who will digest the cell and recycle it consituents.

So a cell who is killed will swell and explode, a cell who commits suicide and shrink, having an appearance as if it is boiling down to nothing. Other cells can be seen having another cell in its interior because of canibalism.
 
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  • #2
Very intriguing.

Quick question: What process could have let to the evolution of such sophisticated mechanism of self-destruction? Any idea when these evolved?
 
  • #3
My immediate guess would be to avoid extensive DNA damage. A cell that has a lot of damaged DNA can get out of control and start dividing rapidly without noticing the nearby cells which tell it to quite down. Such a cell is a cancer cell and will destroy the organism.

The cell has developed mechanism that detect the DNA damage and activate the process of apoptosis. Right now in all your cells there are many inactive forms of the protein needed to start the death-cycle, all they need is the go signal.
 
  • #4
apoptosis

Hi.

Apoptosis is not just a response to DNA damage (though clearly that is one stimulus).

In development, apoptosis is important in the shaping of limbs and digits (etc. etc.).
T cell attack of altered-self cells (eg. virus infected cells) induces apoptosis in those cells.
B-cells undergoing a process called somatic hypermutation (Activated B-cells gather in a germinal center and mutate their immunoglobulin (Ig or antibody) genes. A selection process occurs by which only B-cells making the highest affinity antibodies live, and the others die by apoptosis.

As for the evolution of the process, damaged (necrotized) cells are a good danger signal for the immune system and cause inflammation. This type of immunity long predates the evolution of the adaptive immune system (ie: B cells, T cells, etc.)
Apoptosis is a way of eliminating cells while not causing this type of inflammation. It didn't evolve to fix only one problem that life encounters, but as a general mechanism of taking out your trash... Which would have been necessary from the beginning.

Cheers! :)
-K
 
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  • #5
Hi Kris! Welcome to the forum. But wouldn't you agree that it would be more likely for the mechanism to have evolved for one specific survival reason and then have evolved to branch out and include other pathways? For instance, you mention digit formation. This is very true, but that type of cell-cell communication mediated apoptosis must have evolved much later in the process of development.

That is why I thought that apoptosis as a response to DNA damage would be the basic underlying selective pressure.
 
  • #6
I see you are a grad student working in the lab? :) What do you research, if I may ask?
 

1. What is the main focus of "Murder, Suicide, and Cannibalism: the life of a cell"?

The main focus of this book is to explore the various ways in which cells can behave in a seemingly violent or destructive manner, and how these behaviors ultimately contribute to the overall function and survival of an organism.

2. How does the author approach the topics of murder, suicide, and cannibalism in relation to cells?

The author takes a scientific approach, using research and evidence to explain how these behaviors are beneficial for the cell and the organism as a whole. The book also delves into the evolutionary and ecological reasons behind these behaviors.

3. Are there any real-life examples of murder, suicide, and cannibalism in cells?

Yes, there are many examples of these behaviors in various types of cells. For example, some immune cells are known to sacrifice themselves in order to protect the body from infection, and some cells will cannibalize damaged or infected cells to prevent further harm.

4. How does the book address the ethical implications of these behaviors in cells?

The book discusses the idea that these behaviors may seem violent or immoral to us, but they are essential for the survival and function of the organism. It also raises questions about the definition of life and the role of cells in our understanding of morality.

5. Who would benefit from reading "Murder, Suicide, and Cannibalism: the life of a cell"?

This book would be beneficial for anyone with an interest in biology, evolution, and the complexities of life. It may also be of interest to those interested in ethical debates and the intersection of science and philosophy.

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