More Thoughts on Phagocytosis

[Anonymous]

Is it possible that there are lysosomes involved in phagocytosis that are specialized to not breakdown the zoox, but to store them instead?

There are cellular inherited disorders in animal cells that store toxins instead of digesting them. These lysosomes either lack an active hydrolytic enzyme or have an inactive lysosomal enzyme.

Is it possible that the coral larvae have an active code that translates into enzymes that are inactive to the zoox? That way they can safely pass through the cytosol. Specialized lysosomes? Possible? If they were, there must be some sort of switch that turns the production on and off, depending on the animal's needs.

 

[Anonymous]

The zoox are contained within vacuoles, but there has to be a cue not to have lysosomes fuse with the vacuoles...this may be cell surface mediated by a coating (opsin, other glycoproteins, etc.). The question that begs answering is what happens in the coelenteron....why is it that if zoox are to be readmitted intot he animal, they are swallowed and vacuolated, and when they are expelled for digestion, they are un-vacuolated and then digested by external enzymes from the mesenteries.. and, possibly, pieces then phagocytized and digested intracellularly. This "switch hypothesis" works for intracellular events, but not extracellular events.

Eric

 

[Anonymous]

Eric... where can I find the article you used as a reference by RK Trench? I know in the past he did research on the phases of recognition between animal and plant cells. What has he published lately about the issue?

 

[Anonymous]

When the vacoules ingest the zoox (without digestion), is it possible that the zoox releases some of it's photosynthetic products so that the vacoule recognizes it? That way the vacoule knows it's not to fuse with the lysosome for digestion?

Do the glycoproteins or glycolipids keep the zoox attached to the outer cell membrane until the vacuoles can form around it?

 

[Anonymous]

Hi Scott

Which Trench article? The Proc 8th Int Coral Reef Symp is going to be harder to find..some University libraries carry them, some don't. The other should be available at Universities...its from a book. Bob Trench had two papers at the 9ICRS Bali, including a session devoted to him and Len Muscatine. If you want to see what he has done lately, I'd use one of the publication search engines like BIOSIS. If you can't locaate the articles, let me know.

As to your other questions, I don't know. I don't think it has been determined yet, and these were speculations...source for such topics is Invertebrate Immunity (Rinkevich, ed.) and Vol 23 and 24 of EL Cooper's (ed.) Invertebrate Immune Response books.

Eric