Choosing a Model Organism

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Adam Cadwallader
Adam Cadwallader's picture
Choosing a Model Organism

I hear the same thing from a variety of scientists  - How do you choose a model organism?

What are the pros and cons to using zebrafish vs mouse vs another system?

If you use a model organism, weigh in on your thoughts!

Omai
Omai's picture
Hey Adam!

Hey Adam!

Personally, I like using mice if you are studying human disease. I don't have much experience using other models, flies, frogs, fish . . . but I really feel mice have a leg up over other models for study of certain topic areas including immunology, infectious disease, cancer, and auto immune disease. I think the other model organisms are more successful in the study of early development, neuroanatomy, and more basic cellular function. Mice are mammals and do a pretty good job of mimicing human disease (even though we can cure many diseases in mice and that research has not translated well into human beings). Some of the cons from my own mouse studies have included generation time. This one is a real drag. A lot of transgenic mouse work requires a good amount of waiting around for the mice to breed and grow to adulthood, develop disease etc. . . I find mice to be docile, easy to handle, and there is a vast array of tools and experiments at your disposal if you work in mice.

I know you have experience in both mice and zebrafish. How do you compare the two organisms?

Omai

Adam Cadwallader
Adam Cadwallader's picture
Hi Omai,

Hi Omai,

I have experience with many model systems, including mice, fish, xenopus and C. elegans.  Mice certainly are the best model system for studying human disease, but zebrafish are being breed to do the same.  Many labs are using zebrafish in studies of cancers, especially leukemias.  The generation times for mice and fish are comparable so there is no difference there.  The one major drawback to zebrafish is the ability to create targeted knockouts and knockins.  Technology is advancing on these fronts with the ability to do TILLING (a method borrowed from the plant community) and zinc-finger nucleases (ZFNs).  However, the ability to see development from the very start in a clear embryo is definitely a plus.  Morpholinos are both a positive and a negative for the system.  WIth morpholinos, you can knockout entire gene families by combining morpholinos.  However, the effects of most morpholinos only last between 5-10 days post injection, so studying long-term effects is greatly reduced.

Xenopus, on the other hand, is biochemical, not a genetic model system.  It takes nearly 2 years for Xenopus to reach maturity.  How would you like to create mutants for your thesis work?

Adam