Quote Originally Posted by Namio View Post
Carlos just opened a can of worms (Jakub, too, in that regard). Excellent approach and input from both Carlos and Grif. I suppose we can agree on raising a frogs to at least one year of age before attempting estivation. I'd recommend to have more than one clutch of tadpoles--the more the merrier! But often times researches are limited by money, time, and space.

I was thinking somewhere along the line of what constitutes a frog's immunity. Frog immunity has two components--innate and adaptive responses (see below for more details). First it lies on their skin. The innate immunity is determined by the antimicrobial peptides defenses. It can be quite simple as most of those peptides have already been successfully isolated and sequenced. And the innate immunity can be determined by the production/concentration of these peptide defenses. With PCR (DNA replication) and genetic sequencing, we can test for significant differences in the concentration of antimicrobial peptides produced by individuals in our control (no estivation) and treatment (estivation) groups. This part is nice and clean for a scientific study. It is when you have to start introducing pathogens to frogs that it gets tricky, because the variables multiply.

This brings me to my next point, the adaptive immunity. This is the second defense mechanism that will kick in when the innate immunity (skin peptide defenses) fails. It's initiated by T and B lymphocytes (commonly known as the white blood cells). It gets trickier because we now need to test frogs with different kinds of pathogen, with the same amount of exposure & period, and how these frogs respond. Assessing how well the frogs are handling the infection is also tricky. Carlos had ady provided us with parasites and fecal matter counts, which is great. However, there are many types of pathogen that may need to be included. Bacterial, viral, fungal, and etc. Do we assess success and failure by death? But if they all live, then do we do it by weight loss? For sure tricky business. Especially after the first part we may not have frogs left to test the second part due to the lethal nature of the conventional PCR. Not sure if non lethal swabbing (real time PCR) is an option.
Well the main problem is that all pathogens that infect frogs can be lethal to them. There is no such thing as nonlethal pathogens when it comes to amphibians. All are potentionally fatal without treatment.