Question

i need help in proposing experiment to show why T3 induces apoptosis in tail muscle and cell growth in limb muscle in tadpoles/amphibians. can you pleass provide diffent examples ?

The thyroid hormone triiodothyronine (T3) causes apoptosis of muscle cells in the tail BUT causes muscle cell growth and differentiation in the limbs of tadpoles. You are to design an experiment that will allow you to show exactly how T3 induces such contradictory effects in these different muscle cells. Finally, you must propose an explanation for the divergent responses of these muscle cells to T3.

Answer 1

Hi,

I can suggest you a few facts that will help you design your experiment. Since T3 is inducing different cellular responses in the tail muscle cell and limb muscle cells, the target receptors to which T3 is binding should be different in both muscle types. In the case of tail muscle, it will be binding to a receptor that induces the extrinsic pathway of apoptosis and in case of limb muscle, to a receptor that activates cell proliferation reactions. It will be good if you can tag the T3 with a fluorescent marker and identify the receptor to which it is binding. There are techniques like Fluorescence Resonance Energy Transfer (FRET) to show protein protein interactions, It could be used to show interaction of T3 with receptor. Once you identify the receptor and pathway that is getting activated, you can disrupt activity of receptor via techniques like knock down, knock out, mutagenesis etc and show that your finding are valid. You may target alteing other downstream component proteins/ molecules in the cellular pathways that get activated.