Examination of the jellyfish GFP gene. The GFP protein consists of 238 amino acids. The brilliant, intrinsic fluorescence of GFP has made it useful to molecular biologists as a non-invasive indicator of gene expression. When molecular biologists first tried to express the jellyfish GFP gene in mammalian cells, they were not very successful.
Scientists change their hypotheses all the time.
When this happens, you are about to learn something new.