Biofluorescence is a phenomenon by which organisms are able to absorb light at one wavelength and re-emit light at a longer wavelength. In 2014 it was found that biofluorescence was much more ubiquitous than was previously thought (Sparks et al., 2014). Organisms beyond jellyfish including sharks, eels and other fish were found to exhibit fluorescence in brilliant colors ranging from green to red. Understanding the mechanism of fluorescence in these proteins and future discovery of new fluorescent proteins were major goals of the PI’s proposed research. Fluorescent proteins are critical to the study of biology by allowing labeling of proteins and tracking their movement in cells, among many other applications. 

Intellectual merit: The scope of this project was to identify fluorescent proteins in marine organisms and to understand more about their mechanisms. Our work during the project period resulted in four peer-reviewed publications. 

The first part of the project focused on fluorescent fatty acid binding proteins. We discovered the first fluorescent fatty acid binding protein in a moray eel (Gymnothorax zonipectis). We completed transcriptome analysis on the fluorescent tissue from G. zonipectis. The transcriptome and assembly was deposited in the public NCBI database (https://www.ncbi.nlm.nih.gov/, PRJNA718586). The transcriptome was searched for fatty acid binding proteins and using our lab’s previously found criteria for FABPs that contain a glycine-proline-proline insert, we identified a fluorescent candidate in G. zonipectis. We expressed and characterized this protein. A major goal of this project was to design a workflow which would use a small number of organisms for protein discovery. Our work with G. zonipectis used one eel sample for RNA extraction, transcriptome analysis and initial protein extraction. This work was published in a peer-reviewed journal. 

This work also further characterized ChlopsidFP which our lab first identified in 2015 from the eel Kaupichthys hyoproroides. We generated point mutations and used UV-vis binding studies to probe which amino acids were significant in binding. This was initially an effort to generate red-shifted mutants. We did not see any significant red-shift in our mutants, but did see differences in binding. This work was published in a peer-reviewed journal.

Beyond eels, our work explored two green fluorescent sharks (Cephaloscyllium ventriosum and Scyliorhinus retifer). This fluorescence was not due to a protein, but was from a small molecule. We collaborated with Prof. Jason Crawford at Yale University on this part of the project. We determined the fluorescence was due to brominated tryptophan-kynurenine metabolic products. This work was published in a peer reviewed journal. 

The PI also aimed to identify red fluorescent proteins from lizardfish. This work is ongoing.

Broader Impacts: This NSF grant supported the training of two graduate students who completed their doctorates in 2022. Both students have continued their career paths in the sciences. One is a postdoctoral fellow and the other is working in the pharmaceutical industry. The PI also trained several undergraduate students and two high school students. 

In addition, the PI engaged the community teaching classes on proteins, fluorescent proteins and a software called PyMol (Schrodinger) for rendering protein structures. These courses were taught at Genspace which is a community lab in Brooklyn, NY. Most students in these courses were not scientists. In addition, the PI taught several classes during the pandemic to K-12 students about fluorescence and biofluorescence on Zoom.

The PI engaged in designing new labs for students at Baruch College including one that used model building and 3D printing of Green Fluorescent Protein.

This work has expanded understanding of fluorescence in marine organisms. 

Last Modified: 05/13/2024
Modified by: Jean P Gaffney