FIF Research Grant Expands Investigation of Link Between Island Fox Genetics and Health

Friends of the Island Fox happily announces that the 2025 Research Grant was awarded to Kimberly Schoenberger to expand her investigation of connections between island fox genetics and health: Transcriptomics of the Channel Island Fox (Urocyon littoralis) through RNA-seq.

Schoenberger is a Ph.D. candidate at the University of Southern California and works with the Natural History Museum of Los Angeles County. This second year of grant support will fund RNA genetic sequencing of an additional 40 foxes from across all six Channel Islands. 

The initial 48 island foxes were all adults who had never been vaccinated. (First year of study) This second group includes juveniles and adults that had been previously vaccinated.

Health checks have revealed that San Nicolas Island foxes have similar ear mite infestation to Catalina Island foxes, but the foxes on San Nic do not develop microbial monocultures or cancerous tumors in their ears. Genetically influenced immune-system response may offer insight into why some island populations face health threats that others do not. Similar ear mite infestation with reduced microbial diversity has been found on San Clemente Island and the population there has faced survival declines in the last three years. (More on microbiome and connection to cancer in Catalina Island fox).

Examination of an island fox's ear canal with an otoscope

Schoenberger's RNA research may also provide noninvasive ways to detect dangerous amounts of internal parasites in island foxes. Examination of immune transcriptomes in dogs has shown that  increases in specific interleukins signal the presence of intestinal worms. Currently island foxes are challenged by intestinal parasites, especially spirocerca on San Nicolas Island, an ancanthocephalin on San Miguel Island, and possibly a new parasite on Santa Rosa Island.

 

Researchers like Kimberly Schoenberger are vital to healthy island fox populations. Insight from her work will help inform land managers and protect island foxes into the future. 

Your donations make FIF's support for research possible. 

FIF 2024 Research Grant Investigating Link Between Island Fox Genetics and Health

Meet Kimberly Schoenberger, recipient of FIF’s 2024 Island Fox Research Grant and a PhD candidate at the University of Southern California (USC) Dornsife College of Marine and Environmental Biology.

Schoenberger is initiating the first investigation of island fox genetics using transcriptomics. This leading-edge research uses RNA (the copier of DNA) to look at a species’ genetic material and evaluate it for protein production and vital cell functions. Transcriptomics provides insight into how genes turn on or off in cells and how this may influence health or disease.

 

The project will analyze three important aspects of island fox genetic expression: 1) what are the genetic differences between the six island fox subspecies; 2) how do different environmental conditions and demographics impact gene expression; and 3) will identify genes that are being influenced by disease or parasite exposure.

(As Catalina Island foxes were recovering from a severe population low, they experienced high levels of cancer due to an extreme immune system response to ear mites. This condition does not occur on other islands. Dr. A. DeCandia’s microbiome investigation identified a connection with specific bacteria (elaborated on by Jasmine Lu paper). Husbandry efforts currently control the ear mites, but the epigenetic link between the inflammation and eventual cancer remains unknown.)

Disease and parasites pose some of the greatest current threats to island fox survival. This project could provide valuable insight into which island fox subspecies have the greatest genetic vulnerabilities and help inform conservation measures.

Another important element of Schoenberger’s project is that it integrates directly into the current protocols for health checks. Biologists are currently in the field across the Channel Islands counting island foxes, providing health checks, and administering vaccinations. As part of the 2024 health checks, some individual island foxes will provide a blood sample for transcriptomics. Schoenberger’s genetic study will compliment and build on the individual island fox data currently being collected on diet, microbiome, territory, and health.

Schoenberger was able to travel out to Santa Rosa Island and engage with the National Park biologists as they took samples. She also met individual island foxes that will be part of her investigation.

At USC, Schoenberger explains that she puts the blood samples through a centrifuge “to separate RNA from other particles.”

The samples then go through a chemical processing to isolate and purify the RNA for sequencing.

Schoenberger says: “Transcriptomics can allow insights into gene expression patterns that underlie population health and disease by providing molecular-level understanding of island fox physiology and how they function and respond to differing environmental conditions.” Friends of the Island Fox is thrilled to support Kimberly Schoenberger’s research which will provide a baseline on the differences between populations and “shed light on key genes that are affected by environmental differences and may be crucial for adaptation and survival of the island fox.”

Your donations make this research possible.

photo courtesy of P Bronstein