April, 2021 — Deep in the Department of Embryology’s dark microscopy suite, Dr. Phillip Cleves studies a magnified image of a sea anemone called Aiptasia, his lab’s primary model organism.
Cleves, who joined Embryology as a Principal Investigator last fall, is trying to help stop the global decline of coral reefs. To do this, he needs to understand what happens—at the cellular and molecular levels—when reef-building corals experience heat stress.
This research is of particular importance because coral reefs are dying at an alarming rate due to climate change. The rising temperature of the world’s oceans is forcing corals to oust the nutrient-supplying photosynthetic algae that live within their cells, a process called “bleaching,” causing the corals to starve. As major biodiversity hotspots, their loss looms large, causing significant damage to global economies and human health.
The symbiotic relationship between corals and their algal tenants is critical for the health of coral reefs—and Cleves believes that understanding the mechanics of this symbiosis could help reefs survive the threat of global warming.
Acropora millepora. // Shutterstock
“One thing we're really excited about is seeing the bleaching process in real time. We're using Carnegie's fluorescent microscopy to capture what happens at the cellular level as an anemone experiences heat stress.” – Phillip Cleves
Phillip Cleves displays a series of Aiptasia anemones with symbiotic algae, which gives them their brown color.
Left: Healthy, symbiotic Aiptasia. Right: Bleached, aposymbiotic Aiptasia (loss of symbionts due to heat stress induced by the lab).
Research Assistant Lorna Mitchison-Field feeds brine shrimp to Aiptasia anemones.
“We can recreate what's happening to corals worldwide due to climate change in a small dish of anemones in the lab.” – Phillip Cleves
Kat Henderson, a Johns Hopkins University graduate student on rotation in the Cleves Lab, uses immunofluorescence to study a cross-section of Aiptasia.
DID YOU KNOW?
Aiptasia have a superpower: They can regrow parts of their body that have been damaged or lost. This biological phenomenon, called regeneration, allows the separated piece to develop into a whole new anemone, which is a clone of the original! This is called asexual reproduction.
Lab Technician Natalie Swinhoe slices into an Aiptasia anemone to study the molecular mechanism of regeneration.
In addition to studying how heat stress affects the genetics of coral-algal symbiosis, the Cleves lab is trying to understand how symbiosis impacts Aiptasia’s mysterious ability to regenerate. This is a new frontier for the lab, so check back soon for details about their research!
Graduate student Amanda Tinoco prepares anemone tissue for gene sequencing (top & middle images). Tinoco pours agarose gel for electrophoresis, a method used to separate and analyze macromolecules such as DNA, RNA, and proteins (bottom image).
Cleves plans the layout of a grow room for aquatic organisms inside Carnegie’s Department of Embryology in Baltimore, MD.