Trachymyrmex sepentrionalis, ant, New Jersey, USA
Ant Theme: Research by Dr. Jonathan Klassen
Research in the Klassen lab tries to understand how symbioses (“organisms living together”) function as a unit, despite being made up of different individuals that have different ecologies and evolutionary interests. This research is important because of how widespread such symbioses are in nature, e.g., between humans and their gut microbes, or plants and microbes surrounding their roots in the rhizosphere. However, the complexity of such systems makes them difficult to study. Instead, we study a fungus-growing ant, Trachymyrmex septentrionalis, as a model system where we can understand the precise function of each symbiont and how it interacts with the others. T. septentrionalis is the northernmost fungus growing ant, and is abundant in pine flat forests throughout the Eastern USA, ranging as far north as Long Island, New York. In this symbiosis, T. septentrionalis ants collect plant material and insect feces, which they feed to a specific “cultivar” fungus that they farm in underground gardens. Once the fungus has digested this food, it forms nutrient-rich swellings that the ants feed upon. The ants also protect their cultivar fungus from disease using antibiotic-producing Pseudonocardia bacteria that reside on the ants’ proplueral plates (i.e., “chest”). The ants therefore both farm the cultivar fungus as their food source and protect it by “crop spraying” antibiotics produced by their symbiotic Pseudonocardia bacteria.
In this collaboration, we used macrophotography to visualize the various members of our symbiosis and the interactions between them. We took images of each life cycle stage of the ant, and observed how their bodies developed as they moved first from larvae, to pupae, and finally to fully developed adult workers and the male reproductive caste. We also imaged the underside of a worker adult, which showed how the Pseudonocardia bacteria form an ordered array of white microcolonies covering the ant’s propleural plate. These colonies likely relate to an array of glands on the ant’s body that as thought to feed each colony of bacteria. Finally we also imaged the cultivar fungus to investigate how its structure related to its relationship with the ants. Interestingly, our images revealed patches of necrotic cultivar tissue, perhaps indicating the presence of a melanin-based immune system in this fungus. This has never been observed before, and whether it is caused by the ant or some other factor remains unknown. Together, these macrophotographic images allowed us to view our ants and their symbionts in unprecedented detail, and demonstrates the intimacy of the interactions that occur between them.
EXHIBIT ON DISPLAY NOW AT UCONN'S NATURAL HISTORY MUSEUM
Illuminated with: macroscopicsolutions.com/store/product-category/imaging-p...
Imaged with: macroscopicsolutions.com/store/product/the-macropod-pro-m...
Images in this gallery were captured by:
Mark Smith M.S. Geoscientist mark@macroscopicsolutions.com
Annette Evans Ph.D. Student at the University of Connecticut annette@macroscopicsolutions.com
Trachymyrmex sepentrionalis, ant, New Jersey, USA
Ant Theme: Research by Dr. Jonathan Klassen
Research in the Klassen lab tries to understand how symbioses (“organisms living together”) function as a unit, despite being made up of different individuals that have different ecologies and evolutionary interests. This research is important because of how widespread such symbioses are in nature, e.g., between humans and their gut microbes, or plants and microbes surrounding their roots in the rhizosphere. However, the complexity of such systems makes them difficult to study. Instead, we study a fungus-growing ant, Trachymyrmex septentrionalis, as a model system where we can understand the precise function of each symbiont and how it interacts with the others. T. septentrionalis is the northernmost fungus growing ant, and is abundant in pine flat forests throughout the Eastern USA, ranging as far north as Long Island, New York. In this symbiosis, T. septentrionalis ants collect plant material and insect feces, which they feed to a specific “cultivar” fungus that they farm in underground gardens. Once the fungus has digested this food, it forms nutrient-rich swellings that the ants feed upon. The ants also protect their cultivar fungus from disease using antibiotic-producing Pseudonocardia bacteria that reside on the ants’ proplueral plates (i.e., “chest”). The ants therefore both farm the cultivar fungus as their food source and protect it by “crop spraying” antibiotics produced by their symbiotic Pseudonocardia bacteria.
In this collaboration, we used macrophotography to visualize the various members of our symbiosis and the interactions between them. We took images of each life cycle stage of the ant, and observed how their bodies developed as they moved first from larvae, to pupae, and finally to fully developed adult workers and the male reproductive caste. We also imaged the underside of a worker adult, which showed how the Pseudonocardia bacteria form an ordered array of white microcolonies covering the ant’s propleural plate. These colonies likely relate to an array of glands on the ant’s body that as thought to feed each colony of bacteria. Finally we also imaged the cultivar fungus to investigate how its structure related to its relationship with the ants. Interestingly, our images revealed patches of necrotic cultivar tissue, perhaps indicating the presence of a melanin-based immune system in this fungus. This has never been observed before, and whether it is caused by the ant or some other factor remains unknown. Together, these macrophotographic images allowed us to view our ants and their symbionts in unprecedented detail, and demonstrates the intimacy of the interactions that occur between them.
EXHIBIT ON DISPLAY NOW AT UCONN'S NATURAL HISTORY MUSEUM
Illuminated with: macroscopicsolutions.com/store/product-category/imaging-p...
Imaged with: macroscopicsolutions.com/store/product/the-macropod-pro-m...
Images in this gallery were captured by:
Mark Smith M.S. Geoscientist mark@macroscopicsolutions.com
Annette Evans Ph.D. Student at the University of Connecticut annette@macroscopicsolutions.com