Current Research
Research in the Tift Lab is interdisciplinary. A current focus is on physiological mechanisms that allow certain model systems to tolerate hypoxia and ischemia-reperfusion events. This includes work with human and animal populations at some of the highest elevations in Tibet and Peru, to some of the deepest air-breathing divers in the ocean, and even burrowing animals.
Endogenous Carbon Monoxide (CO):
This project is funded by the National Science Foundation. One specific area of interest has been the beneficial aspects of endogenous carbon monoxide (CO) production in these systems. Carbon monoxide has the reputation of only being a toxic and deadly gas (a.k.a. ‘The silent killer’). However, CO is also naturally produced in virtually all bacteria, plants and animals from the natural breakdown of the heme, found in proteins such as hemoglobin. Recently, it has been found that low concentrations of CO exposure can protect tissues from certain injuries (inflammation, apoptosis) associated with conditions such as chronic hypoxia and ischemia-reperfusion injuries.
My work has recently shown that some deep-diving species with elevated hemoglobin and myoglobin concentrations produce and maintain CO at levels which resemble those in chronic human cigarette smokers (Tift et al., 2014). Although these levels are high, it appears that they also potentially help the animals avoid injuries associated with diving and could even increase oxygen transport in tissues (Tift and Ponganis, 2019). Work with colleagues has also revealed that high-altitude human populations could benefit from increased endogenous CO production (Tift et al., 2020).
Brain Lymphatic System
We have also begun work on the recently discovered brain lymphatic system. This project is funded by the Office of Naval Research and the purpose of this project is to investigate the presence of, and variability in, the brain lymphatic system of several marine mammal species with varying diving abilities (shallow vs. deep divers). To confirm the presence of a brain lymphatic system and identify its localization relative to the intracranial venous system (e.g., dural sinuses, cavernous sinus, etc.) our approach will merge gross and microscopic techniques that are already well-established and routinely practiced in our laboratories. It is not uncommon for animals to strand with identifiable disease states that could impact brain lymphatic function (e.g., Domoic acid and Cetacean Morbillivirus), and it is now becoming more common to identify gas emboli in tissues and vessels of stranded cetaceans, which would allow us to compare results between healthy and diseased/injured animals. Collection and examination of tissues from these animals is essential to establish normal species-related anatomic baselines of the brain lymphatic system. Expanding our knowledge of the brain lymphatic system morphology of several species of mammalian divers is critical to the evaluation of pathobiology, including the assessment of potential disease, injury, and anthropogenic impacts on the organisms.
Crabeater Seal Ecology and Physiology
This is a highly collaborative project funded by NSF to investigate the physiology and ecology of crabeater seals in Antarctica. The crabeater seal is the most important predator of Antarctic krill and is considered an excellent sentinel species through which to examine the effects of a changing climate on the extended krill-dependent predator community and structure of the entire ecosystem. We are combining animal movement, stable isotope analyses, whole-animal physiology, and novel survey technologies (UAS, satellite imagery) to investigate the differences in the trophic ecology, foraging success, diving physiology, and distribution of crabeater seals across a latitudinal gradient along the western Antarctica Peninsula and to build models to project future changes as the environment of the Peninsula continues to change.
Endogenous Carbon Monoxide (CO):
This project is funded by the National Science Foundation. One specific area of interest has been the beneficial aspects of endogenous carbon monoxide (CO) production in these systems. Carbon monoxide has the reputation of only being a toxic and deadly gas (a.k.a. ‘The silent killer’). However, CO is also naturally produced in virtually all bacteria, plants and animals from the natural breakdown of the heme, found in proteins such as hemoglobin. Recently, it has been found that low concentrations of CO exposure can protect tissues from certain injuries (inflammation, apoptosis) associated with conditions such as chronic hypoxia and ischemia-reperfusion injuries.
My work has recently shown that some deep-diving species with elevated hemoglobin and myoglobin concentrations produce and maintain CO at levels which resemble those in chronic human cigarette smokers (Tift et al., 2014). Although these levels are high, it appears that they also potentially help the animals avoid injuries associated with diving and could even increase oxygen transport in tissues (Tift and Ponganis, 2019). Work with colleagues has also revealed that high-altitude human populations could benefit from increased endogenous CO production (Tift et al., 2020).
Brain Lymphatic System
We have also begun work on the recently discovered brain lymphatic system. This project is funded by the Office of Naval Research and the purpose of this project is to investigate the presence of, and variability in, the brain lymphatic system of several marine mammal species with varying diving abilities (shallow vs. deep divers). To confirm the presence of a brain lymphatic system and identify its localization relative to the intracranial venous system (e.g., dural sinuses, cavernous sinus, etc.) our approach will merge gross and microscopic techniques that are already well-established and routinely practiced in our laboratories. It is not uncommon for animals to strand with identifiable disease states that could impact brain lymphatic function (e.g., Domoic acid and Cetacean Morbillivirus), and it is now becoming more common to identify gas emboli in tissues and vessels of stranded cetaceans, which would allow us to compare results between healthy and diseased/injured animals. Collection and examination of tissues from these animals is essential to establish normal species-related anatomic baselines of the brain lymphatic system. Expanding our knowledge of the brain lymphatic system morphology of several species of mammalian divers is critical to the evaluation of pathobiology, including the assessment of potential disease, injury, and anthropogenic impacts on the organisms.
Crabeater Seal Ecology and Physiology
This is a highly collaborative project funded by NSF to investigate the physiology and ecology of crabeater seals in Antarctica. The crabeater seal is the most important predator of Antarctic krill and is considered an excellent sentinel species through which to examine the effects of a changing climate on the extended krill-dependent predator community and structure of the entire ecosystem. We are combining animal movement, stable isotope analyses, whole-animal physiology, and novel survey technologies (UAS, satellite imagery) to investigate the differences in the trophic ecology, foraging success, diving physiology, and distribution of crabeater seals across a latitudinal gradient along the western Antarctica Peninsula and to build models to project future changes as the environment of the Peninsula continues to change.
Research Grants
1. NSF - "NSFGEO-NERC Collaborative Research: Effects of a Changing Climate on the Habitat Utilization, Foraging Ecology and Distribution of Crabeater Seals" (OPP-2042043, 2021-2024)
2. NOAA - "Response to Marine Mammal Strandings in Southern North Carolina with Special Emphasis on Bottlenose Dolphin Post-UME Monitoring, Human Interaction Diagnosis, and Enhanced Ancillary Analyses" (NA21NMF4390398, 2021-2022).
3. ONR - "Central Nervous System Lymphatic Structure in Marine Mammals: A Morphological Comparison of Shallow and Deep Divers" (N000142112365, 2020-2023).
4. NSF - "Role of endogenous carbon monoxide (CO) in hypoxia tolerant species" (IOS-1927616, 2019-2022).
5. NIH - "Identifying protective roles of the heme oxygenase/carbon monoxide pathway in hypoxia-tolerant model systems" (NHLBI-F32HL136202, 2017-2019).
2. NOAA - "Response to Marine Mammal Strandings in Southern North Carolina with Special Emphasis on Bottlenose Dolphin Post-UME Monitoring, Human Interaction Diagnosis, and Enhanced Ancillary Analyses" (NA21NMF4390398, 2021-2022).
3. ONR - "Central Nervous System Lymphatic Structure in Marine Mammals: A Morphological Comparison of Shallow and Deep Divers" (N000142112365, 2020-2023).
4. NSF - "Role of endogenous carbon monoxide (CO) in hypoxia tolerant species" (IOS-1927616, 2019-2022).
5. NIH - "Identifying protective roles of the heme oxygenase/carbon monoxide pathway in hypoxia-tolerant model systems" (NHLBI-F32HL136202, 2017-2019).
Our Research In The News
- Planet Ocean Seminar Series - Dr. Tift on carbon monoxide (CO) research at UNCW
- Listen to Dr. Tift discuss the lab's research on NPR's Coastline
- Carbon Monoxide (CO) Breath Sampling in Cetaceans
- Two Scientists Walk Into A Bar
- UC Natural Reserves System - Seal Breath Inspires Carbon Monoxide (CO) Therapy
- National Science Foundation: Scientists Investigate the Role of the 'Silent Killer' Inside Deep-Diving Animals
- Nature News: Deep-Diving Seals Reveal Secrets of Carbon Monoxide (CO)
- Taste of Science Event: From the Highest Mountains to the Deepest Seas: Understanding Adaptations to Low Oxygen
