Response of CYP1A and VEGF in Cyprinodon variegatus When Exposed to Source/Dispersed Oil and Hypoxia
type: CreativeWork
description: My thesis research focused on the effects of two environmental stressors on the small estuarine fish, Sheepshead minnow (Cyprinodon variegatus). Specifically, I examined the effects of exposure to crude and dispersed oil and hypoxia. I looked for responses using a combination of molecular and ecological endpoints. These stressors were chosen because of the 2010 Deepwater Horizon oil spill which released 4.1 million barrels of crude oil into the northern Gulf of Mexico. An estimated 2.1 million gallons of Corexit 9500 was used in an attempt to disperse the oil slick into the water column. The spill happened in a time and region that is also chronically affected by hypoxia. Previous research has indicated that there may be an interaction between the molecular pathways Sheepshead minnow use to respond or defend against both hydrocarbon and hypoxia stress (specifically that Aryl hydrocarbon Receptor Nuclear Translocator (ARNT) and Hypoxia Inducible Factor 1β (HIF-1β) are hypothesized to be the same protein). Furthermore, much of the research using hydrocarbon exposure on estuarine fish has ignored this potentially critical interaction. Therefore, I focused my thesis research on explaining the effects co-exposure to ecologically relevant levels of crude (non-dispersed) and dispersed (with Corexit 9500) oil and hypoxia could have on the environment. My results indicate that Cytochrome P450 1A (CYP1A) increases in a dose dependent manner when larval and adult C. variegatus are exposed to crude (WAF) and dispersed crude (CEWAF) oil. Vascular Endothelial Growth Factor (VEGF) expression increases in a dose dependent manner when larval C. variegatus are exposed to 2.5 mg/L dissolved oxygen (DO) levels. Also, a synergistic effect is observed on CYP1A expression when co-exposure to WAF + hypoxia, CEWAF + hypoxia occurs. Finally, along with an increase in adult mortality when co-exposed to WAF/CEWAF and hypoxia, I observed a decrease in egg production, egg hatch success and larva…
abstract: My thesis research focused on the effects of two environmental stressors on the small estuarine fish, Sheepshead minnow (Cyprinodon variegatus). Specifically, I examined the effects of exposure to crude and dispersed oil and hypoxia. I looked for responses using a combination of molecular and ecological endpoints. These stressors were chosen because of the 2010 Deepwater Horizon oil spill which released 4.1 million barrels of crude oil into the northern Gulf of Mexico. An estimated 2.1 million gallons of Corexit 9500 was used in an attempt to disperse the oil slick into the water column. The spill happened in a time and region that is also chronically affected by hypoxia. Previous research has indicated that there may be an interaction between the molecular pathways Sheepshead minnow use to respond or defend against both hydrocarbon and hypoxia stress (specifically that Aryl hydrocarbon Receptor Nuclear Translocator (ARNT) and Hypoxia Inducible Factor 1β (HIF-1β) are hypothesized to be the same protein). Furthermore, much of the research using hydrocarbon exposure on estuarine fish has ignored this potentially critical interaction. Therefore, I focused my thesis research on explaining the effects co-exposure to ecologically relevant levels of crude (non-dispersed) and dispersed (with Corexit 9500) oil and hypoxia could have on the environment. My results indicate that Cytochrome P450 1A (CYP1A) increases in a dose dependent manner when larval and adult C. variegatus are exposed to crude (WAF) and dispersed crude (CEWAF) oil. Vascular Endothelial Growth Factor (VEGF) expression increases in a dose dependent manner when larval C. variegatus are exposed to 2.5 mg/L dissolved oxygen (DO) levels. Also, a synergistic effect is observed on CYP1A expression when co-exposure to WAF + hypoxia, CEWAF + hypoxia occurs. Finally, along with an increase in adult mortality when co-exposed to WAF/CEWAF and hypoxia, I observed a decrease in egg production, egg hatch success and larva…
author: Hedgpeth, Bryan Matthew
date published: 2013-05-01T07:00:00Z
date modified: 2026-07-24T05:45:06Z
provider: University of Southern Mississippi
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Southern Mississippi