I am primarily interested in disease ecology and host-parasite coevolution. Though parasites are often thought of as highly virulent pathogens that quickly overrun their host, parasites that kill their hosts too rapidly or cause the population to go extinct will not enjoy long-term reproductive success. In response to the risk of disease, the host mounts defenses against infection (resistance) or controlling infections (tolerance), both of which effectively lessen a parasite’s success. In this sense, many host-parasite systems are embroiled in a constant arms race: the parasite adapting to evade its host’s immune system, and the host adapting to escape the parasite’s new offensive tactics. The “Red Queen hypothesis” addresses this very scenario, where the host is “running” from the pathogen that is “chasing” it.
My PhD research proposes to examine the coevolution of host and parasite in large aquatic salamanders, chiefly the two-toed amphiuma, Amphiuma means, and the greater siren, Siren lacertina. These amphibians are common in the southeast United States and can be found throughout Florida. Both species, though only distantly related, undergo aestivation in periods of drought. I plan on examining the parasite fauna of these salamanders and determining whether infection with parasites affects aestivation success; these animals exhaust their fat reserves while aestivating and pathogens could consume even more resources. I am also interested in whether aestivation is an immune adaptation whereby they can clear infections while in a dormant state. Many intestinal parasites simply absorb nutrients from their hosts’ meals, so a parasite in an empty intestine would most likely starve. Finally, have the parasites adapted to cope with their hosts’ behavior? Parasites often have dormant states (like the metacercariae of trematodes) that can remain inert for long periods of time, or eggs that can remain infective for years (like those of Ascaris). I am always excited to work on parasites, and especially excited to work on those of four-foot-long salamanders!
Brittany F. Sears
Curriculum Vitae
Tel: (813) 215-1346
Email:
Education
2007: B.S. in Zoology (anticipated), summa cum laude. from the University of Florida.
2008: Ph.D. student, Department of Integrative Biology, University of South Florida
Academic Positions
Aug 2008-present: Teaching Assistant, University of South Florida
Fall 2008: Parasitology
Spring 2009: Ecology
MonthAug 2005 – May 2007: Undergraduate Research Assistant. Laboratory of Dr. Marta L. Wayne, Department of Zoology, University of Florida
July 2007- present: Canine Heartworm Project Coordinator. Laboratory of Dr. Ellis Greiner, Department of Pathology and Infectious Disease, University of Florida College of Veterinary Medicine.
Academic Benchmarks
Dean’s ListPresident’s Honor Roll Fall 2005, Spring 2007
Undergraduate GPA: (Overall and Bio or Science)3.53 cumulative, 3.42 science
GRE General Test Score: 1470Scores
B.S. in Zoology, summa cum laude, 2007
Scholarships and Certification
2008: Presidential Fellow, University of South Florida
2006: University Scholar, Department of Infectious Disease and Pathology, University of Florida
2003-2007: University of Florida National Merit Scholarship
2004: Rescue scuba diving certification (YMCA)
2004: Advanced scuba diving certification (YMCA)
2003: Open water scuba diving certification (NAUI)
2002: National Merit Scholar
Work Experience
July 2007-PresentAug 2008: Canine Heartworm Project Coordinator. . Department of Infectious Disease and Pathology, College of Veterinary Medicine, University of Florida.
May 2006-PresentAug 2008: Parasitology Research Assistant. Department of Infectious Disease and Pathology, University of Florida.
Grant Funded
2005-20062006-2007. TitleUniversity Scholars Grant. Program.... Department of Infectious Disease and Pathology. University of Florida. . $2500
The "Red Queen" hypothesis suggests that organisms employing sexual reproduction can evolve to escape parasites by constantly recombining their DNA while asexuals cannot because their genomes are not recombined and thus, evolve much more slowly. I tested this hypothesis by examining the trematode parasites of Campeloma limum, quantifying prevalence and describing the morphologies of the heretofore undescribed flatworms.1-2 sentence synopsis of goals. $ amount
Talks Presented
August 4 – 8 2008: “Parasites in cold stunned green turtles in Florida” by E. Greiner, B. Stacy, T. McIntosh, A. Foley, B. Sears, J. Miller and E. Jacobson.” Wildlife Disease Association, Edmonton, Canada. Presented by E. Greiner.
April 19, 2007: Zoology Undergraduate Research Symposium. “Sex, lies, and trematodes.”
February 17, 2007: University Scholars Program Undergraduate Research Symposium. “Parthenogenesis and parasitism in Campeloma limum.”
Anticipated Publications
As a result of ongoing research with the viviparid snail Campeloma limum, I anticipate authoring be included as an author in atthree least four papers. Two One will stem from my work on trematode parasites of C. limum ; oneit will address the morphology and potential life history of various undescribed species and their correlation with specific populations of C. limum; it, and the other will address its the implications of the snail-trematode relationship implications for the Red Queen Hypothesis, a popular hypothesis thatwhich explains theproposes parasite-mediated evolutionary advantages of to parthenogenesis. A third second publication will address the correlation between water quality indicators (dissolved oxygen, pH) and sexual or parthenogenic populations of C. limum. A fourth third publication will describe embryo size, brood size, and egg capsule resorption in sexual vs. parthenogenic populations of C. limum. I anticipate being first second author on the trematode morphology paper, and second author on the other three publications.the first publication and third on the other publications.
References:
Dr. Jason Rohr, University of South Florida, Integrative Biology Department.
Email:
Dr. Lynn Martin, University of South Florida, Integrative Biology Department.
Email: .
Dr. Ellis Greiner, University of Florida College of Veterinary Medicine: (352) 392-4700 x5861 Email: isa Crummett, ( Ph.D. candidate).: (352) 283-2230 email: give
Dr. Ellis Greiner: (352) 392-4700 x5861 give emaiDr. Frank Mills, DVM: (727) 381-3739