I graduated with my B.S from the University of Vermont in 2005 and I joined the Clayton lab in 2006 with an interest in bird-parasite interactions. My Ph.D. research centers on understanding a variety of interactions between a host and its parasites, and also the interactions among the parasites that might share a particular host.
My interest in hosts and their parasite communities has led me to work on a tractable and easily manipulated captive system of Rock Pigeon (Columbidae: Columba livia) hosts and their parasites. Pigeons have many parasites in the wild; however, my research focuses on two of these parasites: a blood feeding hippoboscid fly (Hippoboscidae: Pseudolynchia canariensis) (figure 1) and a malaria parasite (Apicomplexa: Haemoproteus columbae) (figure 2) and their interactions with the pigeon host and the interactions between them.
|Figure 1: Figure 2: Hippoboscid flies (Pseudolynchia canariensis) in my lab culture
Figure 2: Malaria parasites (Haemoproteus columbae) in the gametocyte stage in pigeon blood. Males stain pink and females stain blue with Giemsa stain.
Hippoboscid flies take their blood meals from pigeons, which are often infected with malaria. The fly then acts as a vector, transferring malaria between bird hosts. The malaria parasite must undergo a sexual reproductive stage in the fly, and an asexual reproductive stage in the host to complete its life cycle, thus potentially impacting the fitness of both the bird and the fly. In order to progress through these life stages, malaria may use resources from the fly vector or from the host. This energetic tradeoff could then reduce the fitness of either the fly vector or the avian host. The malaria parasite might also affect fly or pigeon physiology, for example when the malaria oocyst stage in the fly gut bursts from the fly gut walls it leaves the fly open to bacterial infection, or when the malaria invades host red blood cells consuming the hemoglobin of these cells causing the host to become anemic.
I am investigating this system from two perspectives:
From the parasitic fly’s point of view:
I am interested in the effects of malaria on fly fitness. The captive bird-fly-malaria system allows me to directly measure fly reproduction and survival as proxies for fitness and I can also monitor infection status of the bird host. If there is a cost to the fly of vectoring malaria, I expect to see reduced reproduction and survival in flies fed on malaria-infected birds relative to flies fed on malaria-free birds. Understanding whether malaria impacts the fitness of its vector (the fly), has implications for the transmission dynamics of malaria and possibly other vectored pathogens.
From the hosts’ point of view:
I am also interested in how hosts combat parasites immunologically. I will examine how the avian immune system reacts to multiple challenges (parasitic flies, malaria, etc) in an effort to better understand how the avian immune system functions. I am interested in exploring co-infection dynamics in terms of how one parasite influences the fitness of other parasites within the host and what effect co-infections have on host fitness overall.
One possibility is that a hosts’ immune system may be suppressed by the presence of one parasite, making the host more susceptible to infection by additional parasites. In future research, I plan to look for signs of immunosuppression by challenging hosts that have been exposed to either malaria, flies, or both, to an additional pathogen: attenuated pigeon pox virus. If the presence of malaria or fly antigen act as an immunosuppressant within a host, I expect to see a reduced immune response to attenuated pigeon pox virus in birds that were previously exposed relative to naïve, unexposed birds.
Alternatively, the host’s immune system may be “primed” by the presence of one parasite making the host less susceptible to infection by other parasites. If malaria or fly antigen act as a primer to the host immune system, I expect to see a heightened immune response to attenuated pigeon pox virus in previously exposed birds relative to naïve, unexposed birds. Studies investigating co-infection dynamics within live hosts are rare; however, the pigeon-fly-malaria system lends itself well to studies of this nature.
My work has led to some adaptations of our animal care facility to include a breeding facility to provide a source of parasite-naïve birds (i.e. Baby Pigeons: figure 3). I am also able to culture hippoboscid flies in captivity (figure 2) and maintain a wild-caught population of pigeons as a source of breeding birds and natural malaria infections.
|Figure 3a and b: Baby pigeons! In both egg (a) and "so ugly they're cute" (b) stages.
Jessica Waite Publications
J.F., M. Baze, J.L. Waite, F.G. Hoffmann, J.C. Opazo and J.P. Hayes.
2007. Complex signatures of selection and gene conversion in the duplicated
globin genes of house mice. Genetics 177:481-500.
E.M., J.L. Waite and J.J. Schall. 2007. Morphologically defined subgenera
of Plasmodium from avian hosts: test of monophyly by phylogenetic analysis
of two mitochondrial genes. Parasitology 134:483-490.
3. R. Giordano, E. Weber, J. Waite, N. Bencivenga, P. H. Krogh,and F.
Soto-Adames. 2010. Effect of a High Dose of Three Antibiotics on the
Reproduction of a Parthenogenetic Strain of Folsomia candida
(Isotomidae: Collembola). Environmental Entomology 39:1170-1177.
4. Waite, J.L., A.R. Henry, F.R. Adler, and D.H. Clayton. 2012. Sex-specific effects of an avian malaria parasite on an insect vector: Support for the resource limitation hypothesis. In Press in Ecology
5. Knutie, S.A.*, J.L. Waite*, and D.H. Clayton. 2012. Does avian malaria
(Haemoproteus columbae) reduce fledging success: An experimental test of the selection hypothesis. In Press in Evolutionary Ecology
*these authors contributed equally to this work.
6. Waite, J.L., A.R. Henry and D.H. Clayton. 2012. How effective is preening against mobile ectoparasites? An experimental test with pigeons and pigeon flies. International Journal for Parasitology 42:463-467. (link to article: Preening)
Outside of research
pursuits I enjoy exploring the outdoors, especially by hiking, biking
and on cross country skis.
climbing down Bald
Mountain in the Uintahs.
and her husband,
Isaac, at the top of Bald