Sara Brant   M.S. 1996 University of Nebraska-Lincoln Ph.D. 2002 University of Nebraska-Lincoln Postdoc Associate at Louisiana State University Postdoc Associate, University of New Mexico   email: sbrant1@lsu.edu

Coevolution of parasites and hosts (shrews and nematodes)

EDUCATION

• Ph.D. 2002, Univ. of Nebraska-Lincoln, major advisor G. Ortí --> first one from the GO lab!!!
• 1996 Master's of Science in Biology, University of Nebraska, Lincoln.
• 1994 Bachelor's of Science in Zoology, University of California, Davis.

RESEARCH INTERESTS

Coevolution of parasites and their hosts: Studies of evolutionary and coevolutionary interactions among parasites and hosts have resulted in a wealth of ideas and descriptive data, but typically have been focused at high taxonomic levels. Paucity of comprehensive studies on the population genetic structure of both parasites and their host(s) has limited our power to understand the basic processes operating at microgeographic scales, early in the divergence of their evolutionary trajectories. Adaptation to host immunity, transmission dynamics, and the ecology of speciation are but a few conspicuous issues shaping the distribution of genetic variation among interacting parasite and host populations. The immediate goal of my research is to characterize the population genetic structure and phylogeography of two species of shrews and a parasitic nematode common to these two species using mitochondrial (mt) and nuclear (n) DNA markers. The nematode chosen does not utilize intermediate hosts and the shrew species chosen are known to hybridize along a narrow zone in Nebraska. The host population genetic structure and gene flow across their hybrid zone will be characterized to analyze genetic variation among parasites at several hierarchical levels: (i) nematodes within individual hosts; (ii) among hosts in the same population; (iii) among hosts in different populations; (iv) among hosts of different species; (v) within the host hybrid zone. My specific goals are:

1. To collect species of Blarina and their parasites and document prevalence and intensity of parasitism.
2. To characterize host population genetic structure: (i) phylogenetic relationships among species of Blarina, (ii) mtDNA phylogeography of B. brevicauda and B. hylophaga, (iii) geographic variation at microsatellite loci.
3. To characterize the population genetic structure of the nematode, Longistriata caudabullata, (i) mtDNA phylogeography, (ii) geographic variation at microsatellite loci.
4. To analyze the coevolutionary relationships among the shrews and their nematodes.
   

PUBLICATIONS

• Brant, S. V. and S. L. Gardner. 1997. Two new species of Litomosoides (Nemata: Onchocercidae) from Ctenomys opimus (Rodentia: Ctenomyidae) from the Altiplano of Bolivia. Journal of Parasitology 83: 700-705.
• Brant, S. V. and S. L. Gardner. 2000. Phylogeny of species of the genus Litomosoides (Nemata: Onchocercidae): evidence of rampant host switching. Journal of Parasitology, (In press).
• Brant, S. V., and B. Hanelt. 2000. Quantitative investigations of the crowding effect in Hymenolepis diminuta in Rattus norvwegicus. ABLE Proceedings, (In Press)
• Brant, S.V. and G. Ortí. 2002. A molecular phylogeny of short-tailed shrews, Blarina (Insectivora: Soricidae). Molecular Phylogenetics and Evolution (22): 163-173. get pdf
• Brant, S. and G. Ortí 2003. Evidence for gene flow in parasitic nematodes between two host species of shrews. Molecular Ecology (in press, download proof)
• Brant, S. and G. Ortí 2003. Phylogeography of the Northern short-tailed shrew, Blarina brevicauda (Insectivora: Soricidae): past fragmentation and postglacial recolonization. Molecular Ecology 12: 1435-1449. download pdf

LINKS OF INTEREST

Parasitology labs at UNL:

Dr. John Janovy,
Dr. Brent Nickol,
Dr. Tom O. Powers

Parasitology links:

The American Society of Parasitologists

UNL links:

Biology Graduate Student Association