Evolutionary Biology and Ecology of Host-parasite Interactions; Insect Genomics
Associate Professor
PhD 1994 University of Vermont
Postdoctoral work:1997 University of Wisconsin-Madison
Scientist 1997International Center of Insect Physiology and
Ecology
Assistant Professor 1997 University at Buffalo
Associate Professor 2002
Guiyun Yan
Department of Biological Sciences
219 Hochstetter Hall
State University of New York at Buffalo
Buffalo, NY 14260
(716) 645-2363 ext: 121
To send e-mail: gyan@acsu.buffalo.edu
My research concentrates on malaria epidemiology, population ecology and genetics of African malaria vectors, and molecular genetics of vector competence. The long-term research goal is to develop novel and cost-effective malaria control methods. Contemporary molecular biology techniques, geographic information system/remote sensing technologies, and spatial statistical analyses are integrated into my research program. Another area of interest is the evolutionary biology of host resistance to parasitism.
1. Ecology of African Highland Malaria
The objective is to examine the mechanisms leading to the
resurgence of malaria in African high-elevation areas. Our
hypothesis is that malaria epidemics in the highlands arise
because together with global climate changes, landuse changes
have also altered the microhabitats and microclimatic conditions
of vector mosquitoes and the malaria parasite, making local
malaria transmission possible in previously unsuitable areas. In
collaboration with the Kenya Medical Research Institute, we are
examining how landuse affects mosquito microhabitats and
microclimatic conditions and determining whether changes in
mosquito habitats and microclimatic conditions increase mosquito
vectorial capacity. We will develop and validate spatially
explicit malaria transmission models.
2. Population Ecology and Genetics of
African Malaria Vectors
The goal of is to determine the distribution patterns of malaria
vectors in East Africa and the underlying ecological factors that
influence the spatial heterogeneity of mosquito distribution at
the species and the gene level. Molecular biology, geographic
information system and remote sensing technology are integrated
with field mosquito ecology studies to determine the association
of environmental factors and malaria vector species distribution
and genetic variants. Our study examines 3 major malaria vector
species, Anopheles gambiae, An. arabiensis and An. funestus.
3. Genetics of Mosquito Refractoriness to
Malaria Parasites
The goal is to identify, isolate and characterize the genes that
determine mosquito vector competence for malaria parasites, and
to apply the information to develop new malaria control methods
applicable in the field. We use Aedes aegypti/Plasmodium
gallinaceum as a model system to investigate the genetic and
physiological basis of mosquito refractoriness. Refractoriness is
a naturally occurring phenomenon in which mosquitoes inhibit
Plasmodium oocyst formation. We are using molecular and
ecological experiments, and bioinformatics to: (1) conduct
high-resolution quantitative trait loci (QTL) mapping to better
define the genome regions that contain P. gallinaceum-refractory
genes and to identify candidate genes through whole-genome
expression analysis, (2) characterize the physiological basis of
refractoriness with particular emphasis on the mosquito midgut
barrier, and (3) determine the genetic association between
refractoriness and mosquito fitness.
4. Evolutionary Genetics of Host
Resistance to Parasitism
Many parasites, including some protozoans, nematodes, trematodes,
cestodes and all acanthocephalans, require intermediate hosts to
complete their life cycles, but there is virtually no knowledge
on the evolution of life history of this type parasites. This
project will determine the genetic basis of beetle resistance to
a tapeworm parasite and test whether the evolution of resistance
is constrained by fitness costs associated with resistance, using
the red flour beetle and tapeworm parasite as a model system.
A section of Aedes aegypti mosquito midgut specific cDNA array. The green color represents genes up-regulated in Plasmodium gallinaceum susceptible strains.
Zhong D., A. Pai and G. Yan. 2003. Quantitative trait loci for susceptibility to tapeworm infection in the red flour beetle. Genetics 165: 1307-1315
Zhou G. and G. Yan. 2003. Dynamics of the Severe Acute Respiratory Syndrome (SARS) Epidemic in Asia. Emerging Infectious Diseases 9: 1608-1610.
Braginets O.P.N. Minakawa, C. N. Mbogo, and G. Yan. 2003. Microsatellite markers revealed significant population genetic structure of African malaria mosquito Anopheles funestus in Kenya. American Journal of Tropical Medicine and Hygiene 69: 303-308.
Oketch BA, Gouagna LCV, Knols BGJ, Kabiru EW, Beier JC, Yan G, Githure JI, Killeen GF. 2003. Influence of sugar availability and indoor microclimate on survival of Anopheles gambiae under semi-field conditions in western Kenya. J Med Entomol 40: 657-663.
Pai A., I. V. Sharakhov, O. Braginets, C. Costa and G. Yan. 2003. Identification of microsatellite markers in the red flour beetle, Tribolium castaneum. Molecular Ecology Notes 3: 425-427
Pai A. and G. Yan. 2003. The effects of tapeworm infection on male reproductive success and mating vigor in the red flour beetle. Journal of Parasitology 89: 516-521.
Pai, A. and G. Yan. 2003. Rapid female multiple mating in red flour beetles (Tribolium castaneum). Canadian Journal of Zoology 81: 888-896.
Yan G. and D. W. Severson. 2003. Dynamics of QTL markers linked to the resistance loci in a mosquito-Plasmodium system. Genetics 164: 511-519
Mbogo C. M., J. M. Mwangangi, J. G. Nzovu, G. Yan, J. Gunter, C. Swalm, J. Regens, J. Shililu, J. I. Githure and J. C. Beier. 2003. Spatial and temporal heterogeneity of Anopheles mosquitoes and Plasmodium falciparum transmission along the Kenyan coast. American Journal of Tropical Medicine and Hygiene 68: 734-742.
Cui L., C. Mascorro, Q. Fan, K. Rzomp, B. Khuntirat, G. Zhou, H. Chen, G. Yan and J.Sattabongkot. 2003. Genetic diversity and multiple infection of Plasmodium vivax malaria in Thailand. American Journal of Tropical Medicine and Hygiene 68:613-619.
Gu W., C. M. Mbogo, J. I. Githure, J. L. Regens, G. F. Killeen, F. E. McKenzie, C. M. Swalm, G. Yan, J. C. Beier. 2003. Low recovery rates stabilize malaria endemicity in areas of low transmission in coastal Kenya. Acta Tropica 86: 71-81.
Pai A. and G. Yan. 2002 Female mate choice in relation to heterozygosity in Tribolium castaneum. Journal of Evolutionary Biology 15: 1076-1082.
Minakawa N., G. Sonye, N. Mogi, A. K. Githeko and G. Yan. 2002 The effects of climatic factors on the distribution and abundance of malaria vectors in Kenya. Journal of Medical Entomology 39: 833-841.
Minakawa N., P. B. Seda , and G. Yan. 2002 Influence of host and larval habitat distribution on the abundance of African malaria vectors in western Kenya. American Journal of Tropical Medicine and Hygiene 67:32-38.
Okanda F. M., A. Dao, B. N. Njiru, J. Arija, H. A. Akelo, Y. TourŽ, A. Odulaja, J. C. Beier, J. I. Githure, G. Yan, L. C. Gouagna, B. G. J. Knols, and G. F. Killeen. 2002 Behavioural determinants of gene flow in malaria vector populations: Anopheles gambiae males select large females as mates. Malaria Journal 1:10. (available http://www.malariajournal.com/content/1/1/10 )
Pai A. and G. Yan. 2002 Polyandry produces sexy sons at the cost of daughters in red flour beetles. Proceedings of Royal Society London B 269: 361-368.
Sharakhov, I. V., O. Braginets, C. N. Mbogo, and G. Yan. 2001 Isolation and characterization of trinucleotide microsatellites in African malaria mosquito Anopheles funestus. Molecular Ecology Note 1: 289-292.
Sharakhov I. V., M. V. Sharakhova, C. M. Mbogo, L. L. Koekemoer and G. Yan. 2001 Linear and spatial organization of polytene chromosomes of African malaria vectors, Anopheles funestus. Genetics 159: 211-218.
Minakawa N., J. I. Githure, J. C. Beier, and G. Yan. 2001 Anopheline mosquito survival strategies during the dry period in western Kenya. Journal of Medical Entomology 38: 388-392.
Kaplan R. A., S. H. Zwiers and G. Yan. 2001 Plasmodium gallinaceum: ookinete formation and proteolytic enzyme dynamics in highly refractory Aedes aegypti populations. Experimental Parasitology 98: 115-122.
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