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UT Tyler Department of Biology

Srini Kambhampati Research

I am broadly interested in evolutionary biology. Much of my research is focused on the evolution of insects. My most recent work has been on the evolution, population genetics, molecular phylogenetics, and genomics of cockroaches and termites. The following synopses provide a brief overview of our research focus. Please see my complete CV for a full list of publications.

Cryptocercus Evolution and biogeography of the wood roach, Cryptocercus: Members of the cockroach genus  Cryptocercus are xylophagous, subsocial insects that live inside decaying logs in temperate forests.  Only nine species are recognized worldwide: five in the United States and two each in eastern Russia and southwestern China.  Until 1997, all individuals in the United States were considered a single species; however extensive genetic analysis of mitochondrial DNA led to the description of new species bringing the total to five (Kambhampati et al. 1996; Burnside et al. 1999).  The mtDNA results have been confirmed using a nuclear region as well (Hossain and Kambhampati 2001).  The distribution of Cryptocercus in the eastern United States has been studied in detail (Steinmiller et al. 2001).  We have recently demonstrated that the bacterial endosymbionts harbored by Cryptocercus have also diverged along with the hosts, leading to a classic case of coevolution (Clark et al. 2001; Clark and Kambhampati 2001). Divergence estimates based on the clock-like evolution of the bacterial 16S rRNA gene indicated that Cryptocercus represents an ancient lineage, dating back to at least the Jurassic (Clark et al. 2001).  We also used allozymes and morphology to further distinguish among the species native to the United States (Aldrich et al., 2004a, 2004b, 2005), More recently we investigated the evolution of host and habitat association in this cockroach using GIS, land cover, and elevation data (Kambhampati et al. 2001; Kambhampati and Peterson 2007).  Studies on Cryptocercus were funded by the National Science Foundation . 

Relevant papers:

Kambhampati, S. and A.T. Peterson. 2007. Ecological niche conservation and differentiation in the wood-feeding cockroach, Cryptocercus, in the United States. Biological Journal of Linnean Society 90: 457-466. (PDF)

Aldrich, B.T., S. Kambhampati, and E. Krafsur. 2005. Population genetics of wood-feeding cockroaches in the genus Cryptocercus. Journal of Heredity 96: 572-575. (PDF)

Aldrich, B.T., E. Krafsur, and S. Kambhampati. 2004. Species-specific allozyme markers for wood-feeding cockroaches (Blattodea: Cryptocercidae). Biochemical Genetics 42: 149-164. (PDF)

Aldrich, B.T., G. Zolnerowich, and S. Kambhampati. 2004. Interspecific morphological variation in the wood-feeding cockroach, Cryptocercus (Dictyoptera: Cryptocercidae). Arthropod Structure and Development 33: 443-451. (PDF)

Clark, J.W. and S. Kambhampati. 2002. Phylogenetic relationships among Blattabacterium, endosymbiotic bacteria from the wood roach, Cryptocercus. Molecular Phylogenetics and Evolution 26: 82-88. (PDF)

Kambhampati, S., J.W. Clark and B.L. Brock. 2002. Evolution of host- and habitat association in a cockroach. Biological Journal of the Linnean Society 75: 163-172. (PDF)

Steinmiller, B., S. Kambhampati, and B.L. Brock. 2001. Geographic distribution of, and genetic variation, in the wood roach,Cryptocercus (Dictyoptera: Cryptocercidae). Annals of the Entomological Society of America 94: 732-742. (PDF)

Hossain, S. and S. Kambhampati.  2001. Phylogeny of Cryptocercus (Blattodea: Cryptocercidae) species inferred from nuclear ribosomal DNA. Molecular Phylogenetics and Evolution 21:162-165. (PDF)

Clark, J.W., S. Hossain, C.A. Burnside and S. Kambhampati.  2001. Coevolution between a cockroach and its bacterial endosymbiont: A biogeographical perspective. Proceedings of the Royal Society of London, Series B268:393-398. (PDF)

Burnside, C.A., P.T. Smith and S. Kambhampati. 1999. Three new species of the wood roach, Cryptocercus (Blattodea: Cryptocercidae), from eastern North America. Journal of Kansas Entomological Society 72: 361-378. (PDF)

Kambhampati, S., P. Luykx and C.A. Nalepa. 1996. Evidence for sibling species in the wood roach, Cryptocercus punctulatus, from variation in mitochondrial DNA and karyotype. Heredity 76: 485-496. (PDF)

Kambhampati, S. 1996. Phylogenetic relationship among cockroach families inferred from mitochondrial 12S rRNA gene sequence. Systematic Entomology 21: 89-98.

Kambhampati, S. 1995. A phylogeny of cockroaches and related insects based on DNA sequence of mitochondrial ribosomal RNA genes. Proceedings of the National Academy of Sciences, USA 92: 2017-2020. (PDF)

 

Termites Evolution of Termites: Termites are a large and diverse group of eusocial insects.  Unlike the Hymenoptera, members of Isoptera are all eusocial and both males and females are diploid.  They play a major role in the community ecology of various ecosystems such as rain forests and savannas.  Because they are one of the few animals that can digest cellulose, they play a  major role in its recycling.  It is safe to say that without termites, rain forests as we know them probably would not exist.  Despite their importance, termite evolution, especially their phylogenetics, has only recently begun to be studied.  A recent review summarizes the outstanding issues (Kambhampati and Eggleton 2000).  We published the first phylogenetic analysis of relationships among termite families (Kambhampati et al. 1996).  We investigated the colony structure of two closely related Zootermopsis species (Aldrich and Kambhampati 2007). We also studied a zone of contact (hybrid zone) between the same species (Aldrich and Kambhampati 2009) using microsatellites (Aldrich and Kambhampati 2004).  Our studies on termites were funded by the National Science Foundation

Relevant papers:

Aldrich, B.T. and S. Kambhampati. 2009. Preliminary analysis of a hybrid zone between two subspecies of Zootermopsis nevadensis. Insectes Sociaux 56: 439-450. (PDF)

 Aldrich, B.T. and S. Kambhampati. 2007. Population structure and colony composition of two Zootermopsis nevadensis subspecies. Heredity 99: 443-451. (PDF)

Aldrich, B.T., S. Kambhampati. 2004. Microsatellite markers for three species of dampwood termites in the genus Zootermopsis (Isoptera: Termopsidae). Molecular Ecology Notes 4: 719-721. (PDF)

Kambhampati, S. and P. Eggleton. 2000. Taxonomy and phylogenetics of Isoptera.  pp. 1-23.  In: T. Abe, D.A. Bignell and M. Higashi (eds.): Termites: Evolution, Sociality, Symbioses and Ecology. Kluwer Academic Publishers, Dordrecht, The Netherlands.

Kambhampati, S., K.M. Kjer and B.L. Thorne. 1996. Phylogenetic relationship among termite families based on DNA sequence of mitochondrial 16S ribosomal RNA gene. Insect Molecular Biology 5: 229-238. (PDF)

 

Termite Genomics: We have recently initiated research on the genomics of termites. We established an EST library from several castes and life stages of the Eastern subterranean termite, Reticulitermes flavipes. We (along with Dr. Michael Scharf’s group) are currently in the process of sequencing the genome of Reticulitermes flavipes.

Relevant papers:

Schwinghammer, M.A., X. Zhou, S. Kambhampati, G.W. Bennett and M.E. Scharf. 2010. A novel gene from the takeout family involved in termite trail-following behavior. Gene doi:10.1016/j.gene.2010.11.012. (PDF)

Steller, M., S. Kambhampati, D. Caragea. 2010. Comparative analysis of expressed sequence tags from three castes and two life stages of the termite, Reticulitermes flavipes. BMC Genomics 11 :463; doi:10.1186/1471-2164-11-463. (PDF)

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