Ranjan Ganguly, Ph.D.

Research Statement

Research of my laboratory focuses on the molecular and genetic basis of insecticide resistance.  We use Drosophila melanogaster as a model insect to understand how insects become resistant to insecticides. Specifically, we study transcriptional regulation of cytochrome P450 (Cyp) genes which code for a family of enzymes involved in detoxification of xenobiotic (foreign) compounds including DDT and other insecticides.  In resistant strains of Drosophila, multiple Cyp genes which map close to the resistance loci show significantly higher level of expression compared to the susceptible strains.  However, it is not known whether only one or multiple Cyp genes are involved in DDT metabolism.  The mechanism of overtranscription of these genes is also not known.  My lab is working on these two problems. We also study induction of Cyp genes by various xenobiotics.  We found caffeine, the most heavily consumed xenobiotic induces several Cyp genes including the ones showing resistance-associated overtranscription.  We use various molecular biology and genetic techniques, cloning, sequencing, transgenic technology and microarray to study the resistance mechanism, metabolic functions of selected P450 enzymes, Cyp gene regulation and the mechanism of Cyp gene induction by caffeine.  Our research has been supported by grants from USDA.

Selected Publications

Bhaskara, S., Chandrasekharan, M. B., and Ganguly, R (2008) Caffeine induction of Cyp6a2 and Cyp6a8 genes of Drosophila melanogaster is modulated by cAMP and D-JUN protein levels. Gene 415, 49-59

Kuruganti, S., Lam, V., Zhou, X., Bennett, G., Pittendrigh, B. R. and Ganguly, R (2007) High expression of Cyp6g1, a cytochrome P450 gene, does not necessarily confer DDT resistance in Drosophila melanogaster. Gene 388:43-53.

Bhaskara, S., Dean, E. D., Lam. V and Ganguly, R. (2006) Induction of two cytochrome P450 genes, Cyp6a2 and Cyp6a8, of Drosophila melanogaster by caffeine in adult flies and in cell culture. Gene 377:56-64.

Boake CRB, McDona K, Maitra S and Ganguly R (2003) Forty years of solitude: life-history divergence and behavioral isolation between laboratory lines of Drosophila melanogaster. J. Evol. Biol. 16:83-90.

Maitra S, Price C and Ganguly R (2002) Cyp6a8 of Drosophila melanogaster: Gene structure, and sequence and functional analysis of the upstream DNA. ­Insect  Biochem. Mol. Biol. 32: 859-870.

Maitra S, Dombrowski SM, Basu M, Raustol O, Waters LC and Ganguly R (2000) Factors on the third chromosome affect the level of Cyp6a2 and Cyp6a8 expression in Drosophila melanogaster. Gene 248:147-156.

Dombrowski SM, Krishnan R, Witte M, Maitra S, Diesing C, Waters LC and Ganguly R (1998) Constitutive and barbital-induced expression of the Cyp6a2 allele of a high producer strain of CYP6A2 in the genetic background of a low producer strain. Gene 221:69-77.

Maitra S, Dombrowski SM, Waters LC and Ganguly R (1996) Three second chromosome-linked clustered Cyp6 genes show differential constitutive and barbital-inducible expression in DDT-resistant and susceptible strains of Drosophila melanogaster. Gene 180:165-171.

Krishnan R and Ganguly R (1995) A 3.5-kb DNA fragment contains the cis-regulatory elements for retina-specific expression and partial male-specific hypertranscription of the X1R-linked Arrestin B (ArrB) gene of Drosophila miranda. Gene 160:185-190.

Ray K and Ganguly R (1994). Organization and expression of the Drosophila melanogaster G protein gamma subunit gene (D-Gg1). Gene 148: 315-319.

Swanson KD and Ganguly R (1992) Characterization of a Drosophila melanogaster gene similar to the mammalian genes encoding tyrosine/tryptophan activator and protein kinase C inhibitor proteins. Gene 113: 183 - 190.

Ray K and Ganguly R (1992) The Drosophila G protein gamma subunit gene (D-Gg1) produces three developmentally regulated transcripts and is expressed in the central nervous system.   J. Biol. Chem. 267: 6086 - 6092.

Ganguly R Swanson KD, Ray K and Krishnan R (1992) A BamHI repeat is predominantly associated with the degenerating neo-Y chromosome of D.miranda but absent in D.melanogaster genome.  Proc. Natl. Acad. Sci., USA  89: 1340 -1344.

Krishnan R, Swanson KD and Ganguly R. (1991) Dosage compensation of a retina‑specific gene in Drosophila miranda.  Chromosoma. 100: 123‑131.

Contact Information

Office:
Room F-231
Walters Life Sciences
Phone: (865) 974-3602

Lab:
Room C-202
Walters Life Sciences
Phone: (865) 974-3798

Email: rganguly@utk.edu