In silico characterization and comparative genomic analysis of the Culex quinquefasciatus glutathione S-transferase (GST) supergene family

• Published in: Parasitology research (1987) Vol. 109; no. 4; pp. 1165 - 1177
• Main Authors: Niranjan Reddy, B. P., Prasad, G. B. K. S., Raghavendra, K.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.10.2011; Springer
• Subjects: Amino Acid Sequence; Animals; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Culex; Culex - genetics; Culex - metabolism; Culex quinquefasciatus; Databases, Genetic; Evolution, Molecular; Exons; Fundamental and applied biological sciences. Psychology; Gene Duplication; General aspects; General aspects and techniques. Study of several systematic groups. Models; Genes; Genome, Insect; Genomes; Genomics - methods; Glutathione transferase; Glutathione Transferase - classification; Glutathione Transferase - genetics; Glutathione Transferase - metabolism; Immunology; Insect Proteins - classification; Insect Proteins - genetics; Insect Proteins - metabolism; Insecticide Resistance - genetics; Insecticides; Introns; Invertebrates; Medical Microbiology; Microbiology; Molecular Sequence Data; Multigene Family; Original Paper; Pesticide resistance; Phylogeny; Sequence Alignment; Software; Gain Event; Intron Position; Intron Loss; Supergene Family; Intron Gain; Enzyme; Glutathione transferase; Arthropoda; Insecta; Transferases; Culicidae; Parasite; Invertebrata; Diptera; Culex quinquefasciatus
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-011-2364-x

The glutathione S -transferases (GSTs) are phase II class of detoxification enzymes that are involved both directly and indirectly in insecticide resistance mechanisms. The Culex quinquefasciatus GST superfamily was analyzed by utilizing the public domain Culex genome sequence. In total, 35 cytosolic (seven classes) and 5 microsomal putatively active GSTs were retrieved, classified, and annotated. The study revealed the presence of three unclassified GSTs. Of 35 cytosolic GSTs, 65% contributed by insect specific Delta–Epsilon classes. Gene cluster analysis revealed that most of the genes of Delta, Epsilon, and Theta classes were organized into gene clusters. The gene organization analysis revealed the dominance of phase “0” introns in the Culex GST family. The studies on intron loss and gain events revealed that the Delta GSTs have experienced a higher number of loss and gains during their evolution. A positive correlation was observed between the phylogenetic relationship of members of the GST superfamily and their corresponding exon–intron organization. In addition, the genes within the gene clusters revealed the monophyletic phylogenetic relationship implying the importance of gene duplication events in the gene families' evolution. Finally, the comparative genomic analysis has shown a complex evolutionary scenario associated with the GST supergene family evolution in insects.