Biography:

Dr. Radhey S. Gupta is a Professor of Biochemistry at McMaster University in Canada. He joined McMaster in 1978 and became a Full Professor in 1986. His research interests have covered many subjects including studies on drug resistant mutants, heat shock proteins, structure-function studies on enzymes and novel aspects of mitochondria. Since 1990s, his primary research interests are in using molecular sequence data to understand the early evolutionary history of life. His earlier work challenged the view that Archaea constitute the third domain of life and suggested that they are related to Gram-positive bacteria. His work also provided earliest evidence that eukaryotic cell nucleus is formed by fusion between an archaebacterium and a bacterium.
For the past 10 years, he is using genomic sequence data to understand microbial systematics and evolution. The main objectives of his work are to develop novel molecular means for identifying different groups of Bacteria and to understand their branching order from a common ancestor. His lab has pioneered the discovery of conserved indels and whole proteins that are specific for different bacterial groups as novel tools for various studies. His work has identified numerous protein signatures for different groups of bacteria. In addition to providing definitive means for identifying different bacterial groups in molecular terms, these signatures also provide powerful tools for genetic, biochemical and evolutionary studies. The use of conserved inserts and signature proteins for similar studies is also currently extended to eukaryotic organisms. Prof. Gupta has published >250 articles in peer-reviewed articles, many of which are highly cited.

Abstract:

Novel Comparative Genomic Approaches for Understanding Microbial Phylogeny

Prokaryotic organisms were the sole inhabitants of this planet for the first 1.5 - 2.0 billion years. Hence, a detailed knowledge of their evolution is critical for understanding the origin of life and various associated processes. In recent years, although much has been learnt about prokaryotic diversity, many critical issues pertaining to microbial evolution are unresolved. Presently, all main groups of prokaryotes are distinguished solely on the basis of branching in phylogenetic trees and in most cases no distinctive characteristic for them are known. The branching order and evolutionary relationships among different prokaryotic groups is also not resolved. The availability of genome sequences has provided an unprecedented opportunity for understanding these critical issues. Two new approaches based on rare genomic changes (RGCs) are providing important insights in these regards. The first approach involves identification of RGCs comprising of conserved inserts and deletions (i.e. indels) in widely distributed proteins that are specific for different groups of organisms. In the second approach, whole proteins that are unique to different taxonomic groups are identified. These approaches have identified large numbers of conserved indels as well as whole proteins that are distinctive characteristics of most major groups within Bacteria. The usefulness of these molecular signatures for identifying different groups of prokaryotes and for understanding their evolution will be described in my presentation. Studies on the cellular functions of these proteins and RGCs that are being carried out should also lead to discovery of novel biochemical and physiological characteristics that are unique to different groups of prokaryotes.