Biography:

Dr. Galande obtained his PhD in Biochemistry from the Indian Institute of Science in 1996. As a postdoctoral fellow at the Lawrence Berkeley National Laboratory, USA from 1996-2001, he studied the role of MAR-binding proteins in tumorigenesis. Dr. Galande joined the National Centre for Cell Science in Pune, India in 2001 as a senior scientist. Research in Galande laboratory is focused on studying dynamic changes at the level of chromatin architecture during various immunological phenomena such as activation and differentiation of T cells and pathogenesis of diseases involving T cells. To fulfil this goal he has established a multidisciplinary program engaged at the interface of biochemistry, molecular biology, bioinformatics, cell biology, proteomics and genomics. Findings from his laboratory have played a seminal role in establishing the function of SATB1 as the key factor integrating gene regulation with higher-order chromatin organization. Current research in Galande laboratory also includes studies on the evolution of mechanisms of gene regulation and genome organization using diverse model systems. Additionally, his lab has contributed a number of innovative technologies for biological research, including a novel cassette for expression and purification of recombinant proteins and a method for assaying interactions between remotely situated genomic loci. Dr. Galande is a recipient of the Bioscience career development award from the Department of Biotechnology, the Swarnajayanti Fellowship from the Department of Science and Technology, Government of India, and the International Senior Research Fellowship from the Wellcome Trust, UK.

Abstract:

Evolution of organismal complexity and genome size: lessons from the genome sequencing projects

Mapping and sequencing of genomes from large number of evolutionarily diverse species in the past decade revealed that sequence per se is not sufficient to understand genome function, the higher-order organization of the genome and its various modifications are also important. In eukaryotic nuclei genome is packaged by association with number of basic proteins to form chromatin. However, chromatin is highly heterogeneous at both micro and macro levels due to differential chemical modifications of DNA and histone proteins which can mark various functional states of chromatin. This projects a very dynamic scenario in which the environmental and cell-type specific signals can inflate the finite coding capacity of the genome into an epigenome with virtually infinite possibilities of combinations and regulation. The accumulation and maintenance of vast excess of non-coding sequences is suggestive of evolutionary advantages offered by these elements to the cell. As we examine the genomic organization of different organisms, it turns out that complexity of highly evolved organism is not reflected by the number of genes that they are made of. For example, the nematode worm (Coenorhabditis elegans) has more genes than house flies (Drosophila melanogaster) although flies are relatively more evolved creatures and display far more complex body structures and behavior. Human genome consists of about 25000 genes. This is ~ 1.5 fold the number of genes found in flies although the human genome itself is ~ 20 times bigger in size compared to that of flies. This suggests that more and more of non-coding DNA and fewer genes were incorporated in the genome of evolving organisms. It is also becoming increasingly clear that regulation of gene expression in higher eukaryotes is more complex and that this complexity is achieved through epigenetic mechanisms enabled by the additional non-coding part of the genome. I will discuss emerging concepts of how DNA sequence can dictate chromatin organization at the domain level and how the incorporation of the so called non-coding elements has helped in evolution of complex organisms.