(i) Proteomics is the identification, analysis and large scale characterisation of proteome (i.e., the total protein components) expressed by any given cells, tissues and organs under the defined conditions. The major objectives of proteomics are
• to characterise post- transcriptional modifications in protein, and
• to prepare 3D map of cell indicating the exact location of protein.
Proteomics is the direct outcome of advancement made for nucleotide sequencing of different genomes in large scale. This helps to identify various proteins. Generation of information about protein is necessary. Because protein governs the phenotypic characters of the cells. Merely genome study cannot provide the understanding of mechanism of disease development and various developmental changes occurring in organisms including humans. Moreover, target drugs for many kinds of diseases can be prepared only after understanding the protein modification and protein functions. There are many areas of modem proteomics such as protein expression, protein structure, protein localization, protein-protein interaction, etc.
(ii) Dedifferentiation: It is a cellular process which occurs in lower life forms such as worms and amphibians in which a partially or terminally differentiated cell reverts to an earlier developmental stage.
Redifferentiation : It is a process by which a group of once differentiated cells returns to their original specialised form.
