Blocks of horizontally acquired foreign sequences occur in chromosomes of prokaryotes. The first known foreign DNA blocks that were proved to be associated with virulent genes of pathogenic bacteria were named as pathogenicity islands. Later on, genomes of non-pathogenic bacteria have been shown to contain foreign gene blocks, which are not associated with virulence. These gene blocks determine various accessory functions like secondary metabolic activities, antibiotic resistance, symbiosis and other special functions related to the survival in harsh environmental conditions. Subsequently, all foreign gene blocks are collectively named in the literature as genomic islands (GIs). 
Design-Island (an acronym for Detection of Statistically Significant Genomic Island) tries to detect Genomic Islands in prokaryotic genomes. It is based on a method, which is unsupervised in nature and uses Monte-Carlo statistical tests based on randomly selected segments of a chromosome. Such tests are supported by precise statistical distribution theory. Design-Island runs in two phases. Some putative GIs are identified in the first phase, and those are refined into smaller segments that are likely to contain horizontally acquired genes. 

Raghunath Chatterjee
Associate Professor

Research Interest: Genetic and epigenetic basis of Human disease.

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  1. Chatterjee R, Chaudhuri K, Chaudhuri P. "On detection and assessment of statistical significance of Genomic Islands." BMC Genomics. 2008 Apr 1;9:150. 
  2. Nag S, Chatterjee R, Chaudhuri K, Chaudhuri P. "Unsupervised statistical identification of genomic islands using oligonucleotide distributions with application to Vibrio genomes." Sadhana. 2006 April 31(2):105-115. 
  3. Dutta, A, Kundu, J, Chatterjee, R and Chaudhuri, K "In-silico comparative study of the Genomic Islands of Vibrio cholerae MJ1236 with those of Classical and El Tor N16961 strains of Vibrio cholera" FEMS Microbiol Lett, 2011; 321(1): 75-81.