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Book of Abstracts: Albany 2005

category image Volume 22
No. 6
June 2005

Conservation and Variation: A Balancing Act in the Genome

The genome architecture of a large number of prokaryotic and eukaryotic organisms are being unravelled. At this juncture two things have become clear. When we compare different organisms, we observe some regions of the coding sequences are invariant across the evolutionary scale whereas some are highly variable in spite of the gene/protein participating in identical functions across organisms (1, 2). In the present talk, over 12,000 such invariant coding sequences from 8 to 88 amino acids derived from prokaryotic genomes and their conservation in higher eukaryotes including the human genome will be presented. The second observation we have is that several repetitive sequence elements, in the non coding regions of the genome, which are known to exhibit polymorphism also exhibit unique positional preference and conservation in orthologous genes (3, 4). The role of such positional preference and conservation in regulation of gene expression in the context of human and other eukaryotic genomes will be discussed (5). Besides, Alu repeats which belong to the family of SINE elements are unique to primate genomes and present in over a million copies in the human. We have found that these repeats have non random distribution in the genome and show positional preferences with respect to various functional categories of genes. Comparative analysis of Alu repeats in primate genomes will also be presented.

References and Footnotes
  1. Prakash, T., Khandelwal, M., Dasgupta, D., Dash, D., Brahmachari, S.K. Bioinformatics 20, 2886-2888 (2004).
  2. Prakash, T., Ramakrishnan, C., Dash, D., and Brahmachari, S.K. J Mol Biol. 345, 937-955 (2005).
  3. Grover, D., Majumder, P.P., Rao, C.B., Brahmachari, S.K., Mukerji, M. Mol Biol Evol. 20, 1420-1424 (2003).
  4. Grover, D., Mukerji, M., Bhatnagar, P., Kannan, K., Brahmachari, S.K. Bioinformatics 20, 813-817 (2004).
  5. Sharma, A., Sharma, V.K., Horn-Saban, S., Lancet, D., Ramachandran, S., Brahmachari, S.K. Physiol Genomics. Jan 11, 2005; [Epub ahead of print].

Samir K. Brahmachari

Institute of Genomics and Integrative Biology (CSIR)
Mall Road
Delhi University Campus
Delhi - 110007, India

Email: skb@igib.res.in