title: (TG:CA)(n) repeats in human housekeeping genes.
abstract: The unravelling of human genome sequence gives a new opportunity to investigate the role of repetitive sequences in gene regulation. Among the various types of repetitive sequences, the dinucleotide (TG:CA)(n) repeats are one of the most abundant in human genome and exhibit polymorphism. Early on, it was observed that the (TG:CA)(n) repeats could modulate gene expression and has the propensity to undergo conformational transitions in in vivo conditions. Recent reports describe the role of polymorphic (TG:CA)(n) repeats in gene regulation in several genes. In this work, we have analysed the distribution of (TG:CA)(n) (n >or= 6) repeats in human 'housekeeping genes' on which recently released Gene Chip data is available. Our results indicate that (i). The number of short intragenic (TG:CA)(n) repeats is significantly higher than the number of long repeats (ii). the proportion of genes with (TG:CA)(n) repeats (n >or= 12 units) had lower mean expression levels compared to those without these repeats, (iii). the genes belonging to the functional class of 'signalling and communication' had a positive association with repeats in contrast to the genes belonging to the 'information' class that were negatively associated with repeats.
authors.affiliation: G N Ramachandran Knowledge Centre for Genome Informatics, Institute of Genomics and Integrative Biology, Mall Road, Delhi 110 007, India.
authors.forename: Vineet K
authors.initials: VK
authors.lastname: Sharma
authors.forename: Chandrika
authors.initials: C
authors.lastname: B-Rao
authors.forename: Anu
authors.initials: A
authors.lastname: Sharma
authors.forename: Samir K
authors.initials: SK
authors.lastname: Brahmachari
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Ramachandran
mesh_terms: D001482:Base Composition; D030561:Databases, Nucleic Acid; D018900:Dinucleotide Repeats; D020869:Gene Expression Profiling; D015894:Genome, Human; D006801:Humans; D011110:Polymorphism, Genetic