Satellite DNAs are tandemly repeated sequences preferentially clustered within constitutive heterochromatin. However, in some cases, they are found partially dispersed in the vicinity of genes within euchromatin.
Such mixed organization and interplay between repeats located within heterochromatin and euchromatin is proposed to be responsible for the gene-modulatory effect of satellite DNA which was first shown in the beetle Tribolium castaneum.
The primary aim of the proposed project is to investigate the gene-modulatory role of human alpha satellite DNA. Alpha satellite DNA is a major human satellite located in the (peri)centromeric regions of all human chromosome and is common for all primates. In addition to (peri)centromeric location, a bioinformatics search of the human genome reveals alpha satellite repeats dispersed within euchromatin, adjacent to genes, and points to a similar genomic organization of major Tribolium castaneum satellite and alpha satellite DNA.
Based on this observation it could be proposed that alpha satellite transcripts could induce an epigenetic mechanism that modifies chromatin at dispersed alpha satellite repeats, leading consequently to changes in the expression of nearby genes.
Using experimental approach, we plan to study influence of a major human alpha satellite DNA on the expression of adjacent genes as well as a molecular mechanism of its gene modulatory activity.
In addition, bioinformatics analysis and comparison of alpha satellite repeats dispersed within euchromatin of all sequenced primate genomes and characterization of their associated genes will be performed. Based on obtained data we expect to reveal the possible role of alpha satellite DNA in physiology and in the evolution of gene modulatory networks in primates.