Theoretical Estimation of Nucleosome Density for Gene Sequences of Different Orthologs upon Euchromatic and Heterochromatic Locations
Institute of Molecular Genetics, Russian Academy of Science, Kurchatov Sq., 2, Moscow, 123182
Abstract. A comparison is carried out for orthologs of some genes localized at heterochromatic and euchromatic portions in different Drosophila species by using computer methods for calculation of nucleosome preference and estimation of cluster dimensions of the preference and their inter-distances. It was elucidated that average level of nucleosome location is lower in the case of euchromatin as well as specters of linear dimensions of nucleosome preference are different. In the case of heterochromatin location light, concertina genes incorporate introns that are enriched by short regions of strong nucleosome preferences. The presence of large peaks of nucleosome binding is associated with the numerous repeats of LINE and LTR classes in the introns of heterochromatic gene whereas euchromatic ortholog doesn’t include corresponding repeats and so long introns. In the latter case the local peaks characteristic of nucleosome binding potential are fussy and of smaller amplitude. Upon the heterochromatin location concertina gene characterized by the highest average signal of the nucleosome positioning expresses at the embryonic stage, while light gene with lower average value is viable for different stages of fly development.
Key words: nucleosome location, orthologs, exon-intron structure.