Large-Scale Periodicities in the Nucleotide Sequences of Drosophila Early Developmental Gene Loci

Resumo

An improved Fourier analysis and wavelet transform revealed a large-scale periodicity in the locations of sites with a characteristic local AT–GC composition in the nucleotide sequences of Drosophila early developmental genes. A localization of periodic locus sections indicated that they predominantly occur in transcription regulation modules (enhancers). The period lengths observed in ranges of 80–85, 165–180, and 330–400 nt agree well with the lengths typical of the nucleosomal level of chromatin organization. The harmonic periods in a range of 600–750 nt are approximately four nucleosomal repeats and are close to the minimum enhancer length typical of the Drosophila genome.