The genome organization of Drosophila melanogaster and mammals exhibits significant differences in terms of size, complexity, and repetitive sequences, reflecting their evolutionary divergence and functional requirements. Drosophila, a model organism extensively used in genetics, has a relatively compact genome of approximately 180 million base pairs, organized into four pairs of chromosomes: three autosomes and one pair of sex chromosomes. Its genome is highly gene-dense, with minimal non-coding DNA compared to mammals. Most of the Drosophila genome consists of euchromatin, which is transcriptionally active, while heterochromatin is restricted to centromeric and telomeric regions. Gene clustering in Drosophila is often functionally significant, with co-expressed genes sometimes forming operon-like structures, and introns are generally short, allowing efficient transcription. In contrast, mammalian genomes, such as those of humans and mice, are considerably larger, ranging from