Supplemental Material for de Lima, Hanlon, and Gerton, 2020
Figures are generally photos, graphs and static images that would be represented in traditional pdf publications.
Satellite DNAs (satDNAs) are a ubiquitous feature of eukaryotic genomes and are usually the major components of constitutive heterochromatin. The 1.688satDNA, also known as the 359 bp satellite, is one of the most abundant repetitive sequences in Drosophila melanogasterand has been linked to several different biological functions. We investigated the presence and evolution of the 1.688satDNA in 16 Drosophilagenomes. We find that the 1.688satDNA family is much more ancient than previously appreciated, being shared amongst part of the melanogastergroup that diverged from a common ancestor ~27 Mya. We found that the 1.688satDNA family has two major subfamilies spread throughout Drosophilaphylogeny (~360 bp and ~190 bp). Phylogenetic analysis of ~10,000 repeats extracted from 14 of the species revealed that the 1.688satDNA family is present within heterochromatin and euchromatin. A high number of euchromatic repeats are gene proximal, suggesting the potential for local gene regulation. Notably, heterochromatic copies display concerted evolution and a species-specific pattern, whereas euchromatic repeats display a more typical evolutionary pattern, suggesting that chromatin domains may influence the evolution of these sequences. Overall, our data indicate the 1.688satDNA as the most perduring satDNA family described in Drosophilaphylogeny to date. Our study provides a strong foundation for future work on the functional roles of 1.688satDNA across many Drosophila species.