The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D. erecta, D. mojavensis, and D. grimshawi F elements and euchromatic domains from the Muller D element. We find that F elements have greater transposon density (25–50%) than euchromatic reference regions (3–11%). Among the F elements, D. grimshawi has the lowest transposon density (particularly DINE-1: 2% vs. 11–27%). F element genes have larger coding spans, more coding exons, larger introns, and lower codon bias. Comparison of the Effective Number of Codons with the Codon Adaptation Index shows that, in contrast to the other species, codon bias in D. grimshawi F element genes can be attributed primarily to selection instead of mutational biases, suggesting that density and types of transposons affect the degree of local heterochromatin formation. F element genes have lower estimated DNA melting temperatures than D element genes, potentially facilitating transcription through heterochromatin. Most F element genes (~90%) have remained on that element, but the F element has smaller syntenic blocks than genome averages (3.4–3.6 vs. 8.4–8.8 genes per block), indicating greater rates of inversion despite lower rates of recombination. Overall, the F element has maintained characteristics that are distinct from other autosomes in the Drosophila lineage, illuminating the constraints imposed by a heterochromatic milieu.

The rich fabric of place names knitting together the Americas weaves into a complex intercultural network of naming practices that span thousands of years as well as the globe. Indigenous, European, and settler communities each bestowed names upon places near and far whose meanings describe the place, its resources, or one's experiences there. Names define the people who occupy a place. They commemorate an event or person in ways that evidence the gendered and racialized nature of place naming in the Americas, especially after 1492, through a predominately masculine lens. This study considers how women and people of color are represented in place names and the impacts of masculinist approaches to place nomenclature while contrasting Indigenous approaches to toponymy and the European reception of Indigenous place names in the Americas, with a focus on North America. KEYWORDS gender; race; place names; toponymy; North America; colonization RésuméLe tissu riche des noms des lieux qui lie les Amériques forme un réseau complexe et interculturel des pratiques d'établir les noms des lieux qui s'étend sur des milliers d'années aussi bien que sur le monde. Les communautés indigènes, européennes, et coloniales ont chacune donné des noms aux lieux de près ou de loin dont les significations décrivent le lieu, ses ressources, ou les expériences y vécues. Les noms définissent ceux qui occupent un lieu. Ils commémorent un événement ou une personne de manière de montrer la nature sexuée ou

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