A chromosome-level genome assembly of the Tristram's Bunting (Emberiza tristrami)

Emberiza tristrami (Tristram’s bunting) is a migratory passerine within the genus Emberiza, a taxonomic group that has undergone rapid diversification despite broadly conserved avian karyotypes. Here, we present the first high-quality, chromosome-level reference genome for E. tristrami, generated using PacBio HiFi long reads combined with Hi-C sequencing. The final assembly spans 1.33 Gb, with a contig N50 of 22.42 Mb and a scaffold N50 of 64.94 Mb. Hi-C scaffolding anchored 1.23 Gb (92.46%) of assembled sequences into 40 pseudochromosomes, consistent with the known karyotype of the species. We annotated 17,401 protein-coding genes and identified 427.25 Mb of repetitive sequences, accounting for 32.09% of the genome. Genome completeness was assessed using BUSCO (passeriformes_odb10), recovering 99.3% of expected single-copy orthologs in genome mode and 91.7% in gene annotation mode, indicating a highly complete assembly and annotation. This chromosome-level genome provides a foundational resource for comparative analyses within Emberiza and other passerines, enabling investigations into chromosome evolution, repeat dynamics, and lineage-specific genomic features associated with rapid species radiation and ecological differentiation.