Fraxinus excelsior Assembly and Gene Annotation

About Fraxinus excelsior

Ash trees (genus Fraxinus, family Oleaceae) are widespread throughout the Northern Hemisphere, but are being devastated in Europe by the fungus Hymenoscyphus fraxineus, causing ash dieback, and in North America by the herbivorous beetle Agrilus planipennis.

Assembly

European ash (F. excelsior) was sequenced from a tree generated from self-pollination of a woodland tree in Gloucestershire, UK. The sequenced tree (Earth Trust accession number 2451S) appeared free of ash dieback (ADB) when sampled in 2013 and 2014, but showed symptoms in February 2016. The haploid genome size was measured by flow cytometry as 877.24 ± 1.41 megabase pairs (Mbp). Total genomic DNA was sequenced to 192× coverage. We assembled the genome into 89,514 nuclear scaffolds with an N50 (the length at which scaffolds include half the bases of the assembly) of 104 kilobase pairs (kbp), 26 mitochondrial scaffolds, and one plastid chromosome, where the non-N assembly constitutes 80.5% of the predicted genome size.

Annotation

Genome was annotated using an evidence-based workflow incorporating protein and RNA-seq data, predicting 38,852 protein-coding genes and 50,743 transcripts

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Picture credit: Wikipedia