The draft genome of sweet orange (Citrus sinensis).

Document Type


Publication Date



Chimera, Chromosome Mapping, Citrus sinensis, Cluster Analysis, Computational Biology, Evolution, Molecular, Gene Expression Profiling, Gene Expression Regulation, Plant, Gene Order, Genome, Plant, Heterozygote, High-Throughput Nucleotide Sequencing, Molecular Sequence Data, Phylogeny, Vitamins

JAX Source

Nat Genet 2013 Jan; 45(1):59-66.




Oranges are an important nutritional source for human health and have immense economic value. Here we present a comprehensive analysis of the draft genome of sweet orange (Citrus sinensis). The assembled sequence covers 87.3% of the estimated orange genome, which is relatively compact, as 20% is composed of repetitive elements. We predicted 29,445 protein-coding genes, half of which are in the heterozygous state. With additional sequencing of two more citrus species and comparative analyses of seven citrus genomes, we present evidence to suggest that sweet orange originated from a backcross hybrid between pummelo and mandarin. Focused analysis on genes involved in vitamin C metabolism showed that GalUR, encoding the rate-limiting enzyme of the galacturonate pathway, is significantly upregulated in orange fruit, and the recent expansion of this gene family may provide a genomic basis. This draft genome represents a valuable resource for understanding and improving many important citrus traits in the future. Nat Genet 2013 Jan; 45(1):59-66.