RT Journal A1 Wu, Jun A1 Wang, Zhiwen A1 Shi, Zebin A1 Zhang, Shu A1 Ming, Ray A1 Zhu, Shilin A1 Khan, M. Awais A1 Tao, Shutian A1 Korban, Schuyler S. A1 Wang, Hao A1 Chen, Nancy J. A1 Nishio, Takeshi A1 Xu, Xun A1 Cong, Lin A1 Qi, Kaijie A1 Huang, Xiaosan A1 Wang, Yingtao A1 Zhao, Xiang A1 Wu, Juyou A1 Deng, Cao A1 Gou, Caiyun A1 Zhou, Weili A1 Yin, Hao A1 Qin, Gaihua A1 Sha, Yuhui A1 Tao, Ye A1 Chen, Hui A1 Yang, Yanan A1 Song, Yue A1 Zhan, Dongliang A1 Wang, Juan A1 Li, Leiting A1 Dai, Meisong A1 Gu, Chao A1 Wang, Yuezhi A1 Shi, Daihu A1 Wang, Xiaowei A1 Zhang, Huping A1 Zeng, Liang A1 Zheng, Danman A1 Wang, Chunlei A1 Chen, Maoshan A1 Wang, Guangbiao A1 Xie, Lin A1 Sovero, Valpuri A1 Sha, Shoufeng A1 Huang, Wenjiang A1 Zhang, Shujun A1 Zhang, Mingyue A1 Sun, Jiangmei A1 Xu, Linlin A1 Li, Yuan A1 Liu, Xing A1 Li, Qingsong A1 Shen, Jiahui A1 Wang, Junyi A1 Paull, Robert E. A1 Bennetzen, Jeffrey L. A1 Wang, Jun A1 Zhang, Shaoling T1 The genome of the pear (Pyrus bretschneideri Rehd.) JF Genome Research JO Genome Research YR 2013 FD February 01 VO 23 IS 2 SP 396 OP 408 DO 10.1101/gr.144311.112 UL http://genome.cshlp.org/content/23/2/396.abstract AB The draft genome of the pear (Pyrus bretschneideri) using a combination of BAC-by-BAC and next-generation sequencing is reported. A 512.0-Mb sequence corresponding to 97.1% of the estimated genome size of this highly heterozygous species is assembled with 194× coverage. High-density genetic maps comprising 2005 SNP markers anchored 75.5% of the sequence to all 17 chromosomes. The pear genome encodes 42,812 protein-coding genes, and of these, ∼28.5% encode multiple isoforms. Repetitive sequences of 271.9 Mb in length, accounting for 53.1% of the pear genome, are identified. Simulation of eudicots to the ancestor of Rosaceae has reconstructed nine ancestral chromosomes. Pear and apple diverged from each other ∼5.4–21.5 million years ago, and a recent whole-genome duplication (WGD) event must have occurred 30–45 MYA prior to their divergence, but following divergence from strawberry. When compared with the apple genome sequence, size differences between the apple and pear genomes are confirmed mainly due to the presence of repetitive sequences predominantly contributed by transposable elements (TEs), while genic regions are similar in both species. Genes critical for self-incompatibility, lignified stone cells (a unique feature of pear fruit), sorbitol metabolism, and volatile compounds of fruit have also been identified. Multiple candidate SFB genes appear as tandem repeats in the S-locus region of pear; while lignin synthesis-related gene family expansion and highly expressed gene families of HCT, C3′H, and CCOMT contribute to high accumulation of both G-lignin and S-lignin. Moreover, alpha-linolenic acid metabolism is a key pathway for aroma in pear fruit.