ntly several reports have described the generation of large scale transcriptome sequences in cucurbit spe cies using next generation sequencing technologies, including melon, cucumber, and Cucurbita pepo. Although sequences generated under these efforts are much shorter than traditional Sanger ESTs, they represent inhibitor purchase a significant expansion of cucurbit functional genomics resources. We undertook to expand the melon transcript catalog in the framework of the International Cucurbit Genome Initiative, which was established in 2005, being one of its major objectives to sequence approximately 100,000 ESTs from different melon genotypes and tissues. We have constructed eleven full length enriched cDNA Inhibitors,Modulators,Libraries libraries and four standard cDNA libraries from various melon tissues and cultivars and generated 94,000 ESTs.
These melon ESTs were analyzed to determine the structure and putative functions of the correspond ing transcripts. In addition, a number Inhibitors,Modulators,Libraries of new SSR and SNP markers were identified in this EST collection. All of this data has been integrated in the Cucurbit Geno mics Database. The ESTs generated from the pre sent study, especially those from full length enriched cDNA libraries, will be a useful resource for the ongoing melon whole genome sequencing project and for char acterizing gene expression patterns and traits of interest in melon and closely related species. Results and discussion Construction and sequencing of melon cDNA libraries We constructed eleven full length enriched and four standard cDNA libraries from various melon tissues and culti vars under normal conditions or upon infection with melon necrotic spot virus Ma5.
The flower, fruit and callus libraries were derived from two climacteric and two non climac teric cultivars. For the flower and fruit, RNA pools were prepared from various developmental stages. The leaf, root and cotyledon libraries were constructed from Inhibitors,Modulators,Libraries tis sues infected with MNSV Ma5. EST Inhibitors,Modulators,Libraries sequencing was carried out independently on full length enriched and standard cDNA clones. For full length enriched cDNA libraries, 70,576 randomly selected clones were sequenced from the 5 end, producing 69,196 use ful reads after trimming vector, adaptor and low quality sequences and identifying and removing all possible contaminated sequences. Assembly of these ESTs pro duced 6,469 clusters, among which 2,721 non redundant clones were selected for 3 end sequencing, Brefeldin_A yielding a total of 2,381 high quality 3 reads.
For the four standard callus libraries, 26,112 randomly selected clones were sequenced from the 5 end, generating 22,179 high quality EST sequences. In total, we have generated 93,756 high quality melon ESTs from the constructed cDNA libraries and the aver age length of these ESTs is 629. 6 bp. The EST sequences have been deposited in GenBank and are sellectchem also available at the Cucurbit Genomics Database. Melon EST sequence assembly and annotation The 93,756 high quality melon ESTs generated under this study, together with 35,000 ES