Plant & Animal Genomes XV Conference Plant & Animal Genomes XV ConferenceJanuary 13-17, 2007
Town & Country Convention Center
San Diego, CA
Javier Terol , Miguel A Naranjo , Manuel Talon
Three genomic BAC libraries from Citrus clementina (cv clemenules) were constructed using three different restriction enzymes (EcoRI, BamHI, HindIII). 56.000 clones (18x coverage of the Citrus genome) were picked. A total of 28000 BAC clones were selected for BAC-end sequencing, producing 46339 high quality readings. The number of BAC clones that had both ends sequenced was 22118, representing 7,3 genomic equivalents.
More than 28,7 Mb were sequenced, and after filtration of sequences for repeats (Repeatmasker) and chloroplastic DNA (BLASTN), 38503 useful readings were obtained. Assembly with CAP3 produced 25907 unique sequences, corresponding to 19 Mb of genomic DNA.
Annotation was based on BLASTX searches against GenBank refseq and TAIR protein databases. A significant number of sequences presented low similarities with respect different types of transposible elements and retroviruses, indicating that the portion of repetitive sequences could be as high as 30% of the total. These sequences might correspond to Citrus specific transposible elements.
Aproximately 40500 ESTs from different Citrus species were mapped on 7832 BAC clones, showing the presence of coding regions in the 8290 genomic sequences derived from these clones. More than 7600 SSRs were identified with the software Sputnik, that will be explored as potential markers for physical and genetical mapping in Citrus.