Identification and Sequencing of a BAC Clone Belonging to the Phaseolus vulgaris (L.) Insecticidial Arc4 lectin locus

The BAC library, consisting of 30,720 clones, was screened by PCR and filter hybridization. Thirty-nine positive clones were selected and analysed in order to identify overlapping BAC clones necessary to represent the entire APA locus. Preliminary results revealed that the complete locus is covered by at least three or four overlapping BAC clones. One of these clones (P58-F18) was chosen and sequenced. Putative coding sequences were predicted using FGENESH (http://www.softberry.com) and TWINSCAN (http://genes.cs.wustl.edu/) while repeated DNA sequences and microsatellites were identified using Tandem Repeats Finder Program (http://tandem.bu.edu/) and Sputnik Program (http://espressosoftware.com/pages/sputnik.jsp) respectively. The BAC clone P58-F18 has an insert of about 130 Kb and sequencing data show that, besides many repetitive DNA sequences, microsatellites and retrotrasposons, it contains three full CDS for PHA-L, ARC4-I, ARL4 (Lioi et al. 2003) and a new gene sharing 87% of similarity with ARL4 (called ARL4-I). In addition, several interrupted lectin and arcelin related sequences were also found.