Cloning and Characterizing the 2RJ Inversion Breakpoints in the Malaria Vector Anopheles Gambiae S.S.

A BAC clone already known to map to the vicinity of the proximal breakpoints the 2Rj+ (standard) was used as a starting material to identify the 2Rj (inverted) breakpoints in Bamako chromosomal form. The 2Rj distal and proximal breakpoints have been identified, cloned and sequenced. The structure of the breakpoints showed that it is more that a simple cut and flip. A 14.6 kb insertion at each breakpoint but opposite orientation has been identified. This fragment is made of two almost perfect 5.3kb inverted repeats separated by a 4 kb section and is structurally very similar to type 3 fold back transposable elements. Sequence analysis of the flanking regions of the breakpoints revealed the presence of four genes. However we found no evidence of interrupted transcripts by the inversion breaks. A simple PCR assay was designed to diagnose the 2Rj inversion.