Mutation in sequenced strain: frameshift (-2) (see FBrf0218054).
There is a 2 base deletion in Cby in iso-1, the reference sequence strain relative to wild type strains. Two bases (AT) are missing between 3R:21868609 and 3R:21868610 in iso-1. This leads to a frameshift after codon 120 and early translation termination after the addition of 5 novel amino acids.