Expression of 2 splice variants of the FANCD2 gene. (A) Schematic representation of 2 splice variants of FANCD2. A 24–amino acid (aa) sequence, containing 50% acidic residues, is encoded by exon 44 sequence. (B) Detection of FANCD2-44 and FANCD2-43 mRNAs by RT-PCR in various FA cell lines. (C) Detection of FANCD2-44 and FANCD2-43 mRNAs by RT-PCR throughout the cell cycle or following exposure to MMC. The indicated primer pairs (A) were used to amplify the alternatively spliced mRNAs. The mRNA was prepared from either uncorrected lymphoblasts from the indicated FA subtypes, from cells in different stages of the cell cycle, or following exposure to MMC. Ub indicates ubiquitin.