Fig. 1

Modification of dADD1 expression levels results in chromosomal disorganization. a Polytene chromosome squash from a wild-type organism. DNA was stained with DAPI (shown in gray), arrows point to telomeric regions, the chromocenter is shown within the dashed box a’) magnification of the chromocenter, a”) magnification of the telomeres. b Polytene chromosome squash from salivary glands in which over-expression of dADD1 isoform was performed using the UAS-GAL4 system, as in “a” arrows point to telomeric regions and the chromocenter is in the dashed box, b’) magnification of the chromocenter, b”) magnification of a telomeric region. Scale bar 20 μm. c Semi-quantitative analysis of the transcript levels of dADD1 isoforms in salivary glands. Lanes in the gel correspond to 1) wild-type, 2) H₂O, 3) UAS-dadd1; Sgs3-GAL4 genotypes. Rp49 transcript was used as a control. Note that all transcripts isoforms are overexpressed (compare lanes 1 to 3). d Western blot from total protein extracts from salivary glands where pan-dADD1 and anti-β tubulin antibodies were used. Lanes correspond to 1) wild-type and 3) UAS-dadd1; Sgs3-GAL4, molecular weight markers are shown on the left side of the panels. On the right side of the panels, the antibodies used for each membrane are specified. e Schematic representation of the dADD1 protein isoforms. The ADD domain shared by all isoforms is shown in green; a dashed line delimits the common region. MADF domains of the dADD1b and c isoforms are shown in blue. dADD1a is 1199 aa long (130 kDa), dADD1b is 1125 aa (127 kDa) and dADD1c is 979 aa (112 kDa)