Figure 4.

Telomere structure of dyskerin-mutated D. discoideum strains, (A) Telomere length was determined by PCR reaction using an oligonucleotide probe complementary to the A(G)n repeats of D. discoideum telomeres and another complementary to the close subtelomeric region. The migration of the amplification products obtained from DNA isolated from the wild-type (AX4) and mutant strains (Knockin-1 and -2) is shown for one experiment representative of the four made with similar results. The MW line shows the migration of the Ladder VII molecular weight marker (Nzytech, Lisbon, Portugal). The size of some of the markers is shown to the right. (B) Telomere structure was analyzed by Southern blot of DNAs obtained from AX4, knockin-1 or knockin-2 strains and either non-digested (−NheI) or digested with the NheI restriction enzyme (+NheI). The panel shows the results obtained after hybridization with a telomere-specific probe. (C) The blot shown in panel B was washed and hybridized with a probe complementary to the 26S rRNA. Arrows indicate specific hybridization bands obtained after NheI digestion. The migration of Ladder VII molecular weight marker (Nzytech, Lisbon, Portugal) is shown to the left of panels B and C.