Telomere anchoring in embryos depends on GEI-17, SUN-1, and POT-1. (A) RNAi in early embryos (20–60 cell stage) shows that SUN-1 but not LMN-1 anchors telomeres to the NE. Quantification is done as in Fig. 1. A single plane from a representative FISH-IF image is shown; lamin (Alexa Fluor 488) is marked in green and telomeres (Atto 647N) in red. During lmn-1 RNAi, the nuclear periphery was defined using the edge of the DAPI signal. (B) Telomere anchoring in embryos requires the telomere binding protein POT-1 but not POT-2. (C) Quantifying telomere position in L1 larvae shows that POT-1 is not required for telomere position in postmitotic muscle cells. (D) The PIAS-type E3 SUMO ligase GEI-17, but not the E3 SUMO ligase ZK1248.11, is required for telomere anchoring. The red dotted lines denote a hypothetical random distribution. *, P < 10−5 compared with a random distribution. All images were increased in size sevenfold using bilinear interpolation. The experiments shown in A, B, and D were conducted in parallel, and all comparisons are presented relative to the same control image.
