JCS003186 Supplementary Material

Files in this Data Supplement:

• Supplemental Table S1 -

  Adobe PDF

• Supplemental Figure 1 -

  Fig. S1. Identification and reconstruction of cohesin axes in Sycp3^-/- oocytes. (A,E,I,M) Merged images of the REC8 and FISH signals of four different oocytes. The numbers in these panels represent the chromosome numbers, as identified by the size and color of the FISH signals. (B,F,J,N) Cutouts of analyzable bivalents in these images, including the FISH signals. Other analyzable FISH-labeled bivalents in panels I and M are indicated by arrowheads. Most of the chromosomes 1, 2, 18 and 19 were not analyzable, because we were unable to discriminate between two chromosomes with the same FISH-label color (panel I, chromosomes 1/19), or the cohesin axes could not be traced unambiguously (panel M, chromosomes 1 and 19; panel E, chromosomes 1 and 2), or because the ends of their cohesin axes could not be identified (panel A, chromosomes 1 and 19; panel E, chromosome 19), or combinations of these (e.g. chromosome 18 in panel A: the axes could not be traced and the ends could not be identified). (C,G,K,O) The same cutouts as B,F,J and N, but excluding the FISH signals, and including the MLH1 and SYCP1 signals. SYCP1 was always found on converged cohesin axes; regions of synapsis are visible as pink stretches of converged cohesin axes in these panels. (D,H,L,P) Reconstructions of the cohesin axes of the relevant bivalents. (Q,R) Two possible interpretations of the gaps between the REC8 signals. If the gaps were due to breakage of the cohesin axes (Q), possibly as a result of the spreading conditions, then the gaps should not be included in the measurements. However, if the gaps were due to a discontinuous localization of REC8 to chromosomal axes that are themselves continuous (R), we should include the gaps between the cohesin fragments in the length measurements. Because the lengths of homologous unsynapsed stretches should be the same (x and x’ in Q and R), and therefore, we compared sutch stretches for a series of 11 individual bivalents where we could unambiguously trace the homologous unsynapsed stretches. In all cases the length differences between the homologous stretches were smaller if we excluded the gaps (Supplementary material Table S1). We therefore excluded the gaps between the cohesin fragments in all our measurements. Bars, 10 μm.