Altered Cohesin Gene Dosage Affects Mammalian Meiotic Chromosome Structure and Behavior
Figure 2
Recombination levels are reduced in cohesion heterozygotes.
(A) The number of MLH1 foci in pachytene cells from Smc1b heterozygotes was significantly decreased by comparison with wild-type controls (mean MLH1 foci/cell ± SE = 25.0±0.25 and 27.9±0.25, respectively; t = 8.2; p<0.0001). Data represent 126 cells from 5 heterozygous females (grey bars) and 113 cells from 5 wild-type siblings (black bars). (B) A similar reduction was evident in Rec8 heterozygotes (mean MLH1 foci/cell ± SE = 26.6±0.26 and 28.7±0.28, respectively; t = 5.3; p<0.0001). Data represent 181 cells from 7 heterozygotes (grey bars) and 124 cells from 5 sibling controls (black bars). (C, D) SC length was also significantly decreased for both (C) Smc1b (mean ± SE = 186.7±1.18 µm for 126 cells from 5 heterozygotes (grey bars) and 211.7±1.05 µm for 113 cells from 5 controls (black bars); t = 7.2; p<0.0001) and (D) Rec8 heterozygotes (181.1±0.96 µm for 179 cells from 7 heterozygotes (grey bars) and 194.3±1.14 µm for 123 cells from 5 controls (black bars); t = 3.1; p<0.001).