Figure 6. Two or more symmetric DSBs can be sufficient for synapsis.

The probability of less than one symmetric DSB per chromosome is ~4 times lower than the asynapsis rate observed in PB6F₁ hybrid males (i.e. the estimate of probability of asynapsis), implying that ~75% of all asynapsis occurs when there is one or more repairable DSBs. The probability of less than two symmetric DSBs is a good estimate of the probability of asynapsis, whereas the probability of less than three symmetric DSBs overestimates the probability of asynapsis. This shows that, in the simplest explanation, two or more symmetric DSBs could be sufficient for synapsis. The probabilistic distribution of symmetric DSBs is calculated on the basis of the model described in the 'Discussion'.

Figure 6—figure supplement 1. Two and more DSBs within symmetric hotspots can be sufficient for synapsis in 2-chr cross males.

See Figure 6 for details.

Figure 6—figure supplement 2. Two or more DSBs within symmetric hotspots can be sufficient for synapsis in 4-chr cross hybrid males.

See Figure 6 for details.