Table 1. The total length of SC and the number of MLH1 foci (mean  ±  S.D.) per cell in M. arvalis, M. levis and their F1 hybrids.

Genotype	n	SC length, μm	n	MLH1 foci number
M. arvalis, males	150	144.7 ± 14.8	150	27.6 ± 1.2
M. levis, males	64	150.9 ± 17.6	64	27.8 ± 1.4
M. levis, females	50	163.6 ± 21.2	58	28.8 ± 1.4
F1 hybrids, males	30	170.4 ± 24.2	50	0
F1 hybrids, females	30	168.7 ± 23.5	40	24.6 ± 2.9

n - number of cells examined.