Fig 1.
The flycatcher pedigree and illustration of crossover detection.
(a) The three-generation pedigree used in this study. (b) Schematic illustration of phasing. A SNP can be phased when the grandparental genotypes differ from each other (either because they are homozygous for different alleles, or one is homozygous and the other is heterozygous) and the F1 is heterozygous. If the phase can be traced also in the F2 generation, it is possible to pinpoint recombination events in the F1 gametes. (c) Haploblocks identified in the five largest chromosomes in one male F2 offspring. The left chromosome in each pair represents the paternally transmitted chromosome and the right the maternally transmitted chromosome. Light blue is the contribution from the paternal grandfather, green the paternal grandmother, orange the maternal grandfather, and red the maternal grandmother. Note that the Z chromosome does not recombine in female meiosis, with the exception of in the pseudoautosomal region (PAR, insert).
Fig 2.
The relationship between chromosome size and crossover rate.
The figure shows the sex-average crossover rate per chromosome.
Table 1.
Recombination distance per chromosome calculated from the number of observed recombination events in the pedigree and linkage map length from the corresponding chromosomes.
Linkage map data are from Kawakami et al. [55] and refer to the sex-average best-order map length per chromosome.
Fig 3.
Distribution of the number of crossover events in relation to distance to nearest chromosome end.
(a) chromosomes >100 Mb (males, black; female, white) and chromosomes 50–100 Mb (males, grey; females dotted) for 10 Mb intervals, and (b) the terminal 10 Mb of all chromosomes in 1 Mb intervals (males, black; female, white).
Fig 4.
Mean crossover interference in relation to the distance of double crossovers.
Interference was measured as the coefficient of coincidence (CoC). The horizontal dashed line at a CoC of 1 indicates an interference of 0.
Fig 5.
The association between recombination and genes.
(a) Distribution of recombination events in relation to distance to the closest gene. The large bar at position 0 represents the number of events overlapping with genes. (b) Density of CO events in different sequence categories of genes, and in intergenic DNA. c) Density of NCO events in different sequence categories of genes, and in intergenic DNA.