Figure 1.
An animal of the dual-purpose Fleckvieh breed with ambilateral circumocular pigmentation.
A white head is characteristic for animals of the Fleckvieh (FV) breed. However, in some half-sib families animals with pigmented skin around the eyes prevail. The pigmentation is restricted to the circumocular area and is not connected to the body pigmentation. Although there is variation regarding both the dimension and shape of ambilateral circumocular pigmentation (ACOP) in FV cattle, ACOP is routinely assessed as categorical trait only. The figure was kindly supplied by BAYERN-GENETIK GmbH (http://www.fleckvieh.de).
Figure 2.
Manhattan plot of association of 658,385 SNPs with the proportion of daughters with ambilateral circumocular pigmentation in 3579 bulls of the Fleckvieh breed.
The chromosomes are separated with alternating colours. Orange and red dots indicate chromosome-wide and genome-wide (P<7.59×10−8) significantly associated SNPs, respectively. The vertical axis is truncated for P values below -log10(10–41). Twelve identified QTL regions are indicated with arrows and gene identifiers.
Table 1.
The most significantly associated SNP for each of the twelve identified QTL regions for ambilateral circumocular pigmentation in the Fleckvieh breed.
Table 2.
The most significantly associated SNPs on chromosomes 6 and 22 after analysis conditional on the top SNP.
Figure 3.
The effect of 14 significantly associated SNPs on the proportion of daughters with ambilateral circumocular pigmentation.
3579 Fleckvieh animals are grouped according to the number of alleles that predispose to ambilateral circumocular pigmentation (ACOP). The blue boxplots represent the proportion of daughters with ACOP for each group. The grey bars indicate the number of sires with an increasing number of predisposing alleles.
Figure 4.
Chromosomal partitioning of the phenotypic variance.
The grey and blue bars indicate the fraction of phenotypic variance attributed to a particular chromosome and QTL region, respectively. The triangles represent the cumulative proportion of phenotypic variance attributable to the 30 chromosomes.
Table 3.
Proportion of phenotypic variance attributable to the twelve identified QTL regions.