Fig 1.
Plumage patterns of an adult non-spot(A) and spot(B) phenotype.
Fig 2.
The phylogeny tree of endothelin receptors amino acid sequences.
The Neighbor-Joining(NJ) method of MEGA6.0 was used to construct the phylogeny tree. The number at the branches denotes the bootstrap majority consensus values on 1000 replicates, the branch lengths represent the relative genetic distance among these species.
Fig 3.
Chromatogram of EDNRB2 DNA with different genotypes.
(A) homozygous for the non-spot individuals; (B) homozygous for the spot individuals; (C) heterozygous for the non-spot individuals. The respective amino acids are shown above the second base pair for the homozygous sequences. The different amino acid are indicated in red, the amino acid sequence at the position 314 and 332 are indicated with bold fonts. The nucleotide mutations are underlined.
Fig 4.
Non-synonymous substitutions in the deduced protein of duck EDNRB2.
(A) Schematic diagram representing duck EDNRB2. Prediction of the secondary protein structure was obtained using online website ExPASy (http://www.expasy.org/vg/index/Protein). The extracellular and intracellular loops are shown as white boxes. The seven transmembrane domains are indicated as green boxes. Non-synonymous mutations identified in chicken [13], Japanese quail [14] and duck (in this study) are marked at the corresponding position. (B) Multiple sequence alignment of partial EDNR receptors. * Indicates amino acid identity. V314M and R332H mutations are indicated in red color.
Fig 5.
Polymorphism analyses of EDNRB2 gene in non-spot and spot ducks.
(A) SfaNI-PCR-RFLP analysis for the c.995G>A site. M1, molecular marker (low ladder); lane 1, GG genotype; lanes 2 to 4, GA genotype; lane 5, AA genotype. (B) NlaIII-PCR- RFLP analysis for the c.940 G>A site. M2, molecular marker (marker I); lane 1, AA genotype; lane 2, GA genotype; lanes 3 to 5, GG genotype.
Table 1.
Association analyses between duck plumage pattern phenotypes and EDNRB2 genotypes.
Table 2.
Segregation ratios of duck plumage pattern phenotypes in offspring of mating tests.
Fig 6.
The amplified product results of duck genes.
Amplification of genes from different sources, (A) MITF (B)TYR (C) TYRP1 and (D) β-actin gene, Lanes 1 to 6: cDNA obtained from non-spot duck, Lanes 7 to 12: cDNA obtained from spot duck. cDNA from different area of the duck body, lanes 1 and 7: mantle; lanes 2 and 8: rump; lanes 3 and 9: breast; lanes 4 and 10: abdomen; lanes 5 and 11, the proximal part of the wings; lanes 6 and 12, the distal part of the wings; lane 13, negative control. β-actin gene was used as reference.