Variations in endothelin receptor B subtype 2 (EDNRB2) coding sequences and mRNA expression levels in 4 Muscovy duck plumage colour phenotypes

Abstract

1. Endothelin receptor B subtype 2 (EDNRB2) is a paralog of EDNRB, which encodes a 7-transmembrane G-protein coupled receptor. Previous studies reported that EDNRB was essential for melanoblast migration in mammals and ducks. 2. Muscovy ducks have different plumage colour phenotypes. Variations in EDNRB2 coding sequences (CDSs) and mRNA expression levels were investigated in 4 different Muscovy duck plumage colour phenotypes, including black, black mutant, silver and white head. 3. The EDNRB2 gene from Muscovy duck was cloned; it had a length of 6435 bp and encoded 437 amino acids. The coding region was screened and potential single nucleotide polymorphisms were identified. Eight mutations were obtained, including one missense variant (c.64C > T) and 7 synonymous substitutions. The substitutions were associated with plumage colour phenotypes. 4. The EDNRB2 mRNA expression levels were compared between feather pulp from black birds and black mutant birds. The results indicated that EDNRB2 transcripts in feather pulp were significantly higher in black feathers than in white feathers. 5. The results determined the variation of EDNRB2 CDS and mRNA expression in Muscovy ducks of various plumage colours.

Effects of polymorphisms in the endothelin receptor B <i>subtype 2</i> gene on plumage colour in mule ducks

“…Whether the paternal A allele from Muscovy drakes also has an impact on white plumage coloration in its offspring remains to be elucidated. However, no similar SNPs and amino acid substitutions were found in EDNRB2 gene in domestic ducks (Anas platyrhynchos) and Muscovy drakes (Wu et al, 2017). These findings indicate that the EDNRB2 gene polymorphism that has associated with plumage colour in Muscovy drakes is completely different from domestic ducks (Li et al, 2015).…”

“…Over the past few years, only two studies have reported findings on the association between the polymorphism of EDNRB2 gene and plumage colour in duck species (Li et al, 2015;Wu et al, 2017). It has been reported that the domestic ducks (Anas platyrhynchos) from a cross between white Kaiya and the white Liancheng duck with spot phenotype displayed predominant AA genotype of c.995G>A SNP (Li et al, 2015).…”

“…Single nucleotide polymorphism variations in the EDNRB2 gene influence plumage colour in avian species (Miwa et al, 2007;Kinoshita et al, 2014;Li et al, 2015;Wu et al, 2017). It has been reported that Cys244Phe and Arg332His amino acid substitutions in the EDNRB2 gene are associated with plumage colour in Japanese native chickens (Kinoshita et al, 2014), Japanese quail (Miwa et al, 2007), and common ducks (Anas platyrhynchos) (Li et al, 2015).…”

“…It has been reported that Cys244Phe and Arg332His amino acid substitutions in the EDNRB2 gene are associated with plumage colour in Japanese native chickens (Kinoshita et al, 2014), Japanese quail (Miwa et al, 2007), and common ducks (Anas platyrhynchos) (Li et al, 2015). In Muscovy drakes (Cairina moschata), the SNPs in EDNRB2 gene that are associated with plumage colour differ from other avian species (Wu et al, 2017). However, little is known about the relationship between EDNRB2 gene polymorphisms and plumage coloration in intergeneric hybrids.…”

“…The authors' recent study demonstrated that maternal melanocortin 1 receptor SNP genotypes have a significant influence on white plumage coloration in mule ducks (Tu et al, 2019). Previous studies demonstrated that polymorphisms of EDNRB2 gene are associated with plumage coloration in avian species (Miwa et al, 2007;Kinoshita et al, 2014), including the parental lines of the mule duck (Li et al, 2015;Wu et al, 2017). However, the potential association between EDNRB2 gene and plumage colour phenotypes in intergeneric hybrids such as mule ducks has not been validated.…”