OMIA:000142-9031 : Eggshell colour, blue in Gallus gallus (chicken)

In other species: ducks , Japanese quail

Categories: Pigmentation phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 605495 (gene) , 237450 (trait)

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal dominant

Considered a defect: no

Key variant known: yes

Year key variant first reported: 2013

Species-specific name: Oocyan

Species-specific symbol: O

History: This trait was first described as occurring in American Araucana chickens by Punnett (1933).

Inheritance: Punnett (1933) reported autosomal dominant inheritance for this trait.

Mapping: Wang et al. (2010) mapped this trait to a region from 67.3–69.1 Mb on chromosome GGA1 in the Dongxiang chicken breed. Wragg et al. (2012) refined the location in the native Chilean Mapuche fowl (the original source of the Araucana breed of North America and Europe) and in derivative European breeds to "two small regions (Gga 1:67.25–67.28 Mb, Gga 1:67.28–67.32 Mb) totalling ~75 Kb". Using linkage analysis in the candidate region on data from 146 F2 hens from a cross between homozygous blue and homozygous non-blue birds of the Dongxiang breed, Wang et al. (2013) refined the location to "a ~120 kb region from 67296991 bp to 67416784 bp on chromosome 1 on the UCSC chicken genome (May 2006 assembly)".

Molecular basis: The refined location determined by Wang et al. (2013) contains four positional candidate genes. Only one of these, SLCO1B3, is expressed in the shell gland of the uterus of blue-shelled hens but not in non-blue-shelled hens. Sequencing revealed the causal mutation to be "a ~4.2 kb [retroviral] EAV-HP insertion in the 5′ flanking region of SLCO1B3" (Wang et al., 2013). A genotyping survey of 38 chickens from two other breeds in which blue-eggshell segregates (Lushi and Araucana, the latter from North America) showed complete correlation of the presence/absence of the insertion mutation with blue-eggshell genotype. Eight other breeds in which blue eggshells do not appear were homozygous for the absence of the insertion mutation. Interestingly, the site of the insertion in the Araucana breed is 23bp upstream of the (identical) insertion site for the two Chinese breeds (Dongxiang and Lushi), indicating that the Chinese and American mutations arose independently (Wang et al., 2013). Later in the same year, Wragg et al. (2013) reported the same insertion mutation in native chickens of Chile (Mapuche fowl) and in European derivative breeds. Consistent with the Araucana breed having arisen from the Chilean Mapuche fowl, the insertion in these chickens is at the same location as reported by Wang et al. (2013) for the Araucana breed. Wragg et al. (2013) also confirmed the different site of insertion in Chinese breeds, thus confirming the independent occurrence of the insertion in native Chinese and native Chilean chickens. As noted by Wragg et al. (2013), the fact that all European breeds with blue eggshells have the Mapuche insertion site rather than the Chinese insertion site suggests "that the presence of blue eggs in Mapuche fowl, modern European and American breeds, did not involve birds from Asia". As also noted by Wragg et al. (2013), the fact that the insertion is not present in any of the jungle fowl species from which domestic chickens arose, and the near-identity of sequence of the Chinese and Chilean insertions, suggest that the insertions are recent, post-domestication events. Li et al. (2019) showed that "methylation of the promoter region of SLCO1B3 was significantly negatively correlated with both SLCO1B3 expression in the shell gland tissue and eggshell color. In addition, we predicted that CpG5 and CpG8 may be key sites for regulating SLCO1B3 gene transcription. Our findings show that as the level of methylation increases, methylation of the CpG5 and CpG8 sites hinders the binding of transcription factors to the promoter, reducing SLCO1B3 expression during the late period and resulting in a lighter eggshell color." Chen et al. (2020) "observed an alteration in the expression patterns of SLCO1B3 ... due to the retroviral EAV-HP insertion in different genotypes and sexes of blue-eggshell Yimeng chickens." Chen and Wang (2022): "did not detect the EAV-HP in BGC [blue-greenish coloration] samples of [Lueyang black-boned chicken] LBC, but found a strong positive correlation between SLCO1B3 expression levels in shell glands and eggshell biliverdin concentration." The authors propose "a new molecular mechanism that single nucleotide variants at the promoter region of SLCO1B3 can alter gene expression and result in chicken BGC." Altgilbers et al. (2022) "demonstrated that after testing multiple gRNAs, one CRISPR/Cas9 guide pairing successfully eliminated the entire provirus (EAV-HP) on chromosome 1 in male chicken cell lines carrying the blue allele." This study involves genetically modified organisms (GMO).

Breeds: Araucana (Chicken) (VBO_0000445), Crèvecoeur (Chicken) (VBO_0000517), Dong, an chicken, China (Chicken) (VBO_0006672), Gallina Mapuche, Argentina (Chicken) (VBO_0006532), Legbar (Chicken) (VBO_0000559), Lueyang, China (Chicken) (VBO_0006723), Lushi, China (Chicken) (VBO_0006725), Yimeng Blue, China (Chicken) (VBO_0016867).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
SLCO1B3 Gallus gallus 1 NC_052532.1 (65222023..65245482) SLCO1B3 Homologene, Ensembl , NCBI gene


By default, variants are sorted chronologically by year of publication, to provide a historical perspective. Readers can re-sort on any column by clicking on the column header. Click it again to sort in a descending order. To create a multiple-field sort, hold down Shift while clicking on the second, third etc relevant column headers.

WARNING! Inclusion of a variant in this table does not automatically mean that it should be used for DNA testing. Anyone contemplating the use of any of these variants for DNA testing should examine critically the relevant evidence (especially in breeds other than the breed in which the variant was first described). If it is decided to proceed, the location and orientation of the variant sequence should be checked very carefully.

Since October 2021, OMIA includes a semiautomated lift-over pipeline to facilitate updates of genomic positions to a recent reference genome position. These changes to genomic positions are not always reflected in the ‘acknowledgements’ or ‘verbal description’ fields in this table.

OMIA Variant ID Breed(s) Variant Phenotype Gene Allele Type of Variant Source of Genetic Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
717 Araucana (Chicken) Blue eggshell SLCO1B3 insertion, gross (>20) Naturally occurring variant 1 A different location for the same insertion: "a ~4.2 kb [retroviral] EAV-HP insertion in the 5' flanking region of SLCO1B3" but 23bp upstream of where the insertion occurs in Chinese breeds Dongxiang and Lushi 2013 23359636
864 Dong, an chicken, China (Chicken) Lushi, China (Chicken) Blue eggshell SLCO1B3 insertion, gross (>20) Naturally occurring variant 1 "a ~4.2 kb [retroviral] EAV-HP insertion in the 5' flanking region of SLCO1B3" 2013 23359636

Cite this entry

Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2022). OMIA:000142-9031: Online Mendelian Inheritance in Animals (OMIA) [dataset].


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.

2023 Wang, H., Cahaner, A., Lou, L., Zhang, L., Ge, Y., Li, Q., Pan, Y., Zhang, X. :
Genetics and breeding of a black-bone and blue eggshell chicken line. 3. Visual eggshell color and colorimeter parameters in 3 consecutive generations. Poult Sci 102:103052, 2023. Pubmed reference: 37734360. DOI: 10.1016/j.psj.2023.103052.
Wang, H., Ge, Y., Zhang, L., Wei, Y., Li, Q., Zhang, X., Pan, Y. :
The pigments in eggshell with different colour and the pigment regulatory gene expression in corresponding chicken's shell gland. Animal 17:100776, 2023. Pubmed reference: 37043933. DOI: 10.1016/j.animal.2023.100776.
Wang, Z., Chen, Q., Wang, Y., Wang, Y., Liu, R. :
Refine localizations of functional variants affecting eggshell color of Lueyang black-boned chicken in the SLCO1B3. Poult Sci 103:103212, 2023. Pubmed reference: 37980747. DOI: 10.1016/j.psj.2023.103212.
2022 Altgilbers, S., Dierks, C., Klein, S., Weigend, S., Kues, W.A. :
Quantitative analysis of CRISPR/Cas9-mediated provirus deletion in blue egg layer chicken PGCs by digital PCR. Sci Rep 12:15587, 2022. Pubmed reference: 36114266. DOI: 10.1038/s41598-022-19861-7.
Chen, Q., Wang, Z. :
A new molecular mechanism supports that blue-greenish egg color evolved independently across chicken breeds. Poult Sci 101:102223, 2022. Pubmed reference: 36283143. DOI: 10.1016/j.psj.2022.102223.
2021 Chen, S., Chen, K., Xu, J., Li, F., Ding, J., Ma, Z., Li, G., Li, H. :
Insights into mRNA and long non-coding RNA profiling RNA sequencing in uterus of chickens with pink and blue eggshell colors. Front Vet Sci 8:736387, 2021. Pubmed reference: 34692811. DOI: 10.3389/fvets.2021.736387.
2020 Chen, J., Dalirsefat, S.B., Han, D., Dong, X., Hua, G., Zheng, X., Xia, T., Shao, T., Deng, X., Wu, C. :
An EAV-HP insertion in the 5' flanking region of SLCO1B3 is associated with its tissue-expression profile in blue-eggshell Yimeng chickens (Gallus gallus). Poult Sci 99:6371-6377, 2020. Pubmed reference: 33248552. DOI: 10.1016/j.psj.2020.09.002.
2019 Darwish, H.Y.A., Dalirsefat, S.B., Dong, X., Hua, G., Chen, J., Zhang, Y., Li, J., Xu, J., Li, J., Deng, X., Wu, C. :
Genome-wide association study and a post replication analysis revealed a promising genomic region and candidate genes for chicken eggshell blueness. PLoS One 14:e0209181, 2019. Pubmed reference: 30673708. DOI: 10.1371/journal.pone.0209181.
Li, Z., Ren, T., Li, W., Zhou, Y., Han, R., Li, H., Jiang, R., Yan, F., Sun, G., Liu, X., Tian, Y., Kang, X. :
Association between the methylation statuses at CpG sites in the promoter region of the <i>SLCO1B3</i>, RNA expression and color change in blue eggshells in Lushi chickens. Front Genet 10:161, 2019. Pubmed reference: 30863430. DOI: 10.3389/fgene.2019.00161.
Noorai, R.E., Shankar, V., Freese, N.H., Gregorski, C.M., Chapman, S.C. :
Discovery of genomic variations by whole-genome resequencing of the North American Araucana chicken. PLoS One 14:e0225834, 2019. Pubmed reference: 31821332. DOI: 10.1371/journal.pone.0225834.
2016 Leroy, G., Besbes, B., Boettcher, P., Hoffmann, I., Capitan, A., Baumung, R. :
Rare phenotypes in domestic animals: unique resources for multiple applications. Anim Genet 47:141-53, 2016. Pubmed reference: 26662214. DOI: 10.1111/age.12393.
2015 Dalirsefat, S.B., Dong, X., Deng, X. :
Molecular phylogenetic analysis of Chinese indigenous blue-shelled chickens inferred from whole genomic region of the SLCO1B3 gene. Poult Sci 94:1776-86, 2015. Pubmed reference: 26069255. DOI: 10.3382/ps/pev146.
2013 Wang, Z., Qu, L., Yao, J., Yang, X., Li, G., Zhang, Y., Li, J., Wang, X., Bai, J., Xu, G., Deng, X., Yang, N., Wu, C. :
An EAV-HP insertion in 5' Flanking region of SLCO1B3 causes blue eggshell in the chicken. PLoS Genet 9:e1003183, 2013. Pubmed reference: 23359636. DOI: 10.1371/journal.pgen.1003183.
Wragg, D., Mwacharo, J.M., Alcalde, J.A., Wang, C., Han, J.L., Gongora, J., Gourichon, D., Tixier-Boichard, M., Hanotte, O. :
Endogenous retrovirus EAV-HP linked to blue egg phenotype in Mapuche fowl. PLoS One 8:e71393, 2013. Pubmed reference: 23990950. DOI: 10.1371/journal.pone.0071393.
Wragg, D., Mwacharo, J.M., Alcalde, J.A., Wang, C., Han, J.L., Gongora, J., Gourichon, D., Tixier-Boichard, M., Hanotte, O. :
Correction: Endogenous Retrovirus EAV-HP Linked to Blue Egg Phenotype in Mapuche Fowl. PLoS One 8, 2013. Pubmed reference: 24039664. DOI: 10.1371/annotation/2727de85-899f-4104-955d-1c5f3c0d3319.
2012 Wragg, D., Mwacharo, J.M., Alcalde, J.A., Hocking, P.M., Hanotte, O. :
Analysis of genome-wide structure, diversity and fine mapping of Mendelian traits in traditional and village chickens. Heredity (Edinb) 109:6-18, 2012. Pubmed reference: 22395157. DOI: 10.1038/hdy.2012.9.
2011 Wang, Z.P., Wang, X.T., Liu, R.F., Wang, A.R., Li, J,Y., Deng, X.M. :
Discover of a novel SNP highly associated with chicken blue egg. Journal of Animal and Veterinary Advances 10:92-95, 2011.
Wang, Z.P., Liu, R.F., Wang, A.R., Li, J.Y., Deng, X.M. :
Expression and activity analysis reveal that heme oxygenase (decycling) 1 is associated with blue egg formation. Poult Sci 90:836-41, 2011. Pubmed reference: 21406370. DOI: 10.3382/ps.2010-01143.
2010 Wang, X.T., Bai, J.R., Zhao, C.J., Zhang, H., Bao, H.G., Xu, G.Y., Li, J.Y., Lian, L.S., Wu, C.X., Deng, X.M. :
Localisation of the genomic sequence interval for the blue eggshell gene using an F2 resource population of Dongxiang chickens. Br Poult Sci 51:507-9, 2010. Pubmed reference: 20924844. DOI: 10.1080/00071668.2010.502520.
Wang, Z.P., Wang, X.T., Liu, R.F., Li, J.Y., Deng, X.M. :
Refined localization of the O gene for blue egg phenotype on chicken chromosome 1. J Anim Vet Adv 9:2947–2950, 2010. DOI: 10.3923/javaa.2010.2947.2950.
2009 Wang, X.L., Zheng, J.X., Ning, Z.H., Qu, L.J., Xu, G.Y., Yang, N. :
Laying performance and egg quality of blue-shelled layers as affected by different housing systems. Poult Sci 88:1485-92, 2009. Pubmed reference: 19531721. DOI: 10.3382/ps.2008-00417.
Wang, X.T., Zhao, C.J., Li, J.Y., Xu, G.Y., Lian, L.S., Wu, C.X., Deng, X.M. :
Comparison of the total amount of eggshell pigments in Dongxiang brown-shelled eggs and Dongxiang blue-shelled eggs. Poult Sci 88:1735-9, 2009. Pubmed reference: 19590090. DOI: 10.3382/ps.2008-00434.
2007 Yuan, Q.Y., Lu, L.Z. :
[Progresses in inheritance of genes for avian eggshell color]. Yi Chuan 29:265-8, 2007. Pubmed reference: 17369144. DOI: 10.1360/yc-007-0265.
Zhao, R., Liu, Z.Z., Xu, G.Y. , Yang, N. :
Analysis of SNP markers for chicken blue-shelled gene using PCR-SSCP. Chin J Agric Biotech 4:53-56, 2007.
2006 Zhao, R., Xu, G.Y., Liu, Z.Z., Li, J.Y., Yang, N. :
A study on eggshell pigmentation: biliverdin in blue-shelled chickens. Poult Sci 85:546-9, 2006. Pubmed reference: 16553287. DOI: 10.1093/ps/85.3.546.
2004 Lima-Rosa, C.A., Canal, C.W., Streck, A.F., Freitas, L.B., Delgado-Cañedo, A., Bonatto, S.L., Salzano, F.M. :
B-F DNA sequence variability in Brazilian (blue-egg Caipira) chickens. Anim Genet 35:278-84, 2004. Pubmed reference: 15265066. DOI: 10.1111/j.1365-2052.2004.01160.x.
2000 Bitgood, JJ., Briles, RW., Briles, WE. :
Further tests for genetic linkages of three morphological traits, three blood groups, and break points of two chromosome translocations on chromosome one in the chicken. Poult Sci 79:293-5, 2000. Pubmed reference: 10735192.
1996 Bartlett, J.R., Jones, C.P., Smith, E.J. :
Linkage analysis of endogenous viral element 1, blue eggshell, and pea comb loci in chickens Journal of Heredity 87:67-70, 1996. DOI: 10.1093/oxfordjournals.jhered.a022957.
1993 Carefoot, WC. :
Further studies of linkage and mappings of the loci of genes in group 3 on chromosome 1 of the domestic fowl. Br Poult Sci 34:205-9, 1993. Pubmed reference: 8467400. DOI: 10.1080/00071669308417576.
Shoffner, R.N., Otis, J.S., Garwood, V.A. :
Association of dominant marker traits and metric traits in chickens. Poult Sci 72:1405-10, 1993. Pubmed reference: 8378215. DOI: 10.3382/ps.0721405.
1991 Merat, P., Bordas, A., Coquerelle, G., Monvoisin, J.L. :
Effect of the Na (Naked Neck) and O (Blue Eggshell) Genes on Egg Production, Egg Traits and Female Reproductive Performances According to the Ambient Temperature Archiv Fur Geflugelkunde 55:130-133, 1991.
1983 Bitgood, J.J., Otis, J.S., Shoffner, R.N. :
Refined linkage value for comb and blue Egg: lack of effect of pea comb, blue egg, and naked on age at first egg in the domestic fowl. Poultry Science 62:235–238, 1983. DOI: 10.3382/ps.0620235.
1980 Bitgood, JJ., Shoffner, RN., Otis, JS., Briles, WE. :
Mapping of the genes for pea comb, blue egg, barring, silver, and blood groups A, E, H, and P in the domestic fowl. Poult Sci 59:1686-93, 1980. Pubmed reference: 7413575. DOI: 10.3382/ps.0591686.
1973 Kennedy, G.Y., Vevers, H.G. :
Eggshell pigments of the Araucano fowl. Comp Biochem Physiol B 44:11-25, 1973. Pubmed reference: 4683993. DOI: 10.1016/0305-0491(73)90336-2.
1939 Bruckner, JH., Hutt, FB. :
Linkage of pea comb and blue egg in the fowl Science 90:88, 1939. Pubmed reference: 17798917. DOI: 10.1126/science.90.2326.88.
1933 Punnett, R.C. :
Genetic studies in poultry. IX. The blue egg Journal of Genetics 27:465-470 , 1933. DOI: 10.1007/BF02981757.

Edit History

  • Created by Frank Nicholas on 06 Sep 2005
  • Changed by Frank Nicholas on 01 Jul 2012
  • Changed by Frank Nicholas on 27 Jan 2013
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  • Changed by Frank Nicholas on 01 Sep 2013
  • Changed by Frank Nicholas on 30 Mar 2019
  • Changed by Imke Tammen2 on 01 Dec 2020
  • Changed by Imke Tammen2 on 03 Nov 2021
  • Changed by Imke Tammen2 on 10 Nov 2022
  • Changed by Imke Tammen2 on 26 Nov 2022