Comparative transcriptome profiles of Lindian chicken eyelids identify melanin genes controlling eyelid pigmentation

ABSTRACT

1. During the long history of chicken domestication, eyelid colour, like skin colour and shank colour, has been one of the physical traits of Chinese indigenous chickens that influence consumer buying behaviour. In China, the Lindian chicken, which has coloured feathers, is renowned for the appetizing flavour of its meat and eggs, and its eyelid colours vary from deep (black) to light shades (light yellow).

2. To investigate genes involved in eyelid colour, the expression profiles of black and light-yellow eyelids of Lindian chickens were analysed with transcriptome sequencing.

3. A total of 13 466 genes were detected in the eyelids, among which 14 were differentially expressed. Among these differentially expressed genes (DEGs), three key genes, premelanosome protein (PMEL), dopachrome tautomerase (DCT), and tyrosinase (TYR), encoded proteins that positively regulate melanogenesis and melanin deposition. PMEL, DCT and TYR were expressed much more strongly in the black eyelids than in the light-yellow eyelids. A Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that tyrosine metabolism and melanogenesis genes were significantly enriched among these DEGs (corrected P < 0.05).

4. In conclusion, melanin may be one of the main factors involved in Lindian chicken eyelid colour. Furthermore, these results provide a valuable resource for the future study of the physical traits of Lindian chicken.

KEYWORDS:

• Black and light-yellow eyelid
• differentially expressed genes
• Lindian chicken
• melanogenesis
• RNA-seq

Acknowledgments

The authors would like to thank the members of the Lindian chicken National Protection Farm in Lindian county of Heilongjiang Province for their help in managing the birds and collecting the data.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

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Additional information

Funding

This research was supported by the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province [no. UNPYSCT-2016003]; the China Agriculture Research System [no. CARS-41]; Nursing Program of Scholars with Creative Talents in Harbin city of Heilongjiang Province [no. 2017RAQXJ081].