Pigment concentrations in eggshell and their related gene expressions in uterus of Changshun blue eggshell chickens

ABSTRACT

1. The goal of this study was to investigate the colour diversity of egg shells and expression of related genes in the uterus of chickens that produce eggs of different colours.

2. Four colour types of Changshun blue-shell chickens, producing dark or light blue, greenish-brown and brown shelled eggs, were selected. The eggshell pigment concentration and colour values in each group were examined. The relative gene expression of solute carrier organic anion transporter family member 1C1 (SLCO1C1), ferrochelatase (FECH), haem oxygenase 1 (HO-1), ovotransferrin (OF) and biliverdin reductase A (BLVRA) in eggshell gland were measured.

3. The Δb, ΔE and protoporphyrin in brown and greenish-brown groups were significantly higher in the blue egg group (P < 0.01), whereas ΔL was significantly lower than that in the blue eggs (P < 0.01). There was no significant difference in biliverdin concentration between the brown and blue groups.

4. The Δa values, in descending order, were 8.27 ± 2.76 in the brown, −3.79 ± 2.39 in the greenish-brown and −7.29 ± 2.27 in the blue groups, respectively. The relative expression of HO-1 in the greenish-brown and light blue groups was significantly higher than in the dark blue and brown groups. The relative expression of FECH in the light blue group was significantly lower than that in the dark blue, greenish-brown or brown group (P < 0.01). The relative expression of HO-1 and BLVRA genes in the dark blue group was significantly higher than that in the light blue, greenish-brown and the brown group (P < 0.01).

5. The Δa might provide a better index than protoporphyrin and biliverdin contents for eggshell colour breeding. Overall, HO-1 as well as BLVRA were important candidate genes for the selection of dark blue eggs.

KEYWORDS:

• Changshun blue-eggshell chickens
• pigmentation
• colour breeding
• gene expression
• HO-1
• BLVRA

Acknowledgments

The authors appreciate Prof. Yuansheng Tan for proof-reading the English grammar throughout the paper. They wish to express thanks for the support from Guangdong Provincial Key Laboratory of Animal Molecular Design and Precise Breeding for their kind assistance in the study.

Data availability

All data generated or analysed during this study are available from the corresponding author upon reasonable request.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Open Foundation of the Guangdong Provincial Key Laboratory of Animal Molecular Design and Precise Breeding (2019B030301010), the Foundation for Key Laboratory (2019KSYS011), the Creative Team (2019KCXTD006) in Guangdong Higher Education Institutes and the Foundation for the Germplasm Improvement Talent Base in Guizhou Changshun Tinoo’s Green Shell Laying Hen Industrial Co. Ltd.