National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, Department of Animal Genetics and Breeding, China Agricultural University, 100193, Beijing, China.
National Animal Husbandry Service, 100125, Beijing, China.
BMC Genomics. 2021 Nov 2;22(1):786. doi: 10.1186/s12864-021-08103-1.
Eggshell is a bio-ceramic material comprising columnar calcite (CaCO) crystals and organic proteinaceous matrix. The size, shape and orientation of the CaCO crystals influence the microstructural properties of chicken eggshells. However, the genetic architecture underlying eggshell crystal polymorphism remains to be elucidated.
The integral intensity of the nine major diffraction peaks, total integral intensity and degree of orientation of the crystals were measured followed by a genome-wide association study in 839 F2 hens. The results showed that the total integral intensity was positively correlated with the eggshell strength, eggshell thickness, eggshell weight, mammillary layer thickness and effective layer thickness. The SNP-based heritabilities of total integral intensity and degree of orientation were 0.23 and 0.06, respectively. The 621 SNPs located in the range from 55.6 to 69.1 Mb in GGA1 were significantly associated with TA. PLCZ1, ABCC9, ITPR2, KCNJ8, CACNA1C and IAPP, which are involved in the biological process of regulating cytosolic calcium ion concentration, can be suggested as key genes regulating the total integral intensity.
The findings greatly advance the understanding of the genetic basis underlying the crystal ultrastructure of eggshell quality and thus will have practical significance in breeding programs for improving eggshell quality.
蛋壳是一种生物陶瓷材料，由柱状方解石（CaCO）晶体和有机蛋白质基质组成。CaCO 晶体的大小、形状和取向影响着鸡蛋壳的微观结构特性。然而，蛋壳晶体多态性的遗传结构仍有待阐明。
在 839 只 F2 母鸡中进行了全基因组关联研究，测量了 9 个主要衍射峰的积分强度、总积分强度和晶体的取向度。结果表明，总积分强度与蛋壳强度、蛋壳厚度、蛋壳重量、乳突层厚度和有效层厚度呈正相关。总积分强度和取向度的 SNP 遗传力分别为 0.23 和 0.06。位于 GGA1 621 个 SNP 位于 55.6 到 69.1 Mb 的范围内，与 TA 显著相关。PLCZ1、ABCC9、ITPR2、KCNJ8、CACNA1C 和 IAPP 参与调节细胞质钙离子浓度的生物学过程，可作为调节总积分强度的关键基因。
这些发现极大地促进了对蛋壳质量晶体超微结构遗传基础的理解，因此在改善蛋壳质量的育种计划中具有实际意义。
