| Eggshell quality is closely related to the edible,machinability and storage of egg products,improving the eggshell quality can conducive to reducing the egg processing cost and increase economic efficiency,while preventing pathogens against eggs,protect eggfood safety.Poultry varieties(lines),which specialize in high-strength eggshells,have become one of the important research work of modern poultry breeding.Conventional breeding needs to determine a large number of eggshell quality indicators,the cost is higher and it need longer time,some researchers believe that the eggshell color and eggshell strength have a certain connection,whether the eggshell color as the measurement indicators of eggshell strength,and then promote the cultivation of specialized high-strength egg breeds,which also need more in-depth study.Duck eggs are the main raw material of China's egg products.In this study,the relationship between eggshell color and eggshell quality was analyzed,and the molecular mechanism of both was studied,for breeding the specialize in high-strength eggshells of ducks to provide reference research,the experimental study and results are as follows:In this study,ducks were selected from four groups,M1 strains of Peking duck,Mallard and eciprocal cross of Pekin duck Z2 and Mallard,each group selected 300 duck eggs for determination of egg shell color,egg shell strength,eggshell thickness and the eggshell pigment content.The results showed that the content of biliverin in the eggshell was negatively correlated with the L * value,and the coefficient of regression was 0.8459,which indicated that the L * value could distinguish the eggshell color,In addition,There was a significant correlation between the intensity,the correlation coefficient was 0.25 ~ 0.46.The results showed that eggshell color as an indicator should be considered different varieties.The results of eggshell ultrastructure showed that the high-strength shells have smaller mastoid effective thickness and mastoid space than the the low-strength eggshells.The results of M1 group eggshell ultrastructure showed that the shell thickness has a greater effect on shell strength than mastoid layer.The research shows that the density of calcium carbonate crystals in eggshells and the thickness are the main reasons for the differences in eggshell strength.The above two studies demonstrated that eggshell color can be used as an indicator of eggshell strength,then eggshell color was used as a phenotype,the duck uterus were sampled.The results of transcriptome sequencing showed that the total number of genes was 8,216,and the number of significant genes was 266,including 83 up-regulated genes and 183 down-regulated genes.Functional enrichment results showed significant differences in the expression of genes mainly involved in metabolic pathways interacting with the neuroactive ligand-receptors,calcium signaling pathways were also significantly enriched,finally found a total of 16 genes related to calcium transport and 4 pigmentation genes.Through the clustering analysis of these 20 genes,it was found that the calcium voltage-gated channel chould change the concentration of calcium ions.The four genes,GPR14,PAX3,OCA2 and TYR,may light the eggshell color by increasing expression.Real time PCR results showed that the expression of LOC101792412,LOC101798111 and LOC101800520 in the high and low eggshell intensity group were consistent with the results of transcriptome sequencing.In summary,this study found that the color of eggshell can be used as an indicator of eggshell strength,but as a measure of the indicators should pay attention to differences between varieties,The density of calcium carbonate crystals in eggshells and the thickness are the main reasons for the differences in eggshell strength.The difference molecular mechanism of eggshell strength may be related to the calcium voltage-gated channel changed the concentration of calcium ions,and GPR14,PAX3,OCA2 and TYR can be the candidate genes for study shell color. |
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