DNA methylome and transcriptome identified Key genes and pathways involved in Speckled Eggshell formation in aged laying hens

Abstract

Background The quality of poultry eggshells is closely related to the profitability of egg production. Eggshell speckles reflect an important quality trait that influences egg appearance and customer preference. However, the mechanism of speckle formation remains poorly understood. In this study, we systematically compared serum immune and antioxidant indices of hens laying speckled and normal eggs. Transcriptome and methylome analyses were used to elucidate the mechanism of eggshell speckle formation. Results The results showed that seven differentially expressed genes (DEGs) were identified between the normal and speckle groups. Gene set enrichment analysis (GSEA) revealed that the expressed genes were mainly enriched in the calcium signaling pathway, focal adhesion, and MAPK signaling pathway. Additionally, 282 differentially methylated genes (DMGs) were detected, of which 15 genes were associated with aging, including ARNTL, CAV1, and GCLC. Pathway analysis showed that the DMGs were associated with T cell-mediated immunity, response to oxidative stress, and cellular response to DNA damage stimulus. Integrative analysis of transcriptome and DNA methylation data identified BFSP2 as the only overlapping gene, which was expressed at low levels and hypomethylated in the speckle group. Conclusions Overall, these results indicate that aging- and immune-related genes and pathways play a crucial role in the formation of speckled eggshells, providing useful information for improving eggshell quality.

Runs of homozygosity and selection signature analyses reveal putative genomic regions for artificial selection in layer breeding

“…Caveolin-1 (CAV1) is involved in several physiological activities such as signaling, apoptosis, and lipid metabolism. It has been reported to be associated with eggshell quality and organismal aging [ 28 ]. Caveolin-2 (CAV2) and CAV1, are members of the CAV family and are involved in the formation of lipid rafts (cholesterol-rich microdomains within membranes).…”

Effects of dietary supplementation of glycerol monolaurate on laying performance, egg quality, antioxidant capacity, intestinal morphology and immune function in late-phase laying hens

“…Egg weight, thin-shelled egg rate and malformed egg rate increased, while the Haugh unit, yolk color and eggshell breaking strength decreased with increasing age of hens ( Bozkurt and Tekerli, 2009 ; Ketta and Tumova, 2016 ; Molnar et al, 2016 ). It has been observed that the formation of spotted eggs is also related to the aging of laying hens ( Cheng et al, 2023 ). After the peak of egg production, the follicle numbers in laying hens markedly decline, while the number of atretic follicles increased, thus leading to a decrease in the laying rate ( Yao et al, 2020 ; Hao et al, 2021 ; Wu et al, 2023 ).…”

Ovarian transcriptome profile from egg-laying period to incubation period of Changshun green-shell laying hens

“…Changshun green-shell laying hen is a Chinese indigenous chicken breed with strong broodiness. Due to its strong tendency for broodiness, Changshun hen has recently become an important model to study avian incubation behaviour [22]. In the present study, we comprehensively analyzed the ovarian transcriptomes of Changshun hens at LP and BP.…”