Aberrant expression of the DCT gene is implicated in the hyperpigmentation of the visceral peritoneum of the chicken
Hyperpigmentation of the visceral peritoneum (HVP) has recently garnered significant attention within the poultry industry due to its potential implications for the health of afflicted animals and its adverse effects on the appearance of commercial chicken carcasses.  Unfortunately, the heritable characteristics of HVP are not yet fully understood. Motivated by poultry industry demand, we deployed multi-omics comparing the clinical HVP and normal samples profiling the potential regulating molecular landscape in cell and genome resolution, specifically, aiming to decipher the precise molecular genomic marker. Specifically, we identified the signature genes for the HVP phenotype and found that the signature gene of melanogenesis strongly enriched in the HVP group. At the melanocyte level, overexpression of the DCT gene can promote the proliferation of melanocytes, with exogenous Tyr addition. On the contrary, significantly lower melanin content in the supernatant of cells was detected after siRNA interference relative to untreated cells. Through single-cell sequencing, the hyperexpression of melanogenesis-associated genes in melanocytes was echoed. In summary, molecular features of the HVP phenotype were systematically revealed, which may partially explain the strong heterogeneities of the peritoneum phenotype. The hyperpigmentation of the peritoneum is attributed to an excess deposition of melanin, where the DCT hyperexpression can be regarded as a molecular marker related to the deposition of peritoneal melanin. Future directions should deploy gene editing technology to alert the gene expression of DCT to change the phenotype of pigmentation in the visceral peritoneum. Overall design: In this experiment, ten 40-day-old Huiyang Bearded Chickens, each with normal and black peritoneum color, were selected. Following humane slaughter in compliance with animal welfare requirements, peritoneum tissues were swiftly separated using scissors. The tissues were immediately rinsed 2-3 times in 4-degree pre-chilled 1×PBS on ice and then transferred to a 1.5mL centrifuge tube for scRNA-seq.