Visceral Peritoneum Hyperpigmentation in Chickens Is Associated with DCT Expression.

Area of Science:

• Poultry Genetics and Physiology
• Molecular Biology and Biochemistry

Background:

• Hyperpigmentation of the visceral peritoneum (HVP) negatively impacts chicken carcass quality and consumer acceptance.
• The genetic underpinnings and molecular mechanisms driving HVP remain largely uncharacterized.

Purpose of the Study:

• To elucidate the genetic basis and regulatory mechanisms of HVP in chickens.
• To identify potential molecular markers for genetic selection to mitigate HVP.

Main Methods:

• Employed high-performance liquid chromatography (HPLC), bulk and single-cell RNA sequencing (RNA-seq), qRT-PCR, Western blotting, and siRNA interference.
• Utilized spectrophotometry, hematoxylin and eosin (HE) staining, and genetic polymorphism analysis.
• Investigated the role of dopachrome tautomerase (DCT) through overexpression and silencing studies.

Main Results:

• Confirmed eumelanin deposition in the peritoneum of HVP-affected chickens using HPLC and spectrophotometry.
• RNA-seq identified 61 differentially expressed genes, with dopachrome tautomerase (DCT) showing significant upregulation.
• Overexpression of DCT increased melanin production and melanocyte proliferation, while DCT silencing inhibited these processes. A DCT polymorphism (g.147917398 C > T) was associated with HVP (p=0.033).

Conclusions:

• HVP is primarily caused by DCT overexpression, leading to excessive eumelanin deposition in the chicken peritoneum.
• DCT serves as a potential molecular marker for genomic selection to enhance poultry carcass quality and reduce economic losses.