Novel Candidate Genes Involved in an Initial Stage of White Striping Development in Broiler Chickens.

Simple Summary: White striping (WS) is a condition frequently observed in poultry farming, which reduces consumer acceptability and causes economic losses for the industry. Although common, the development of WS during the animal's growth remains unclear. Therefore, the objective of this study was to identify genes involved in the occurrence of WS in broiler chickens at 35 days of age and through which processes they act. For this, breast samples were collected from normal and WS-affected chickens, and complete RNA sequencing was performed. Thirty genes showing an altered expression were identified, of which 23 were more expressed and 7 were less expressed in affected chickens compared to normal ones. Fourteen of these genes were related to WS for the first time and are associated with muscle development (CEPBD, DUSP8, METTL21EP, NELL2, UBE3D), lipid metabolism (PDK4, DDIT4, FKBP5, DGAT2, LIPG, TDH, and RGCC), and collagen (COL4A5 and COL4A6). Genes related to muscle, as well as cellular processes, are possibly involved with the initial phase of WS development. Genes linked to lipid metabolism and collagen may be more related to the progression of this condition. White striping (WS) is a myopathy characterized by the appearance of white stripes parallel to the muscle fibers in the breast of broiler chickens, composed of adipose and connective tissues. This condition causes economic losses and, although common, its etiology remains poorly understood. Hence, the objective was to identify genes and biological mechanisms involved in the early stages of WS using a paternal broiler line that grows slightly slower than commercial ones, at 35 days of age, through the RNA sequencing of the pectoralis major muscle. Thirty genes were differentially expressed between normal and WS-affected chickens, with 23 upregulated and 7 downregulated in the affected broilers. Of these, 14 genes are novel candidates for WS and are implicated in biological processes related to muscle development (CEPBD, DUSP8, METTL21EP, NELL2, and UBE3D), lipid metabolism (PDK4, DDIT4, FKBP5, DGAT2, LIPG, TDH, and RGCC), and collagen (COL4A5 and COL4A6). Genes related to changes in muscle fiber type and the processes of apoptosis, autophagy, proliferation, and differentiation are possibly involved with the initial stage of WS development. In contrast, the genes linked to lipid metabolism and collagen may have their expression altered due to the progression of the myopathy. [ABSTRACT FROM AUTHOR]