Objective The purpose of this study was to systematically analyze the evolutionary level and structural characteristics of the oxysterol-binding protein (OSBP)-related proteins (ORPs) family in cattle, and to explore the potential function of ORP10 in lipid metabolism and adipocyte differentiation.

Method The ORPs family members were identified based on the bovine reference genome. The physical and chemical properties, chromosomal localization, phylogenetic relationship, conserved motifs, domain characteristics, and cross-species collinearity of the of the family members were systematically analyzed. STRING was used to predict the protein interaction network, and RT-qPCR was used to detect the expression pattern of ORP10 in different tissues and during adipocyte differentiation.

Result A total of 11 ORPs family members were identified in the bovine genome. Most proteins contain 800–900 aa, with ORP1 having the largest number of amino acids (1012 aa). Family members are dispersed across the chromosomes. Phylogenetic analysis showed that the ORPs family was divided into three subgroups, and six conserved motifs and nine typical domains were identified. Most members contain both the pleckstrin homology (PH) domain and the OSBP-related domain (ORD), and ORP1 specifically contains an ankyrin (ANK) repeat domain. Colinearity analysis showed that ORP8, ORP9, ORP10, and ORP11 were highly conserved between cattle and related species, while ORP3, ORP6, and ORP7 showed complex collinearity relationships. Protein interaction prediction suggested that ORP10 was significantly associated with lipid metabolism-related proteins such as PPARG. RT-qPCR results showed that ORP10 was highly expressed in the spleen and rumen, with the lowest expression in muscle-related tissues, and was significantly up-regulated in the early and middle stages of adipocyte differentiation, reaching the peak on the 4th day and then decreasing.

Conclusion This study systematically revealed the evolutionary conservation and member differentiation characteristics of bovine ORPs family, suggesting that ORP10 may be involved in lipid metabolism in the early stage of bovine adipocyte differentiation, which provides a theoretical basis for further analysis of the molecular mechanism of lipid homeostasis and intramuscular fat deposition in ruminants.