Fatty acid profiles unveiled: gene expression in Yanbian yellow cattle adipose tissues offers new insights into lipid metabolism

Abstract. Objectives. The objectives of this study were twofold: to analyze the composition and content of fatty acids in various adipose tissues (including kidney, abdominal, subcutaneous, and omental) of Yanbian yellow cattle and to observe the morphology of adipocytes within these tissues and to assess the level of expression of specific genes – kinase insert domain receptor (KDR), apolipoprotein L domain containing 1 (APOLD1), stearoyl-CoA desaturase 1 (SCD1), secreted frizzled-related protein 4 (SFRP4), fatty-acid-binding protein 5 (FABP5), and sterol carrier protein-2 (SCP2) – in different adipose tissues (kidney, abdominal, posterior belly, ribeye, prothorax, striploin, upper brain, and neck) of Yanbian yellow cattle. Method. Castrated Yanbian yellow cattle, 24 months old, with identical genetic backgrounds and raised under the same breeding management conditions, were selected. The fatty acid composition and content were assessed using gas chromatography, while the size and diameter of adipocytes were analyzed via paraffin sectioning. The level of expression was determined using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Results. In total, 16 distinct fatty acids were identified in abdominal adipose tissue. Additionally, henicosanoic acid (C21:0) and behenic acid (C22:0) were detected exclusively in subcutaneous adipose tissue. Caprylic acid (C8:0) was found in both kidney and omental adipose tissues. The size of individual adipocytes in kidney adipose tissue was notably larger compared to the adipocytes in the other three regions (p<0.05). Regarding gene expression, APOLD1 exhibits its highest expression in striploin adipose tissues (p<0.05), while SCD1 shows its peak expression in prothorax adipose tissues (p<0.05). Moreover, both FABP5 and SCP2 demonstrate their highest level of expression in prothorax adipose tissue (p<0.05). Furthermore, the level of expression of KDR and SFRP4 across these seven adipose tissue regions exhibits significant differences (p<0.05). Conclusion. In conclusion, Yanbian yellow cattle exhibit variations in both the composition and content of fatty acids across different adipose tissue depots, including the kidney, abdominal, subcutaneous, and omental regions. Moreover, adipocytes display distinct morphological differences across these tissue types. Furthermore, the level of expression of KDR, APOLD1, SCD1, SFRP4, FABP5, and SCP2 varies significantly among adipose tissues located in the kidney, abdominal, posterior belly, ribeye, prothorax, striploin, upper brain, and neck regions.