The Influence of the FGF8 Gene on the Proliferation and Differentiation of Preadipocytes in Sheep

The growth and development of adipose tissue in sheep tails are closely associated with adipocyte proliferation and differentiation. However, the functional role and regulatory mechanisms of the FGF8 gene in sheep preadipocytes remain incompletely understood. In this study, liposome-mediated transfection was employed to overexpress the FGF8 gene and assess its effects on the proliferation and differentiation of sheep preadipocytes. The results of the Cell Counting Kit-8 (CCK-8) assay indicated that the overexpression of FGF8 promoted preadipocyte viability of preadipocytes. Subsequently, this was verified by RT-qPCR analysis, which showed significant upregulation of proliferation marker genes, including CyclinB (p < 0.001) and Proliferating Cell Nuclear Antigen (PCNA) (p < 0.01), while CyclinD mRNA expression increased compared with the control group, though the increase was not statistically significant. During adipogenic induction, the mRNA expression levels of differentiation markers, such as Peroxisome Proliferator-Activated Receptor Gamma (PPARγ), CCAAT/Enhancer Binding Protein Alpha (C/EBPα), Adipocyte type Fatty Acid Binding Protein 4 (FABP4), and Adiponectin, initially increased and then decreased. The expression of all four markers peaked on day 10 of induction, exceeding levels observed in the control group. In vitro experiments showed that FGF8 affected the proliferation and differentiation of sheep preadipocytes and may be involved in the regulation of tail fat deposition.