Institute of Animal Sciences, Chinese Academy of Agricultural Science, Beijing, 100193, China.
State Key Laboratory of Animal Nutrition, Beijing, 100193, China.
BMC Genomics. 2018 May 9;19(1):344. doi: 10.1186/s12864-018-4737-3.
Caponization results in reduced androgen levels, which leads to abdominal fat accumulation in capons. In this study, we sought to understand the molecular mechanisms behind this fat accumulation.
Abdominal fat (AF) content increased significantly (P < 0.05) and serum and AF testosterone levels decreased significantly (P < 0.05 or P < 0.01) after caponization. In AF tissue, 90 differentially expressed genes related to lipid metabolism were screened by gene expression profiling in caponized and sham-treated chickens. Among these, six representative genes were significantly up-regulated (APOA1, SCD, FABP7, RXRG, and FADS2) or down-regulated (FABP3) (P < 0.05 or P < 0.01) and were strongly associated with the PPAR pathway. In addition, cell junction pathways were also enriched. In vitro, Fat content was significantly lower in cells treated with testosterone compared with control cells (P < 0.01), and mRNA levels of RXRG, FABP7, and FABP3 changed accordingly, confirming the effect of testosterone on fat deposition.
The results of this study indicate that testosterone reduction likely regulates gene expression through PPAR and cell junction pathways resulting in increased fat accumulation. These results provide increase our understanding of the biological mechanisms by which caponization induces greater fat accumulation.
去势会导致雄激素水平降低，从而导致阉鸡腹部脂肪堆积。在这项研究中，我们试图了解这种脂肪堆积背后的分子机制。
去势后，腹部脂肪（AF）含量显著增加（P < 0.05），血清和 AF 中的睾丸酮水平显著降低（P < 0.05 或 P < 0.01）。在去势和假处理的鸡的 AF 组织中，通过基因表达谱筛选出与脂质代谢相关的 90 个差异表达基因。其中，六个代表性基因（APOA1、SCD、FABP7、RXRG 和 FADS2）显著上调（P < 0.05 或 P < 0.01）或下调（FABP3）（P < 0.05 或 P < 0.01），与 PPAR 途径强烈相关。此外，细胞连接途径也得到了富集。体外，与对照细胞相比，用睾丸酮处理的细胞中的脂肪含量显著降低（P < 0.01），RXRG、FABP7 和 FABP3 的 mRNA 水平也随之改变，证实了睾丸酮对脂肪沉积的影响。
本研究结果表明，睾丸酮的减少可能通过 PPAR 和细胞连接途径调节基因表达，从而导致脂肪堆积增加。这些结果增加了我们对去势引起脂肪堆积增加的生物学机制的理解。
