Institute of Animal Breeding and Genetics, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan 625014, PR China.
Comp Biochem Physiol B Biochem Mol Biol. 2012 Sep;163(1):154-60. doi: 10.1016/j.cbpb.2012.05.014. Epub 2012 May 29.
In vivo de novo lipogenesis (DNL) in the liver and adipose tissues of ducks during early developmental stages after hatching has not previously been investigated. In this study, female Peking ducks (Anas platyrhynchos) at weeks 1 to 8 post-hatching were selected for experimentation. We measured the mRNA levels of 6 DNL-related genes in the duck liver, subcutaneous adipose tissue and abdominal adipose tissue by real-time PCR during the 8 weeks. Correlations of the plasma triacylglycerol (TG) and very low density lipoprotein (VLDL) concentrations with fat deposition at these sites were also detected during growth. Our results showed that fat content was highest in the subcutaneous adipose tissue and lowest in the liver during the growth period we studied. Additionally, plasma VLDL and TG were significantly associated with lipid content in adipose tissue (P<0.05), but not in the liver. Lastly, in the growing birds, the expression levels of lipogenic genes (with the exceptions SREBP-1c and SCD1) were much higher in the liver than in the adipose tissues, and the maximal expression levels of these genes occurred at week 4 or 5 at these sites. These findings indicated that the main site of DNL is always the liver in post-hatching ducks, and adipose tissues are of little importance for DNL. Taken together, our results suggested that the plasma lipoproteins contribute greatly to fat deposition in adipose tissues originating from hepatic lipogenesis.
在孵化后早期发育阶段，鸭的肝脏和脂肪组织中的体内从头合成脂肪（DNL）尚未被研究过。本研究选择了孵化后 1 到 8 周的雌性北京鸭（Anas platyrhynchos）进行实验。在 8 周内，我们通过实时 PCR 测量了鸭肝脏、皮下脂肪组织和腹部脂肪组织中 6 种 DNL 相关基因的 mRNA 水平。在生长过程中，还检测了这些部位的血浆三酰甘油（TG）和极低密度脂蛋白（VLDL）浓度与脂肪沉积的相关性。结果表明，在我们研究的生长期间，脂肪含量在皮下脂肪组织中最高，在肝脏中最低。此外，血浆 VLDL 和 TG 与脂肪组织中的脂质含量显著相关（P<0.05），但与肝脏无关。最后，在生长中的鸟类中，肝脏中脂肪生成基因（除 SREBP-1c 和 SCD1 外）的表达水平明显高于脂肪组织，这些基因在这些部位的第 4 或 5 周达到最高表达水平。这些发现表明，在孵化后的鸭子中，DNL 的主要部位始终是肝脏，脂肪组织对 DNL 不重要。总之，我们的研究结果表明，血浆脂蛋白对来自肝脂肪生成的脂肪组织中的脂肪沉积有很大贡献。
