Institute of Animal Breeding and Genetics, Sichuan Agricultural University, Ya'an, People's Republic of China.
Poult Sci. 2012 Oct;91(10):2588-97. doi: 10.3382/ps.2012-02273.
The objective of the current research was to investigate the pattern of subcutaneous adipose tissue growth during Peking duck (Anas platyrhynchos) early development and to determine the reasons for regional differences. The morphological characteristics in 5 regions of subcutaneous tissue, including the neck area (NSF), chest area (CSF), lower abdomen area (ASF), back area (BSF), and leg area (LSF), were analyzed by comparing the morphology of the sections, adipocyte volume and number, and lipid content from wk 1 to 8. Moreover, the mRNA expression of several molecular marker genes, including 47-kDa tail interacting protein (TIP47), adipose differentiation-related protein (ADRP), and perilipin, were detected from wk 1 to 8 using quantitative real-time PCR. Our results revealed that the average cell number declined greatly as fattening proceeded (except in the NSF) and changed very little after wk 4 in all 5 regions. In contrast, the average cell volume and triglyceride content per cell increased gradually during early duck growth. The BSF and LSF lipid content had a different pattern of change than the other regions. The NSF, CSF, and ASF regions had the highest lipid content values at all stages, the BSF was intermediate, and the LSF was the lowest at all weeks except wk 3. The highest TIP47 expression level was found in the NSF from wk 1 to 2 and BSF at wk 1. The relative expression level of TIP47 was higher in the CSF than in the ASF and BSF at wk 4, and was higher in the NSF than in the ASF at wk 6. The highest levels of ADRP and perilipin were detected in the LSF. These results suggest that a combination of adipocyte hyperplasia and hypertrophy is mainly responsible for the development of duck adipose tissue before wk 4, after which adipose expansion is accomplished by adipocyte hypertrophy only. Adipocyte hyperplastic and hypertrophic capacity, fat storage capacity, and metabolic activity may be partial explanations for the regional differences during duck growth.
本研究旨在探讨北京鸭早期皮下脂肪组织生长的模式，并确定区域差异的原因。通过比较 1 至 8 周时颈部（NSF）、胸部（CSF）、下腹（ASF）、背部（BSF）和腿部（LSF）5 个部位的组织学切片、脂肪细胞体积和数量以及脂肪含量，分析了皮下组织的形态特征。此外，采用实时定量 PCR 法检测了 47kDa 尾相互作用蛋白（TIP47）、脂肪分化相关蛋白（ADRP）和脂滴包被蛋白（ perilipin）等几种分子标记基因的 mRNA 表达水平。结果表明，除 NSF 外，随着育肥的进行，平均细胞数量急剧下降，在所有 5 个部位，第 4 周后变化很小。相比之下，在早期鸭生长过程中，平均细胞体积和每细胞甘油三酯含量逐渐增加。BSF 和 LSF 的脂质含量变化模式与其他区域不同。在所有阶段，NSF、CSF 和 ASF 区域的脂质含量最高，BSF 居中，LSF 除第 3 周外均最低。在 1 至 2 周时，NSF 中 TIP47 的表达水平最高，在第 1 周时，BSF 中 TIP47 的表达水平最高。在第 4 周时，CSF 中 TIP47 的相对表达水平高于 ASF 和 BSF，在第 6 周时，NSF 中 TIP47 的相对表达水平高于 ASF。ADRP 和 perilipin 的表达水平最高的部位是 LSF。这些结果表明，在第 4 周之前，鸭脂肪组织的发育主要是由脂肪细胞的增生和肥大共同作用的，之后脂肪的扩张仅由脂肪细胞的肥大来完成。脂肪细胞的增生和肥大能力、脂肪储存能力和代谢活性可能是鸭生长过程中区域差异的部分原因。
