ABSTRACT

1. The objective of this study was to characterise the regulation of the pathways that synthesise long-chain polyunsaturated fatty acids (PUFA) on developing adipose deposits in broiler embryos and chicks. Subcutaneous adipose depots were harvested from embryos and embryonic d E13, E15 and E17. Subcutaneous, abdominal and crop (neck) adipose, as well as liver, were collected at 7 and 14 d post-hatch.

2. Targeted RNA sequencing was used to quantify expression of 6 elongation of very long-chain fatty acid (ELOVL) genes, two isoforms of stearoyl-CoA desaturase (SCD and SCD5), and three fatty acid desaturases (FADS1, FADS2, and FADS6) in each depot and in the liver. Expression levels of marker genes for fatty acid oxidation and adipogenesis (peroxisome proliferator-activated receptor gamma (PPARG)) were quantified. Fatty acid composition of subcutaneous adipose was analysed using gas chromatograph–mass spectrometry (GC/MS).

3. Genes in the PUFA synthetic pathway were differentially expressed across developmental ages and between depots. These include elongase and desaturase genes, that have not previously been characterised in chicken. Correlation analyses identified subsets of co-regulated genes and fatty acids and highlighted relationships that may influence adipose metabolism and development.

4. It was concluded that PUFA synthesis is an active and dynamically regulated pathway in developing adipose deposits in the broiler chick. These data highlighted potential novel roles for specific elongase and desaturase genes in adipose deposition and metabolism.

摘要

1.这项研究的目的是表征合成长链多不饱和脂肪酸（PUFA）对肉鸡胚胎和雏鸡中脂肪沉积途径的调节。从胚胎和胚胎d E13，E15和E17收获皮下脂肪库。在孵化后第7和14天收集皮下，腹部和作物（颈部）脂肪以及肝脏。

2.靶向RNA测序用于量化6个超长链脂肪酸（ELOVL）基因，两个硬脂酰-CoA去饱和酶同工型（SCD和SCD5）和三个脂肪酸去饱和酶（FADS1，FADS2和FADS6）的表达。）在每个仓库和肝脏中。定量用于脂肪酸氧化和脂肪形成的标记基因（过氧化物酶体增殖物激活的受体γ（PPARG））的表达水平。使用气相色谱-质谱法（GC / MS）分析皮下脂肪的脂肪酸组成。

3. PUFA合成途径中的基因在发育年龄之间和贮库之间差异表达。这些包括延伸酶和去饱和酶基因，以前在鸡中没有被鉴定过。相关分析确定了共同调控的基因和脂肪酸的子集，并突出了可能影响脂肪代谢和发育的关系。

4.结论是，PUFA合成是发展肉鸡脂肪沉积的一个活跃且动态调节的途径。这些数据突出了特定的延伸酶和去饱和酶基因在脂肪沉积和代谢中的潜在新作用。