Luo He-Feng, Wei Hong-Kui, Huang Fei-Ruo, Zhou Zheng, Jiang Si-Wen, Peng Jian
Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture, College of Animal Science and Technology, Huazhong Agricultural University, 430070, Wuhan, People's Republic of China.
Lipids. 2009 Nov;44(11):999-1010. doi: 10.1007/s11745-009-3346-y. Epub 2009 Oct 2.
The aim of the study was to investigate the effect of n-3 PUFA enrichment in longissimus muscle on intramuscular fat (IMF) content and expression of related genes in growing-finishing barrows. Two isoenergetic, isonitrogenous and isolipidic diets were formulated: one was basal diet and the other contained 10% linseed. Twenty-four Landrace x NewDamLine barrows weighing 35 +/- 3.7 kg were randomly assigned to four treatment groups with six pigs per group. During the whole experimental period of 90 days, all groups were first fed the basal diet and then the linseed diet for 0, 30, 60, and 90 days before slaughter, respectively. Meat quality, fatty acid composition, and expression of genes involved in adipogenesis in longissimus muscle were measured and analyzed. The IMF content increased linearly (P < 0.05) as the linseed diet feeding time prolonged. Meanwhile, n-3 PUFA content and expression of peroxisome proliferator-activated receptor delta (PPARdelta), PPARgamma, adipocyte fatty acid-binding protein (aP2) and lipoprotein lipase (LPL) increased linearly (P < 0.01) as well, while the expression of wingless related MMTV integration site 10b (Wnt10b) linearly decreased (P < 0.01). Furthermore, significant (P < 0.01) quadratic or linear relation was observed between n-3 PUFA enrichment and expression of these genes, while significant (P < 0.01) quadratic or linear relation was observed between the expression of PPARgamma, aP2 or Wnt10b and IMF content. These data show that enhancing n-3 PUFA enrichment in muscle leads to significant increase in IMF content. A possible explanation is due to alterations in the expression of genes involved in adipogenesis, however this will need to be confirmed by protein and enzyme activity studies.
本研究的目的是调查在生长育肥公猪的背最长肌中富集n-3多不饱和脂肪酸（PUFA）对肌内脂肪（IMF）含量及相关基因表达的影响。配制了两种等能量、等氮和等脂的日粮：一种是基础日粮，另一种含有10%的亚麻籽。将24头体重为35±3.7 kg的长白×新丹系公猪随机分为4个处理组，每组6头猪。在整个90天的实验期内，所有组首先饲喂基础日粮，然后分别在屠宰前0、30、60和90天饲喂亚麻籽日粮。测定并分析了背最长肌的肉质、脂肪酸组成以及参与脂肪生成的基因表达。随着亚麻籽日粮饲喂时间的延长，IMF含量呈线性增加（P<0.05）。同时，n-3 PUFA含量以及过氧化物酶体增殖物激活受体δ（PPARδ）、PPARγ、脂肪细胞脂肪酸结合蛋白（aP2）和脂蛋白脂肪酶（LPL）的表达也呈线性增加（P<0.01），而无翅相关MMTV整合位点10b（Wnt10b）的表达呈线性下降（P<0.01）。此外，n-3 PUFA富集与这些基因的表达之间存在显著（P<0.01）的二次或线性关系；而PPARγ、aP2或Wnt10b的表达与IMF含量之间存在显著（P<0.01）的二次或线性关系。这些数据表明，提高肌肉中n-3 PUFA的富集导致IMF含量显著增加。一种可能的解释是参与脂肪生成的基因表达发生了改变，然而这需要通过蛋白质和酶活性研究来证实。
