Barber M C, Ward R J, Richards S E, Salter A M, Buttery P J, Vernon R G, Travers M T
Hannah Research Institute, Ayr, UK.
J Anim Sci. 2000 Jan;78(1):62-8. doi: 10.2527/2000.78162x.
The basis for the variation in fatty acid composition in different ovine adipose tissue depots was investigated. The proportion of stearic (C18:0) and oleic (C18:1) acids vary in a site-specific fashion; abdominal depots (omental and perirenal) contain relatively more C18:0 than C18:1, and carcass depots, especially sternum, have a markedly higher proportion of C18:1. Additionally, expression of a number of lipogenic enzyme genes (stearoyl-CoA desaturase [SCD], acetyl-CoA carboxylase-alpha [ACC-alpha], lipoprotein lipase [LPL]) and the cytoskeletal protein gene alpha-tubulin vary among depots, although the pattern of variation differs for each mRNA. When these expression data were related to the mean cell volume of adipocytes pooled from all depots, a significant pattern emerged: expression of the ACC-alpha, LPL, and alpha-tubulin genes was highly correlated with the size of adipocytes. In contrast, when the expression of SCD mRNA was assessed as a function of mean cell volume, two populations of adipocytes emerged: no significant correlation was found between the expression of SCD mRNA per adipocyte and mean cell volume for the abdominal depots, although a highly significant correlation was observed between SCD gene expression and mean cell volume for the carcass and epicardial depots. Similarly, a highly significant correlation was found for the amount of C18:1 per adipocyte and the abundance of SCD mRNA per adipocyte for the carcass and epicardial depots, whereas no significant correlation was observed for these traits for the omental and perirenal depots. Thus, the SCD gene seems to be regulated in a depot-specific fashion and in a manner distinct from that of the ACC and LPL genes.
对不同绵羊脂肪组织库中脂肪酸组成变化的基础进行了研究。硬脂酸（C18:0）和油酸（C18:1）的比例呈现位点特异性变化；腹部脂肪库（网膜和肾周）中C18:0的含量相对高于C18:1，而胴体脂肪库，尤其是胸骨部位，C18:1的比例明显更高。此外，一些生脂酶基因（硬脂酰辅酶A去饱和酶[SCD]、乙酰辅酶A羧化酶α[ACC-α]、脂蛋白脂肪酶[LPL]）和细胞骨架蛋白基因α-微管蛋白的表达在不同脂肪库间存在差异，尽管每个mRNA的变化模式有所不同。当将这些表达数据与从所有脂肪库中汇集的脂肪细胞平均细胞体积相关联时，出现了一个显著的模式：ACC-α、LPL和α-微管蛋白基因的表达与脂肪细胞大小高度相关。相比之下，当将SCD mRNA的表达作为平均细胞体积的函数进行评估时，出现了两类脂肪细胞：腹部脂肪库中单个脂肪细胞的SCD mRNA表达与平均细胞体积之间未发现显著相关性，而在胴体和心外膜脂肪库中，SCD基因表达与平均细胞体积之间观察到高度显著的相关性。同样，胴体和心外膜脂肪库中单个脂肪细胞的C18:1含量与SCD mRNA丰度之间存在高度显著的相关性，而网膜和肾周脂肪库中这些性状之间未观察到显著相关性。因此，SCD基因似乎以脂肪库特异性方式进行调控，且调控方式与ACC和LPL基因不同。
