Grubbs J K, Huff-Lonergan E, Gabler N K, M Dekkers J C, Lonergan S M
Department of Animal Science, Iowa State University, Ames 50011.
J Anim Sci. 2014 May;92(5):1995-2007. doi: 10.2527/jas.2013-7391. Epub 2014 Mar 26.
Animals selected for residual feed intake (RFI) can be used as a model to elucidate molecular explanations for differences in growth efficiency. The objective of this study was to determine the extent to which the protein profile and posttranslational modifications of mitochondria from skeletal muscle and liver relate to feed efficiency gains in pigs divergently selected for RFI. Mitochondria were isolated from the longissimus dorsi (LD) muscle and the liver from pigs (n = 9 each for the high and low RFI line; BW = 95.8 kg). Mitochondria protein profile differences were determined using two-dimensional difference in gel electrophoresis. Proteins were identified using electrospray ionization mass spectrometry. In the line comparison, the β subunit of ATP synthase, heat shock protein (HSP) 60, and HSP70, were identified as being increased in mitochondria from the liver of the low RFI line (23 to 50%; P < 0.1). These differences were not observed in the other comparisons. In the LD, proteins identified as being different between RFI phenotypes included HSP70 and subunit 1 of the cytochrome bc1 complex. These data indicate that genetic selection for RFI tends to result in a consistent change in mitochondrial protein profile. In contrast, classification by phenotype demonstrates that phenotypic differences in RFI are not specifically associated with alterations of the mitochondria protein profile.
选择用于研究剩余采食量（RFI）的动物可作为一种模型，以阐明生长效率差异的分子解释。本研究的目的是确定从骨骼肌和肝脏中分离出的线粒体的蛋白质谱和翻译后修饰与因RFI而被差异选择的猪的饲料效率提高之间的关联程度。从猪的背最长肌（LD）和肝脏中分离出线粒体（高RFI系和低RFI系各9头猪；体重=95.8千克）。使用二维差异凝胶电泳确定线粒体蛋白质谱差异。通过电喷雾电离质谱法鉴定蛋白质。在品系比较中，发现低RFI系猪肝脏线粒体中的ATP合酶β亚基、热休克蛋白（HSP）60和HSP70增加（23%至50%；P<0.1）。在其他比较中未观察到这些差异。在背最长肌中，被鉴定为RFI表型之间存在差异的蛋白质包括HSP70和细胞色素bc1复合体的亚基1。这些数据表明，对RFI进行遗传选择往往会导致线粒体蛋白质谱发生一致变化。相比之下，按表型分类表明，RFI的表型差异与线粒体蛋白质谱的改变并无特定关联。
