Liver and skeletal muscle mitochondria proteomes are altered in pigs divergently selected for residual feed intake1,2

Abstract

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. ABSTRACT: 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 twodimensional 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.

Improving efficiency in meat production

“…Effects on mRNA or miRNA associated with mitochondria appear to be a recurring theme in the low RFI studies (33,34) and this agrees with some of our growth promoter studies, where we also see downregulation of a number of genes associated with mitochondria, including both tricarboxylic acid cycle and oxidative phosphorylation genes (JM Brameld, T Parr et al, unpublished results).…”

Proteomic changes to the sarcoplasmic fraction of predominantly red or white muscle following acute heat stress

“…An increase in total ATP synthase would therefore indicate greater potential for ATP production via oxidative phosphorylation. Previous work has shown that an increase in ATP synthase abundance is associated with a more efficient phenotype in pigs [34,57]. While this result could be indicative of greater oxidative phosphorylation, it could also be a response to reduced substrate and a lack of negative feedback in the electron transport chain.…”

“…It was also increased 16% (P b 0.01) in the RST and 30% (P = 0.01) in the WST of HS versus PFTN pigs. Increased mtHsp70 has been linked to better mitochondrial function with less reactive oxygen species production in non HS pigs [33,34]. The increased mtHsp70 during HS suggests that the mitochondria are attempting to maintain function despite the decreased pyruvate flux into the TCA cycle (described below).…”

Caracterização proteômica do fígado de bovinos Nelore divergentes para eficiência alimentar

“…A análise da expressão gênica pela transcriptômica também tem sido amplamente difundida, com diversos órgãos alvo, relacionando diferenças na expressão e redes de interação gênica a este fenótipo BENEDETI et al, 2018;KHANSEFID et al, 2017;PARADIS et al, 2015;SALLEH et al, 2017;TIZIOTO et al, 2015TIZIOTO et al, , 2016WEBER et al, 2016;ZAREK et al, 2017). Estes estudos confirmaram a relação entre este et al, 2017a;2017b;KONG et al, 2016) e suínos (FU et al, 2017;GRUBBS et al, 2013GRUBBS et al, , 2014VINCENT et al, 2015). O conhecimento do perfil de abundância dos genes em diferentes condições auxilia no conhecimento da função do gene e das rotas de regulação (BUNNIK; LE ROCH, 2013).…”