Differences in muscle transcriptome among pigs phenotypically extreme for fatty acid composition

Anna Puig-Oliveras (1, 2) , Yuliaxis Ramayo Caldas (3) , Jordi Corominas (1, 2) , Jordi Estellé (3, 4) , Dafne Pérez-Montarelo (5) , Nicholas J Hudson (6) , Joaquim Casellas (2, 7) , Josep M Folch (1, 2) , Maria Ballester (8, 2)

1 Departament de Genètica Animal
2 Departament de Ciència Animal i dels Aliments
3 GABI - Génétique Animale et Biologie Intégrative
4 LREG - Laboratoire de radiobiologie et d'étude du génome
5 Departamento de Genética Animal
6 Animal, Food and Health SciencesQLD
7 Departament de Genètica i Millora Animal
8 Departament de Genètica Animal

Central nervous system neurons, cultured as monolayers at low density, need exogenous pyruvate for their survival. The pyruvate concentrations required by embryonic day 8 (E8) chick forebrain neurons are reduced substantially by other low molecular weight agents present in Dulbecco's modified Eagle's medium (DMEM) and in astroglia-conditioned Eagle's basal medium (EBM). To examine the nature of these pyruvate-sparing molecules, E8 chick forebrain neurons were cultured in EBM containing a concentration of pyruvate too low to support neuronal survival, unless sparing agents were supplied. This strategy permitted the identification of the pyruvate-sparing DMEM constituents, omission of which had led to neuronal loss. Pyruvate sparing required a mixture of (i) serine, (ii) pyridoxal (or riboflavin and biotin), and (iii) six essential amino acids: arginine, cystine, leucine, isoleucine, tyrosine, and tryptophan (each replaceable by corresponding amino acids, except tryptophan). All pyruvate-sparing contributors were optimally needed at or near their DMEM concentrations.[br/] Besides having an impact on human health, the porcine muscle fatty acid profile determines meat quality and taste. The RNA-Seq technologies allowed us to explore the pig muscle transcriptome with an unprecedented detail. The aim of this study was to identify differentially-expressed genes between two groups of 6 sows belonging to an Iberian × Landrace backcross with extreme phenotypes according to FA profile.[br/] We sequenced the muscle transcriptome acquiring 787.5 M of 75 bp paired-end reads. About 85.1% of reads were mapped to the reference genome. Of the total reads, 79.1% were located in exons, 6.0% in introns and 14.9% in intergenic regions, indicating expressed regions not annotated in the reference genome. We identified a 34.5% of the intergenic regions as interspersed repetitive regions. We predicted a total of 2,372 putative proteins. Pathway analysis with 131 differentially-expressed genes revealed that the most statistically-significant metabolic pathways were related with lipid metabolism. Moreover, 18 of the differentially-expressed genes were located in genomic regions associated with IMF composition in an independent GWAS study in the same genetic background. Thus, our results indicate that the lipid metabolism of FAs is differently modulated when the FA composition in muscle differs. For instance, a high content of PUFA may reduce FA and glucose uptake resulting in an inhibition of the lipogenesis. These results are consistent with previous studies of our group analysing the liver and the adipose tissue transcriptomes providing a view of each of the main organs involved in lipid metabolism.[br/] The results obtained in the muscle transcriptome analysis increase the knowledge of the gene regulation of IMF deposition, FA profile and meat quality, in terms of taste and nutritional value. Besides, our results may be important in terms of human health.

Domaines: Sciences du Vivant [q-bio]

Anna Puig-Oliveras, Yuliaxis Ramayo Caldas, Jordi Corominas, Jordi Estellé, Dafne Pérez-Montarelo, et al.. Differences in muscle transcriptome among pigs phenotypically extreme for fatty acid composition. PLoS ONE, 2014, 9 (6), ⟨10.1371/journal.pone.0099720⟩. ⟨hal-01194006⟩