RNA-seq analysis of bovine adipose tissue in heifers fed diets differing in energy and protein content

Hilde K L Wærp; Sinéad M Waters; Matthew S McCabe; Paul Cormican; Ragnar Salte

doi:10.1371/journal.pone.0201284

RNA-seq analysis of bovine adipose tissue in heifers fed diets differing in energy and protein content

PLoS One. 2018 Sep 20;13(9):e0201284. doi: 10.1371/journal.pone.0201284. eCollection 2018.

Authors

Hilde K L Wærp¹, Sinéad M Waters², Matthew S McCabe², Paul Cormican², Ragnar Salte¹

Affiliations

¹ Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway.
² Animal and Bioscience Research Department, Animal and Grassland Research and Innovation Centre, Teagasc, Dunsany, Co. Meath, Ireland.

Abstract

Adipose tissue is no longer considered a mere energy reserve, but a metabolically and hormonally active organ strongly associated with the regulation of whole-body metabolism. Knowledge of adipose metabolic regulatory function is of great importance in cattle management, as it affects the efficiency and manner with which an animal converts feedstuff to milk, meat and fat. However, the molecular mechanisms regulating metabolism in bovine adipose tissue are still not fully elucidated. The emergence of next-generation sequencing technologies has facilitated the analysis of metabolic function and regulation at the global gene expression level. The aim of this study was to investigate the effect of diets differing in protein and energy density level on gene expression in adipose tissue of growing replacement dairy heifers using next-generation RNA sequencing (RNAseq). Norwegian Red heifers were fed either a high- or low-protein concentrate (HP/LP) and a high- or low-energy roughage (HE/LE) diet from 3 months of age until confirmed pregnancy to give four treatments (viz, HPHE, HPLE, LPHE, LPLE) with different growth profiles. Subcutaneous adipose tissue sampled at 12 months of age was analyzed for gene expression differences using RNAseq. The largest difference in gene expression was found between LPHE and LPLE heifers, for which 1092 genes were significantly differentially expressed, representing an up-regulation of mitochondrial function, lipid, carbohydrate and amino acid metabolism as well as changes in the antioxidant system in adipose tissue of LPHE heifers. Differences between HPHE and HPLE heifers were much smaller, and dominated by genes representing NAD biosynthesis, as was the significantly differentially expressed genes (DEG) common to both HE-LE contrasts. Differences between HP and LP groups within each energy treatment were minimal. This study emphasizes the importance of transcriptional regulation of adipose tissue energy metabolism, and identifies candidate genes for further studies on early-stage obesity and glucose load in dairy cattle.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animal Feed*
Animals
Cattle
Dietary Proteins / pharmacology*
Energy Metabolism / drug effects*
Female
Gene Expression Regulation / drug effects
Pregnancy
RNA / biosynthesis*
Sequence Analysis, RNA*
Subcutaneous Fat / metabolism*

Substances

Dietary Proteins
RNA

Grants and funding

This study was partly was funded by The Research Council of Norway (Oslo) project number 199448: The salary of Hilde Waerp was partly from this grant, TINE SA Norwegian dairies, Felleskjøpet agricultural cooperative and Animalia AS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.