Jersey steer ruminal papillae histology and nutrigenomics with diet changes
JOURNAL OF ANIMAL PHYSIOLOGY AND ANIMAL NUTRITION
Authors: Novak, Taylor E.; Rodriguez-Zas, Sandra L.; Southey, Bruce R.; Starkey, Jessica D.; Stockler, Ricardo M.; Alfaro, Gaston F.; Moisa, Sonia J.
Abstract
The transition from a high forage to a high concentrate diet is an important milestone for beef cattle moving from a stocker system to the feedlot. However, little is known about how this transition affects the rumen epithelial gene expression. This study assessed the effects of the transition from a high forage to a high concentrate diet as well as the transition from a high concentrate to a high forage diet on a variety of genes as well as ruminal papillae morphology in rumen fistulated Jersey steers. Jersey steers (n = 5) were fed either a high forage diet (80% forage and 20% grain) and transitioned to a high concentrate diet (20% forage and 80% grain) or a high concentrate diet (40% forage and 60% grain) and transitioned to a high forage diet (100% forage). Papillae from the rumen were collected for histology and RT-qPCR analysis. Body weight had a tendency for significant difference (p = .08). Histological analysis did not show changes in papillae length or width in steers transitioning from a high forage to a high concentrate diet or vice versa (p > .05). Genes related to cell membrane structure (CLDN1, CLDN4, DSG1), fatty acid metabolism (CPT1A, ACADSB), glycolysis (PFKL), ketogenesis (HMGCL, HMGCS2, ACAT1), lactate/pyruvate (LDHA), oxidative stress (NQO1), tissue growth (AKT3, EGFR, EREG, IGFBP5, IRS1) and the urea cycle (SLC14A1) were considered in this study. Overall, genes related to fatty acid metabolism (ACADSB) and growth and development (AKT3 and IGFBP5) had a tendency for a treatment x day on trial interaction effect. These profiles may be indicators of rumen epithelial adaptations in response to changes in diet. In conclusion, these results indicate that changes in the composition of the diet can alter the expression of genes with specific functions in rumen epithelial metabolism.
Dietary betaine supplementation in hens modulates hypothalamic expression of cholesterol metabolic genes in F1 cockerels through modification of DNA methylation
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY
Authors: Idriss, Abdulrahman A.; Hu, Yun; Hou, Zhen; Hu, Yan; Sun, Qinwei; Omer, Nagmeldin A.; Abobaker, Halima; Ni, Yingdong; Zhao, Ruqian
Abstract
Betaine is widely used in animal nutrition to promote growth, development and methyl donor during methionine metabolism through nutritional reprogramming via regulation of gene expression. Prenatal betaine exposure is reported to modulate hypothalamic cholesterol metabolism in chickens, yet it remains unknown whether feeding hens with betaine-supplemented diet may affect hypothalamic cholesterol metabolism in F1 offspring. In this study, hens were fed with basal or betaine-supplemented (0.5%) for 30 days, and the eggs were collected for incubation. The hatchlings were raised under the same condition up to 56 days of age. Betaine-treated group showed significantly (P < 0.05) higher plasma concentration of total cholesterol and HDL-cholesterol, together with increased hypothalamic content of total cholesterol and cholesterol ester. Concordantly, hypothalamic gene expression of SREBP2, HMGCR, and LDLR was significantly up regulated (P < 0.05). Also, mRNA abundances of SREBP1, ACAT1 and APO-A1 were up-regulated, while that of CYP46A1 was significantly down-regulated (P < 0.05). These changes coincided with a significant down-regulation of BDNF and CRH, and a significant up regulation of NPY mRNA expression. Moreover, genes involved in methyl transfer cycle were also modulated. DNMT1 and BHMT were up-regulated (P < 0.05) at both mRNA and protein levels, which was associated with significant modifications of CpG methylation on the promoter of SREBP-1, SREBP-2 and APO-Al genes as detected by bisulfate sequencing. These results indicate that feeding betaine to hens modulates hypothalamic expression of genes involved in cholesterol metabolism and brain functions in F1 cockerels with modification of promoter DNA methylation.