Anti-ACAT1 monoclonal antibody, clone BU3D6

Ruminal genes differentially expressed in crossbred beef steers from USMARC with variation in gain and feed intake were identified in a previous study. Several of the genes identified with expression patterns differing between animals with high gain-low feed intake and low gain-high feed intake were evaluated in a separate, unrelated population of Angus x Hereford beef steers from the University of Wyoming that was classified to differ in residual feed intake (RFI). Of the 17 genes tested, two were differentially expressed by RFI class in the Angus x Hereford animals. These genes included NAD(P) H dehydrogenase, quinone 1 (NQO1; P = 0.0009) and regulator of G-protein signaling 5 (RGS5; P = 0.01). A third gene, acetyl-CoA acetyltransferase 1 (ACAT1; P = 0.06), displayed a trend toward association with RFI. These data suggest that some of the genes identified in a previous rumen transcriptome discovery study may have utility for identifying or selecting for animals with superior feed efficiency phenotypes across cattle breeds and populations.

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.