单碳代谢物(OCM)是代谢物和辅因子,包括叶酸,维生素B12,蛋氨酸,和支持甲基化反应的胆碱。这项研究的目的是研究在肉牛妊娠的前63天期间,母体体重增加的中度变化与OCM补充剂对(1)母体血清中的B12和叶酸浓度的影响(2)母体和胎儿肝脏中的叶酸循环中间体,尿囊液(ALF),羊水(AMF)和(3)代谢产物参与母体和胎儿肝脏的一碳代谢和相关代谢途径。小母牛要么被限制摄入(RES),要么被喂食以损失0.23千克/天,或饲料增加0.60公斤/天(CON)。补充(+OCM)母牛每周注射B12和叶酸盐,每天喂食瘤胃保护的蛋氨酸和胆碱,而非补充(-OCM)母牛每周注射生理盐水。这两种处理以2×2阶乘排列组合,产生四种处理:CON-OCM,CON+OCM,RES-OCM,和RES+OCM。母体血清样本,母体和胎儿肝脏,ALF,在妊娠第63天屠宰时收集AMF。限制母体营养最显着增加(P≤0.05):母体血清中维生素B12的浓度,母体肝脏中的5,10-亚甲基四氢叶酸和5,10-亚甲基四氢叶酸,和胎儿肝脏中的胱硫醚;相反,母体限制降低(P=0.05)胎儿肝脏中5,10-亚甲基四氢叶酸的浓度。补充OCM增加(P≤0.05)的浓度:母体血清B12,叶酸和叶酸中间体,ALF和AMF5-甲基四氢叶酸浓度,并改变(P≤0.02)其他母体肝脏中间体,包括S-腺苷甲硫氨酸,二甲基甘氨酸,谷胱甘肽还原,谷胱甘肽氧化,牛磺酸,丝氨酸,肌氨酸,还有吡哆醇.这些数据表明OCM补充在增加母体OCM状态方面是有效的。此外,这些数据与以前发表的文献相似,在文献中,限制母体营养也会影响母体OCM状态.改变大坝和胎儿的OCM状态可能会影响胎儿的发育结局和生产效率。最后,这些数据表明,胎儿代谢物的丰度受到高度调节,尽管维持体内平衡所需的变化可能是出生后计划改变的代谢。
One-carbon metabolites (OCM) are metabolites and cofactors which include folate, vitamin B12, methionine, and choline that support methylation reactions. The objectives of this study were to investigate the effects of moderate changes in maternal body weight gain in combination with OCM supplementation during the first 63 d of gestation in beef cattle on (1) B12 and folate concentrations in maternal serum (2) folate cycle intermediates in maternal and fetal liver, allantoic fluid (ALF), and amniotic fluid (AMF) and (3) metabolites involved in one-carbon metabolism and related metabolic pathways in maternal and fetal liver. Heifers were either intake restricted (RES) and fed to lose 0.23 kg/d, or fed to gain 0.60 kg/d (CON). Supplemented (+ OCM) heifers were given B12 and folate injections weekly and fed rumen-protected methionine and choline daily, while non-supplemented (-OCM) heifers were given weekly saline injections. These two treatments were combined in a 2 × 2 factorial arrangement resulting in 4 treatments: CON-OCM, CON + OCM, RES-OCM, and RES + OCM. Samples of maternal serum, maternal and fetal liver, ALF, and AMF were collected at slaughter on day 63 of gestation. Restricted maternal nutrition most notably increased (./ ≤ 0.05) the concentration of vitamin B12 in maternal serum, 5,10-methylenetetrahydrofolate and 5,10-methenyltetrahydrofolate in maternal liver, and cystathionine in the fetal liver; conversely, maternal restriction decreased (P = 0.05) 5,10-methylenetetrahydrofolate concentration in fetal liver. Supplementing OCM increased (P ≤ 0.05) the concentrations of maternal serum B12, folate, and folate intermediates, ALF and AMF 5-methyltetrahydrofolate concentration, and altered (P ≤ 0.02) other maternal liver intermediates including S-adenosylmethionine, dimethylglycine, cystathionine Glutathione reduced, glutathione oxidized, taurine, serine, sarcosine, and pyridoxine. These data demonstrate that OCM supplementation was effective at increasing maternal OCM status. Furthermore, these data are similar to previously published literature where restricted maternal nutrition also affected maternal OCM status. Altering OCM status in both the dam and fetus could impact fetal developmental outcomes and production efficiencies. Lastly, these data demonstrate that fetal metabolite abundance is highly regulated, although the changes required to maintain homeostasis may program altered metabolism postnatally.
Maternal stresses that occur during pregnancy, such as restricted nutrition, can impact the developmental outcomes of the offspring in a process known as developmental programming. This programming can occur through epigenetics, which involves changes in fetal gene expression and can occur through the addition of methyl groups to DNA. These changes regulate gene transcription in the offspring and can alter offspring health, efficiency, and life-long outcomes. One-carbon metabolites (OCM), which are nutrients like the amino acid methionine and the vitamins B12, folate, and choline, act as intermediates or cofactors for the donation of methyl groups to DNA. This study investigated the effects of differing maternal rates of gain along with OCM supplementation during early gestation on OCM and related metabolite concentrations in the dam and fetus. We found that supplementing OCM to beef heifers increased maternal OCM and related metabolite concentrations and fetal fluid OCM concentrations. We also found that low maternal gain increased maternal serum and liver OCM concentrations. We can conclude from these findings that both maternal rate of gain and OCM supplementation can impact maternal OCM concentrations at day 63 of gestation and further research is needed to see if those maternal impacts will affect the developing fetus or calf later in its life.