J Anim Sci. 2017 Dec;95(12):5563-5572. doi: 10.2527/jas2017.1983.
We hypothesized that maternal nutrition and day of gestation would impact utero-placental mRNA expression of the nutrient transporters , , , , and in beef heifers. Crossbred Angus heifers (n = 49) were estrous synchronized, bred via AI, assigned to nutritional treatment (CON = 100% of NRC requirements for 0.45 kg/d gain and RES = 60% of CON) and ovariohysterectomized on d 16, 34, or 50 of gestation (n = 6 to 9/d); Non-bred, non-pregnant (NB-NP) controls were fed the CON diet, not bred, and were ovariohysterectomized on d 16 of the synchronized estrous cycle = 6). The resulting arrangement of treatments was a 2 × 3 factorial + 1 (CON vs. RES × d 16, 34, or 50 + NB-NP controls). Caruncle (CAR), intercaruncular endometrium (ICAR), and fetal membranes (FM [chorioallantois]), were obtained from the pregnant uterine horn (the uterine horn containing the conceptus) immediately after ovariohysterectomy. On d 50 cotyledons (COT), intercotyledonary placenta (ICOT) and amnion (AMN) were also collected. Relative expression of nutrient transporters was determined for each tissue utilizing NB-NP-CAR and NB-NP-ICAR tissues as the baseline. For FM, NB-NP endometrium served as the baseline. There was no interaction of day × treatment ( ≥ 0.20) for any genes in CAR. However, CAR expression of was greater ( < 0.01) on d 16 compared with d 34 and 50, and , , and were greater ( ≤ 0.05) on d 34 compared with d 16 and 50. In ICAR, was the only gene to be influenced by the day × treatment interaction ( = 0.01), being greater in d 50 CON compared with d 34 CON and d 16 and 50 RES. In ICAR, expression of was greater ( < 0.01) on d 16 compared with d 34, and expression of was greater ( < 0.01) on d 34 and 50 compared with d 16. In FM, expression of was greater ( = 0.04) on d 16 compared with d 50 of gestation, and expression of was greater ( < 0.01) on d 34 and 50 compared with d 16. On d 50, expression of , , and expression were all greater ( < 0.05) in AMN compared with COT and ICOT, and expression of was greater ( < 0.01) in ICOT compared with COT and AMN. These data indicate that day was a more influential factor for mRNA expression of utero-placental glucose and cationic AA transporters than maternal nutritional status in heifers during early pregnancy.
我们假设母体营养和妊娠天数会影响肉牛胎儿胎盘组织中养分转运体的 mRNA 表达。杂交安格斯小母牛（n = 49）被同期发情，通过人工授精配种，分为营养处理组（CON = 满足 0.45kg/d 增重需要的 100%NRC 水平，RES = CON 的 60%），并于妊娠 16、34 或 50 天（n = 6-9/天）行卵巢子宫切除术；非配种非妊娠（NB-NP）对照组给予 CON 饮食，不进行配种，于同期发情周期的第 16 天（n = 6）行卵巢子宫切除术。处理的结果是一个 2×3 析因+1（CON 与 RES×d 16、34 或 50+NB-NP 对照组）。妊娠子宫角的胎盘（胎盘组织 CAR）、胎盘间组织（胎盘组织 ICA）和胎膜（绒毛尿囊膜 FM）在卵巢子宫切除后立即从怀孕的子宫角获得。妊娠 50 天，还收集绒毛膜（COT）、胎盘间绒毛膜（ICOT）和羊膜（AMN）。利用 NB-NP-CAR 和 NB-NP-ICAR 组织作为基线，利用 NB-NP 胎盘组织确定每个组织中养分转运体的相对表达。对于 FM，NB-NP 子宫内膜作为基线。在 CAR 中，任何基因都没有日×处理（≥0.20）的交互作用。然而，与 d34 和 d50 相比，d16 时 CAR 中基因的表达更高（<0.01），且 d34 时基因的表达高于 d16 和 d50。在 ICA 中，只有基因受到日×处理的相互作用（=0.01）的影响，d50CON 时的基因表达高于 d34CON 和 d16 和 d50RES。在 ICA 中，基因的表达在 d16 时高于 d34，基因的表达在 d34 和 d50 时高于 d16。在 FM 中，d16 时基因的表达高于 d50，d34 和 d50 时基因的表达高于 d16。在 d50 时，AMN 中基因的表达高于 COT 和 ICOT（<0.05），ICOT 中基因的表达高于 COT 和 AMN（<0.01）。这些数据表明，在妊娠早期，母畜营养状况对肉牛胎儿胎盘葡萄糖和阳离子 AA 转运体的 mRNA 表达的影响不如天数。
