RAPID COMMUNICATION: Isolation of glucose transporters GLUT3and GLUT14in bovine uteroplacental tissues from days 16 to 50 of gestation1

Glucose transporter solute carrier family 2 member 14 (GLUT14) is a duplicon of glucose transporter solute carrier family 2 member 3 (GLUT3) with a 95% shared homology to GLUT3and has not previously been isolated in ruminant uteroplacental tissues. The GLUT3transporter has been previously isolated in Holstein heifer uterine epithelium but not in ovine epithelium. We hypothesized that GLUT3and its duplicon GLUT14would be found in bovine uteroplacental tissues and that maternal nutrition and day of gestation would impact mRNA expression of GLUT3and GLUT14. Crossbred Angus heifers (n= 49) were estrus synchronized, bred via AI, and assigned to nutritional treatment (CON = 100% of requirements to gain 0.45 kg/d; RES = 60% of CON) at breeding. Ovariohysterectomy was performed on d 16, 34, or 50 of gestation (n= 6 to 9/d); nonpregnant (NP) controls were not bred and ovariohysterectomized on d 16 of the synchronized estrous cycle (n= 6). The resulting treatment arrangement was a 2 × 3 factorial + 1. Uteroplacental tissues (caruncle, CAR; intercaruncular endometrium, ICAR; and fetal membrane [chorioallantois], FM) were obtained from the pregnant uterine horn immediately after ovariohysterectomy. For NP controls, only CAR and ICAR were obtained. There were no day × treatment interactions for GLUT3or GLUT14gene expression in CAR, ICAR, or FM. Expression of GLUT3in CAR was greater (P= 0.03) on d 50 compared with d 16. In ICAR, GLUT3was greatest (P= 0.02) on d 50 compared with d 16 and 34 of gestation. In FM, GLUT3was greater (P= 0.04) on d 16 compared with d 50. Expression of GLUT3was greater (P= 0.05) in pregnant compared with nonpregnant heifers. Additionally, expression of GLUT3was greater (P= 0.01) on d 34 and 50 compared with d 16. Expression of GLUT14in CAR was greater (P= 0.03) on d 50 compared to d 16 and 34. In CAR, GLUT14tended (P= 0.07) to be greater on d 34 and 50 than on d 16 and was greater (P= 0.02) on d 50 than on d 34. There was no effect of treatment for either GLUT3or GLUT14in CAR, ICAR, or FM. These data demonstrate that glucose transporters GLUT3and GLUT14are expressed in beef heifer uteroplacental tissues and that they are expressed differentially by day of gestation in bovine uteroplacental tissues.