RAPID COMMUNICATION: Isolation of glucose transporters GLUT3 and GLUT14 in bovine uteroplacental tissues from days 16 to 50 of gestation

摘要

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 GLUT3 and has not previously been isolated in ruminant uteroplacental tissues. The GLUT3 transporter has been previously isolated in Holstein heifer uterine epithelium but not in ovine epithelium. We hypothesized that GLUT3 and its duplicon GLUT14 would be found in bovine uteroplacental tissues and that maternal nutrition and day of gestation would impact mRNA expression of GLUT3 and 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 x 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 x treatment interactions for GLUT3 or GLUT14 gene expression in CAR, ICAR, or FM. Expression of GLUT3 in CAR was greater (P = 0.03) on d 50 compared with d 16. In ICAR, GLUT3 was greatest (P = 0.02) on d 50 compared with d 16 and 34 of gestation. In FM, GLUT3 was greater (P = 0.04) on d 16 compared with d 50. Expression of GLUT3 was greater (P = 0.05) in pregnant compared with nonpregnant heifers. Additionally, expression of GLUT3 was greater (P = 0.01) on d 34 and 50 compared with d 16. Expression of GLUT14 in CAR was greater (P = 0.03) on d 50 compared to d 16 and 34. In CAR, GLUT14 tended (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 GLUT3 or GLUT14 in CAR, ICAR, or FM. These data demonstrate that glucose transporters GLUT3 and GLUT14 are expressed in beef heifer uteroplacental tissues and that they are expressed differentially by day of gestation in bovine uteroplacental tissues.