An examination on the expression of glucose transporters in chickens

Cellular glucose uptake and disposal are at the center for energy balance, adipose tissue development and diabetes. Glucose uptake is facilitated by a family of glucose transporters called GLUTs that move glucose passively across the cell membrane. Previous investigations have shown that, similar to mammalian species, the chicken expresses eleven of the GLUT members. In chicken adipose tissue, glucose transporter 1 (GLUT1) and glucose transporter 8 (GLUT8) genes contribute to the mechanisms of fat deposition. In order to assess the roles of G¬LUT1 and GLUT8, as well as other glucose transporters in chicken adipose tissue development, we studied the developmental regulation and responses to dietary manipulation on adipose fat. The mRNA levels of GLUTs in adipose tissue development were assayed using RT-qPCR. Results showed that (1) GLUT1 mRNA level was significantly affected by age and diet, and (2) GLUT8 mRNA had the highest expression level and was modulated by dietary manipulation effect on GLUT expression. In addition to adipose tissue, we also examined mRNA levels of glucose transporters among other tissue types, including heart, pancreas, intestine, liver and kidney. Results showed that (1) GLUT5 has a high level of mRNA expression in the chicken heart, followed by GLUT1, (2) GLUT5 is the most highly expressed glucose transporter in the chicken pancreas, followed by GLUT8, GLUT9 and GLUT12, (3) GLUT5 is very highly expressed in the chicken intestine, followed by GLUT2 and GLUT9, (4) GLUT2 and GLUT5 are most highly expressed in the chicken liver, and (5) GLUT5 is highly expressed in the chicken kidney, followed by GLUT2. These results highlight the tissue-specific regulation mechanism of GLUTs