Response of facilitative glucose transporter 1 to salinity stress and dietary carbohydrate nutrition in white shrimp Litopenaeus vannamei

Facilitative glucose transporter 1 (GLUT1) is a transporter protein for glucose transport via the plasma membrane of the cells to provide energy through carbohydrate metabolism. GLUT1 cDNA from Litopenaeus vannamei was obtained and analysed in this study. Full-length GLUT1 cDNA is 2062 bp long and contained a 1506-bp ORF encoding a 502 amino acid protein, a 270-bp 5′UTR and a 284-bp 3′UTR. When shrimp were under acute low salinity stress, the expression in hepatopancreas, muscle, gill and eyestalk was all up-regulated at 12 h (P < 0.05) and 96 h (P < 0.05), while the expression in the four tissues was all down-regulated at 6 h (P < 0.05) and 48 h (P < 0.05). The expression in the muscle of shrimp at water salinity of 3 was lower than that at water salinity of 30 independent of dietary carbohydrate levels, while expression in hepatopancreas, gill and eyestalk was up-regulated at 200 and 300 g kg⁻¹ carbohydrate levels. The expression in all tissues fed glucose was up-regulated when compared to the expression in shrimp held at a water salinity of 30. This study suggests that GLUT1 is a conserved protein in L. vannamei, and changes in expression due to environmental salinity and dietary carbohydrate level and source.