Xenopus glucose transporter 1 (xGLUT1) is required for gastrulation movement in Xenopus laevis

Abstract

Glucose transporters (GLUTs) are transmembrane proteins that play an essential role in sugar uptake and energy supply. Thirteen GLUT genes have been described and GLUT1 is the most abundantly expressed member of the family in animal tissues. Deficiencies in human GLUT1 are associated with many diseases, such as metabolic abnormalities, congenital brain defects and oncogenesis. It was suggested recently that Xenopus GLUT1 (xGLUT1) is upregulated by Activin/ Nodal signaling, although the developmental role of xGLUT1 remains unclear. Here, we investigated the expression pattern and function of xGLUT1 during Xenopus development. Wholemount in situ hybridization analysis showed expression of xGLUT1 in the mesodermal region of Xenopus embryos, especially in the dorsal blastopore lip at the gastrula stage. From the neurula stage, it was expressed in the neural plate, eye field, cement gland and somites. Loss-of-function analyses using morpholino antisense oligonucleotides against xGLUT1 (xGLUT1MO) caused microcephaly and axis elongation error. This elongation defect of activin-treated animal caps occurred without downregulation of early mesodermal markers. Moreover, dorsal-marginal explant analysis revealed that cell movement was suppressed in dorsal marginal zones injected with xGLUT1MO. These findings implicate xGLUT1 as an important player during gastrulation cell movement in Xenopus.

Will the original glucose transporter isoform please stand up!

“…Furthermore, these morpholinos against GLUT1 suppressed cell movement in dorsal marginal zones, supporting an important role for GLUT1 during gastrulation cell movement (121). Using morpholinos targeted against GLUT1 in a Danio rerio (zebra fish) embryonic model, a decline in embryonic growth along with disruption of the developing brain structure was evident secondary to apoptosis (61).…”

The Xenopus Bowline/Ripply family proteins negatively regulate the transcriptional activity of T-box transcription factors

“…The procedures used for RT-PCR were as previously described (Suzawa et al, 2007). Xenopus embryos were injected with 500 pg of Tbx6, mespb, and E47 mRNA.…”

Retinoic acid metabolizing factor xCyp26c is specifically expressed in neuroectoderm and regulates anterior neural patterning in Xenopus laevis

“…RT-PCR analysis was performed as described above (Suzawa et al, 2007). Primers for PCR were as follows: xCyp26c; 5'-ACG AGG GGA AAC TGG GCA AAT TCA AC-3' and 5'-TCA GGC AAG TGA CCC ATT TCT TGC TGC-3', xCyp26a; 5'-CTT GCG GAG GTG GAG TGA GGT G-3' and 5'-GCT TAA ATA GAG CTG GAG AAG GG-3', ODC; 5'-GCC ATT GTG AAG ACT CTC TCC ATT C-3' and 5'-TTC GGG TGA TTC CTT GCC AC-3', xRX1; 5'-GGC TAT GGA GAT CCA TAT TCA GG-3' and 5'-CTC TTC TCT GCT GTA TAC GTC GG-3', xOtx2; 5'-GGA TGG ATT TGT TAC ATC CGT C-3' and 5'-CAC TCT CCG AGC TCA CTT CCC-3'.…”