Establishment of An Alloxan-induced Diabetes Model in Daphnia Pulex

Objective To establish a Daphnia model of alloxan-induced diabetes. Methods Daphnia were exposed to three different concentrations of alloxan (3, 5, and 10 mmol/L) for 30 minutes. Blood glucose and survival rate were recorded for 72 hours after alloxan insult. Sequence analysis and phylogenetic inference for glucose transporters (GLUT) were clustered with the maximum-likelihood method. Using reverse transcription and quantitative polymerase chain reaction techniques, we investigated the transcriptional changes of GLUT at 12 hours after alloxan (5 mmol/L) exposure. Results Compared with control, 3 mmol/L, and 5 mmol/L as well as 10 mmol/L alloxan initially induced transient blood glucose decline by 15% for 2 hours and 12 hours respectively. In Daphnia with 5 and 10 mmol/L alloxan, their blood glucose was persistently raised by about 150% since after 24-hour insult. Survival rate of Daphnia exposure to alloxan with concentrations of 3, 5, and 10 mmol/L were 90%, 75%, and 25% respectively. We predicted seven GLUT genes in the Daphnia genome and successfully amplified them using real-time polymerase chain reaction. Two of seven GLUT transcripts were down-regulated in Daphnia with 5 mmol/L alloxan-induced diabetes. Conclusion Alloxan-induced diabetes model was successfully established in the Daphnia pulex, suggesting diabetes-relevant experiments can be conducted using Daphnia.