Abstract PR429

Abstract

Background & Objectives: To establish a Daphnia model of alloxan-induced diabetes contributing to conduct diabetes-relevant experiments in daphnid. Materials & Methods: Daphnid were exposure to 30-min 3 concentrations of alloxan (3 mM, 5 mM and 10 mM). Blood glucose and survival rate were recorded for 72 hrs after alloxan insult. Sequence analysis and phylogenetic inference for glucose transporters (GLUTs) were clustered with the maximum-likelihood method. Using reverse transcription and quantitative PCR techniques, we investigated the transcriptional changes of GLUTs at 12 hrs after alloxan (5 mM) exposure. Results: Compared with control, 3 mM, and 5 mM as well as 10 mM alloxan initially induced transient blood glucose decline by 15% for 2 hrs and 12 hrs respectively. In daphnid with 5 and 10 mM alloxan, their blood glucose was persistently raised about 250% since after 24-hr insult. Survival rate of daphnid with 3 mM, 5mM and 10 mM were 90%, 75% and 25%. We predicted seven GLUTs genes in the Daphnia genome and successfully amplified them using RT-PCR. Two of 7 GLUTs transcripts were downregulated in Daphnia with 5 mM alloxan-induced diabetes. Conclusion: This study provides the first evidence that alloxan can induce diabetes in Daphnia pulex possibly by downregulation of glucose transporters (GLUT1 and GLUT2), a new invertebrate model for diabetes.