Effects of LiCl and Praziquantel on Regenerative Polarity and Survival in Planarian Worms
Faculty Mentor Information
Dr. Tom Pirtle, College of Idaho
Presentation Date
7-16-2026
Abstract
Planarian flatworms are widely used as a model system for studying regeneration due to their robust capacity for anterior–posterior patterning. Because anterior-posterior polarity is regulated by conserved signaling pathways, we hypothesized that treatment with Praziquantel (PZQ) and Lithium chloride (LiCl) would induce abnormal body plans. Tail fragments were exposed to one of four concentrations of aqueous LiCl or a spring water control, while head fragments were exposed to one of three concentrations of PZQ dissolved in dimethyl sulfoxide (DMSO) or the appropriate vehicle control (n = 10). Worms were monitored daily for survival, and regeneration outcomes were assessed for morphological abnormalities. No two-headed or two-tailed phenotypes were observed in any treatment group. Kaplan–Meier survival analysis revealed significant differences in survivorship among LiCl treatment groups (log-rank test: χ²(4) = 9.96, p = 0.040). In contrast, no significant differences in survival were observed among PZQ treatment groups (log-rank test: χ²( (3) = 3.047, p = 0.384). These results do not support the hypothesis that LiCl and PZQ alter regenerative polarity under the conditions tested. However, LiCl exposure was associated with altered survivorship, while PZQ did not significantly affect survival, suggesting compound-specific effects on planarian viability rather than regenerative patterning.
Effects of LiCl and Praziquantel on Regenerative Polarity and Survival in Planarian Worms
Planarian flatworms are widely used as a model system for studying regeneration due to their robust capacity for anterior–posterior patterning. Because anterior-posterior polarity is regulated by conserved signaling pathways, we hypothesized that treatment with Praziquantel (PZQ) and Lithium chloride (LiCl) would induce abnormal body plans. Tail fragments were exposed to one of four concentrations of aqueous LiCl or a spring water control, while head fragments were exposed to one of three concentrations of PZQ dissolved in dimethyl sulfoxide (DMSO) or the appropriate vehicle control (n = 10). Worms were monitored daily for survival, and regeneration outcomes were assessed for morphological abnormalities. No two-headed or two-tailed phenotypes were observed in any treatment group. Kaplan–Meier survival analysis revealed significant differences in survivorship among LiCl treatment groups (log-rank test: χ²(4) = 9.96, p = 0.040). In contrast, no significant differences in survival were observed among PZQ treatment groups (log-rank test: χ²( (3) = 3.047, p = 0.384). These results do not support the hypothesis that LiCl and PZQ alter regenerative polarity under the conditions tested. However, LiCl exposure was associated with altered survivorship, while PZQ did not significantly affect survival, suggesting compound-specific effects on planarian viability rather than regenerative patterning.