Effect of low-dose cyhalothrin on motor behavior in zebrafish embryos
GUO Yingzi1, LUAN Ya’nan1, ZHOU Yuling1, BAI Chenglian2, REN Xiangpeng1.
1.Laboratory Center, the Eye Hospital of Wenzhou Medical University, Wenzhou, 325027; 2.School of Public Health and Environment, Wenzhou Medical University, Wenzhou, 325035
GUO Yingzi,LUAN Ya’nan,ZHOU Yuling, et al. Effect of low-dose cyhalothrin on motor behavior in zebrafish embryos[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2016, 46(7): 476-481.
Abstract：Objective: To study the effects of low-dose cyhalothrin on motor behavior in zebrafish embryos. Methods: The dose-response effects and malformation phenotype were evaluated by observing zebrafish embryos exposed to different concentrations of 0, 10, 20, 40, 80, 100 µg/L cyhalothrin solutions. The impact of low-dose of 0, 2.5, 5, 10 µg/L cyhalothrin on several motor behaviors in zebrafish embryos was then explored, including embryonic spontaneous movement, touch response and larval swimming speed. Results: The predominant malformation phenotypes observed in surviving embryos were edema of pericardialsac, bent spine, curved tail and yolk sac edema. Compared with the control group, zebrafish embryos exposed to 20 µg/L and above concentrations showed significantly increased malformation rate (P<0.05), while 10 µg/L cyhalothrin exhibited no influence on embryonic development. Cyhalothrin concentration that led to 50% malformations (EC50) of the embryos at 120 hours post fertilization (hpf) was 38.61 µg/L. A series of motor behavior tests revealed that embryos exposed to 2.5 µg/L cyhalothrin displayed remarkably elevated spontaneous movement frequency at 19, 21 and 22 hpf (P<0.05), while this frequency was decreased in embryos treated with 10 µg/L cyhalothrin at 20-21 hpf (P<0.05); besides, 5, 10 µg/L cyhalothrin exposure induced markedly reduction of touch response movement in zebrafish embryos at both 27 and 48 hpf (P<0.05); moreover, 10 µg/L cyhalothrin reduced larval swimming movement speed at 120 hpf (P<0.01). Conclusion: Cyhalothrin causes severe embryonic toxicity in a dose-dependent manner. Low dose of cyhalothrin exposure which shows no effect on embryonic development significantly alters several motor behaviors at early life stage.
