微塑料对热带爪蟾蝌蚪变态全过程中组织器官分化与发育的影响机制

蝌蚪作为蟾蜍类和蛙类的幼体，具有广泛的摄食特性，易于摄入微塑料并产生潜在的毒害作用。当前研究主要集中在微塑料对早期发育阶段蝌蚪的短期影响上，较少关注从蝌蚪到成体变态全过程中微塑料的长期效应。而蝌蚪在变态发育过程中需经历多个组织器官的分化、吸收和重构，在此期间对微塑料等污染物同样十分敏感脆弱。鉴于此，本项目拟选取典型两栖模式生物——热带爪蟾蝌蚪作为实验对象，从其变态过程中组织器官动态变化的角度出发，通过荧光示踪手段，研究不同粒径微塑料在蝌蚪新分化的、已有的和重组的组织器官中的分布和积累特征；结合微塑料的组织器官特异性分布，考察微塑料对蝌蚪组织器官病理毒性和生理生化指标的影响，探讨微塑料体内分布与蝌蚪变态发育的相互影响关系，揭示微塑料对蝌蚪变态全过程中组织器官分化与发育的影响机制，筛选表征微塑料毒性的敏感生物学指标。预期结果将为准确评估微塑料对淡水生物的毒性效应提供科学依据。

As the larva of the toads and frogs, tadpoles exhibit extensive feeding activity that exposes them directly to microplastics present in the aquatic environment, resulting in the negative impacts of microplastic ingestion. Previous researches concentrated on the short-term effects of microplastics on the early stages of metamorphosis development of tadpoles. To date, however, studies on the long-term influences of microplastics during Xenopus tropicalis metamorphosis from tadpoles to froglets are limited. During metamorphosis, tadpoles need to undergo differentiation, resorption and remodeling of multiple tissues and organs, and are also vulnerable to contaminants such as microplastics. Therefore, X. tropicalis, which is an amphibian model animal, will be selected as the study organism in this project. Firstly, based on the dynamic changes of tissues and organs during metamorphogenesis, the distribution and accumulation characteristics of microplastics with different sizes in the newly differentiated, existed and remodeling tissues and organs of tadpoles will be studied by fluorescence tracing method. According to the above distribution characteristics of microplastics, afterwards, the pathological toxicity and biochemical indexes of important tissues and organs of tadpoles will be examined, and the interaction between the internal distribution of microplastics and the metamorphosis development of tadpoles will be discussed, so as to reveal the influence mechanisms of microplastics on the differentiation and development of tissues and organs in the whole process of metamorphosis of tadpoles. Finally, sensitive biological indexes to characterize the toxicity of microplastics will be filtered. The research findings will provide a scientific basis for accurately assessing the toxicity effects of microplastics on freshwater organisms.