Chervy Lenta
Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic.
Folia Parasitol (Praha). 2024 Jan 22;71:2024.001. doi: 10.14411/fp.2024.001.
Based on long-term and often frustrating experiences with the poor quality of tapeworms (Cestoda) collected throughout the world for taxonomic and phylogenetic studies, and considering the increasing obstacles to obtaining new material, a simple, easy-to-use and illustrated methodological guide (manual) is provided. It focusses mainly on key steps in examining hosts, collecting cestodes from poikilothermous vertebrates except elasmobranchs, i.e., from ray-finned fish (Actinopterygii), amphibians and 'reptiles' (a paraphyletic group comprising all sauropsids except birds), and fixing them for subsequent morphological and molecular study. It is proposed that the following methodological points should be followed: (i) ideally only freshly euthanised hosts (not previously frozen) should be used for parasitological examination; (ii) hosts examined should be documented by photographs; host tissue should also be preserved for future genotyping if necessary; (iii) tapeworms should be detached carefully to keep the scolex intact and properly cleaned before fixation; (iv) a small piece of cestode tissue should be always preserved in molecular grade ethanol for DNA sequencing; (v) tapeworms should be fixed as quickly as possible after collecting them and while they are still alive, always using hot (heated) fixatives; this prevents unnatural contraction or deformation and ensures uniform fixation; (vi) each sample (vial) should be properly labelled (a unique code should be given to every cestode sample); (vii) vouchers of sequenced specimens (hologenophores or paragenophores) should always be preserved for identification, and deposited in internationally recognised collections. It is hoped that this guide helps researchers and students to properly process valuable material of cestodes to make it suitable for reliable identification including genotyping and comparative anatomy, which is a prerequisite for any subsequent ecological, biogeographical, phylogenetic life cycle or molecular study.
基于在全球范围内收集用于分类学和系统发育研究的绦虫（ cestoda ）质量不佳的长期且常常令人沮丧的经历，并考虑到获取新材料的障碍日益增加，本文提供了一份简单、易用且配有插图的方法指南（手册）。它主要关注检查宿主、从除板鳃亚纲以外的变温脊椎动物（即硬骨鱼纲（ Actinopterygii ）、两栖动物和“爬行动物”（一个包括除鸟类以外所有蜥形纲动物的并系群））收集绦虫并将其固定以便后续进行形态学和分子研究的关键步骤。建议遵循以下方法要点：（i）理想情况下，仅应使用刚安乐死的宿主（未预先冷冻）进行寄生虫学检查；（ii）检查的宿主应通过照片记录；如有必要，宿主组织也应保存以备将来进行基因分型；（iii）应小心分离绦虫，以保持头节完整，并在固定前妥善清洁；（iv）应始终保留一小片绦虫组织于分子级乙醇中用于DNA测序；（v）绦虫收集后应尽快在其仍存活时进行固定，始终使用热（加热）固定剂；这可防止不自然的收缩或变形，并确保均匀固定；（vi）每个样本（小瓶）都应妥善标记（每个绦虫样本都应给予一个唯一代码）；（vii）测序标本的凭证（全模式标本或副模式标本）应始终保存用于鉴定，并存放在国际认可的收藏机构中。希望本指南能帮助研究人员和学生正确处理绦虫的宝贵材料，使其适合进行可靠的鉴定，包括基因分型和比较解剖学，这对于任何后续的生态、生物地理、系统发育生命周期或分子研究都是先决条件。
