European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 1, 9713AV, Groningen, The Netherlands.
Department of Cell Biology, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 1, 9713AV, Groningen, The Netherlands.
Sci Rep. 2018 Feb 16;8(1):3192. doi: 10.1038/s41598-018-21107-4.
Free-living flatworms, such as the planarian Schmidtea mediterranea, are extensively used as model organisms to study stem cells and regeneration. The majority of flatworm studies so far focused on broadly conserved genes. However, investigating what makes these animals different is equally informative for understanding its biology and might have biomedical value. We re-analyzed the neoblast and germline transcriptional signatures of the flatworm M. lignano using an improved transcriptome assembly and show that germline-enriched genes have a high fraction of flatworm-specific genes. We further identified the Mlig-sperm1 gene as a member of a novel gene family conserved only in free-living flatworms and essential for producing healthy spermatozoa. In addition, we established a whole-animal electron microscopy atlas (nanotomy) to visualize the ultrastructure of the testes in wild type worms, but also as a reference platform for different ultrastructural studies in M. lignano. This work demonstrates that investigation of flatworm-specific genes is crucial for understanding flatworm biology and establishes a basis for such future research in M. lignano.
自由生活的扁形动物，如地中海扁形虫 Schmidtea mediterranea，被广泛用作研究干细胞和再生的模式生物。迄今为止，大多数扁形动物的研究都集中在广泛保守的基因上。然而，研究是什么使这些动物与众不同，同样有助于了解它们的生物学特性，并且可能具有医学价值。我们使用改进的转录组组装重新分析了扁形动物 M. lignano 的成体干细胞和生殖细胞转录特征，并表明生殖细胞富集的基因具有很高比例的扁形动物特异性基因。我们进一步鉴定了 Mlig-sperm1 基因，它是一个仅在自由生活的扁形动物中保守的新基因家族的成员，对于产生健康的精子至关重要。此外，我们建立了一个完整的动物电子显微镜图谱（nanotomy），以可视化野生型蠕虫睾丸的超微结构，同时也为 M. lignano 中的不同超微结构研究提供了参考平台。这项工作表明，研究扁形动物特异性基因对于理解扁形动物生物学至关重要，并为 M. lignano 中的此类未来研究奠定了基础。
