Marine Biological Association, The Laboratory, Citadel Hill, Plymouth, United Kingdom.
School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom.
Elife. 2022 Mar 1;11:e73933. doi: 10.7554/eLife.73933.
The chytrids (phylum Chytridiomycota) are a major fungal lineage of ecological and evolutionary importance. Despite their importance, many fundamental aspects of chytrid developmental and cell biology remain poorly understood. To address these knowledge gaps, we combined quantitative volume electron microscopy and comparative transcriptome profiling to create an 'atlas' of the cellular and molecular basis of the chytrid life cycle, using the model chytrid . From our developmental atlas, we describe the transition from the transcriptionally inactive free-swimming zoospore to the more biologically complex germling, and show that lipid processing is multifaceted and dynamic throughout the life cycle. We demonstrate that the chytrid apophysis is a compartmentalised site of high intracellular trafficking, linking the feeding/attaching rhizoids to the reproductive zoosporangium, and constituting division of labour in the chytrid cell plan. We provide evidence that during zoosporogenesis, zoospores display amoeboid morphologies and exhibit endocytotic cargo transport from the interstitial maternal cytoplasm. Taken together, our results reveal insights into chytrid developmental biology and provide a basis for future investigations into non-dikaryan fungal cell biology.
壶菌（Chytridiomycota 门）是具有生态和进化重要性的主要真菌谱系。尽管它们很重要，但壶菌的发育和细胞生物学的许多基本方面仍然知之甚少。为了填补这些知识空白，我们结合定量体积电子显微镜和比较转录组分析，使用模型壶菌来创建壶菌生命周期的细胞和分子基础的“图谱”。从我们的发育图谱中，我们描述了从转录不活跃的自由游动的游动孢子到更具生物学复杂性的芽体的转变，并表明脂质处理在整个生命周期中是多方面且动态的。我们证明，壶菌的顶生器是一个具有高度细胞内运输功能的分隔区域，将进食/附着的假根与生殖游动孢子囊连接起来，并构成了壶菌细胞计划中的分工。我们提供的证据表明，在游动孢子发生过程中，游动孢子表现出变形虫形态，并从间质母细胞质中表现出内吞货物运输。总之，我们的研究结果揭示了壶菌发育生物学的新见解，并为未来对非双核真菌细胞生物学的研究提供了基础。
