Abstract：
Unlike the mechanism of ballistospore discharge, which was not solved until the 1980s, the operation of asci as pressurized squirt guns is relatively straightforward and was understood in the nineteenth century. Since then, mycologists have sought to understand how structural adaptations to asci have allowed the ascomycetes to expel spores of different shapes and sizes over distances ranging from a few millimeters to tens of centimeters. These modifications include the use of valves at the tips of asci that maintain ascus pressure and expel spores at the highest speeds, and gelatinous appendages that connect spores after release and create larger projectiles with greater momentum than single spores. Clever experiments in the twentieth century coupled with meticulous microscopic studies led investigators to understand how asci with complicated apical structures worked and mathematical models produced estimates of launch speeds. With the recent application of high-speed video microscopy, these inferences about ascus function have been tested by imaging the motion of spores on a microsecond timescale. These experiments have established that ascospore discharge is the fastest fungal movement and is among the fastest movements in biology. Beginning with the history of the study of asci, this review article explains how asci are pressurized, how spores are released, and how far spores travel after their release. We also consider the efficiency of ascospore discharge relative to the mechanism of ballistospore discharge and examine the way that the squirt gun mechanism has limited the morphological diversity of ascomycete fruit bodies.
摘要：
与孢子排出的机制不同，直到1980年代才解决，作为加压水枪的操作是相对简单的，在19世纪被理解。从那以后,真菌学家试图了解对asci的结构适应如何使子囊细胞在几毫米到几十厘米的距离内排出不同形状和大小的孢子。这些修改包括在asci的尖端使用阀门，以保持自然压力并以最高速度排出孢子，和凝胶状附属物，它们在释放后连接孢子，并产生比单孢子动量更大的弹丸。20世纪的巧妙实验加上细致的微观研究，使研究人员了解了具有复杂根尖结构的asci如何工作，以及数学模型产生了发射速度的估计。随着高速视频显微镜的应用,通过在微秒时间尺度上对孢子的运动进行成像来测试这些关于子囊功能的推论。这些实验已经确定子囊孢子排出是最快的真菌运动，并且是生物学中最快的运动之一。从阿西研究的历史开始，这篇评论文章解释了如何对asci加压，孢子是如何释放的，以及孢子释放后传播了多远。我们还考虑了子囊孢子排出相对于孢子孢子排出机制的效率，并研究了喷射枪机制限制子囊孢子子实体形态多样性的方式。
