PDF(Pubmed)
Abstract：
Venom is a remarkable innovation found across the animal kingdom, yet the evolutionary origins of venom systems in various groups, including spiders, remain enigmatic. Here, we investigated the organogenesis of the venom apparatus in the common house spider, Parasteatoda tepidariorum. The venom apparatus consists of a pair of secretory glands, each connected to an opening at the fang tip by a duct that runs through the chelicerae. We performed bulk RNA-seq to identify venom gland-specific markers and assayed their expression using RNA in situ hybridisation experiments on whole-mount time-series. These revealed that the gland primordium emerges during embryonic stage 13 at the chelicera tip, progresses proximally by the end of embryonic development and extends into the prosoma post-eclosion. The initiation of expression of an important toxin component in late postembryos marks the activation of venom-secreting cells. Our selected markers also exhibited distinct expression patterns in adult venom glands: sage and the toxin marker were expressed in the secretory epithelium, forkhead and sum-1 in the surrounding muscle layer, while Distal-less was predominantly expressed at the gland extremities. Our study provides the first comprehensive analysis of venom gland morphogenesis in spiders, offering key insights into their evolution and development.
摘要：
毒液是整个动物王国发现的一项非凡的创新，然而，毒液系统在不同群体中的进化起源，包括蜘蛛,仍然神秘。这里,我们调查了普通家蜘蛛的毒液器官的发生，假单胞菌。毒液装置由一对分泌腺组成，每个都通过一条穿过龟头的管道连接到方头的开口。我们进行了大量RNA-seq以鉴定毒腺特异性标志物，并在整个时间序列上使用RNA原位杂交实验测定了它们的表达。这些揭示了腺体原基在胚胎期13在龟头出现，在胚胎发育结束时向近侧进展，并在卵裂后延伸到前瘤。晚期胚胎中重要毒素成分的表达开始标志着毒液分泌细胞的激活。我们选择的标记在成年毒腺中也表现出不同的表达模式：鼠尾草和毒素标记在分泌上皮中表达，叉头和sum-1在周围的肌肉层，而无远端主要在腺体末端表达。我们的研究首次全面分析了蜘蛛的毒腺形态发生，提供有关其演变和发展的关键见解。
