Embryonic and larval development of the olfactory system in malacostracan crustaceans: a comparative approach

与昆虫相反，甲壳类动物的中枢和外周嗅觉通路的发育尚未得到很好的理解，尽管在小龙虾和多刺龙虾等甲壳类动物的代表中对成年嗅觉系统的功能形态进行了广泛的分析。由于全变性昆虫和甲壳类动物在发育周期中表现出明显的差异，目前的项目提出的问题是，这两个分类群之间的这种差异是否也存在于嗅觉系统的个体发生中。为了解决这个问题，我们将分析三种马拉沙星目代表动物的胚胎和幼虫，小龙虾原螯虾，欧洲海岸蟹，和片脚类夏威夷Parhyale。我们之所以选择这三个分类群，是因为它们的发育阶段很容易从实验室培养物中获得，因为它们在发育周期中表现出差异，因为它们在嗅觉系统的复杂程度上表现出差异。利用一组我们之前用来分析成年甲壳类动物嗅觉系统的标记，我们将分析触角嗅觉感觉神经元和嗅觉中间神经元（局部嗅觉中间神经元和嗅觉投射神经元）的出现和成熟的动力学，这些神经支配着大脑主要的化学感觉中心——嗅叶。具体来说，我们对控制嗅叶中肾小球（密集突触神经区域）形成的过程以及胶质细胞和血管在该过程中的可能作用感兴趣。我们的研究不仅将为节肢动物神经遗传过程的进化提供新的见解，而且将为甲壳类动物嗅觉系统的功能形态学提供新的见解。

Contrary to the insects, the development of the crustacean central and peripheral olfactory pathway is not well understood although the functional morphology of the ADULT olfactory system has been extensively analysed in representaives of the malacostracan crustaceans such as crayfish and spiny lobster. Because holometabolous insects and crustaceans display distinct differences in their developmental cycles, the current project asks the question if such differences between the two taxa may also exist concerning the ontogeny of the olfactory system. To adress this question we will analyse embryos and larvae of three malacostaracn representatives, the crayfish Procambarus virginalis, the European shore crab Carcinus maenas, and the amphipod Parhyale hawaiensis. We have choosen these three taxa because developmental stages are easily accessible from lab cultures, because they display differences in their developmental cycles, and because they display differences in the level of complexitiy of thier olfactory systems. Using a set of markers which we previously employed to analyse the ADULT crustacean olfactory system we will analyse the dynamics of emergence and maturation of the olfactory sensory neurons of the antennae and also of olfactory interneurons (local olfactory interneurons and olfactory projection neurons) innervation the primary chemosensory centers in the brain, the olfactory lobes. Specifically, we are interested in the processes that govern formation of the glomeruli (areas of dense synaptic neuropil) in the olfactory lobes and possible roles of glial cells and blood vessels in this process. Our study will not only provide new insights into the evolution of neurogenetic processes in arthropods but also into the functional morphology of the olfactory system in crustaceans.