Ungerer Petra, Geppert Maria, Wolff Carsten
Humboldt University Berlin, Department of Biology, Comparative Zoology, Berlin, Germany.
Integr Zool. 2011 Mar;6(1):28-44. doi: 10.1111/j.1749-4877.2010.00227.x.
We describe the formation of the major axon pathways in the embryonic central and peripheral nervous systems of the amphipod crustacean Orchestia cavimana Heller, 1865 by means of antibody staining against acetylated alpha-tubulin. The data add to a long list of previous studies of various other aspects of development in Orchestia and provide a basis for future studies of neurogenesis on a deeper cellular and molecular level. Orchestia exhibits a tripartite dorsal brain, which is a characteristic feature of euarthropods. Its anlagen are the first detectable structures in the developing nervous system and can be traced back to distinct neuronal cell clusters in the early embryo. The development of the ventral nervous system proceeds with an anteroposterior gradient of development. In each trunk segment, the longitudinal connectives and the anterior commissure form first, followed by the intersegmental nerve, the posterior commissure and segmental nerves, respectively. A single commissure of a vestigial seventh pleonal segment is found. In the peripheral nervous system we observe a spatial and temporal pattern of leg innervation, which is strikingly similar in both limb types, the uniramous pereopods and the biramous pleopods. A proximal leg nerve splitting distally into two separated nerves probably reflects a general feature of crustaceans.
我们通过针对乙酰化α-微管蛋白的抗体染色，描述了1865年发现的双甲目甲壳动物海滨沙钩虾（Orchestia cavimana Heller）胚胎中枢和外周神经系统中主要轴突通路的形成。这些数据补充了之前对海滨沙钩虾发育其他各个方面的大量研究，并为未来在更深层次的细胞和分子水平上进行神经发生研究提供了基础。海滨沙钩虾具有三部分组成的背脑，这是真节肢动物的一个特征。其原基是发育中的神经系统中最早可检测到的结构，可追溯到早期胚胎中的不同神经元细胞簇。腹侧神经系统的发育以前后梯度进行。在每个躯干节段中，纵向连接索和前连合首先形成，随后分别是节间神经、后连合和节段神经。发现了一个残留的第七腹节的单一连合。在周围神经系统中，我们观察到腿部神经支配的时空模式，在两种肢体类型（单枝步足和双枝腹足）中都非常相似。一条近端腿部神经在远端分成两条分开的神经，这可能反映了甲壳类动物的一个普遍特征。
