The protocerebrum and its sensory organs in maxillopodan crustaceans: testing the basal phylogenetic relationships within Tetraconata/Pancrustacea

前脑是甲壳类动物大脑的最前部。它接受来自主要感觉器官的输入，如无节幼体的眼睛和复眼，以及来自神秘的额丝器官。原脑的进化起源，在甲壳类动物和节肢动物一般，是在辩论和正在进行的研究的重点。遗憾的是，只有很少的细节是已知的颚足类甲壳动物，如鱼虱（鳃），藤壶（Cirripedia），桡足类，介形类和间质mystacocarids。然而，这些群体在理解Tetraconata/Pancrustacea的进化方面发挥着至关重要的作用。我们的项目将使用最先进的技术，如免疫组织化学，体积电子显微镜和X-射线微机断层扫描，提供新的数据在不同的颌面足动物的前脑及其感觉器官。拟议项目的目标是了解前脑和前脑感觉器官的神经结构，并提供形态学特征，这将有助于更好地理解上足目甲壳动物和一般甲壳动物的进化形态（感觉Richter & Wirkner 2014）。我们将研究（1）在不同的颚足类动物中存在着前脑中央复合体的哪些成分，（2）两个视叶的神经结构，测试它们与鳃足类和其他Tetraconata的同源性，（3）复眼的超微结构，测试六足动物外初级色素细胞的存在，（4）无节幼体眼睛的超微结构，绒毡层的同源性检验;（5）神秘的额丝器的神经支配和超微结构，为它们在甲壳动物中的同源性提供证据或反证。

The protocerebrum is the anteriormost part of the crustacean brain. It receives input from major sensory organs such as the nauplius eye and compound eyes as well as from the enigmatic frontal filament organs. The evolutionary origin of the protocerebrum, in crustaceans and arthropods in general, is under debate and the focus of ongoing research. Regrettably, only very few details are known from maxillopodan crustaceans such as fish lice (Branchiura), barnacles (Cirripedia), copepods, ostracodes and interstitial mystacocarids. These groups, however, play a crucial role in understanding the evolution of Tetraconata/Pancrustacea. Our project will provide new data on the protocerebrum and its sensory organs in various maxillopodans using state of the art techniques such as immunohistochemistry, volume electron microscopy and x-ray microcomputer tomography. The goal of the proposed project is to understand the neuroarchitecture of the protocerebrum and the protocerebral sense organs and to contribute morphological characters which will lead to a better understanding of the evolutionary morphology (sensu Richter & Wirkner 2014) of maxillopodan crustaceans and crustaceans in general. We will investigate (1) which components of a protocerebral central complex are present in the various maxillopodan taxa, (2) the neuroarchitecture of the two optic lobes, testing their homology to those in branchiopods and other Tetraconata, (3) the ultrastructure of the compound eyes, testing the presence of primary pigment cells outside hexapods, (4) the ultrastructure of the nauplius eye, testing the homology status of the tapetum layer, and (5) the innervation and ultrastructure of the enigmatic frontal filament organs, providing evidence or counter-evidence for their homology throughout crustaceans.