Rhode Birgit
Institut für Zoologie der Freien Universität Berlin D-1000 Berlin 33, Federal Republic of Germany.
J Morphol. 1992 Apr;212(1):71-85. doi: 10.1002/jmor.1052120108.
The nereid polychaete, Platynereis dumerilii, possess two pairs of post-trochophoral eyes with one vitreous body each. The development of these eyes has first been observed in 2-day-old larvae. Whether the eye anlagen arise from stem cells or from undifferentiated ectodermal tissue was not determined. At first, the anlagen of the anterior and the posterior eyes adjoin each other. They separate in late 3-day-old larvae. The first separated eye complexes consist each of two supporting and two sensory cells. The supporting cells synthesize two different kinds of granules, the pigment granules of the pigment cup and the prospective tubules of the vitreous body. These tubules accumulate in the distal process of the supporting cell. The vitreous body is formed by compartments of the supporting cells filled with the osmiophilic vitreous body tubules. The short, bulbar photosensory processes bear microvilli that emerge into the ocular cavity. At the apex of each sensory cell process, a single cilium (or occasionally two) arises. The sensory cells contain a different kind of pigment granule within their necks at the level of the pigment cup. The rate of eye development and differentiation varies. New supporting cells are added to the rim of the eye cup. They contribute to the periphery of the vitreous body like onion skins, and sensory cells move between supporting cells. The older the individual compartments of the vitreous body are, the more densely packed is their content of vitreous body tubules. Elongation of the sensory and supporting cell processes of the older cells increases the volume of the eye. The eyespots of the trochophore are briefly described as of the two-celled rhabdomeric type with a single basal body with ciliary rootlet.
沙蚕多毛纲动物杜氏阔沙蚕（Platynereis dumerilii）有两对担轮幼虫后的眼睛，每只眼睛有一个玻璃体。这些眼睛的发育最早在2日龄幼虫中被观察到。眼睛原基是由干细胞还是未分化的外胚层组织产生尚未确定。起初，前眼和后眼的原基彼此相邻。它们在3日龄后期分开。最初分离的眼复合体各由两个支持细胞和两个感觉细胞组成。支持细胞合成两种不同类型的颗粒，色素杯的色素颗粒和玻璃体的预期小管。这些小管积聚在支持细胞的远端突起中。玻璃体由充满嗜锇性玻璃体小管的支持细胞隔室形成。短的球根状光感突起带有伸入眼腔的微绒毛。在每个感觉细胞突起的顶端，出现一根（偶尔两根）纤毛。感觉细胞在色素杯水平的颈部含有一种不同类型的色素颗粒。眼睛发育和分化的速度各不相同。新的支持细胞被添加到眼杯边缘。它们像洋葱皮一样为玻璃体的周边做出贡献，并且感觉细胞在支持细胞之间移动。玻璃体的各个隔室越老，其玻璃体小管的含量就越密集。较老细胞的感觉和支持细胞突起的伸长增加了眼睛的体积。担轮幼虫的眼点被简要描述为具有单个带有纤毛小根的基体的双细胞视小杆型。
