FINE-STRUCTURE OF EYESPOTS IN TORNARIAN LARVAE (PHYLUM-HEMICHORDATA)
FINE-STRUCTURE OF EYESPOTS IN TORNARIAN LARVAE (PHYLUM-HEMICHORDATA)
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DOI：
10.1007/bf00306706
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发表时间：
1973-01-01
期刊：
影响因子：
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通讯作者：
EAKIN, RM
中科院分区：
文献类型：
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作者：
BRANDENBURGER, JL;WOOLLACOTT, RM;EAKIN, RM
通过电子显微镜研究了肠菌（来自夏威夷水域的黄叶霉和来自南加州的未知物种）的眼斑。眼细胞由两种类型的细胞组成：感觉细胞和支持细胞。前者的特征是其远端有球状纤毛（具有 9+2 轴丝），纤毛下方侧面有一个或有时两个微绒毛阵列，以及一个基底轴突。后者具有大而透明的囊泡，其中可能含有在活体幼虫的眼孔中看到的红橙色色素。五天大的龙眼草P. flava 具有正趋光性。纤毛和微绒毛都可以起到光感受器的作用。将所研究的泪眼眼与其他无脊椎动物的眼斑进行比较，并讨论其假定的光感受器的进化意义。
The eyespots of tornariae of enteropneusts (Ptychodera flavafrom Hawaiian waters and an unknown species from southern California) were studied by electron microscopy. An ocellus is composed of two types of cells: sensory and supportive. The former is characterized by a bulbous cilium (with 9+2 axoneme) at its distal end, one or sometimes two arrays of microvilli from its sides below the cilium, and a basal axon. The latter features large, clear vesicles which presumably contained the reddish-orange pigment seen in the ocellus of a living larva. Five-day old tornariae ofP. flavaare positively phototactic. Both cilium and microvilli may function as photoreceptors. The tornarian ocellus studied is compared with eyespots of other invertebrates, and the evolutionary significance of its putative photoreceptors is discussed.