Cloney R A
Cell Tissue Res. 1977 Oct 14;183(4):423-44. doi: 10.1007/BF00225658.
The larava of Distaplia occidentalis bears three cup-shaped adhesive papillae, each with a prominenta axial protrusion, At the onset of metamorphosis these organs rapidly evert through fenestrations in the cuticular layers of tunic exposing hyaline caps of adhesive. Additional adhesive material is secreted from collocytes during eversion. The stickiness of the papillae facilitates attachment to a variety of substrates. Each papilla is composed of more than 900 cells; six different types were identified. The wall of the cup contains about 260 myoepithelial cells with long attenuated processes. These extend from the rim of the cup to the base in the parietal (inner) layer. The apices of the myoepithelial cells are held in place by 11 pairs of specialized anchor cells bearing long bulbous microvilli. When the myoepithelial cells contract they force the axial protrusion forward and transform the papilla into a hyperboloidal configuration. The papilla is innervated by small motor fibers, but sensory fibers were not detected. The adhesive papillae of Distaplia are discussed in relationship to nine other recognizable types of papillae in the ascidians.
西方聚瘤海鞘的幼虫有三个杯状附着乳头，每个乳头都有一个突出的轴向突起。在变态开始时，这些器官会通过被囊表皮层的小孔迅速外翻，露出附着的透明帽。外翻过程中，胶细胞会分泌额外的附着物质。乳头的粘性有助于附着在各种基质上。每个乳头由900多个细胞组成；已鉴定出六种不同类型。杯壁含有约260个具有长而细长突起的肌上皮细胞。这些细胞从杯缘延伸到壁层（内层）的底部。肌上皮细胞的顶端由11对带有长球形微绒毛的特殊锚定细胞固定在位。当肌上皮细胞收缩时，它们会将轴向突起向前推，使乳头变成双曲线状。乳头由小运动纤维支配，但未检测到感觉纤维。本文结合海鞘中其他九种可识别的乳头类型，对西方聚瘤海鞘的附着乳头进行了讨论。
