Jeun G, Locke M
Department of Zoology, University of Western Ontario, London, Canada.
Tissue Cell. 1993;25(2):289-93. doi: 10.1016/0040-8166(93)90026-h.
The fifth stage larval epidermis of Calpodes ethlius (Lepidoptera, Hesperiidae) is a syncytium of doublets where sibling cells remain connected by residual midbodies between mitoses. These twins resemble one another more than their other neighbours in features such as the shape and number of nucleolar particles, the number of actin bundles, the position of condensed chromosomes in female cells and the timing of mitosis. Although the patterns of arrangement of structures may be similar in twinned nuclei they differ in their orientation. We have now found that twins also differ in the orientation of their division planes with respect to the previous plane of division. Similarity of structural pattern but not orientation is most easily explained if nuclei, together with determinants for the plane of division, are free to rotate in the plane of the epithelium.
埃氏角翅弄蝶（鳞翅目，弄蝶科）的五龄幼虫表皮是一种双核体的合胞体，其中姊妹细胞在有丝分裂期间通过残留的中间体保持连接。这些孪生细胞在核仁颗粒的形状和数量、肌动蛋白束的数量、雌性细胞中浓缩染色体的位置以及有丝分裂时间等特征上，彼此之间的相似程度超过它们与其他相邻细胞的相似程度。尽管孪生细胞核中结构的排列模式可能相似，但它们的方向不同。我们现在发现，孪生细胞在其分裂平面相对于先前分裂平面的方向上也存在差异。如果细胞核连同分裂平面的决定因素能够在上皮平面内自由旋转，那么结构模式的相似性而非方向的相似性就最容易得到解释。
