The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa 903-0213, Japan.
Sci Rep. 2017 Jan 17;7:40705. doi: 10.1038/srep40705.
Butterfly wing eyespot patterns are determined in pupal tissues by organisers located at the centre of the prospective eyespots. Nevertheless, organiser cells have not been examined cytochemically in vivo, partly due to technical difficulties. Here, we directly observed organiser cells in pupal forewing epithelium via an in vivo confocal fluorescent imaging technique, using 1-h post-pupation pupae of the blue pansy butterfly, Junonia orithya. The prospective eyespot centre was indented from the plane of the ventral tissue surface. Three-dimensional reconstruction images revealed that the apical portion of "focal cells" at the bottom of the eyespot indentation contained many mitochondria. The mitochondrial portion was connected with a "cell body" containing a nucleus. Most focal cells had globular nuclei and were vertically elongated, but cells in the wing basal region had flattened nuclei and were tilted toward the distal direction. Epithelial cells in any wing region had cytoneme-like horizontal processes. From 1 h to 10 h post-pupation, nuclear volume increased, suggesting DNA synthesis during this period. Morphological differences among cells in different regions may suggest that organiser cells are developmentally ahead of cells in other regions and that position-dependent heterochronic development is a general mechanism for constructing colour patterns in butterfly wings.
蝴蝶翅膀眼斑图案是由位于潜在眼斑中心的组织者在蛹组织中决定的。然而，由于技术上的困难，组织者细胞尚未在体内进行细胞化学检查。在这里，我们使用活体共聚焦荧光成像技术，直接观察了蓝凤蝶蛹前翅上皮组织中的组织者细胞。在 1 小时龄的蛹中，预测的眼斑中心从腹面组织表面的平面凹陷。三维重建图像显示，眼斑凹陷底部的“焦点细胞”的顶端部分含有许多线粒体。线粒体部分与含有核的“细胞体”相连。大多数焦点细胞具有球形核，并且垂直拉长，但翅膀基部区域的细胞具有扁平的核，并向远端倾斜。任何翅膀区域的上皮细胞都具有类似纤毛的水平突起。从 1 小时龄到 10 小时龄，核体积增加，表明在此期间进行了 DNA 合成。不同区域细胞之间的形态差异可能表明，组织者细胞在发育上先于其他区域的细胞，并且位置依赖的异时性发育是构建蝴蝶翅膀颜色图案的一般机制。
