Qiu Xudong, Vanhoutte Kurt A J, Stavenga Doekele G, Arikawa Kentaro
Graduate School of Integrated Science, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan.
Cell Tissue Res. 2002 Mar;307(3):371-9. doi: 10.1007/s00441-002-0517-z. Epub 2002 Feb 23.
The ommatidia in the ventral two-thirds of the compound eye of male Pieris rapae crucivora are not uniform. Each ommatidium contains nine photoreceptor cells. Four cells (R1-4) form the distal two-thirds of the rhabdom, four cells (R5-8) approximately occupy the proximal one-third of the rhabdom, and the ninth cell (R9) takes up a minor basal part of the rhabdom. The R5-8 photoreceptor cells contain clusters of reddish pigment adjacent to the rhabdom. From the position of the pigment clusters, three types of ommatidia can be identified: the trapezoidal (type I), square (type II), and rectangular type (type III). Microspectrophotometry with an epi-illumination microscope has revealed that the reflectance spectra of type I and type III ommatidia peak at 635 nm and those of type II ommatidia peak at 675 nm. The bandwith of the reflectance spectra is 40-50 nm. Type II ommatidia strongly fluoresce under ultra-violet and violet epi-illumination. The three types of ommatidia are randomly distributed. The ommatidial heterogeneity is presumably crucial for color discrimination.
菜粉蝶雄性复眼腹侧三分之二区域的小眼并不均匀。每个小眼包含九个感光细胞。四个细胞（R1 - 4）构成视杆的远端三分之二，四个细胞（R5 - 8）大约占据视杆近端三分之一，第九个细胞（R9）占据视杆基部的一小部分。R5 - 8感光细胞在视杆附近含有红色素簇。根据色素簇的位置，可以识别出三种类型的小眼：梯形（I型）、方形（II型）和长方形（III型）。落射照明显微镜的显微分光光度法显示，I型和III型小眼的反射光谱在635nm处有峰值，II型小眼的反射光谱在675nm处有峰值。反射光谱的带宽为40 - 50nm。II型小眼在紫外和紫光落射照明下强烈荧光。这三种类型的小眼随机分布。小眼的异质性可能对颜色辨别至关重要。
