White Richard H, Xu Huihong, Münch Thomas A, Bennett Ruth R, Grable Erin A
Department of Biology, University of Massachusetts-Boston, 100 Morrissey Blvd, Boston, MA 02125-3393, USA.
J Exp Biol. 2003 Oct;206(Pt 19):3337-48. doi: 10.1242/jeb.00571.
Spectral sensitivities of individual photoreceptors in the compound eye of Manduca sexta were verified by immunocytochemistry, and the retinal mosaic was mapped, using polyclonal antisera raised against amino-terminal sequences of three identified rhodopsins: P520, P450 and P357. Retinulae are composed of a small proximal cell and seven or eight elongate cells extending across the retina. In each retinula, one or two elongate dv cells oriented in the dorsal-ventral axis of the retinal lattice express either P450 or P357. Six elongate ap and ob cells in the anterior-posterior and oblique axes express P520. The small proximal pr cell also appears to express P520. The retinal mosaic is regionalized into three distinct domains: ventral and dorsal domains that divide the main retina, and a large dorsal rim area. The immunocytochemical data provide a high-resolution map of the Manduca retina that confirms and refines earlier low-resolution ERG spectral sensitivity measurements. The dorsal and ventral domains, separated at a well-defined equatorial border, are distinguished by differences in the proportion of blue-sensitive dv cells: these cells dominate the ventral retina but are less abundant in the dorsal retina. Green-sensitive ap and ob receptors are uniformly distributed across the dorsal and ventral domains, and UV-sensitive dv cells are fairly uniformly distributed because many retinulae in the dorsal domain contain only one dv cell. Similarly, dorsal rim retinulae contain only the ventral member of the dv pair of receptors, two-thirds of which express P357. Otherwise, dorsal rim receptors express none of the three sequenced Manduca opsins; they must express rhodopsins that have yet to be cloned.
通过免疫细胞化学方法验证了烟草天蛾复眼中单个光感受器的光谱敏感性，并利用针对三种已鉴定视紫红质（P520、P450和P357）氨基末端序列产生的多克隆抗血清绘制了视网膜镶嵌图。小眼由一个小的近端细胞和七个或八个横跨视网膜延伸的细长细胞组成。在每个小眼内，一两个沿视网膜晶格背腹轴排列的细长dv细胞表达P450或P357。六个沿前后轴和斜轴排列的细长ap和ob细胞表达P520。小的近端pr细胞似乎也表达P520。视网膜镶嵌图可分为三个不同的区域：将主要视网膜分开的腹侧和背侧区域，以及一个大的背侧边缘区域。免疫细胞化学数据提供了烟草天蛾视网膜的高分辨率图谱，证实并细化了早期低分辨率的视网膜电图光谱敏感性测量结果。背侧和腹侧区域在明确的赤道边界处分开，其区别在于对蓝光敏感的dv细胞比例不同：这些细胞在腹侧视网膜中占主导，但在背侧视网膜中数量较少。对绿光敏感的ap和ob受体均匀分布在背侧和腹侧区域，对紫外线敏感的dv细胞分布相当均匀，因为背侧区域的许多小眼只包含一个dv细胞。同样，背侧边缘小眼只包含dv受体对中的腹侧成员，其中三分之二表达P357。否则，背侧边缘受体不表达三种已测序的烟草天蛾视蛋白中的任何一种；它们必定表达尚未克隆的视紫红质。
