brakeless is required for lamina targeting of R1-R6 axons in the Drosophila visual system.
brakeless is required for lamina targeting of R1-R6 axons in the Drosophila visual system.
复制标题
果蝇视觉系统中 R1-R6 轴突的层板靶向需要无制动。
作者：
K. Senti;K. Keleman;F. Eisenhaber;B. Dickson
果蝇眼睛中的光感受器将轴突投射到大脑视叶的目标上。光感受器细胞R1-R6的轴突终止于第一个视神经节，即神经板，而R7和R8轴突穿过视神经板，终止于第二个神经节，即延髓的不同层面。在这里，我们报告了无刹车基因(BKS)的鉴定，并表明它的功能在发育中的眼睛中是必需的，特别是针对R1-R6轴突的板靶向。在眼睛缺乏bks功能的马赛克动物中，R1-R6轴突通过板层投射到延髓。视觉系统发育的其他方面看起来完全正常：光感受器和板层细胞的命运被正确地指定，R7轴突被正确地定位于延髓，被正确定位的R7轴突和被错误定位的R1-R6轴突都保持了它们相对于前后轴和背腹轴的视网膜定位顺序。BKS编码两种异常亲水的核蛋白亚型，其中一种可能含有一个C(2)H(2)锌指结构域。任何一种BKS亚型的转基因表达都足以恢复BKS嵌合体中R1-R6轴突的板靶向，但不能将R7或R8轴突重定向到板层。这些数据证明了果蝇视觉系统中存在一种针对R1-R6轴突的板层特异性靶向机制，并为这一过程的分子表征提供了第一个切入点。
Photoreceptors in the Drosophila eye project their axons retinotopically to targets in the optic lobe of the brain. The axons of photoreceptor cells R1-R6 terminate in the first optic ganglion, the lamina, while R7 and R8 axons project through the lamina to terminate in distinct layers of the second ganglion, the medulla. Here we report the identification of the gene brakeless (bks) and show that its function is required in the developing eye specifically for the lamina targeting of R1-R6 axons. In mosaic animals lacking bks function in the eye, R1-R6 axons project through the lamina to terminate in the medulla. Other aspects of visual system development appear completely normal: photoreceptor and lamina cell fates are correctly specified, R7 axons correctly target the medulla, and both correctly targeted R7 axons and mistargeted R1-R6 axons maintain their retinotopic order with respect to both anteroposterior and dorsoventral axes. bks encodes two unusually hydrophilic nuclear protein isoforms, one of which contains a putative C(2)H(2) zinc finger domain. Transgenic expression of either Bks isoform is sufficient to restore the lamina targeting of R1-R6 axons in bks mosaics, but not to retarget R7 or R8 axons to the lamina. These data demonstrate the existence of a lamina-specific targeting mechanism for R1-R6 axons in the Drosophila visual system, and provide the first entry point in the molecular characterization of this process.
影响因子：
56.9
作者：
GOLIC, KG
通讯作者：
GOLIC, KG
影响因子：
4.6
作者：
Gerard Campbell;Harald H.H. Göring;Tina Lin;E. Spana;S. Andersson;C. Doe;Andrew Tomlinson
通讯作者：
Gerard Campbell;Harald H.H. Göring;Tina Lin;E. Spana;S. Andersson;C. Doe;Andrew Tomlinson
DOI：
10.1073/pnas.89.6.2002
发表时间：
1992-03-15
影响因子：
11.1
作者：
BRENDEL, V;BUCHER, P;KARLIN, S
通讯作者：
KARLIN, S