Dscams是免疫球蛋白超級家族的黏附分子,。果蠅Dscams已被發(fā)現(xiàn)與神經(jīng)聯(lián)結的組織相關，但人們對脊椎動物中密切相關的分子的功能卻知之甚少?，F(xiàn)在，Masahito Yamagata和Joshua Sanes發(fā)現(xiàn),，Dscams-1和Dscams-2在雞視網(wǎng)膜特定層聯(lián)結的成形中能發(fā)揮一定作用,。另外兩種黏附分子，即Sidekick-1和Sidekick-2,，以一種類似的方式發(fā)揮作用,。這些分子廣泛分布在神經(jīng)系統(tǒng)中，可能是使大腦中神經(jīng)聯(lián)結成形的一個“黏附代碼”的構成部分,。關于Dscams在脊椎動物神經(jīng)成形中重要性的進一步證據(jù)來自Fuerst等人,，他們發(fā)現(xiàn)DSCAM（即“唐氏綜合征細胞黏附分子”的英文首字母縮寫）在小鼠視網(wǎng)膜神經(jīng)回路的形成中發(fā)揮一定作用。
生物谷推薦英文原文：
Nature 451, 465-469 (24 January 2008) | doi:10.1038/nature06469; Received 31 August 2007; Accepted 12 November 2007
Dscam and Sidekick proteins direct lamina-specific synaptic connections in vertebrate retina
Masahito Yamagata1 & Joshua R. Sanes1
Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, Massachusetts 02138, USA
Correspondence to: Joshua R. Sanes1 Correspondence and requests for materials should be addressed to J.R.S. (Email: [email protected]).
Synaptic circuits in the retina transform visual input gathered by photoreceptors into messages that retinal ganglion cells (RGCs) send to the brain. Processes of retinal interneurons (amacrine and bipolar cells) form synapses on dendrites of RGCs in the inner plexiform layer (IPL). The IPL is divided into at least 10 parallel sublaminae; subsets of interneurons and RGCs arborize and form synapses in just one or a few of them1, 2, 3. These lamina-specific circuits determine the visual features to which RGC subtypes respond3, 4, 5. Here we show that four closely related immunoglobulin superfamily (IgSF) adhesion molecules—Dscam (Down's syndrome cell adhesion molecule), DscamL (refs 6–9), Sidekick-1 and Sidekick-2 (ref. 10)—are expressed in chick by non-overlapping subsets of interneurons and RGCs that form synapses in distinct IPL sublaminae. Moreover, each protein is concentrated within the appropriate sublaminae and each mediates homophilic adhesion. Loss- and gain-of-function studies in vivo indicate that these IgSF members participate in determining the IPL sublaminae in which synaptic partners arborize and connect. Thus, vertebrate Dscams, like Drosophila Dscams11, 12, 13, 14, 15, 16, 17, 18, 19, play roles in neural connectivity. Together, our results on Dscams and Sidekicks suggest the existence of an IgSF code for laminar specificity in retina and, by implication, in other parts of the central nervous system.
