Murray Karl D, Rubin Carol M, Jones Edward G, Chalupa Leo M
Center for Neuroscience and Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, California 95616, USA.
J Neurosci. 2008 Nov 12;28(46):12010-22. doi: 10.1523/JNEUROSCI.3800-08.2008.
In anthropoid primates, cells in the magnocellular and parvocellular layers of the dorsal lateral geniculate nucleus (dLGN) are distinguished by unique retinal inputs, receptive field properties, and laminar terminations of their axons in visual cortex. To identify genes underlying these phenotypic differences, we screened RNA from magnocellular and parvocellular layers of adult macaque dLGN for layer-specific differences in gene expression. Real-time quantitative reverse transcription-PCR and in situ hybridization were used to confirm gene expression in adult and fetal macaque. Cellular localization of gene expression revealed 11 new layer-specific markers, of which 10 were enriched in magnocellular layers (BRD4, CAV1, EEF1A2, FAM108A1, INalpha, KCNA1, NEFH, NEFL, PPP2R2C, and SFRP2) and one was enriched in parvocellular and koniocellular layers (TCF7L2). These markers relate to functions involved in development, transcription, and cell signaling, with Wnt/beta-catenin and neurofilament pathways figuring prominently. A subset of markers was differentially expressed in the fetal dLGN during a developmental epoch critical for magnocellular and parvocellular pathway formation. These results provide new evidence for the molecular differentiation of magnocellular and parvocellular streams through the primate dLGN.
在类人灵长类动物中，背外侧膝状核（dLGN）大细胞层和小细胞层中的细胞具有独特的视网膜输入、感受野特性以及它们的轴突在视觉皮层中的层状终末，以此相互区分。为了确定这些表型差异背后的基因，我们筛选了成年猕猴dLGN大细胞层和小细胞层的RNA，以寻找基因表达的层特异性差异。实时定量逆转录PCR和原位杂交被用于确认成年和胎儿猕猴中的基因表达。基因表达的细胞定位揭示了11个新的层特异性标记物，其中10个在大细胞层中富集（BRD4、CAV1、EEF1A2、FAM108A1、INα、KCNA1、NEFH、NEFL、PPP2R2C和SFRP2），1个在小细胞层和侏儒细胞层中富集（TCF7L2）。这些标记物与发育、转录和细胞信号传导所涉及的功能相关，其中Wnt/β-连环蛋白和神经丝途径尤为突出。在对大细胞和小细胞通路形成至关重要的发育时期，一部分标记物在胎儿dLGN中差异表达。这些结果为通过灵长类dLGN的大细胞和小细胞流的分子分化提供了新证据。
