At the optic chiasm, retinal ganglion cell axons from each eye converge and segregate into crossed and uncrossed projections, a pattern critical for binocular vision. Here, we review recent findings on optic chiasm development, highlighting the specific transcription factors and guidance cues that implement retinal axon divergence into crossed and uncrossed pathways. Although mechanisms underlying the formation of the uncrossed projection have been identified, the means by which retinal axons are guided across the midline are still unclear. In addition to directives provided by transcription factors and receptors in the retina, gene expression in the ventral diencephalon influences chiasm formation. Throughout this review, we compare guidance mechanisms at the optic chiasm with those in other midline models and highlight unanswered questions both for retinal axon growth and axon guidance in general.

中文翻译：

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视交叉处的视网膜轴突生长：交叉或不交叉。

在视交叉处，每只眼睛的视网膜神经节细胞轴突会聚并分离成交叉和非交叉的投影，这是双眼视觉的关键模式。在这里，我们回顾了最近关于视交叉发展的发现，强调了将视网膜轴突分化成交叉和非交叉通路的特定转录因子和指导线索。尽管已经确定了未交叉投影形成的潜在机制，但视网膜轴突穿过中线的方式仍不清楚。除了视网膜中的转录因子和受体提供的指令外，腹侧间脑中的基因表达也会影响交叉形成。在整个审查过程中，