Transcriptional regulation of crb and mpp5 genes in nuclear space: Coupling nuclear polarization with cell polarization at the level of transcription

差异基因表达对于正常的组织发育和功能是必不可少的。基因的表达不仅受顺式和反式调控元件的调控，而且还受三维(3D)核空间中染色质的组织调控。然而，功能相关基因的转录如何在体内3D核空间中协调尚不清楚。这个项目将研究与细胞极化和图案相关的基因的差异转录如何在斑马鱼视网膜细胞的细胞核中进行空间协调。由此产生的偏振和图案在视网膜细胞的光传感中很重要。这项研究的意义也适用于其他组织，因为极性基因需要以协调的方式表达，以实现适当的组织极化、完整性和功能。这项研究还将通过一个结构化的指导计划，为早期职业科学家和STEM工作人员的培训做出贡献。Crumbs和MPP5基因与斑马鱼视网膜形成了一个独特的系统来研究3D核组织在基因表达调控中的作用。Crumbs基因家族有五个成员，MPP5基因家族有两个成员。在基因家族中，基因在视网膜细胞中差异表达；然而，在这两个家族之间，一些成员在同一组细胞类型中共表达，以实现协调功能。斑马鱼红色、绿色和蓝色视锥感受器(RGB视锥)的细胞核几乎是其他视网膜细胞的两倍大，这为高分辨率3D基因定位提供了可能性。此外，这些核以镜像对称的五聚体模式排列，以允许对基因定位进行明确的空间登记。这项研究将通过原位杂交和染色质标记来评估这些基因在体内的核定位与其差异表达模式的相关性。此外，crb2b和mpp5b基因增强子在基因定位中的作用将通过遗传和转基因方法进行评估。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Differential gene expression is essential for normal tissue development and functions. Gene expression is regulated not only by cis- and trans-regulatory elements but also by the organization of the chromatin in the three-dimensional (3D) nuclear space. However, how the transcription of functionally-related genes is coordinated in 3D nuclear space in vivo is not clearly understood. This project will study how the differential transcription of the genes related to cell polarization and patterning are spatially coordinated in the nuclei of zebrafish retinal cells. The resultant polarization and patterning are important in light sensing in retinal cells. The significance of this study is also applicable to other tissues because polarity genes are required to be expressed in a coordinated fashion for proper tissue polarization, integrity, and function. The research will also contribute to the training of early career scientists and STEM workers through a structured mentoring program. The Crumbs and MPP5 genes and zebrafish retina form a unique system to study the roles of 3D nuclear organization in gene expression regulation. The Crumbs gene family has five members, and the MPP5 gene family has two members. Within the gene families, genes are differentially expressed in retinal cells; however, between the two families, some members are coexpressed in the same set of cell types for coordinated functions. The nuclei of zebrafish red, green, and blue cone photoreceptors (RGB cones) are almost twice as large as the nuclei of other retinal cells, offering the possibility of high-resolution 3D gene mapping. In addition, these nuclei are aligned in a mirror-symmetric pentameric pattern to allow defined spatial registration of gene positioning. This research will evaluate how in vivo nuclear positioning of these genes is correlated with their differential expression patterns by in situ hybridization and chromatin tagging. In addition, the roles of the enhancers of crb2b and mpp5b genes in gene positioning will be evaluated by genetic and transgenic approaches.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.