Analysis on how RNA splicing factors change global gene expression patterns and regulate male fertility.

不孕不育影响了许多夫妇，但导致不孕的原因通常不清楚，正常生育所需的机制也是如此。该项目将分析与男性不育有关的RNA结合蛋白，以了解它们在正常精子发生中的作用。我们将利用现有的小鼠模型，制造出我们可以在体外操纵的细胞系。该项目将包括世界级的分子生物学和生物信息学培训，这将使学生在就业市场上处于有利地位。背景：最近，埃利奥特实验室发现一种名为RBMXL2的核糖核酸结合蛋白对于正常的精子发生是必不可少的，但为什么还不完全清楚(PMID：34927545)。在韦尔特曼实验室，影响核糖核酸结合蛋白的杂合从头突变已被确定，这些突变会阻碍睾丸的正常健康发育(例如，rbm5基因的错义突变，pMID：35013161)。这些RNA结合蛋白通过哪些基因表达途径影响精子的正常健康发育，目前尚不清楚。RBMXL2和RBM54都参与了剪接的控制。剪接是至关重要的，因为大多数人类基因在外显子和内含子之间分裂。一种名为剪接体的大分子机器识别外显子序列，并将它们拼接成mRNA。大多数基因可以不止一种方式拼接，拼接模式的变化可以改变基因功能。剪接因子蛋白质控制外显子是否被识别，这可以以重要的方式改变基因功能。但这些RNA结合蛋白也可能在正常健康的生殖细胞中具有额外的意想不到的作用。假设和目的：我们假设人RBM5基因和小鼠RBMXL2基因发生突变将影响睾丸的正常健康发育。我们的目标是使用小鼠组织和人类细胞系来研究这一点。方法：学生将分析RBMXL2基因敲除小鼠和野生型小鼠的基因表达和细胞生物学模式，以确定动物模型中RBMXL2缺失造成的缺陷。这些将包括剪接和基因表达的变化，以及对精子发生重要的细胞过程的相应变化。这名学生将使用人类培养细胞的基因组工程来研究RBM5的功能，以及显性负突变如何改变这一功能。预测的差异剪接基因库将使用RT-PCR和毛细管凝胶电泳法进行验证。学生将使用基因组扩增产生的迷你基因，并将其导入野生型和突变的RBM5和RBMXL2细胞，询问关键基因的正常基因表达模式是如何实现的。作为分析内生目标的补充，学生还将描述RBM5和RBMXL2功能的从头突变对已有的候选微基因的影响。潜在影响：高达7%的男性患有不育症。尽管如此，人们对男性不育的机制还知之甚少。该项目将在我们合作小组最近工作的基础上，开始解决由于这些从头突变而导致哪些基因表达途径的全球途径调控不当。如果成功，我们可以通过对其他在男性不育中发现突变的剪接基因进行类似的研究来扩展这项工作。这项工作将有助于改善不育男性的基因诊断，这将提供更多关于辅助生殖技术的潜在成功、通过这些方法传递不孕不育的机会以及与不孕症相关的共病的更多洞察力。

Infertility affects many couples, but the reasons causing it are usually unknown, as are the mechanisms required for normal fertility. This project will analyse RNA binding proteins implicated in male infertility, to understand their role in normal spermatogenesis. We will take advantage of existing mouse models and make cell lines that we can manipulate in vitro. This project will include world class training in both molecular biology and bioinformatics which will place the student in a strong place in the jobs market. Background: Recently the Elliott lab found that an RNA binding protein called RBMXL2 is essential for normal spermatogenesis, but why is not fully clear (PMID: 34927545). In the Veltman lab, heterozygous de novo mutations affecting RNA binding proteins have been identified that prevent normal healthy development of the testis (for example, mis-sense mutations in the RBM5 gene, PMID: 35013161). What gene expression pathways are affected by these RNA binding proteins, and why they affect normal healthy development of sperm is unknown. Both RBMXL2 and RBM54 are involved in controlling splicing. Splicing is critical since most human genes are split between exons and introns. A macromolecular machine called the spliceosome recognises exon sequences and splices them into mRNAs. Most genes can be spliced in more than one way, and changes in splicing patterns can alter gene function. Splicing factor proteins control whether exons are recognised or not, and this can change gene function in important ways. But these RNA binding proteins could also have additional unexpected roles in normal healthy germ cells.Hypothesis and aims: We hypothesise that mutations occurring in the human RBM5 gene and the mouse RBMXL2 gene will change impact normal healthy development of the testis. Our aim is to use mouse tissue and human cell lines to investigate this. Methodology: The student will analyse patterns of gene expression and cell biology in RBMXL2 knockout mice and wild type mice to identify defects caused by loss of RBMXL2 within an animal model. These will include splicing and gene expression changes, and corresponding changes in cellular processes important for spermatogenesis. The student will use genome engineering of human cultured cells to investigate the function of RBM5 and how this is changed by dominant negative mutations. A pool of predicted differentially spliced genes will be validated using RT-PCR and capillary gel electrophoresis. The student will interrogate mechanisms how normal patterns of gene expression of key genes is achieved, using minigenes made by genomic amplification and transfected into cells with the wild type and mutated versions of RBM5 and RBMXL2. As a backup to analysing endogenous targets the student will also characterise the effects of de novo mutations on RBM5 and RBMXL2 function on candidate minigenes that are already available. Potential impact: Up to 7% of men suffer from infertility. Despite this, the mechanisms of male infertility are very poorly understood. This project will follow on from recent work in our collaborating groups to start to address what global pathways of gene expression pathways are mis-regulated as a result of these de novo mutations. If successful, we can expand on this work by performing similar studies in other splicing genes found to be mutated in male infertility. This work will contribute to improving the genetic diagnosis in infertile men, which will provide more insight into the potential success of assisted reproductive technologies, the chance of passing on infertility with these approaches and co-morbidities associated with the infertility.