Identification and characterisation of a new gene that is mutated in an autosomal recessive form of nonsyndromic hearing impairment

我之前的DFG研究计划题为“非综合征性听力障碍常染色体隐性基因突变的新基因的鉴定和表征”，其目的是发现并初步表征一种常染色体隐性听力障碍突变的新基因，称为DFNB42。在2009/2010年DFG资助期间，我在DFNB42位点发现了ILDR1基因突变导致听力障碍。因此，ILDR1是一种新的耳聋基因。这项研究的结果发表在2011年1月的《美国人类遗传学杂志》上。在2年的随访中，我在这里提出了资助申请，我计划更好地描述ILDR1在内耳和生理听力过程中所起的作用。ILDR1编码一种功能未知的跨膜受体。我们之前通过mRNA原位杂交表明，小鼠同源基因Ildr1在耳蜗毛细胞和支持细胞以及前庭器官毛细胞中表达。我计划通过免疫化学在小鼠内耳中精确定位Ildr1蛋白来扩展这些结果。此外，我将使用新的蛋白质生物化学方法寻找ILDR1配体和相互作用伙伴，通过这种方法不仅可以识别胞质蛋白，还可以识别跨膜蛋白的相互作用伙伴。最后，我计划通过在模式生物斑马鱼中敲低ILDR1类似物的表达来创建DFNB42的第一个动物模型，这将使我们更好地了解ILDR1对脊椎动物听力的贡献。这些分析有望有助于更好地了解ILDR1在听力和耳聋中的作用，并更广泛地深入了解听力本身的复杂过程。

The aim of my previous DFG research proposal entitled “Identification and characterisation of a new gene that is mutated in an autosomal recessive form of nonsyndromic hearing impairment“ was to find and initially characterize a novel gene which is mutated in an autosomal-recessive form of hearing impairment, called DFNB42. During the 2009/2010 funding period of this DFG grant I have identified mutations of the ILDR1 gene as causative for hearing impairment at the DFNB42 locus. Thus, ILDR1 is a novel deafness gene. The results of this study have been published in the January 2011 issue of the Amercian Journal of Human Genetics. In the 2 years of follow-up for which I present the grant application here, I plan to better characterize the role that ILDR1 plays in the inner ear and in the pysiological hearing process. ILDR1 encodes a putative transmembrane receptor of unknown function. We have previously shown by mRNA in situ hybridization that the mouse ortholog Ildr1 is expressed in hair cells and supporting cells of the cochlea and in hair cells of the vestibular organ. I plan to extend these results by pecisely localizing the Ildr1 protein in the mouse inner ear by immunochemistry. Moreover, I will search for ILDR1 ligands and interaction partners by using novel methods of protein biochemistry by which interaction partners can be identified not only for cytosolic but also for transmembrane proteins. Finally, I plan to create a first animal model for DFNB42 by knocking down the expression of ILDR1 paralogs in the model organism, zebrafish, which will allow for a better understanding of the the contribution of ILDR1 to hearing in vertebrates. These analyses will hopefully contribute to a better understanding of the role that ILDR1 plays in hearing and deafness and more generally to a deeper understanding of the complex process of hearing itself.