Identification of Novel Loci Interacting with the Kallmann Syndrome Gene Kal-1

描述（由申请人提供）：卡尔曼综合征是一种遗传性疾病，其特征是嗅觉丧失和促性腺功能低下，导致不孕。这种疾病的男性发病率为1 / 10000，女性发病率为1 / 40000，但由于性腺功能减退或性腺功能减退的轻微病例，可能未被诊断出来。迄今为止，已鉴定出5个与KS相关的基因，即KAL1、FGFR1、FGF8、PROKR2和PROK2；尽管这些只占所有KS病例的30%左右。该项目的目标是鉴定和表征与kal-1基因相互作用的新基因，kal-1基因编码细胞外基质的细胞粘附蛋白。我们建议使用秀丽隐杆线虫功能轴突分支表型kal-1增益的修饰筛选来实现这一目标。我们的研究小组已经成功地利用这种表型的试点筛选，在蠕虫和人类中发现了几个与KAL-1基因相互作用的新位点。新分离的突变将通过单核苷酸多态性定位和全基因组测序方法进行分子鉴定。RNAi介导的敲低实验和转基因拯救实验将进一步证实突变的身份。然后，将通过三种互补的方法对鉴定的基因进行分子和遗传表征，以更深入地了解kal-1如何与这些基因一起作用于神经系统的发育以及细胞外基质在这一过程中的作用。首先，我将对修饰突变体进行详细的神经解剖学和表型分析，重点是神经系统。其次，确定它们的表达位点和亚细胞定位，这将为蛋白质的功能提供重要线索。第三，将进行双突变和上位分析，以便将新突变置于已知的遗传环境中。最后，随着更多与KAL-1相互作用的基因被识别出来，我们将更好地了解它们的功能以及它们在人类中的破坏是如何导致Kallmann综合征的。

DESCRIPTION (provided by applicant): Kallmann Syndrome is a hereditary condition characterized by anosmia (the inability to smell) and hypogonadotropic hypogonadism resulting in infertility. This disorder affects 1 in 10,000 males and 1 in 40,000 females, but may be under diagnosed due to mild cases of hypogonadism or hyposmia. To date, five genes associated with KS have been identified, namely, KAL1, FGFR1, FGF8, PROKR2, and PROK2; though these only account for approximately 30% of all KS cases. The goal of this project is to identify and characterize novel genes that genetically interact with kal-1, a gene that codes for a cell adhesion protein of the extracellular matrix. We propose to accomplish this using a modifier screen of a kal-1 gain of function axon branching phenotype in C. elegans. A pilot screen of this phenotype has been used successfully by our group to identify several novel loci that genetically interact with KAL-1, both in worms and humans. The newly isolated mutations will be molecularly identified through single nucleotide polymorphism mapping and whole genome sequencing approaches. RNAi mediated knock down experiments and transgenic rescue experiments will be performed to further corroborate the identity of the mutation. The identified genes will then be molecularly and genetically characterized by three complementary approaches to gain a deeper understanding of how kal-1 acts in concert with these genes on the development of the nervous system and the role of the extracellular matrix in this process. First, I will perform a detailed neuroanatomical and phenotypic analysis of the modifier mutants with a focus on the nervous system. Second, their site of expression and the sub cellular localization will be determined, which will give important clues to the function of the protein. Third, double mutant and epistasis analyses will be performed in order to place the new mutations within a known genetic context. In the end, as more genes that interact with KAL-1 are identified, we will have a better understanding of their function and how their disruption in humans results in Kallmann Syndrome. PUBLIC HEALTH RELEVANCE: Kallmann Syndrome (KS) is a genetic disease with neuronal targeting and migration defects that manifest in the inability to smell and infertility. We are using a genetic approach in C. elegans to identify genes that interact with the KS gene kal-1 in order to gain a deeper understanding of its function during the development of the nervous system. The identified genes are candidate disease genes to be mutated in molecularly unexplained cases of Kallmann Syndrome.