GENES INVOLVED IN INNER EAR DEVELOPMENT

2000年约有1人患有遗传性先天性耳聋 每年出生的孩子。 对遗传性耳聋起源的研究， 和潜在的治疗方法，将大大促进发展 人类耳聋的小鼠模型。 许多有听觉的突变老鼠 损伤已经存在，但大多数负责基因是 不容易进行分子克隆。 加快 了解听力和耳聋的遗传基础， 同时识别和突变基因参与发展 这里提出了鼠的听觉系统。 新的lacZ基因诱捕载体 旨在增加可检测的基因组整合位点的数量， 并有助于鉴定β-半乳糖苷酶（β-gal）- 使用分子克隆技术构建表达细胞。 这些载体将被导入多能小鼠胚胎干细胞中， (ES)细胞，并将筛选所得细胞系， 在体外分化后，F或β-gal活性， 从载体整合到表达的基因中。 ES细胞克隆显示 体外β-半乳糖醛酸活性的调节模式将用于 产生嵌合体胚胎，其将被分析β-gal活性 在不同的发展阶段。 产生β-半乳糖的克隆 在发育中的听觉系统和/或 被认为是诱发听觉系统的周围组织， 以产生携带基因陷阱插入物的小鼠品系。 遗传 分析将被用来确定被破坏的基因是否引起 在胚胎和/或成年人的听觉系统中表现出明显的突变表型。 对听觉系统发育重要的基因，使用这种方法鉴定 方法，可以很容易地克隆凭借其连接到lacZ 序列，随后将通过DNA序列分析进行鉴定。 这项研究产生的DNA探针可能会被用于 在未来的连锁研究，以确定基因参与人类疾病。

Congenital deafness with a genetic origin affects approximately 1 in 2000 children born every year. Studies of the origins of genetic deafness, and potential treatments, would be greatly facilitated by the development of mouse models of human deafness. Many mouse mutants with auditory impairment already exist, but the majority of the responsible genes are not readily accessible to molecular cloning. To accelerate the understanding of the genetic basis of hearing and deafness, a scheme to simultaneously identify and mutate genes involved in the development of the murine auditory system is proposed here. New lacZ gene trap vectors designed to increase the number of detectable genomic integration sites, and facilitate the identification of beta-galactosidase (beta-gal)- expressing cells will be constructed using molecular cloning techniques. These vectors will be introduced into pluripotent murine embryonic stem (ES) cells, and the resulting cell lines will be screened, both before and after in vitro differentiation,f or beta-gal activity that results from vector integration into an expressed gene. ES cell clones that show a regulated pattern of beta-gal activity in vitro will be used to generate chimeric embryos which will be analyzed for beta-gal activity at various developmental stages. Clones that give rise to beta-gal expression in components of the developing auditory system and/or the surrounding tissues thought to induce the auditory system, will be used to generate mouse strains that carry the gene trap insertions. A genetic analysis will be used to determine whether the disrupted genes give rise to overt mutant phenotypes in the embryonic and/or adult auditory system. Genes important for auditory system development, identified using this approach, can be cloned easily by virtue of their linkage to lacZ sequences, and will subsequently be identified by DNA sequence analysis. The DNA probes that result from this research could potentially be used in future linkage studies to identify genes involved in human disorders.