Role of Math1 in brain stem & cerebellar development

描述（由申请人提供）：小鼠无调同源物1（Math 1）编码一种碱性螺旋-环-螺旋转录因子，其在内耳毛细胞、小脑颗粒细胞、脊髓背侧中间神经元、几种脑干核、默克尔细胞和肠分泌细胞的祖细胞中表达。 还值得注意的是，Math 1和HATH 1的表达分别在来自小鼠模型和人样品的髓母细胞瘤中上调。 基因靶向已经证明Math 1对于许多这些细胞的发生是必需的。 然而，其中一些细胞群在出生后分化，并且由于Math 1 null小鼠在出生时因无法呼吸而死亡，因此这些细胞的命运及其对Math 1功能的依赖性尚未得到充分分析。 为了研究所有Math 1表达细胞的命运，我们将诱导型Cre重组酶靶向Math 1基因组位点。 当这些小鼠与报告菌株杂交时，这种Cre/loxP系统将永久标记表达Math 1的细胞，使得它们的整个下游谱系可以追溯到成年期。 我们还将使用现有的条件等位基因删除Math 1在脑干和小脑在特定的胚胎和出生后的时间点，以确定所需的呼吸缺陷的Math 1空的脑干核，并研究Math 1在小脑颗粒细胞增殖和分化的作用。 结合这些命运定位和条件性基因敲除研究，应该提供有关Math 1表达细胞类型的发展、呼吸的启动以及神经元祖细胞增殖和分化之间的联系的基本知识。 这些信息可以提供深入了解后脑疾病，如髓母细胞瘤，和围产期呼吸功能障碍，如婴儿猝死综合征。

DESCRIPTION (provided by applicant): The mouse atonal homolog 1 (Math1) encodes a basic helix-loop-helix transcription factor that is expressed in the progenitors of the inner ear hair cells, cerebellar granule cells, spinal cord dorsal interneurons, several brain stem nuclei, merkel cells, and the secretory cells of the intestine. Of note also is that the expression of Math1 and HATH1 is upregulated in medulloblastomas from mouse models and human samples, respectively. Gene targeting has demonstrated that Math1 is necessary for the genesis of many of these cells. However, some of these cell populations differentiate postnatally, and because Math1 null mice die at birth from an inability to breathe, the fate of these cells and their dependence on Math1 function have not been fully analyzed. To study the fate of all Math1-expressing cells, we have targeted an inducible Cre recombinase to the Math1 genomic locus. When these mice are crossed to a reporter strain, this Cre/loxP system will permanently label Math1-expressing cells such that their entire downstream lineage can be traced into adulthood. We will also use an existing conditional allele to delete Math1 in the brainstem and cerebellum at specific embryonic and postnatal time points in order to identify the brainstem nucleus required for the respiratory defect in the Math1 nulls and to study the role of Math1 in cerebellar granule cell proliferation and differentiation. The combination of these fate-mapping and conditional knock-out studies should provide basic knowledge about the development of Math1-expressing cell types, the initiation of breathing, and the connection between neuronal progenitor proliferation and differentiation. This information may provide insight into hindbrain diseases such as Medulloblastomas, and perinatal respiratory dysfunction such as Sudden Infant Death Syndrome.