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排序方式: 共有174条查询结果,搜索用时 15 毫秒
81.
Mutations in alpha-tubulin cause abnormal neuronal migration in mice and lissencephaly in humans 总被引:7,自引:0,他引:7
Keays DA Tian G Poirier K Huang GJ Siebold C Cleak J Oliver PL Fray M Harvey RJ Molnár Z Piñon MC Dear N Valdar W Brown SD Davies KE Rawlins JN Cowan NJ Nolan P Chelly J Flint J 《Cell》2007,128(1):45-57
The development of the mammalian brain is dependent on extensive neuronal migration. Mutations in mice and humans that affect neuronal migration result in abnormal lamination of brain structures with associated behavioral deficits. Here, we report the identification of a hyperactive N-ethyl-N-nitrosourea (ENU)-induced mouse mutant with abnormalities in the laminar architecture of the hippocampus and cortex, accompanied by impaired neuronal migration. We show that the causative mutation lies in the guanosine triphosphate (GTP) binding pocket of alpha-1 tubulin (Tuba1) and affects tubulin heterodimer formation. Phenotypic similarity with existing mouse models of lissencephaly led us to screen a cohort of patients with developmental brain anomalies. We identified two patients with de novo mutations in TUBA3, the human homolog of Tuba1. This study demonstrates the utility of ENU mutagenesis in the mouse as a means to discover the basis of human neurodevelopmental disorders. 相似文献
82.
Species-specific shifts in centromere sequence composition are coincident with breakpoint reuse in karyotypically divergent lineages 总被引:2,自引:0,他引:2
Background
It has been hypothesized that rapid divergence in centromere sequences accompanies rapid karyotypic change during speciation. However, the reuse of breakpoints coincident with centromeres in the evolution of divergent karyotypes poses a potential paradox. In distantly related species where the same centromere breakpoints are used in the independent derivation of karyotypes, centromere-specific sequences may undergo convergent evolution rather than rapid sequence divergence. To determine whether centromere sequence composition follows the phylogenetic history of species evolution or patterns of convergent breakpoint reuse through chromosome evolution, we examined the phylogenetic trajectory of centromere sequences within a group of karyotypically diverse mammals, macropodine marsupials (wallabies, wallaroos and kangaroos). 相似文献83.
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Although the control of cell proliferation has been studied intensively at the level of the single cell, less is known about how cell numbers are controlled in developing populations and organs. Often, proliferation provides a pool of cells for organ construction, but the rate of this proliferation must be coordinated with patterning to avoid imbalances in cell numbers. Recent research on the development of the Drosophila eye and the proliferation signals (mitogens) can act to coordinate cell numbers. 相似文献
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M D Rawlins 《BMJ (Clinical research ed.)》1990,301(6754):729-733
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