小脑 (cerebellum)是脊椎动物(Vertebrates) 大脑组织里很重要的一个组织，它所构成的神经组织，控制着身体的运动功能，因此小脑的发育，就显得非常的重要。三月份刚出版的 PNAS期刊上，科学家发表最新的研究结果显示，研究人员已经找到了一个关键的基因，负责调控胚胎发育过程中的小脑组织。
主要领导这个研究计划的 Eduardo Soriano博士解释指出，这次参与的科学家找到了一个称为 Ptf1a/p48的基因，就初步的研究结果显示，缺少 Ptf1a/p48这个基因的活动，神经母细胞虽然在发育的过程中，会变化成浦金氏神经细胞 (Purkinje neuron)，但却无法再进一步分化成为功能成熟的神经细胞，因此 Ptf1a/p48基因活动的功能，就好像一个决定小脑发育的开关一样，决定着小脑的命运。
为了了解 Ptf1a/p48基因的活动角色，研究人员利用基因剔除技术，设计出新的分析模式，去了解小脑相关细胞的分化方式，之后证实了一个特殊的转录分子 (transcription factor)，也参与这些神经细胞的分化。
相关的科学家指出，这个 Ptf1a/p48基因的现身，给了相关研究人员一个切入的机会，也许在不久的将来，小脑运动失调 (cerebellar ataxias)的疾病 就不再是个不知道发病原因的疾病了。
(资料来源 : Bio.com)
英文原文：
Researchers discover gene essencial to cerebellum formation
Scientists have identified a molecular switch that causes the differentiation of neurons in the cerebellum, a part of the brain that helps to regulate motor functions.
A study published this week in the scientific journal PNAS provides new information on the origin of different cells in the cerebellum, an important component of the central nervous system found in all vertebrates, including humans, and the part of the brain that controls movement. The study was completed by researchers from the Institute for Research in Biomedicine (IRB Barcelona), the Department of Cell Biology of the University of Barcelona (UB), the IMIM-Hospital del Mar, Pompeu Fabra University (UPF) and Vanderbilt University (Nashville, Tennessee, USA). The main authors of the study are Dr. Marta Pascual (IRB Barcelona and UB) and Ibane Abasolo (IMIM-Hospital del Mar-UPF).
Co-author of the study, Francisco X. Real, coordinator of the Research Unit on Cell and Molecular Biology at IMIM-Hospital del Mar and Professor at the UPF, explains that "this discovery sheds new light on the mechanisms of brain formation and has potential future applications for regenerative medicine. It provides crucial insight into the manipulation of truncal nerve cells (or stem cells) and their selective differentiation into 'gabergic' neurons, or cells that contain the neurotransmitter gamma-aminobutyric acid (GABA) and that act as inhibitors.
Eduardo Soriano, Principal Investigator of the Developmental Neurobiology and Regeneration laboratory at IRB Barcelona, and professor at the UB, maintains that the study explains two important principles: first, "that the protein Ptf1a/p48 is needed for the production and differentiation of Purkinje neurons, the most important cells in the cerebellum"; and second, "that in the absence of this protein, the progenitor cells that should produce Purkinje neurons do not differentiate correctly and instead produce a different type of neuron, granular cells, indicating that Ptf1a/p48 acts as a molecular switch."
The researchers hypothesized that a transcription factor, whose function is well known in the pancreas and which appears to play a role in the nervous system, is also involved in the development of the cerebellum. In order to test their idea, and characterize the new mechanism of cell differentation, the authors used mice with a disactivated gene that codes for the Ptf1a/48 protein, and compared them with mice that express the gene normally. Their conclusions provide new insight into origin of nerve cells that form the cerebellum in higher organisms.
In a second research project, led by Francisco Real and Eduardo Soriano and funded by the Fundaci?La Caixa, the scientists aim to explore the potential of this gene to produce Purkinje neurons in a laboratory setting. The researchers will investigate whether the expression of Ptf1a/p48 can induce the production of Purkinje cells from stem cells and neurospheres, progenitor cells of adult neurons. This study is an important step toward understanding rare diseases, such as cerebellar ataxias, which is characterized by the degeneration of Purkinje cells. Producing this type of cell in the lab may lead to future neuronal replacement therapy.
