美国西北大学在Science发表了一项重大发现:多细胞动物中,单个细胞对环境的反应要听从神经元细胞的指挥。
以往人们一直认为,多细胞动物中每一个细胞都会独自应对外界刺激,好似一个单细胞生物。然而西北大学的科学家发现,线虫在感知温度时,单个细胞的“反应权”被移交给了两个专门感受温度的神经元,它俩会组织起整个机体的反应。也就是说,两个神经细胞控制了其他957个细胞的反应。
实验中,研究者通过基因手段阻断了上述两个神经元,使其不能感受温度,发现整个机体中再无细胞能够对温度变化作出反应。研究者检查其他957个细胞发现,单个细胞仍然可以感受到升温,然而由于神经元未发出信号,所以细胞无应有的反应。研究者认为,其他多细胞动物包括人类,也应有类似的组织反应的神经元。这一发现有助于加深对多细胞动物的理解。(生物谷www.bioon.com)
生物谷推荐原始出处:
Science,Vol. 320. no. 5877, pp. 811 - 814,Veena Prahlad,Richard I. Morimoto
Regulation of the Cellular Heat Shock Response in Caenorhabditis elegans by Thermosensory Neurons
Veena Prahlad, Tyler Cornelius, Richard I. Morimoto*
Temperature pervasively affects all cellular processes. In response to a rapid increase in temperature, all cells undergo a heat shock response, an ancient and highly conserved program of stress-inducible gene expression, to reestablish cellular homeostasis. In isolated cells, the heat shock response is initiated by the presence of misfolded proteins and therefore thought to be cell-autonomous. In contrast, we show that within the metazoan Caenorhabditis elegans, the heat shock response of somatic cells is not cell-autonomous but rather depends on the thermosensory neuron, AFD, which senses ambient temperature and regulates temperature-dependent behavior. We propose a model whereby this loss of cell autonomy serves to integrate behavioral, metabolic, and stress-related responses to establish an organismal response to environmental change.
Department of Biochemistry, Molecular Biology, and Cell Biology, Rice Institute for Biomedical Research, Northwestern University, Evanston, IL 60208, USA.