Frequency and orientation of pseudopod formation of Dictyostelium discoideum amebae chemotaxing in a spatial gradient: further evidence for a temporal mechanism.
Frequency and orientation of pseudopod formation of Dictyostelium discoideum amebae chemotaxing in a spatial gradient: further evidence for a temporal mechanism.
复制标题
空间梯度中盘基网柄菌阿米巴趋化性伪足形成的频率和方向：时间机制的进一步证据。
DOI：
10.1002/cm.970080104
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发表时间：
1987
影响因子：
--
通讯作者：
Soll,DR
中科院分区：
文献类型：
--
作者：
Varnum-Finney,BJ;Voss,E;Soll,DR
通常情况下，盘状盘状门的变形虫通过评估向外移动的、不耗散的趋化剂cAMP波的方向向聚集中心趋化。然而,D。disideumamebae还可以评估相对稳定的空间梯度方向。研究表明，在相同的空间梯度下，变形虫向稳定的空间梯度“源”迁移的速度更快，假足延伸较少，并且转向频率较低。此外，变形虫从细胞的前半部分以极化的方式向外侧延伸假足，并且向源和远离源的频率一样高。然而，向震源方向形成的那些比远离震源形成的那些更经常产生转弯。这些结果表明，可能存在两个决策系统，一个定位于假足，另一个沿着整个细胞体；他们支持dictyosteliumamebae可能采用一种时间机制来评估化学引诱剂的空间梯度方向的建议。
Amebae ofDictyostelium discoideumnormally chemotax to aggregation centers by assessing the direction of outwardly moving, nondissipating waves of the chemoattractant cAMP. However,D. discoideumamebae can also assess the direction of a relatively stable spatial gradient. We demonstrate that amebae migrating towards the “source” of a stable, spatial gradient move faster, extend fewer pseudopodia, and turn less frequently than amebae migrating away from the “source” in the same spatial gradient. In addition, amebae extend lateral pseudopods in a polarized fashion from the anterior half of the cell, and do so as frequently towards the source as away from the source. However, those formed towards the source more often produce a turn than those formed away from the source. These results suggest that there may be two decision‐making systems, one localized in the pseudopods, and one along the entire cell body; they support the suggestion thatDictyosteliumamebae may employ a temporal mechanism to assess the direction of a spatial gradient of chemoattractant.