Chemotropism and branching as alternative responses of Achlya bisexualis to amino acids.
Chemotropism and branching as alternative responses of Achlya bisexualis to amino acids.
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趋化性和分支是双性蠹对氨基酸的替代反应。
DOI：
10.1099/00221287-135-9-2519
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Harold,FM
中科院分区：
文献类型：
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作者：
Schreurs,WJ;Harold,RL;Harold,FM
Achlya两性菌丝生长在稀薄的培养基上，它们的伸长朝向氨基酸的来源，也发出分枝。用微管在单个菌丝附近产生氨基酸的梯度。苯丙氨酸和蛋氨酸是最强的引诱剂：0·4 mM氨基酸在吸管中产生重定向，较高的浓度使菌丝在吸管周围卷曲生长到吸管尖端。菌丝在其宽度上检测到低至5%的梯度。蛋氨酸和苯丙氨酸似乎与不同的受体结合。局部应用这些氨基酸也引起了单个分支的出现，靠近吸管和梯度的高端；不同的氨基酸及其类似物的比较表明，分支和趋化性共享共同的受体。相比之下，细胞松弛素A和各种离子载体在随机位置诱导分支，而不涉及受体。我们认为，氨基酸与其受体的结合决定了前体囊泡胞吐的位置，并考虑了可能的机制。
Hyphae ofAchlya bisexualisgrowing on lean media orient their extension towards a source of amino acids, and also put forth branches. Micropipettes were used to generate gradients of amino acids in the vicinity of individual hyphae. Phenylalanine and methionine were the most powerful attractants: 0·4 mmamino acid in the pipette produced reorientation, and higher concentrations made the hyphae curl around the pipette and grow into its tip. Hyphae detected gradients as low as 5% across their width. Methionine and phenylalanine appeared to bind to different receptors. Local application of these amino acids also elicited the emergence of single branches, next to the pipette and on the high side of the gradient; comparison of diverse amino acids and their analogues suggested that branching and chemotropism share common receptors. By contrast, cytochalasin A and various ionophores induced branches at random sites, without receptor involvement. We propose that binding of amino acids to their receptors determines the site of precursor vesicle exocytosis, and consider possible mechanisms.