Grinberg A, Heath IB
Department of Biology, York University, 4700 Keele Street, North York, Ontario, M3J 1P3, Canada.
Fungal Genet Biol. 1997 Oct;22(2):127-39. doi: 10.1006/fgbi.1997.1011.
Grinberg, A., and Heath, I. B. 1997. Direct evidence for Ca2+ regulation of hyphal branch induction. 22, 127-139. Irradiation of growing hyphae of Saprolegnia ferax with microbeams of UV (300-380 and 385-450 nm) light induced an increase in cytoplasmic [Ca2+] followed by precocious formation of one or more branches within about 4 min. The distribution of branches was strongly skewed toward the subapical side of the irradiation site, but otherwise was apparantly random. Apical (10-&mgr;m) irradiations were more effective than subapical (50-&mgr;m) ones in that they induced branches at comparable frequencies but with lower doses, consistent with higher concentrations of putative target intracellular Ca2+ storage structures in this region. Once formed, induced adjacent branches seem to compete for "resources," with those closer than approximately 50 &mgr;m inhibiting each other. The results are most consistent with Ca2+-induced accumulation of branch initiating factors being the cause, not the consequence, of branch formation, thus supporting a primary role for Ca2+ in regulation of hyphal tip growth. Copyright 1997 Academic Press. Copyright 1997 Academic Press
格林伯格，A.，和希思，I. B. 1997年。钙对菌丝分支诱导调控的直接证据。22卷，127 - 139页。用紫外线（300 - 380纳米和385 - 450纳米）微束照射生长中的水霉菌丝，会导致细胞质中钙离子浓度升高，随后在大约4分钟内提前形成一个或多个分支。分支的分布强烈偏向照射部位的亚顶端一侧，但在其他方面显然是随机的。顶端（10微米）照射比亚顶端（50微米）照射更有效，因为它们能以相当的频率诱导分支形成，但所需剂量更低，这与该区域假定的目标细胞内钙离子储存结构浓度较高一致。一旦形成，诱导产生的相邻分支似乎会争夺“资源”，彼此距离小于约50微米的分支会相互抑制。这些结果最符合钙离子诱导分支起始因子积累是分支形成的原因而非结果这一观点，从而支持了钙离子在调控菌丝顶端生长中起主要作用的观点。版权所有1997年学术出版社。版权所有1997年学术出版社
