FIGURE 7.

Hypothetical model of mRNA localization in A. oryzae hyphae. (A) After induction with maltose, amyB mRNAs are highly expressed at each nucleus through the hypha, which might result in not only primary apical secretion but also secretion through the septum, and even intercalary secretion of α-amylase. Note that for simplicity only a few nuclei in each cell are depicted, but generally A. oryzae hyphae contain multiple nuclei in every cell. (B) amyB mRNAs are restricted to locations near each nucleus and excluded from the tip region, and might be targeted to the ER for translation. In contrast, actA mRNAs are mainly localized to the apical region, where actin cables and patches preferentially reside. Since the nucleus closest to the apex normally localizes approximately more than 10 μm from the tip, actA mRNAs are potentially transported to the tip region after their transcription in the nucleus.