page_title: Cytoplasmic streaming
section_title: Contribution to growth
hierarchical_section_title: Cytoplasmic streaming / Cytoplasmic flows created by pressure gradients / In Neurospora crassa / Contribution to growth
caption_attribution_description: Idealized cytoplasmic flow hyphae of Neurospora crassa. (Top) Actual cytoplasmic flow in hyphae of Neurospora crassa. Microtubules (red) orient themselves perpendicular to flow as they exit the septal hole, deaccelerating the flow faster than the idealized case preventing the formation of eddies on the downstream side of the septum. Nuclei and other proteins aggregate on the upstream side which maintain the integrity of the septum. (Bottom)
context_page_description: Cytoplasmic streaming, also called protoplasmic streaming and cyclosis, is the flow of the cytoplasm inside the cell, driven by forces from the cytoskeleton. It is likely that its function is, at least in part, to speed up the transport of molecules and organelles around the cell. It is usually observed in large plant and animal cells, greater than approximately 0.1 mm. In smaller cells, the diffusion of molecules is more rapid, but diffusion slows as the size of the cell increases, so larger cells may need cytoplasmic streaming for efficient function.
  The green alga genus Chara possesses some very large cells, up to 10 cm in length, and cytoplasmic streaming has been studied in these large cells.
  Cytoplasmic streaming is strongly dependent upon intracellular pH and temperature. It has been observed that the effect of temperature on cytoplasmic streaming created linear variance and dependence at different high temperatures in comparison to low temperatures. This process is complicated, with temperature alterations in the system increasing its efficiency, with other factors such as the transport of ions across the membrane being simultaneously affected.
context_section_description: Cytoplasmic flows created through osmotic pressure gradients flow longitudinally along the fungal hyphae and crash into the end causing growth. It has been demonstrated that the greater pressure at the hyphal tip corresponds to faster growth rates.  Longer hyphae have greater pressure differences along their length allowing for faster cytoplasmic flow rates and larger pressures at the hyphal tip. This is why longer hyphae grow faster than shorter ones. Tip growth increases as cytoplasmic flow rate increases over a 24-hour period until a max rate of 1 micron/second growth rate is observed. Offshoots from the main hyphae are shorter and have slower cytoplasmic flow rates and correspondingly slower growth rates.
caption: Top: Idealized cytoplasmic flow in hyphae of Neurospora crassa. Bottom: Actual cytoplasmic flow in hyphae of Neurospora crassa. Microtubules (red) orient themselves perpendicular to flow as they exit the septal hole, deaccelerating the flow faster than the idealized case preventing the formation of eddies on the downstream side of the septum. Nuclei and other proteins aggregate on the upstream side which maintain the integrity of the septum.
exif: {"Image Artist": "Anwar Baksh", "Image ExifOffset": "2134", "Image XPAuthor": "Anwar Baksh", "Image Padding": "[]", "EXIF DateTimeOriginal": "2016:12:11 12:22:50", "EXIF DateTimeDigitized": "2016:12:11 12:22:50", "EXIF SubSecTimeOriginal": "15", "EXIF SubSecTimeDigitized": "15", "EXIF Padding": "[]"}