I am reading this paper "Volume regulation and shape bifurcation in the cell nucleus" (linked below)


I am confused by this sentence "During cell detachment, because the cytoplasmic osmotic pressure decreases dramatically, water flows out of the nucleus and the nuclear volume shrinks."

Since water flows from low to high osmotic pressure, I would have thought that this decrease in osmotic pressure of the cytoplasm would cause water to flow into the nucleus, not out of it. Why does the opposite happen here?

The article also states that the volume of the cytoplasm will decrease. So is this something to do with the extracellular space?

  • 1
    $\begingroup$ After reading a snippet of the article, it seems like you just found a simple mistake that wasn't caught during review, but really shouldn't cause much confusion in the context of the paper. It's clear enough from the preceding paragraphs what they concluded is happening. Cell volume is reduced after detachment, primarily due to water efflux. Because of that change, the difference in osmotic and hydrostatic pressures between the cytoplasm and the nucleus favors water flux from the nucleus to the cytoplasm, reducing the volume of the nucleus and causing it to shrivel. $\endgroup$
    – MikeyC
    Nov 5, 2020 at 15:53


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