In cell biology, a Paraspeckle is an irregularly shaped compartment of the cell, approximately 0.2-1 μm in size, found in the nucleus' interchromatin space."
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Paraspeckles were first discovered (1990's) in human cancer cells, but are now known to be present in all human primary cells, transformed cell lines and tissue sections.
They have also been found in mouse cells, and therefore are likely to be present in other mammals.
Their function is unknown.
One theory is that they provide ordered localisation of the cell's component proteins and help direct their activity. Another is that they may have a role in cancer regulation, reproduction and viral management.