Definition of polysome in US English:



  • A cluster of ribosomes held together by a strand of messenger RNA that each ribosome is translating.

    • ‘The rest are nuclear-encoded and are synthesized as precursor proteins on free cytosolic polysomes.’
    • ‘Anoxia causes polysomes, translating the aerobic proteins, to dissociate, and anaerobic mRNAs are translated from polysomes with a much lower average size.’
    • ‘The peaks of free 40S and 60S subunits, 80S ribosomes (free couples and monosomes), and polysomes are indicated.’
    • ‘This value was lower than the average amount of mRNA detected in all polysomes (two ribosomes per mRNA) in leaves of arabidopsis and rapidly dividing yeast cells.’
    • ‘This loss of protein synthetic capacity is manifested in a loss of polysomes that result from the run-off of ribosomes from mRNAs coupled with a failure in the initiation machinery.’