Before revision: Ab10 differs from the normal chromosome 10 by the presence of a 150-base pair heterochromatic region called 'knob', which has been observed to move faster to the spindle poles in meiosis I and II than the centromeres , causing Ab10 to be preferentially inherited during meiosis .
After revision: Ab10 differs from the normal chromosome 10 by the presence of a 150-base pair heterochromatic region called 'knob', which functions as a centromere during division (hence called 'neocentromere') and moves to the spindle poles faster than the centromeres , causing Ab10 to be preferentially inherited during meiosis .