Mitotic Spindle July 23, 2009 By John Sopko This drawing shows the spindle from end to end. It is roughly 1.5 micons in length, with the kinetochore (green) microtubules making up 350 nm on each end, and the space between them being roughly 800 nm. The interpolar microtubules are drawn in two shades different shades of purple (dark purple ones extend from the left end of the spindle and pink-purple ones extend from the right end of the spindle). The microtubules are drawn straight and rigid, with an overall spindle diameter of 250 nm. Also, the DNA strands (yellow) extend even more outwardly than the microtubules. The two outermost strands of DNA (top and bottom of the spindle) have a few loops of DNA drawn in to show that the diameter of the spindle reaches 400 nm when the loops are included. Each of the other strands has a small break in it that represents a place where extra loops of DNA are attached. They are not drawn because they would make the details of the spindle hard to see. The bottom right corner shows the layout and packing of the microtubules at the spindle pole, not in a “convergence point” formation, but in a more tightly packed formation that has a diameter of 150 nm. Comments are closed.