Cellular Fireworks : To celebrate #4thofjuly .
When a cell embarks on mitosis, the envelope around the nucleus disappears and long rods known as microtubules assemble to form a spindle. Chromosomes line up at the equator of this spindle and are pulled to opposite poles in a carefully orchestrated event driven by chemical gradients of key proteins in the cell. Images of Mitosis From L to R:
⁂ A protein, known as RanGTP (yellow), brings cargo to the neighborhood of the mitotic spindle (red) so it can be assembled. A gradient of this protein, spreading out from the chromosomes, is key to the perfect alignment of chromosomes along the equator of the spindle. http://goo.gl/EgQzv
⁂ Chromosomes (blue) are being pulled to opposite poles of four dividing cells of an embryo by the fibers of the mitotic spindle (orange). http://goo.gl/eKl62
⁂ Chromosomes (red) line up at the equator of the mitotic spindle (green). http://goo.gl/D1G9u