Search results
Results from the WOW.Com Content Network
In cell biology, the spindle apparatus is the cytoskeletal structure of eukaryotic cells that forms during cell division to separate sister chromatids between daughter cells. It is referred to as the mitotic spindle during mitosis , a process that produces genetically identical daughter cells, or the meiotic spindle during meiosis , a process ...
The function of astral microtubules can be generally considered as determination of cell geometry. They are absolutely required for correct positioning and orientation of the mitotic spindle apparatus , and are thus involved in determining the cell division site based on the geometry and polarity of the cells.
Centralspindlin is required for the assembly of the mitotic spindle [3] as well as for microtubule bundling and anchoring of midbody microtubules to the plasma membrane. [ 1 ] [ 2 ] This complex is also implicated in tethering the spindle apparatus to the plasma membrane during cytokinesis [ 4 ] This interaction permits cleavage furrow ingression.
The motor part of the spindle is provided by motor neurons: up to a dozen gamma motor neurons also known as fusimotor neurons. [4] These activate the muscle fibres within the spindle. Gamma motor neurons supply only muscle fibres within the spindle, whereas beta motor neurons supply muscle fibres both within and outside of the spindle.
The actual set of genes essential for kinetochore function varies from one species to another. [7] [8] Kinetochore functions include anchoring of chromosomes to MTs in the spindle, verification of anchoring, activation of the spindle checkpoint and participation in the generation of force to propel chromosome movement during cell division. [9]
The spindle pole body (SPB) is the microtubule organizing center in yeast cells, functionally equivalent to the centrosome. Unlike the centrosome the SPB does not contain centrioles. The SPB organises the microtubule cytoskeleton which plays many roles in the cell. It is important for organising the spindle and thus in cell division.
They are vital to spindle formation in mitotic and meiotic chromosome separation during cell division and are also responsible for shuttling mitochondria, Golgi bodies, and vesicles within eukaryotic cells. Kinesins have two heavy chains and two light chains per active motor.
Prophase is the initial phase when spindle fibers appear that function to move the chromosomes toward opposite poles. This spindle apparatus consists of microtubules, microfilaments and a complex network of various proteins. During metaphase, the chromosomes line up using the spindle apparatus in the middle of the cell along the equatorial plate.