What is a Centriole?

Mary McMahon
Mary McMahon

A centriole is a specialized organelle, also called a cell body, that is found in the cells of most animals. It is roughly tubular in shape and plays an important role in cell division. These cell structures are so tiny that their details cannot be seen without the assistance of an electron microscope; during cell division, their activity can clearly be seen under magnification.

The structure of a centriole is composed of microtubules that form a pinwheel shape when viewed in a cross-section.
The structure of a centriole is composed of microtubules that form a pinwheel shape when viewed in a cross-section.

There are many organelles, including centrioles, that help a eukaryotic cell to run smoothly. A eukaryotic cell is a complex cell with a number of tiny organs that all serve different functions. It also has a cell nucleus and a complex physical structure that sets it aside from prokaryotic cells, like those of bacteria. Humans, among other animals, are made from eukaryotic cells, and these cells periodically divide to renew themselves so that their larger hosts can grow and remain healthy.

A centriole is a vital structure contained within an animal cell.
A centriole is a vital structure contained within an animal cell.

In animals that have centrioles, each cell has a pair. Their shape is actually quite fascinating and beautiful; they consist of nine triplets of microtubules arranged in a pinwheel shape around a central cylinder. The two collectively make up a structure in the cell which is called the centrosome, with one centriole aligned in an orientation that is perpendicular to the other. This organelle is at the core of cell division.

When a cell divides, the centrosome replicates itself, and the two move to opposite ends of the cell. Each then sends out spindles, which are supposed to separate the cell's DNA, differentiating a cell into two copies of itself that can then split into fresh cells. An error during this process can create a mutated cell, which may harmlessly die off or become more malignant, depending on the mutation.

The existence of the centrosome was discovered by Theodor Boveri in 1888, and Boveri also put forward an early theory that cancer was caused by errors during cell division. Although mocked at the time, he was later proved correct. In addition to playing an important role in cell division, a centriole also helps to provide structural support for its parent cell. It would also appear that this organelle has its own unique genetic code that is distinct from the code of the cell; scientists believe that this code allows the centrosome to divide and carry out its various functions in the cell.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


Can someone please give me a one sentence definition to help me understand this better?


While researching the kind of cancer I have, I found out that it was caused by an error during cell differentiation. Sometime during the first couple weeks of my pregnancy, a centriole division went wrong and caused a baby not to form correctly; I was diagnosed as having a partial molar pregnancy.

I had to have a D & C followed by chemotherapy injections. It truly is a miracle how nature works.


Centrioles are self-replicating organelles. Not all organelles are capable of self-replicating. A non-self-replicating organelle is a lysosome, for example. Mitochondria is another type of organelle, in addition to centrioles, which self-replicates.

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