Centromere vs Centriole
Both centriole and centromere are closely associated structures that are important in the process of cell division, in many organisms. During mitosis and meiosis, centrioles produce spindle fibers and centromeres provide the site of attachment to these fibers. Although they are closely associated, there are many structural and functional differences between these two.
Centriole
Centriole is a small organelle present outside the nuclear membrane. It has cylindrical structure that is composed of groupings of microtubules arranged in (9+3) pattern. Centrioles are found mainly in animal cells and other flagellated cells. The main function of centriole is to divide and organize spindle fibers during mitosis and meiosis. A structure called ‘centrosome’ is formed by perpendicularly arranging of two centromeres. It serves as the main microtubule organizing center of the cells as well as a regulator of cell cycle progression.
Centromere
Centromere is a visible point of constriction on a chromosome with repeated DNA sequences that bind specific proteins. These proteins are responsible to make up the kinetochore to which microtubules attach during cell division. Kinetochore has a very complex multiprotein structure that is responsible for binding microtubules and signaling cell cycle to continue next steps. There are two types of centromeres; namely, point centromeres and regional centromeres. Point centromeres form a single microtubule attachment per chromosome and bind to specific proteins, which recognize particular DNA sequences with high efficiency. Regional centromeres form multiple attachments on regions with proffered DNA sequences. Unlike the point centromeres, most organisms have regional centromeres in their cells.
What is the difference between Centriole and Centromere?
• Centriole is an organelle inside a cell, whereas centromere is a region in a chromosome.
• Centromere is the region of attaching microtubules that are produced by centriole during the cell division.
• Unlike the centromere, Centriole has 9+3 microtubule arrangement.
• Centromere is present in both animal and plant cells, whereas centriole is absent in higher plants and most fungi.
• Centrioles forms and organize the spindle, while centromeres provide the site of attachment to these spindles.