What is the difference between centromere and kinetochore?
Centromere and kinetochore are two main structures found in the middle of the chromosomes. They are quite vital during sister chromatid segregation at cell division.
The lesson provides the core difference between centromere and kinetochore with a comparison chart and point form. Take the time to read through.
What Is A Centromere?
A centromere is a replicated region on the chromosome that holds sister chromatids together. The main role of the centromere is to provide a site for binding with microtubule.
There are two types of centromere such as regional centrosomes and point centromere. Point centromere binds with specific proteins to form centromeres while regional chromosomes can be formed on other DNA sequences.
What Is A Kinetochore?
A kinetochore is a protein complex that is assembled on the centromeres of chromosomes via spindle microtubules that pull sister chromatids apart during anaphase of the cell division.
The main role of kinetochore is to hold sister chromatids together along with the cohesion of protein complexes. The kinetochores in human cells tend to turn pink in color during metaphase.
Comparison Chart: Centromere vs Kinetochore
| Basic Terms | Centromere | Kinetochore |
| Composition | Constricted region of DNA on the chromosomes | A protein complex that is assembled on the centromere of chromosomes. |
| Observation | Visible under a light microscope | Visible under the electron microscope |
| Structure | Compose of centric heterochromatin | Compose of specializing types of histones like CENP-A. |
| Position | Has four positions such as metacentric, submetacentric, acrocentric, and telocentric. | Has two layers such as inner kinetochore and the outer kinetochore. |
| Number | It can either be monocentric or holocentric. | Each centromere has one kinetochore complex |
| Binding with Microtubules | Do not bind with microtubules | Outer kinetochore comprises of about 20 points for anchoring kinetochore. |
| Main Function | Holding to sister chromatids together | Provide a site for microtubules attachment |
| Corona | Does not have corona | Tend to have corona |
| Dead or Live | Repetitive DNA | Protein complex |
| Layers | Has no layers | Tend to have two layers |
Core Difference between Centromere and Kinetochore
- The centromere is a primary constriction region of the condensed chromosomes while kinetochore is a protein complex bind with centromere.
- The centromere is quite visible under a light microscope while kinetochore is visible under an electron microscope.
- Centromere can either be monocentric or holocentric whereas kinetochore is one kinetochore complex.
- Centromere comprises centric heterochromatin while kinetochore is made from specialized types of histones.
- Corona is present on kinetochore but absent from centromere.
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Comparison Video
Summary
The centromere is a constricted site in a chromosome and it is highly condensed around the histone proteins. Besides that, it helps to hold sister chromatids together.
The kinetochore is a protein complex assembled around the centromere of the chromosomes. It is a point meant for the attachment of microtubules during cell division.
Both centromere and kinetochore enhance the separation of chromosomes and chromatids during cell division. I hope the core difference between centromere and kinetochore is comprehensive.
More Sources and References
- Centromeres and Kinetochores. Cell
- Kinetochore. Wikipedia
- Kinetochore and Centromere. NCBI