Centromere
(Redirected from Centromeres)
Centromere is a region on a chromosome where the two sister chromatids are joined together during the cell cycle. The centromere plays a crucial role in cell division, particularly during mitosis and meiosis, by ensuring the accurate distribution of chromosomes to daughter cells. It is also the attachment site for kinetochore proteins, which connect the chromosomes to the microtubules of the mitotic spindle.
Structure
The structure of the centromere varies among different species. In most eukaryotes, the centromere is characterized by a distinct region of DNA sequence that is rich in base pairs of adenine (A) and thymine (T), known as satellite DNA. This DNA is tightly packed and forms a specialized type of chromatin called heterochromatin. The specific DNA sequences within centromeres are critical for the binding of centromere-specific proteins, including the centromere protein A (CENP-A), which is essential for the assembly of the kinetochore complex.
Function
The primary function of the centromere is to ensure the correct segregation of chromosomes during cell division. During mitosis and meiosis, the chromosomes are duplicated, and each copy is pulled to opposite poles of the dividing cell. The centromere serves as the pivotal point for this movement, with kinetochores attaching to the microtubules of the spindle apparatus. This attachment allows the chromosomes to be aligned at the metaphase plate and subsequently segregated accurately to ensure that each daughter cell receives the correct number of chromosomes.
Centromere Position
Centromeres can be classified based on their position on the chromosome:
- Metacentric: The centromere is located near the middle of the chromosome, resulting in two arms of equal length.
- Submetacentric: The centromere is off-center, creating one long arm and one short arm.
- Acrocentric: The centromere is situated close to one end of the chromosome, leaving one very long arm and a satellite-bearing short arm.
- Telocentric: The centromere is at the very end of the chromosome, effectively creating a single arm.
Evolution
The evolution of centromeres has been a subject of interest, as they show a high degree of diversity across different species. Despite this diversity, the fundamental role of centromeres in chromosome segregation is conserved. The variation in centromere DNA sequences and the proteins that bind to these sequences suggest a co-evolutionary relationship between centromere DNA and centromere-specific proteins.
Clinical Significance
Abnormalities in centromere structure or function can lead to improper chromosome segregation, which is a hallmark of many genetic disorders and diseases, including cancer. For example, mutations in centromere proteins or misregulation of centromere function can result in aneuploidy, a condition characterized by an abnormal number of chromosomes, which is associated with developmental disorders and tumorigenesis.
Transform your life with W8MD's budget GLP-1 injections from $125.
W8MD offers a medical weight loss program to lose weight in Philadelphia. Our physician-supervised medical weight loss provides:
- Most insurances accepted or discounted self-pay rates. We will obtain insurance prior authorizations if needed.
- Generic GLP1 weight loss injections from $125 for the starting dose.
- Also offer prescription weight loss medications including Phentermine, Qsymia, Diethylpropion, Contrave etc.
NYC weight loss doctor appointments
Start your NYC weight loss journey today at our NYC medical weight loss and Philadelphia medical weight loss clinics.
- Call 718-946-5500 to lose weight in NYC or for medical weight loss in Philadelphia 215-676-2334.
- Tags:NYC medical weight loss, Philadelphia lose weight Zepbound NYC, Budget GLP1 weight loss injections, Wegovy Philadelphia, Wegovy NYC, Philadelphia medical weight loss, Brookly weight loss and Wegovy NYC
WikiMD's Wellness Encyclopedia |
Let Food Be Thy Medicine Medicine Thy Food - Hippocrates |
Medical Disclaimer: WikiMD is not a substitute for professional medical advice. The information on WikiMD is provided as an information resource only, may be incorrect, outdated or misleading, and is not to be used or relied on for any diagnostic or treatment purposes. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition. WikiMD expressly disclaims responsibility, and shall have no liability, for any damages, loss, injury, or liability whatsoever suffered as a result of your reliance on the information contained in this site. By visiting this site you agree to the foregoing terms and conditions, which may from time to time be changed or supplemented by WikiMD. If you do not agree to the foregoing terms and conditions, you should not enter or use this site. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates, categories Wikipedia, licensed under CC BY SA or similar.
Contributors: Prab R. Tumpati, MD