Telomeres shorten during ageing of human fibroblasts
Article Abstract:
DNA (deoxyribose nucleic acid) molecules are arranged in a helical shape in structures known as chromosomes. At the end of the chromosomes, the DNA forms specialized structures known as telomeres. These structures are necessary for the stability and complete replication of the ends. In cells that continue to divide, such as cancer cells, the telomeric ends get smaller, either due to degradation or incomplete replication of the ends. To correct for this, the telomere is elongated. The enzyme that adds DNA sequences to the telomere is known as telomerase. Normal cells can divide only a limited number of times. This limited capacity for division has been thought to be due to the loss of DNA at the telomeres, and the eventual loss of DNA sequences that are essential for the cells to grow. It was shown that the level and amount of telomeres in human fibroblasts, a type of connective tissue cell, gets smaller as the cells age, or divide a number of times. This loss of DNA may be involved in the aging process of cells and may determine how many times a cell can divide before it dies. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1990
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Essential role of mouse telomerase in highly proliferative organs
Article Abstract:
It has been possible to demonstrate progressive negative effects of telomerase deficiency on the reproductive and haematopoietic systems in mice. This research highlights the role of telomerase in normal cellular homeostasis at the biological and genomic levels. Telomerase activity in itself is not directly involved biologically in mammalian development, but telomerase is essential in cell survival and organ homeostasis through maintenance of sufficient telomere structure during cell division.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1998
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Chromosome guardians on duty
Article Abstract:
Proteins known as shugoshins, Japanese for 'guardian spirits', and an associated regulatory enzyme temporally and spatially control the removal of cohesions from chromosomes. Determining precisely how shugoshins function as a chromosome segregation nexus would be fundamental to the understanding of the molecular mechanisms of cell division.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2006
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