The Importance Of Chromosomes And Chromosomal Structure

Werner Syndrome is a premature aging disorder in which individuals appear much older than their actual age, exhibiting many characteristics of normal aging early on. Those affected develop normally until their adolescence, where many of the symptoms of the disease begin to emerge. It is an autosomal recessive disorder in which a mutation occurs on the Werner Syndrome RecQ Like Helicase (WRN) gene (Online https://rarediseases.org/rare-diseases/werner-syndrome accessed 30 October, 2016). There prevalence of this disease in less than 10/1,000,000, with higher occurrence among the Japanese population with a frequency of 1/50,000 (Ishikawa et al. 2000). The WRN gene is involved in DNA metabolic pathways such as DNA repair and also displays an important interaction with telomeres and the p53 protein. Thus, the mutation for this disorder produces genomic instability (Opresko et al. 2003). Common phenotypic characteristics of Werner Syndrome used to diagnose this disease include short stature with thin limbs, premature senescence, and endocrine disorders.

These shortened telomeres are generally associated with aged cells, which lead to the symptoms generally connected to old age. With small frail bodies and skeletal degeneration, most children with progeria don’t have any problem with reproducing, but generally do not live long enough to reach sexual maturity. I found this disease interesting as there has recently been a girl who has been

But the findings didn’t end there. One thing is to stop telomeres from shortening. Another is to actually lengthen them.

The length of the telomere indicates age-related diseases, unhealthy lifestyle, and longevity in the lifespan.

In Chapter 27 “The Secret to Immortality” of The Immortal Life of Henrietta Lacks Rebecca Skloot provided an explanation to why HeLa cells were “immortal” unlike other mortal cancer cells; the p53 tumor suppressor gene had been “turned off” by the Human Papilloma Virus Lacks had. She mentions how according to the Hayflick Limit, human cell’s were able to replicate an average of fifty times. In addition, she explains how telomeres in cells shrink slightly every time the cell divides. According to Aging Cell’s 2004 article “The Cellular Lifespan and Senescence Signalring in Embryonic Stem Cells,” tumor cells “have high telomerase activity” yet they are not immortal. HeLa cells, similarly to Embryonic Stem (ES) Cells have the tumor suppressor gene p53 turned off. This differentiates HeLa from other tumor cells; while other tumor cells will replicated more than the average cell and eventually reach senescence, HeLa continues to replicate to this day thanks to the HPV virus that turned off its

Telomerase is able to add DNA nucleotides to the ends of telomeres (the end of DNA sequences). After replication, a small amount of the telomeres are cut off. When the telomeres are cut too many times, the cell has met its Hayflick limit. It is believed that when an individuals cells have divided too many times, that they die.

Scientist have seen that telomerase expressing clones have no difference in karyotype but have a long lifespan by 20 doublings. With this research, cells have been seen to have a very youthful looking state for much longer. A last area of study is the hypothalamus of the brain. This part of the brain controls reproduction, growth, metabolism, and aging. This is where many of the age related diseases occur. The study of this area can lead to many advancements in age related diseases that can help people live longer. Though this area of study does not have many advancements it holds promising results. Though there have been numerous advancements, many people ask the question whether people need to live longer because of an already over populated Earth.

Instead of losing telomeres after each reproduction, the cells replenish, or lengthen, the telomeres using an enzyme called telomerase.

Most telomere are no more that the simple repetition of the DNA nucleotide sequence TTAGGG — two thymine bases, an adenine base, and three guanine bases. With a full length telomere containing more that 15,000 base pairs, telomeres can perform their functions of preventing chromosome from losing coding regions of the genome during replication for many replications before reaching what Dr. Jerry Shay describes as their “critical length” (Shay & Wright). When the telomeres of a cell reach this critical length and can no longer replicate without damaging the base pair sequences of the chromosomes themselves, programmed cell death occurs in the form of apoptosis. However, the length of a chromosome’s telomere is not only a linear function of erosion, but also a function of how often telomerase rebuilds the strands by adding the TTAGGG base pair sequence. It is this way to “cheat” the critical point that provides medicine with the possibility to extend our

A chromosomal disorder is caused by an abundance or reduction of genes on the chromosomes. This type of disorder may also be caused by structural changes within these chromosomes; this is known as an aneuploidy (Porth, 2015). The most common chromosomal disorder is Down syndrome of which there are three types: complete trisomy 21, translocation, and mosaicism (Porth, 2015). Since its first identification in 1866, researchers have become more knowledgeable about the etiology of Down syndrome. When one studies etiology, pathogenesis, and clinical manifestations of Down syndrome, he or she will begin to understand multiple chromosomal disorders.

Semi-quantitative RT-PCR was used in both articles to examine the expression of the catalytic subunit of telomerase in various cells from the Devil in order to detect the presence and activity of telomerase. Additionally a non-quantitative telomere repeat amplification protocol (TRAP) was used to detect telomerase activity, this involved the use of PCR and gel electrophoresis in order to visualise the results.

In “Does Exercise Slow the Aging Process,” an article looking at exercise in regards to the aging process, Gretchen Reynolds suggests that exercise does in fact give us a higher chance of living longer. Reynolds analyzes the length of telomeres, tiny caps found on the end of DNA strands, which tend to become longer with exercise and thus slow the fraying of the telomeres. This increase in length translates into a longer period of time that the telomeres take to decay. Because telomeres naturally shorten and fray, Reynolds explains that the risk of smaller telomeres declined significantly the more an individual exercised in order to demonstrate the causation between exercise and the aging process. The article offers insight into the aging process of cells to target those who wish to live longer since telomere length is predictive of

Telomerase (or terminal transferase) is an enzyme made of proteins, specifically reverse transcriptase (Telomerase Reverse Transcriptase-TERT), and RNA subunits. Nonetheless, chicken TERT (chTERT) shares 45% amino acid identity with human TERT (hTERT). However, chTERT is larger than the hTERT because of an extensive N-terminal flexible linker region. Also, chTERT is found on chromosome 2q21 near an interstitial telomere site. Generally, the role of this enzyme is to elongate the end of chromosomes by adding the repeated base sequence of TTAGGG, as described above. This enzyme can be found in fetal tissue, germ cells, and tumor cells. Telomerase activity is critical high on development because of the continued growth and division of the cells.

By them shortening, humans begin to age, become sicker, or even die due to the length. So whenever a person a person ages. Many scientist have tried to find a way to reverse the aging process because the idea of been young forever exists. However, scientists can affectedly restore the cells using telomerase. This being known makes researchers wonder whether many of the effects of aging come from the steady restriction of telomeres in the cells of the body that is why many people exercise, diet, or even use plastic surgery to retain that youthful appearance. Because without the effects of the nature , your body will naturally age this results in loose or saggy skin, older appearance, wrinkles , body changes , and health problems. Still that doesn’t stop ongoing experiments. Mariela Jaskelioff and her colleagues at the Dana Farber Cancer Institute in Boston engineered rats with an inactive telomere and it’s length shortened to see what would happen when they turned the enzyme back

Telomeres are directly correlated to the aging of a human body. Although some people might think that shorter telomere lengths are detrimental, the natural shortening of these telomeres are essential to healthy and normal aging. It is natural for cells to divide through mitosis, but each time cells are split telomeres are lost through the process. This is why the telomere maintenance system was evolved to protect the ends of chromosomes (Prescott, Kraft, & Chasman, 2011). Every time a cell is divided, its telomeres are weakened, and stress can accelerate this weakening, and biologically age the person. As a