What Is The Alternative Lengthening Of Telomeres - 900 Words

DNA replication results in the gradual shortening of telomeres over time, leading to the activation of senescence or apoptosis. Therefore, telomere length is a key biological signal to limit the indefinite proliferation of somatic cells (Roumelioti, et al., 2016). However, cancer cells can overcome telomere shortening by synthesising a new telomeric DNA from an RNA template through the expression of telomerase (Roumelioti, et al., 2016). Alternatively, 10-15% of human cancers utilise a DNA template in a homology-directed synthesis mechanism called alternative lengthening of telomeres (ALT) (Cesare Reddel, 2010). However, the process by which DNA damage such as telomeric shortening results in the execution of homology-directed synthesis,†¦show more content†¦However, ATR, Rad51 and Hop2 were not required for break-induced telomere synthesis in ALT cells and in fact, knockdown of each gene increased the levels of nascent telomeres. To further support their findings, Dilley an d colleagues studied VA13 HOP2 CRISPR clones lacking Hop2 protein expression and found that no telomere shortening took place. From these findings, the authors could therefore propose that break-induced telomere synthesis and ALT telomere maintenance can occur independently of Rad51-Hop2 and ATR. Dilley and co-workers subsequently determined that the replicative DNA polymerase Pol , including POLD3, POLD4 and POLD1 subunits, were instead required for break-induced telomere synthesis. Whereas Pol , Pol -primase and MCM2-7 replicative helicase were found to be nonessential and were recruited at far lower levels. The POLD3 subunit is also part of the Pol ÃŽ ¶ complex involved in translesion synthesis. However, the REV3L catalytic subunit of Pol ÃŽ ¶ was not required for break-induced telomere synthesis, suggesting POLD3 primarily acts through Pol . This major role of POLD3 has been supported in studies that revealed POLD3 depletion resulted in decreased frequency of replicated ALT telomeres (Roumelioti, et al., 2016). Overall, the results by Dilley et al led to the suggestion that an alternative replisome is required for ALT telomere synthesis. Having proven that Pol is dominantly recruited to TRF1-FokI damage sites, Dilley et al set outShow MoreRelatedScientific Literature Focused On Chromosomal Dna And Dna, Blood Leukocytes, Sputum, And Buccal Cells2398 Words   |  10 PagesChromosomal Telomere Length (TL) In Blood Leukocytes, Sputum, and Buccal Cells as It Relates to Cancer Occurrences by: Andy Barajas Bio 490, Fall 2014 Department of Biological Sciences California State Polytechnic University, Pomona Abstract This is a conglomeration of scientific literature as it relates telomere length in blood cells to the occurrence of cancer. Telomeres are composed of repeating TTAGGG nucleotides and they are found at the ends of chromosomes. These chromosomal caps are what protect

Synthesis Essay Joseph Vincent Paterno - 1407 Words

Synthesis Essay – Joseph Vincent Paterno MSgt Allen W. Hewitt Air Force Senior Noncommissioned Officer Academy September 10, 2014 Instructor: MSgt Travis Pyle Joe Paterno Picture this, walking down a tunnel into a stadium with 106,000 fans screaming we are PENN STATE! Joe Paterno lived this every Saturday for 46 years. Joseph Vincent Paterno was born 21 December 1926 in Brooklyn, NY. He attended Brown University where he majored in law, while playing football as a quarterback and cornerback. Upon graduation he was on course to become the lawyer that he father wanted, but Penn State University came calling with a coaching offer. They saw the leadership qualities of a visionary and because of†¦show more content†¦Let me now call an audible to the visionary leadership of the man they called â€Å"Joepa†. Visionary Leader Joes vision was to build a powerhouse university program. He took over a not so great football program, but as a visionary his role was to be innovative in educating, mentoring, and guiding young adults who are searching for meaning and purpose. He started with turning the student athlete graduation rate around, using individual consideration, where leaders treat others as individuals with different needs, abilities, and aspirations in just 5 years he took the rate up 10 percent and maintained a 80 percent graduation rate throughout his tenure crushing the NCAA standard of 67 percent. Next was creating an organized group to work together, a team. He took the names off the back of the jerseys and left the helmets plain white promoting the team aspect, teambuilding not me building. Now to build a fan base, he developed and articulated visions from the future. He looked out the window and saw a stadium that barely held 30,000 people in 1968. Joe held a 75 percent winning percentage over 46 years, 37 bowl appearances, and 2 national championships. His inspirational motivation created the second largest college stadium seating 106,157 fans. He spoke at multiple clinics, banquets, and charities extending his knowledge to diverse groups. In 2000 Adam Taliaferro was paralyzed on the first play of

Blue Nile free essay sample

The spreadsheet I did presents a summary of Blue Nile financial results from 2005 to 2009. From 2005 to 2007 revenues and net income both increased. The deep recession which began in late 2007 seriously affected the revenue in 2008. And then in 2009 the revenue recovered and increased slightly. I am going to analysis the financial performance in three parts. First, profitability ratios. Blue Nile had steady return on asset ratios around . 1. The company utilized its assets very efficiently and outperformed their competitors. By doing research on Yahoo Finance, we know the industry return on equity is 0. 18. Blue Nile’s return on equity ratio was much higher. It created better return to investors. Net profit margins were mostly lower than the industry average level. For example in 2009, Blue Nile only had net income of 4 cents for each dollar sale. Its low margins can be explained by its low pricing of products. As Rita said, Blue Nile had a much lower markup than Tiffany. We will write a custom essay sample on Blue Nile or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Blue Nile’s number for liquidity ratios are impressive. Such high ratios from 2005 through 2009 show the company’s great ability to pay short-term debt. One of the company’s strategies is that suppliers finance Blue Nile’s sales growth. ( ) The business model contributed to higher sales volumes with minimal additional capital investment. With respect to leverage ratios, Blue Nile had really low long-term debt to equity ratios compared to the industry. Tiffany’s long-term debt to equity was as high as . 39. Because Blue Nile offered a balance between the debt to equity range and firm’s cost of capital, its capital structure was optimal. The company had low capital investment financed by creditors and bondholders. Its debt to assets ratios are over . 5, which means it, had a lot of debt obligations. However, most of the company’s debt was current and it was able to pay off creditors in a timely manner. Creditors did not need to worry about getting paid. Blue Nile’s strong financial performance intuitively indicated the company’s strategies were pretty well-conceived and well-executed.

Tess of the DUrbervilles free essay sample

Tess of the DUrbervillescharacter Response Paper In literature, vampires are everywhere. No, Im not talking about the recent fad prompted by Stephenie Meyer. There is always a character that preys on another, kind of like Meyers sparkling creations or Count Chocula. Thomas Foster, author of How to Read Literature Like a Professor, goes to say that literary vampirism is inextricably linked to sex. The men of Tess of the DUrbervilles can almost all be seen as vampires(in one sense or another), but the fullest embodiment of this role is Alec DUrberville. Everything about Alec portrays him as a vampire. His dark hair and fair skin; his constant showing up unexpectedly; his obsession with Tess; he is definitely akin to Dracula. Aside from the most obvious way that he preys on Tess, by raping her, he does so emotionally. Even though Alec vanishes after that fateful night in the woods, Tess is left with his baby. We will write a custom essay sample on Tess of the DUrbervilles or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page When Sorrow dies, sorrow is not gone. Tess is left with nothing, a grave reminder of the life that Alec stole from her. When Angel runs off to Brazil, and Tess is again in Alecs arms, he still preys on her emotions by making her believe that Clare will never return. When Tess kills Alec, she does it appropriately for any vampire: a steak(knife) through the heart. Although Alec is a perfect example of a literary vampire, he is not the only in the novel. Angel is very easily classified as a predator, as he he makes Alecs indiscretion Tesss fault, even though he consented with London prostitute. Tess is left with yet another broken heart because of a mans actions. Jack Durbeyfield is also a nocturnal blood-sucker. When Tess killed the familys only horse, he seemed all too willing to give up his daughter for the promise of not ever working again.