Noncoding DNA Sequences Research Paper

Improved Essays
The importance of noncoding DNA sequences

Since the completion of Human Genome Project in 2003, it was found that more than 98% of human genome is occupied by noncoding DNA sequences (Genome.gov, 2003), existing between genes and as introns within genes (Figure-1). In genomic, noncoding DNA regions are defined as the sequences of an organism’s DNA, which do not code for proteins. Although it has been known for decades that some of these sequences code for noncoding RNAs that involve in controlling many cellular processes, recently study suggested that many of them are in fact vital in regulating how our genome works (The Encode Project, 2004), while some research proposed that others may have no known biological function for
…show more content…
According to the observation made during the replication of Drosophila melanogaster chromosomes in 1973, the opening of Drosophila’s DNA double helix, known as replication forks (formerly named as eye forms) at a number of different sites were noted (Kriegstein and Hogness, 1974). The creation of replication forks is the result of the formation of replication bubbles. As shown in Figure-4, replication origins are recognized by the origin recognition complex (ORC) to create a replication bubble in late mitosis and early G1 (Leman and Noguchi, 2013, pp. 5-6). Situated at the ends of the replication bubble are replication forks where initiation of DNA replication occurs allowing the replication to proceed in both directions (Figure-4). Similarly, DNA replication in human cells is also initiated at a number of different replication origins on multiple chromosomes simultaneously so that the duration of S phase of the interphase – about 8 hours (Tortora and Derrickson, 2011, pp.96) - is not limited by the total amount of DNA. The form of DNA replication in human is referred to as semi-conservative replication as each of daughter double helix inherited one of the polynucleotide chains of the parent double (Waston and Crick, 1953; Meselson and Stahl, …show more content…
An American geneticist, Hermann J. Muller, was the first to discover the existence of telomere in 1938. He was irradiating Drosophila melanogaster with X-ray to produce mutation at the Drosophila’s chromosomal ends and he observed no mutants with deletions or inversions during the experiment (Muller, 1938). He suggested the presence of a protective cap, known as telomere, at the chromosomal end. It wasn’t a year later; Barbara McClintock - a cytogeneticist from the University of Cornell - proposed another main function of telomeres. While investigating the behaviour of broken chromosomes in maize plants by studying the cytology of x-rayed plants, she observed that when the breakage occurs on one end of a chromosome, fusion of the broken meiotic chromatids does occur. Such consequence result in anaphase bridge configuration termed as the breakage-fusion-bridge (BFB) cycle to ensure cell death (McClintock, 1939).

Non-functional sequences of noncoding DNA include: 1) transposable elements: Class I (retrotransposons) and Class II (DNA transposons and endogenous retroviruses), 2) highly repetitive DNA, 3) introns, 4) pseudogenes, and 5) conserved sequences (McClintock,

Related Documents

  • Improved Essays

    Bio 1010 Assignment 1

    • 896 Words
    • 4 Pages

    BIOL 1010 ASSIGNMENT 1 OCT 6 BY JORDAN KAPITANY ST 100883963 Among the many scientific achievements of the twentieth century in the field of bio-technology scientists Paul Berg, Herbert W Boyer, Stanley N Cohen and team for their research that lead the party to discover a technique of taking genes from one organism and inserting them into another organism, also more formally known as Deoxyribonucleic Acid or DNA recombinant technology. In 1971 Berg and team successfully isolated DNA of virus found in monkey's known as lambda then placed the genetic material into DNA sequence of a different simian virus called SV4O. This was done by first using a DNA enzyme, a naturally occurring molecule that has the unique chemicals properties to sever the bonds in the DNA sequence, from a very specific kind of…

    • 896 Words
    • 4 Pages
    Improved Essays
  • Superior Essays

    Purpose and Background Cells divide in two ways, mitosis and meiosis. Mitosis is used to produce cells that are genetically identical to the parent cell for growth, asexual reproduction, or repair after injury. Cells that are produced by mitosis are diploid, meaning that they have two complete sets of chromosomes, one from each parent. Meiosis is used to produce haploid cells that have only one set of chromosomes, a mix of chromosomes from both parents. Meiosis produces cells that are genetically unique from their parent cells.…

    • 1551 Words
    • 7 Pages
    Superior Essays
  • Improved Essays

    Prokaryote DNA replication is a semi conservative, bidirectional, template driven process. The phrase ‘semi-conservative’ refers to the fact that the newly synthesised double stranded DNA is made up of one parental (existing) strand, and one newly synthesised strand. The parental duplex is not ‘conserved’ as an entity. This was proved by the Meselson-Stahl experiment by replicating E.Coli in different mediums of of different Nitrogen isotopes. The results consisted of half of normal weight and half with intermediate weight, proving an immortal strand serving as an unchanging template.…

    • 400 Words
    • 2 Pages
    Improved Essays
  • Improved Essays

    3.05 Dna Research Paper

    • 522 Words
    • 3 Pages

    Assignment 3.05 DNA DNA, deoxyribonucleic acid, is the stuff in humans and almost all other organisms. About every cell in you and everyone else's body has the same DNA. DNA is usually located in the cell nucleus (nuclear DNA),however small amounts of DNA can be found in the mitochondria (mitochondrial DNA or mtDNA). The DNA has information stored as a code created by four chemical bases: adenine (A), cytosine (C), guanine (G), and thymine (T). Each base is connected to a sugar molecule and phosphate molecule.…

    • 522 Words
    • 3 Pages
    Improved Essays
  • Decent Essays

    Unit 4 Dna Research Paper

    • 172 Words
    • 1 Pages

    Nucleotide: a nucleic acid monomer, consisting of five carbon sugar covalently bonded to nitrogenous base and phosphate group. DNA “backbone” : chain nucleotide made of sugar and phosphate group that are joined together by covalent bond and are resistant to cleavage Antiparallel: the 2 strands of DNA double helix that run in opposite directions of each other Reactive chemical group at the 5’ end of DNA: phosphate group Reactive chemical group at the 3’ end of DNA : hydroxyl group The four DNA nucleobases thymine (T), adenine (A), Cytosine (C) and guanine (G) , Complementary base pairing adenine and thymine pair (A-T) and guanine and cytosine pair (G-C) Melting temperature: temperature needed to break 50% of the hydrogen bonds Chromatin:…

    • 172 Words
    • 1 Pages
    Decent Essays
  • Improved Essays

    Pt1420 Exercise 1

    • 742 Words
    • 3 Pages

    1. What is the genome? The genome is an organism’s complete set of DNA and vary widely in size. 2.…

    • 742 Words
    • 3 Pages
    Improved Essays
  • Improved Essays

    “All the hereditary information of an organism makes up it genome.” The genome of an organism is partially determined by the sequence of bases. The Human Genome project was founded 1990 and had a major goal of identifying and mapping all of the genes in human DNA, numbering about 20,000-25,000 genes and about 3 billion chemical base pairs. This project was completed in 2003 and contributed to the development of our modern knowledge of human DNA. This information is available to scientists worldwide and has prompted the researching of the genomes of several different species.…

    • 783 Words
    • 4 Pages
    Improved Essays
  • Decent Essays

    Interviewer: What is the first thing you do in the morning? Mitosis: I start my day with prophase. Interviewer: Why is that the first thing you do?…

    • 291 Words
    • 2 Pages
    Decent Essays
  • Improved Essays

    A Modest Proposal

    • 1341 Words
    • 6 Pages

    Telomerase is an enzyme which catalyzes the addition of telomeres to the ends of chromosomes. Telomeres are repetitive non-coding segments found at the end of chromosomes with the sequence TTAGGG. Telomeres act as protective caps for the chromosomes, similar to plastic caps on the ends of shoelaces. Because DNA polymerase can only synthesize in the 5’ to 3’ direction and only adds nucleotides to an existing 3’ end, DNA polymerase is unable to replicate DNA near the 3’ end of chromosomes. This phenomenon, known as the end replication problem, means that each successive replication leads to the shortening of DNA.…

    • 1341 Words
    • 6 Pages
    Improved Essays
  • Improved Essays

    Target article: Green, R.E., Krause, J., Briggs, A.W., Maricic, T., Stenzel, U., Kircher, M. et al. (2010). A draft sequence of the Neandertal genome. Science, 328, 710-722. This study created a draft sequence of approximately 60% of the Neanderthal genome based on nucleotides from three individual Neanderthal samples (Vindija Neanderthal fossils Vi33.16, Vi33.25 and Vi33.26).…

    • 1542 Words
    • 7 Pages
    Improved Essays
  • Improved Essays

    Meiosis Cell Lab

    • 605 Words
    • 3 Pages

    Meiosis starts: DNA Replicates I am going to draw a nucleus with DNA inside it represented with beads as the four pairs of chromosomes. Outside of the nucleus there will be centrioles drawn. This is where meiosis begins and replicates the cell Spindle fibers start to form on the centrioles and chromosome pairs bind together making tetrads. Nuclear membrane starts to dissolve.…

    • 605 Words
    • 3 Pages
    Improved Essays
  • Superior Essays

    ENCODE Project Analysis

    • 866 Words
    • 4 Pages

    Question 1. What were the main findings of the ENCODE project? Only a small percent of the 3.2 Gb human genome encodes for genes but much of the remainder was chalked up a junk. However, the ENCODE project suggests that up to 80% of the genome consist of various active regulatory, and structurally significant regions. Question 2.…

    • 866 Words
    • 4 Pages
    Superior Essays
  • Great Essays

    Introduction When observing a human population there are many phenotypical differences such as; behavior, development, and morphology. Not only are there phenotypical differences amongst a human population, but there are also genotypic differences that can be observed using DNA sequencing data. One way to observe genetic variation amongst humans would be to sequence the Mitochondrial DNA(mtDNA). Mitochondrial DNA is the most commonly used DNA to form phylogenetic trees. Human Mitochondrial DNA is about 16,500 bps in size and consists of 13 protein coding genes, 22 tRNAs (transfer RNA), and 2 rRNAs (ribosomal RNA) (Ingman, 2001).…

    • 1855 Words
    • 8 Pages
    Great Essays
  • Improved Essays

    Mitosis Vs Meiosis Essay

    • 575 Words
    • 3 Pages

    Difference Between Mitosis and Meiosis: Every multicellular organism has originated his life with only a one fertilized egg , which then maximized by the well known process of division of cell. In cell division process the cell is obtained by the already existed cell or pre existed cell stated by Ruolf Virchow in 1855. The process divison of cells is uasuall same in all of the living organisms. Division of cells is furtherly divided into two types :- 1) Mitosis 2) Meiosis Basic Difference Mitosis and Meiosis:- Mitosis and Meiosis both are originally types of division of cells .…

    • 575 Words
    • 3 Pages
    Improved Essays
  • Improved Essays

    Cell division is a complex biological method in which a parent cell divides into two or more daughter cells, depending on whether or not that division is mitosis or meiosis. For simple one-cell organisms, like amoebas, archaea and protozoa, single cell division, mitosis, is akin to reproduction. For multicellular organisms, meiosis produces four haploid daughter cells by undertaking a single round of DNA replication, shadowed by two more cellular divisions. In all, the principal purpose of cell division is the preservation and replication of the original cell 's genome, regardless of whether that cell division is through mitosis or meiosis. Before cellular division can begin, the genetic information that is stored in the gene’s chromosomes…

    • 712 Words
    • 3 Pages
    Improved Essays

Related Topics