Also unlike the lac operon, the trp operon contains a leader peptide and an attenuator sequence which allows for graded regulation. This is an example of the corepressible model. The number and organization of operons has been studied most critically in E. coli. As a result, predictions can be made based on an organism's genomic sequence. One prediction method uses the intergenic distance between reading frames as a primary predictor of the number of operons in the genome. The separation merely changes the frame and guarantees that the read through is efficient. Longer stretches exist where operons start and stop, often up to 40–50 bases.
Artificial chromosomes are manufactured chromosomes in the context of yeast artificial chromosomes (YACs), bacterial artificial chromosomes (BACs), or human artificial chromosomes (HACs). An artificial chromosome can carry a much larger DNA fragment than other vectors. YACs and BACs can carry a DNA fragment up to 300,000 nucleotides long. Three structural necessities of an artificial chromosome include an origin of replication, a centromere, and telomeric end sequences.
In prokaryotes, transcription is carried out by a single type of RNA polymerase, which needs a DNA sequence called a Pribnow box as well as a sigma factor (σ factor) to start transcription. In eukaryotes, transcription is performed by three types of RNA polymerases, each of which needs a special DNA sequence called the promoter and a set of DNA-binding proteins—transcription factors—to initiate the process. RNA polymerase I is responsible for transcription of ribosomal RNA (rRNA) genes. RNA polymerase II (Pol II) transcribes all protein-coding genes but also some non-coding RNAs (e.g., snRNAs, snoRNAs or long non-coding RNAs).
FDAU.S. Food and Drug AdministrationUnited States Food and Drug Administration
The Food and Drug Administration (FDA or USFDA) is a federal agency of the United States Department of Health and Human Services, one of the United States federal executive departments. The FDA is responsible for protecting and promoting public health through the control and supervision of food safety, tobacco products, dietary supplements, prescription and over-the-counter pharmaceutical drugs (medications), vaccines, biopharmaceuticals, blood transfusions, medical devices, electromagnetic radiation emitting devices (ERED), cosmetics, animal foods & feed and veterinary products.
breastbreast carcinomabreast cancers
DNA testing of various types including DNA microarrays have compared normal cells to breast cancer cells. The specific changes in a particular breast cancer can be used to classify the cancer in several ways, and may assist in choosing the most effective treatment for that DNA type. Breast cancer screening refers to testing otherwise-healthy women for breast cancer in an attempt to achieve an earlier diagnosis under the assumption that early detection will improve outcomes. A number of screening tests have been employed including clinical and self breast exams, mammography, genetic screening, ultrasound, and magnetic resonance imaging.
AlzheimerAlzheimer’s diseaseAlzheimer disease
Support for this postulate comes from the location of the gene for the amyloid precursor protein (APP) on chromosome 21, together with the fact that people with trisomy 21 (Down Syndrome) who have an extra gene copy almost universally exhibit at least the earliest symptoms of AD by 40 years of age. Also, a specific isoform of apolipoprotein, APOE4, is a major genetic risk factor for AD. While apolipoproteins enhance the breakdown of beta amyloid, some isoforms are not very effective at this task (such as APOE4), leading to excess amyloid buildup in the brain.
TimeTime MagazineTime'' magazine
Time is an American weekly news magazine and news website published in New York City. It was founded in 1923 and for many years it was run by its influential co-founder Henry Luce. A European edition (Time Europe, formerly known as Time Atlantic) is published in London and also covers the Middle East, Africa, and, since 2003, Latin America. An Asian edition (Time Asia) is based in Hong Kong. The South Pacific edition, which covers Australia, New Zealand, and the Pacific Islands, is based in Sydney. In December 2008, Time discontinued publishing a Canadian advertiser edition.
Legal decisions surrounding the BRCA1 and BRCA2 patents will affect the field of genetic testing in general. In June 2013, in Association for Molecular Pathology v. Myriad Genetics (No. 12-398), the US Supreme Court unanimously ruled that, "A naturally occurring DNA segment is a product of nature and not patent eligible merely because it has been isolated," invalidating Myriad's patents on the BRCA1 and BRCA2 genes.
consentPrior Informed Consentconsensual
Informed consent is a process for getting permission before conducting a healthcare intervention on a person, or for disclosing personal information. A health care provider may ask a patient to consent to receive therapy before providing it, or a clinical researcher may ask a research participant before enrolling that person into a clinical trial. Informed consent is collected according to guidelines from the fields of medical ethics and research ethics.
fluorescent labelfluorescent markerfluorescent labeling
Fluorescence in situ hybridization (FISH), is an example of a genetic labeling technique that utilizes probes that are specific for chromosomal sites along the length of a chromosome, also known as chromosome painting. Multiple fluorescent dyes that each have a distinct excitation and emission wavelength are bound to a probe which is then hybridized to chromosomes. A fluorescence microscope can detect the dyes present and send it to a computer that can reveal the karyotype of a cell. This technique allows abnormalities such as deletions and duplications to be revealed.
repetitive DNArepeat sequencesrepeated sequences
Eukaryotic chromosome fine structure. Noncoding DNA. Intergenic region. Function of Repetitive DNA.
. * Polymerase chain reaction is a method for selective replication of specific DNA and RNA sequences in the test tube. Protein purification involves the isolation of a specific protein of interest from a complex mixture of proteins, often obtained from homogenized cells or tissues. In vitro fertilization is used to allow spermatozoa to fertilize eggs in a culture dish before implanting the resulting embryo or embryos into the uterus of the prospective mother.
genetic diseasegenetic disordersgenetic diseases
A chromosomal disorder is a missing, extra, or irregular portional of chromosomal DNA. It can be from an atypical number of chromosome or a structural abnormality in one or more chromosome. An example of these disorder is Trisomy 21 (Down syndrome), in which there is an extra copy of chromosome 21. Due to the wide range of genetic disorders that are known, diagnosis is widely varied and dependent of the disorder. Most genetic disorders are diagnosed at birth or during early childhood however some, such as Huntington's disease, can escape detection until the patient is well into adulthood. The basic aspects of a genetic disorder rests on the inheritance of genetic material.
HIPAAHealth Insurance Portability and Accountability Act of 1996Health Insurance Portability and Accountability Act (HIPAA)
The Health Insurance Portability and Accountability Act of 1996 (HIPAA or the Kennedy–Kassebaum Act ) was enacted by the 104th United States Congress and signed by President Bill Clinton in 1996. It was created primarily to modernize the flow of healthcare information, stipulate how Personally Identifiable Information maintained by the healthcare and healthcare insurance industries should be protected from fraud and theft, and address limitations on healthcare insurance coverage.
genetic counselorgenetic counsellinggenetic counsellor
Family history of an inherited genetic condition or chromosome abnormality. Genetic carrier screening for recessive and/or X-linked diseases. History of a previous child with a birth defect, developmental delay, or other genetic condition. History of infertility, multiple unexplained miscarriages or cases of unexplained infant deaths. Molecular test for single gene disorder. Genomic counseling. National Society of Genetic Counselors. Reprogenetics. Whole genome sequencing. Medical genetics.
The Genographic ProjectGeno 2.0 Next GenerationGenographic
Genealogical DNA test. Genetic diversity. Human genetics. Human genetic variation. Human migration. Human mitochondrial DNA haplogroups. Human Y-chromosome DNA haplogroups. Mitochondrial Eve. Y-chromosomal Adam. Y-chromosome haplogroups in populations of the world. Personal Genomics. Genographic Project official site at National Geographic. Helix. Arizona Research Laboratories (ARL). Waitt Family Foundation. "Indigenous Peoples Oppose National Geographic", Indigenous Peoples Council on Biocolonialism, 13 April 2005. "Tracking the Truth", DB2 Magazine (IBM), information about IBM's role in the project. December 2006. Genographic Success Stories.
direct-to-consumerdirect to consumer advertisinga pharmaceutical ad
Direct-to-consumer advertising (DTCA) refers to the marketing and advertising of pharmaceutical products directly to consumers as patients, as opposed to specifically targeting health professionals. The term is synonymous primarily with the advertising of prescription medicines via mass media platforms—most commonly on television and in magazines, but also via online platforms.
The pattern of bands are numbered on each arm of the chromosome from the centromere to the telomere.This numbering system allows any band on the chromosome to be identified and described precisely. The reverse of G‑bands is obtained in R‑banding. Banding can be used to identify chromosomal abnormalities, such as translocations, because there is a unique pattern of light and dark bands for each chromosome. It is difficult to identify and group chromosomes based on simple staining because the uniform colour of the structures makes it difficult to differentiate between the different chromosomes. Therefore, techniques like G‑banding were developed that made "bands" appear on the chromosomes.
genome analysisPersonal Genomecomputational analysis
Over 2500 of these diseases (including a few more common ones) have predictive genetics of sufficiently high clinical impact that they are recommended as medical genetic tests available for single genes (and in whole genome sequencing) and growing at about 200 new genetic diseases per year. The cost of sequencing a human genome is dropping rapidly, due to the continual development of new, faster, cheaper DNA sequencing technologies such as "next-generation DNA sequencing". The National Human Genome Research Institute, an arm of the U.S.
molecular geneticmolecularmolecular geneticist
The development of DNA sequencing techniques in the late 1970s, first by Maxam and Gilbert, and then by Frederick Sanger, was pivotal to molecular genetic research and enabled scientists to begin conducting genetic screens to relate genotypic sequences to phenotypes. Polymerase chain reaction (PCR) using Taq polymerase, invented by Mullis in 1985, enabled scientists to create millions of copies of a specific DNA sequence that could be used for transformation or manipulated using agarose gel separation. A decade later, the first whole genome was sequenced (Haemophilus influenzae), followed by the eventual sequencing of the human genome via the Human Genome Project in 2001.
Although mutations are rare, with spontaneous mutations in the pathogen genome occurring at a rate of about 1 in 10 5 to 1 in 10 8 per chromosomal replication, the fact that bacteria reproduce at a high rate allows for the effect to be significant. Given that lifespans and production of new generations can be on a timescale of mere hours, a new (de novo) mutation in a parent cell can quickly become an inherited mutation of widespread prevalence, resulting in the microevolution of a fully resistant colony. However, chromosomal mutations also confer a cost of fitness.
The term epiallele is used to distinguish these heritable marks from traditional alleles, which are defined by nucleotide sequence. A specific class of epiallele, the metastable epialleles, has been discovered in mice and in humans which is characterized by stochastic (probabilistic) establishment of epigenetic state that can be mitotically inherited. • Allozyme • Evolution • Genealogical DNA test • Haploinsufficiency • Meiosis • Mendelian error • Mendelian inheritance • Mitosis • Penetrance • Polymorphism • Punnett square • Single-nucleotide polymorphism * ALFRED: The ALlele FREquency Database
Oswald T. AveryOswald Theodore AveryAvery, Oswald Theodore
Avery was one of the first molecular biologists and a pioneer in immunochemistry, but he is best known for the experiment (published in 1944 with his co-workers Colin MacLeod and Maclyn McCarty) that isolated DNA as the material of which genes and chromosomes are made. The Nobel laureate Arne Tiselius said that Avery was the most deserving scientist not to receive the Nobel Prize for his work, though he was nominated for the award throughout the 1930s, 1940s, and 1950s. The lunar crater Avery was named in his honor. Avery was born in Halifax, Nova Scotia in 1877 to Francis Joseph Avery, a Baptist minister, and his wife Elizabeth Crowdy. The couple had immigrated from Britain in 1873.
circular chromosomecircular bacterial chromosomecircular chromosomes
DNA sequence elements within oriC that are important for its function include DnaA boxes, a 9-mer repeat with a highly conserved consensus sequence 5' – TTATCCACA – 3', that are recognized by the DnaA protein. DnaA protein plays a crucial role in the initiation of chromosomal DNA replication. Bound to ATP, and with the assistance of bacterial histone-like proteins [HU] DnaA then unwinds an AT-rich region near the left boundary of oriC, which carries three 13-mer motifs, and opens up the double-stranded DNA for entrance of other replication proteins.
DNA cross-linking agents are an important source of chromosome/DNA damage. Double-strand breaks occur as intermediates after the crosslinks are removed, and indeed, biallelic mutations in BRCA1 have been identified to be responsible for Fanconi Anemia, Complementation Group S, a genetic disease associated with hypersensitivity to DNA crosslinking agents. BRCA1 is part of a protein complex that repairs DNA when both strands are broken. When this happens, it is difficult for the repair mechanism to "know" how to replace the correct DNA sequence, and there are multiple ways to attempt the repair.