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Glossary of Research Terminology

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Glossary of Research Terminology GLOSSARY OF RESEARCH TERMINOLOGY Allele - one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome. Amino acid - Amino acids, often referred to as the building blocks of proteins, are compounds that play many critical roles in your body. They’re needed for vital processes like the building of proteins and synthesis of hormones and neurotransmitters. Angiogenesis - the development of new blood vessels. Antibodies - a blood protein produced in response to and counteracting a specific antigen. Antibodies combine chemically with substances which the body recognizes as alien, such as bacteria, viruses, and foreign substances in the blood. Heavy-chain vs. Light-chain antibodies - A typical antibody is composed of two immunoglobulin (Ig) heavy chains and two Ig light chains. Several different types of heavy chain exist that define the class or isotope of an antibody. These heavy chain types vary between dif- ferent animals. All heavy chains contain a series of immunoglobulin domains, usually with one variable domain (VH) that is important for binding antigen and several constant domains (CH1, CH2, etc.). Production of a viable heavy chain is a key step in B cell maturation. If the heavy chain is able to bind to a surrogate light chain and move to the plasma membrane, then the developing B cell can begin producing its light chain. Polyclonal antibodies - A Polyclonal Antibody represents a collection of antibodies from different B cells that recognize multiple epitopes on the same antigen. Each of these individual antibodies recognizes a unique epitope that is located on that antigen. Antigen - a toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies. Base editors - Base editors are designed to change one nucleotide, or letter, of DNA into another, without cutting the DNA. They come in two flavors: cytidine base editors, which convert a cytosine (C) nucleotide to a thymine (T), and adenine base editors, which convert an adenosine (A) to a guanosine (G). Base pairs - a pair of complementary bases in a double-stranded nucleic acid molecule, consisting of a purine in one strand linked by hydro- gen bonds to a pyrimidine in the other. Cytosine always pairs with guanine, and adenine with thymine (in DNA) or uracil (in RNA). Cell lines - a cell culture developed from a single cell and therefore consisting of cells with a uniform genetic makeup. Complimentary strand - either of the two chains that make up a double helix of DNA, with corresponding positions on the two chains being composed of a pair of complementary bases. CRISPR - CRISPR is a technique that allows scientists to make precision edits to any DNA, whether bacterial or human. Scientists discovered the technique when studying a bacteria’s immune system, which they gave the acronym CRISPR. (It stands for “clustered regularly inter- spaced short palindromic repeats.”) When a virus attacks one of these bacteria, the CRISPR system captures a piece of the virus’s DNA and slides it into a section of its own DNA, which lets the bacteria’s virus-fighting machinery use it like a “wanted” poster to identify and destroy the virus it came from the next time it attacks. Scientists are now able to take the CRISPR system’s ability to cut, copy, and replace pieces of DNA and use it to their own ends, applying it to virtually any DNA they want to. Deleterious gene - An allele of a gene whose effects on the phenotype are likely to result in a reduced fitness. Such genes are often reces- sive, so that they can be transmitted through families without being detected unless two occur together in the same individual. De Novo mutation - A genetic alteration that is present for the first time in one family member as a result of a variant (or mutation) in a germ cell (egg or sperm) of one of the parents, or a variant that arises in the fertilized egg itself during early embryogenesis. Dephosphorlyation - the removal of a phosphate (PO43−) group from an organic compound by hydrolysis. It is a reversible post-translational modification. Dephosphorylation and its counterpart, phosphorylation, activate and deactivate enzymes by detaching or attaching phos- phoric esters and anhydrides. EEG - An electroencephalogram (EEG) is a test used to evaluate the electrical activity in the brain. Brain cells communicate with each other through electrical impulses. An EEG can be used to help detect potential problems associated with this activity. An EEG tracks and records brain wave patterns. Small flat metal discs called electrodes are attached to the scalp with wires. The electrodes analyze the electrical im- pulses in the brain and send signals to a computer that records the results. www.jordansguardianangels.org @JordansGuardianAngels @JordansGAngels @JordansGuaardianAngles 1 Electrophisiological recordings - Electrophysiological techniques have been integral to our understanding of protein translocation across various membranes, and, in particular, the mitochondrial inner and outer membranes. The activity of protein import channels of native mito- chondrial inner and outer membranes can be studied by directly patch clamping mitochondria and mitoplasts (mitochondria stripped of their outer membrane by French pressing) from various genetically manipulated strains of yeast and mammalian tissue cultured cells. Enzyme - a substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction. Eptitope - the part of an antigen molecule to which an antibody attaches itself. Feeder cells - feeder cells and have routinely been used to support the culturing and maintenance of embryonic stem cells (ESCs) in an undif- ferentiated state without losing their pluripotency. Fibroblasts - a cell in connective tissue which produces collagen and other fibers. Fusion protein - proteins created through the joining of two or more genes that originally coded for separate proteins. Gene editing - the manipulation of the genetic material of a living organism by deleting, replacing, or inserting a DNA sequence, typically with the aim of improving a crop or farmed animal, or correcting a genetic disorder. Gene therapy - the transplantation of normal genes into cells in place of missing or defective ones in order to correct genetic disorders. Gene transcription - Transcription is the first step in gene expression. It involves copying a gene’s DNA sequence to make an RNA molecule. Transcription is performed by enzymes called RNA polymerases, which link nucleotides to form an RNA strand. Genomic - relating to the haploid set of chromosomes in a gamete or microorganism, or the complete set of genes in a cell or organism. Genotype - the genetic constitution of an individual organism. Germline transmission - Germline transmission refers to a process where the ES derived cells of a chimera contribute to the reproductive cells of a mammal (germ cells) and are genetically passed to its offspring. Hematopoietic - An immature cell that can develop into all types of blood cells, including white blood cells, red blood cells, and platelets. Hematopoietic stem cells are found in the peripheral blood and the bone marrow. Heterozygous - having two different alleles of a particular gene or genes. Holoenzyme - a biochemically active compound formed by the combination of an enzyme with a coenzyme. Homozygous - having two identical alleles of a particular gene or genes. Immunotherapy - a treatment that uses certain parts of a person’s immune system to fight diseases such as cancer Inhibitor - a gene whose presence prevents the expression of some other gene at a different locus. Interactomics - a discipline at the intersection of bioinformatics and biology that deals with studying both the interactions and the conse- quences of those interactions between and among proteins, and other molecules within a cell. IPSC Cells - Induced Pluripotent Stem Cells (iPS) iPSC are derived from skin or blood cells that have been reprogrammed back into an embry- onic-like pluripotent state that enables the development of an unlimited source of any type of human cell needed for therapeutic purposes. Isoforms - any of two or more functionally similar proteins that have a similar but not identical amino acid sequence and are either encoded by different genes or by RNA transcripts from the same gene which have had different exons removed. Isogenic Controls - Isogenic human disease models are a family of cells that are selected or engineered to accurately model the genetics of a specific patient population, in vitro. They are provided with a genetically matched ‘normal cell’ to provide an isogenic system to research disease biology and novel therapeutic agents. Isotope - each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element. Isotope labeling - a technique used to track the passage of an isotope (an atom with a detectable variation in neutron count) through a reac- tion, metabolic pathway, or cell. The reactant is ‘labeled’ by replacing specific atoms by their isotope. The reactant is then allowed to undergo www.jordansguardianangels.org @JordansGuardianAngels @JordansGAngels @JordansGuaardianAngles 2 the reaction. The position of the isotopes in the products is measured to determine the sequence the isotopic atom followed in the reaction or the cell’s metabolic pathway. Knockout cell line - A gene knockout is a genetic technique in which one of an organism’s genes is made inoperative (“knocked out” of the organism). However, KO can also refer to the gene that is knocked out or the organism that carries the gene knockout. Human knockout cell lines generated using CRISPR/Cas9 genome-editing. This type of knockout cell line provides a complete loss-of-function phenotype from a single allele knockout and eliminates any masking of the knockout from a second allele seen in diploid cell models .
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