chapter 20: DNA tools and biotechnology

gel electrophoresis

separates and visualizes fragments produced; uses a gel made of polymer to separate a mix of nucleic acids or proteins based on size charge etc

imatinib drug

a small molecule that inhibits overexpression of a specific leukemia-causing receptor

stem cell

can produce itself indefinitely or under certain conditions can differentiate into one or more types of specialized cells

protein

cloned genes can be expressed as _______ in either bacterial or eukaryotic cells

DNA microarray assays

compare patterns of gene expression in different tissues, at different times, or under different conditions

cDNA

complementary DNA to mature RNA; contains only exons

dna cloning

scientists prepare well-defined DNA segments in multiple identical copies

short tandem repeats (STRs)

repeating sequences of noncoding DNA; analyze genetic profiles

polymerase chain reaction (PCR)

A method of producing thousands of copies of DNA segment using the enzyme DNA polymerase

RNA interference (RNAi)

A technique used to silence the expression of selected genes; uses synthetic double-stranded RNA molecules that match the sequence of a particular gene to trigger the breakdown of the gene's messenger RNA

restriction fragments

DNA segment resulting from cutting of DNA by a restriction enzyme

genetic engineering

The direct manipulation of genes for practical purposes

biotechnology

The manipulation of living organisms or their components to produce useful products

expression vector

a cloning vector that contains a highly active bacterial promoter just upstream of a restriction site where the eukaryotic gene can be inserted in the correct reading frame

Pax-6

a gene that directs formation of a vertebrate eye; the same gene in flies directs the formation of an insect eye; this gene in flies and vertebrates can substitute

recombinant dna

a molecule with DNA from two different sources

cloning vector

a plasmid used to clone a foreign gene

dna technology

affect everything from agriculture, to criminal law, to medical research

gene therapy

alteration of an afflicted individual's genes

electroporation

applying a brief electrical pulse to create temporary holes in plasma membranes

heating, cooling, and respiration

brings about a chain reaction that produces an exponentially growing population of identical dna molecules

genetically modified organisms

crops that carry new traits that have been inserted through advanced genetic engineering methods

restriction enzymes

cut DNA at specific sequences called restriction sites; most useful way is staggered and produces sticky ends

Sanger

developed the first automated procedure based on a technique called didexy or chain termination sequencing

pluripotent

embryonic stem cells able to give rise to multiple, but not all, cell types

dna ligase

enzyme that seals the bonds between restriction fragments

neanderthals and wooly manmoths

genome sequences of these 2 extinct species have been completed

eukaryotic cells such as yeasts

hosts for cloning and expressing genes to avoid incompatibility issues

genetic profile

individuals unique dna sequence

nucleic acid probes

locate nucleotide sequence characteristic of species or group

Ti plasmid

most commonly used vector for introducing new genes into plant cells

identify the mRNAs being made

most straightforward way to discover which genes are expressed in certain cells

in vitro mutagenesis

mutations are introduced into a cloned gene, altering or destroying its function

totipotent cell

one that can generate a complete new organism

transgenic

producers of larger amounts of otherwise rare substances for medical use; made by introducing genes from one species into the genome of another animal

next generation sequencing

single template strand that is immobilized and amplified to produce an enormous number of identical fragments

plasmids

small circular DNA molecules that replicate separately from the bacterial chromosome

nucleic acid hybridization

the base pairing of one strand of a nucleic acid to a complementary sequence on another strand

DNA sequencing

the process of determining the precise order of nucleotides within a DNA molecule

gene cloning

the production of multiple copies of a single gene

third generation sequencing

the techniques used are even faster and less expensive than the previous

in situ hybridization

uses fluorescent dyes attached to probes to identify location of specific mRNAs in place in intact organism

phenotype

when the mutated gene is returned to the cell, the normal gene's function might be determined by examining the mutant's ______

bacterial plasmids

widely used as cloning vectors because they are readily obtained, easily manipulated, easily introduced into bacterial cells, and once in the bacteria they multiply rapidly