Chapter 14 Molecular Genetic Analysis and Biotechnology

Exam 3 Vocab

biotechnology

Use of biological processes, particularly molecular genetics and recombinant DNA technology, to produce products of commercial value.

recombinant DNA technology

Set of molecular techniques for locating, isolating, altering, combining, and studying DNA segments; also commonly called genetic engineering.

genetic engineering

Set of molecular techniques for locating, isolating, altering, combining, and studying DNA segments; also called recombinant DNA technology.

restriction endonuclease

Enzyme that recognizes particular base sequences in DNA and makes double-stranded cuts at those sequences; also called a restriction enzyme.

restriction enzyme

Enzyme that recognizes particular base sequences in DNA and makes double-stranded cuts at those sequences; also called a restriction endonuclease.

cohesive end

Short, single-stranded overhanging end on a DNA molecule produced when the DNA is cut by certain restriction enzymes; also called a sticky end. Cohesive ends are complementary and can spontaneously pair to rejoin DNA fragments that have been cut with the same restriction enzyme.

engineered nuclease

Protein consisting of the part of a restriction enzyme that cleaves DNA, combined with another protein that recognizes and binds to a specific DNA sequence; capable of making unique double-stranded cuts in DNA at predetermined sequences. Engineered nucleases can be custom designed to bind to and cut any particular DNA sequence.

zinc-finger nuclease (ZFN)

An engineered nuclease consisting of an array of zinc-finger domains attached to a restriction enzyme.

transcription activator-like effector nuclease (TALEN)

An engineered nuclease in which a protein of a type that normally binds to sequences in promoters is attached to a restriction enzyme.

CRISPR-Cas system

A system used by bacteria and archaea as a defense against foreign DNA. Has been adapted for use as a molecular tool for precisely cutting DNA, providing a powerful way of editing the genome.

prime editing

A modified CRISPR-Cas system that allows a specific DNA sequence to be replaced. A guide RNA directs the Cas protein to a specific DNA sequence, where the protein makes a single-strand cut. Reverse transcriptase then copies an RNA sequence into the DNA at the cut, replacing the original sequence.

gel electrophoresis

Technique for separating charged molecules (such as proteins or nucleic acids) on the basis of molecular size or charge, or both.

gene cloning

Insertion of DNA fragments into bacteria in such a way that the fragments will be stable and will be copied by the bacteria.

polymerase chain reaction (PCR)

Method of enzymatically amplifying DNA fragments.

Taq polymerase

DNA polymerase commonly used in PCR reactions. Isolated from the bacterium Thermus aquaticus, the enzyme is stable at high temperatures, so it is not denatured during the strand-separation step of the cycle.

cloning vector

Stable, replicating DNA molecule to which a foreign DNA fragment can be attached for introduction into a cell.

cosmid

Cloning vector consisting of a plasmid packaged in a viral protein coat that can be transferred to bacteria by viral infection; can carry large pieces of DNA into bacteria.

bacterial artificial chromosome (BAC)

Cloning vector originally constructed from the F plasmid that can hold very large fragments of DNA (as long as 300,000 bp).

expression vector

Cloning vector containing DNA sequences such as a promoter, a ribosome-binding site, and transcription initiation and termination sites that allow DNA fragments inserted into the vector to be transcribed and translated.

DNA library

Collection of clones containing all the DNA fragments from one source.

genomic library

Collection of bacterial colonies or phages containing DNA fragments that constitute the entire genome of an organism.

cDNA (complementary DNA) library

Collection of bacterial colonies or phages containing DNA fragments that have been produced by reverse transcription of cellular mRNA.

probe

A DNA or RNA molecule with a base sequence that is complementary to a sequence of interest and will pair with it; used to find specific DNA sequences.

DNA sequencing

Process of determining the sequence of bases along a DNA molecule.

dideoxyribonucleoside triphosphate (ddNTP)

Special substrate for DNA synthesis used in the Sanger dideoxy sequencing method; identical with dNTP (the usual substrate for DNA synthesis) except that it lacks a 3’ -OH group. The incorporation of a ddNTP into DNA terminates DNA synthesis.

next-generation sequencing technologies

Sequencing methods that are capable of simultaneously determining the sequences of many DNA fragments; these technologies are much faster and less expensive than the Sanger dideoxy sequencing method.

third-generation sequencing technologies

New sequencing technologies that determine the sequence of single DNA or RNA molecules and allow longer fragments to be sequenced.

DNA fingerprinting

Technique used to identify individuals by examining their DNA sequences.

microsatellite

Very short DNA sequence repeated in tandem; also called a short tandem repeat (STR).

short tandem repeat (STR)

Very short DNA sequence repeated in tandem; also called a microsatellite.

forward genetics

Traditional approach to study of gene function that begins with a mutant phenotype and proceeds to a gene that encodes the phenotype.

reverse genetics

A molecular approach to the study of gene function that begins with a genotype (a DNA sequence) and proceeds to the phenotype by altering the sequence or by inhibiting its expression.

transgene

Foreign gene or other DNA fragment carried in germ-line DNA.

knockout mouse

Mouse in which a normal gene has been fully disabled (knocked out).

knock-in mouse

Mouse that carries a foreign DNA sequence inserted at a specific chromosome location.

RNA therapy

A method of treating human diseases that uses specially designed DNA or RNA sequences that bind to target mRNA, interfering with its function or altering its splicing.

gene therapy

The alteration of genes or transfer of genes into human patients to treat disease.