Mechanisms of Microbial Genetics and Horizontal Gene Transfer

This set of vocabulary flashcards covers microbial genetics, including the Central Dogma, mutation types, selection methods in the lab, and horizontal vs. vertical gene transfer based on OpenStax Microbiology.

Central Dogma of Molecular Biology

The process where DNA is replicated, followed by transcription where RNA is made from DNA, and then translation where RNA is used to make protein composed of amino acids.

Mutation

A change in the DNA sequence of a single base, which may affect the amino acid sequence.

Silent mutation

A change in the DNA sequence that results in no change to the amino acid sequence.

Missense mutation

A change in the DNA sequence that results in one change to the amino acid sequence.

Nonsense mutation

A change in the DNA sequence that changes one amino acid into a stop codon, resulting in a protein that will not function.

Frameshift mutation

The addition or removal of one or two bases, causing the reading frame to shift and changing many amino acids.

Positive selection

A lab method where growth media only allows for cells with a specific resistance (such as antibiotic resistance) to grow.

Negative/indirect selection

A replica plating method used to identify mutants by looking for the absence of growth after transferring bacterial cells with sterile velvet to a new plate.

Ames test

A test that detects if a chemical is a mutagen by using a Salmonella strain ($his^-$) to see if it mutates to ($his^+$) in the presence of rat liver extract.

Horizontal transmission

The transfer of DNA from a donor cell to an unrelated recipient cell, including transformation, transduction, and conjugation.

Vertical transmission

The transfer of genetic information from parent to offspring, such as during binary fission.

Transformation

A type of horizontal gene transfer where DNA is taken up from the environment into a recipient; it require competent cells and was demonstrated in Griffith's Experiment.

Transduction

The transfer of a gene or genes from one cell to another via a bacteriophage.

Generalized transduction

A form of transduction where any type of DNA can be transferred.

Specialized transduction

A form of transduction where only certain specific DNA is transferred.

Conjugation

A process where a donor ($F^+$) cell uses a pillus made by an F plasmid to transfer DNA to an ($F^-$) recipient, resulting in two alive ($F^+$) cells.

Transposition

The movement of a mobile piece of DNA (transposon) within the same cell, involving an enzyme that cuts the transposon and inserts it into a new location.