Microbio (Exam 3): Ch 9: Gene Transfer

Transformation

uptake of naked DNA from the environment.

Conjugation

transfer of DNA via cell-to-cell contact.

Transduction

DNA transfer via viral intermediate.

Transposition

transfer of transposons (mobile genetic elements).

Genomic islands

transferred genetic elements containing large number of genes of similar function.

Pathogenicity islands

virulence genes antibiotic resistance genes.

Symbiosis islands

bacteria:host interactions.

Fitness islands

catabolic pathways.

DNA acquired from horizontal transfer may degrade and:

be used as food.

DNA acquired from horizontal transfer may recombine:

with chromosome.

DNA acquired from horizontal transfer may just:

co-exist

RecA

major recombination protein

RecA scans DNA and aligns ________ regions.

homologous.

Competent cells:

are able to take up DNA (transformation).

Competence factors

if enough cells accumulate, cells become competent.

Quorum sensing mechanism controls ________.

competence.

Gram-positive bacteria form this to uptake DNA fragments.

transformasome complex.

Gram-negative bacteria uses a ________ to attach to external DNA fragment and bring it into the cell.

type IV pilus.

Gram-negative bacteria that does transformation via type IV pilus:

Hemophilus, Neisseria.

Artificial transformation induces ________ in cells by chemicals or electric charge.

competence.

If threshold level of competence factors (CF) accumulate, CF bind ________ ________.

sensor protein (ComD).

CF binding of ComD sensor protein initiates:

sigma factor expression.

Sigma factor promotes expression of ________ involved in expression of proteins for transformation (ex. transformasome complex).

operons.

The transformasome imports only one ________ strand of the double helix.

DNA

Inside the cell, transformed DNA may recombine with ________ ________.

host chromosome.

Conjugation involves cell to cell contact and DNA transfer via ________ ________.

s3x pilus.

Conjugation occurs in:

bacterial and archaeal species.

Fertility (F) factor

facilitates conjugation.

F+ cells

have F factor, known as conjugative or transferable plasmids.

Conjugation donor cells are:

F+

Conjugation recipient cells are:

F-

tra genes

conjugation-specific transfer genes.

relaxasome

facilitates bridging of cells and transfer of DNA in conjugation.

oriT

for transfer.

oriV

oriT when not conjuigating.

F+ cell has plasmid with ________ genes and ________.

tra and oriT.

After conjugation, F- cell becomes:

F+ cell.