Microbial Genetics

Your Cousin The Banana

Genome of a Mycoplasma

7.1Bacterial

Recombination

Vertical and Horizontal Transfer of Genes

Genetic information in bacteria can be transferred

vertically and laterally• Bacterial mutation

• Definition of recombination

Genetic information in bacteria can be transferred

vertically and laterally• Bacterial mutation

• Definition of recombination

Genetic Transformation

Bacterial Transformation and Mechanism

The F pilus connecting donor and recipient E. coli cells

Bacteria Conjugating

Some R Factor Plasmids

Transposons migrating into genes involved in synthesis of pigments

The Transformation Experiments of Griffith

Gene Transfer Mechanisms

Conjugation involves cell-to-cell contact for DNA transfer

Genetic Engineering

Genetic engineering was bornin the 1970s

• Discovery of endonucleases• First recombinant DNA• Plasmids and sticky ends

Genetic engineering has many commercial and practical

applications• Pharmaceutical applications• Agricultural applications• Antibiotic production• Detection and diagnosis• Environmental biology• Vaccine production

Construction of a Recombinant DNA Molecule

A plasmid used for cloning

Genetic Engineering

Genetic Engineering (cont’d)

Developing New Products using Genetic Engineering

Plate culture of Luminescent bacteria who live under eye of a flashlight

fish

Transduction involves viruses in the lateral transfer of DNA

• Description• Role of the bacteriophage

Lytic cycleLysogeny

• Generalized transduction• Specialized transduction

Generalized Transduction

Specialized Transduction

DNA Probes

Role of Restriction Enzymesin making recombinant DNA

Polymerase Chain Reaction - PCR

Steps of a single cycle of PCR

Final PCR product

Polymerase Chain Reaction

PCR Amplifies selected DNA sequences

DNA fingerprinting to identify criminals

DNA Fingerprinting (cont’d)

Fingerprints

Gene Libraries

Genetic information in bacteria can be transferred

vertically and laterally• Bacterial mutation• Definition of recombination

Many microbial genomeshave been sequenced

• Analogy for comparing the human and E. coli genome lengths

• First complete bacterial genome• First fungal genome

Microbial genomics will advance our understanding

of the microbial world

• Food production• The environment• Biosensing• Human health

Microbial genomics has produced some interesting

findings• Comparison to the human genome• Large number of gene functions have not been

identified• Genetic (pathogenicity islands)