If post is spelled P-O- S-T and most is spelled M-O-S-T, how do you spell the word for what you put...
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Transcript of If post is spelled P-O- S-T and most is spelled M-O-S-T, how do you spell the word for what you put...
If post is spelled P-O-S-T and most is spelled M-O-S-T, how do you spell the word for what you put in the toaster?
Microbial Genetics
General Biology
SUNY Orange at S. S. Seward Institute
It's At The 20! The 10! Can The Flu Go All The Way?
by Laura Lorson
Tobacco Mosaic Disease
Red Neck Bird Dogs
Bacterial and viral growth curves
Lytic cycle of phage T4
Viral structure
Phage Infecting Bacteria
• Sorenson animation
• T4 Assembly
Viral reproductive cycle
Adenovirus
Reproductive cycle of an enveloped virus
HIV infection
Couple at AIDS quilt
HIV, a retrovirus
Smallpox
Measles
Polio
Hepatitis
Influenza epidemic
Herpes
Emerging viruses
Deer Mouse – vector for hantavirus
Viral infection of plants
Tobacco mosaic virus
Prion Diseases
Creutzfeldt-Jakob Disease
Kuru
A hypothesis to explain how prions propagate
Replication of the bacterial chromosome
E. coli
E. coli dividing
Bacterium releasing DNA with plasmids
Plasmids
Genetic recombination produces new bacterial strains:
Transformation
Transduction
Conjugation
Transformation
• The alteration of a bacterial cell’s genotype by the uptake of naked, foreign DNA from the surrounding environment
Detecting genetic recombination in bacteria
Transduction
• Occurs when a phage carries bacterial genes from one host cell to another
• Generalized transduction – a small piece of the host’s cell degraded DNA is packaged within a capsid
• Specialized transduction – occurs when extra DNA is taken when prophage genome is excised
Transduction
Transduction
Transduction
Transduction
Conjugation
• Transfers genetic material between 2 bacterial cells temporarily joined
• F factor – about 25 genes, most required for production of sex pili– Either in chromosome or on plasmid– Episome – any genetic material that
undergoes reversible incorporation into a cell’s chromosome
• Ex. F plasmid, any temperate phage
Bacterial mating
Conjugation and recombination in E. coli
Conjugation and recombination in E. coli
Conjugation and recombination in E. coli
Conjugation and recombination in E. coli
R Plasmid
• R for resistance
• Also have genes for sex pili
• Therefore can be transferred from one cell to another by conjugation
Transposons
• Pieces of DNA that can move from one location to another in a cell’s genome
• A type of recombination– Chromosome to plasmid– Plasmid to chromosome– Plasmid to plasmid– Chromosome to chromosome (Jumping
gene)
Barbara McClintock, Ph.D., Nobel Prize laureate
Insertion Sequence
• Consists of DNA necessary for the act of transposition
• Requires a transposase gene
• Flanked by a pair of inverted repeat sequences
Insertion sequences, the simplest transposons
Insertion of a transposon and creation of direct repeats
Composite transposon
• Extra genes sandwiched between two insertion sequences
Anatomy of a composite transposon
The control of gene expression enables individual bacteria to adjust their metabolism to environmental change.
Regulation of a metabolic pathway
Regulation of a metabolic pathway
Operon
-a unit of genetic function (bacteria and phages) regulated clusters of genes with related functions
1. gene(s) that it controls
2. Promoter region where RNA polymerase first binds
3. Operator – between promoter and the first gene – acts as on/off switch
The trp operon: regulated synthesis of repressible enzymes
The trp operon: regulated synthesis of repressible enzymes
The lac operon: regulated synthesis of inducible enzymes
The lac operon: regulated synthesis of inducible enzymes
cAMP (Cyclic Adenosine Monophosphate)
Positive control: cAMP receptor protein
Positive control: cAMP receptor protein