L11: Biotechnology Flashcards
vertical gene transfer
transfer of genes from an organism to its offspring
horizontal gene transfer
transfer of genes between cells of different lineages
conjugation
transfer of DNA from 1 bacterium to another via “mating”
CONJUGATION: F- (female)
the recipient cell
CONJUGATION: F+ or Hfr (male)
the donor cell
strains, carries the F factor
CONJUGATION: pilus
the conjugation bridge
CONJUGATION: timed, interrupted matings were used to construct…
the first genetic maps of bacterial chromosomes
transformation
uptake of DNA from the medium by a cell
transduction
transfer of DNA from 1 bacterium to another by a virus (phage) that attacks bacteria
TRANSDUCTION: transducing phage
certain bacterial viruses
TRANSDUCTION: lytic phage
cause lysis of the bacterial cells
TRANSDUCTION: lysogenic phages
integrates their DNA into the host genome, resulting in delayed lysis
biotechnology
the use of microorganisms, cells, or cell components to make a product
examples of biotechnology
food
antibiotics
vitamins
enzymes
recombinant DNA technology
insertion or modification of genes to produce desired proteins
vector
self-replicating DNA used to carry the desired gene to a new cell
what are used as vectors?
plasmids
viruses
clone
population of cells arising from one cell; each carries the new gene
genetic recombination
exchange of genes between 2 DNA molecules; creates genetic diversity
crossing over
2 chromosomes break and rejoin, resulting in the insertion of foreign DNA into the chromosome
what is the most common DNA carrier?
Escherichia coli
DNA can be inserted into a cell through 5 main ways
electroporation
traditional transformation techniques
protoplast fusion
gene gun
microinjection
DNA INSERTION: electroporation
electrical current forms temporary pores in cell membranes
DNA INSERTION: traditional transformation techniques
usually bacterial cells or yeast cells; forms temporary pores in cell membranes
DNA INSERTION: protoplast fusion
removing cell walls from 2 bacteria allows them to fuse
DNA INSERTION: gene gun
bombarding of cells w/ DNA-coated projectiles (usually gold, Au)
DNA INSERTION: microinjection
tiny injections w/ a tiny glass probe; cells must be large
microinjection can be used for what kind of cells?
large cells w/o cell walls
examples of microinjections
deliver DNA to an embryo
supply a gene for a missing enzyme
plasmids
small, circular pieces of DNA that often carry small #’s of genes between cells
plasmids are used for…
recombinant DNA technology
cloning
naturally-occurring plasmids are often the means by which the genes for __________ are carried between bacteria
antibiotic resistance
plasmids must have a ____________so that the bacteria can create copies and pass those copies to both progeny after cell division
origin of replication
conjugative plasmid
carries genes for sex pili and transfer of the plasmid (F factor pyramid)
dissimilation plasmid
encodes enzymes for catabolism of unusual compounds
resistance factors (R factors)
encode antibiotic resistance
transposons
segments of DNA that can move from one region of DNA to another
transposons contain insertion sequences for…
cutting and resealing DNA (transposase enzymes recognize the sequences)
complex transposons carry other genes, such as…
antibiotic resistance
recombinant DNA
DNA from 1 organism cut up and ligated into a plasmid and transformed into a bacteria, fungi, etc.
recombinant DNA: if the plasmid can replicate and the genes can be expressed…
some abilities of the source organism can be transferred
genomic libraries
made of pieces of an entire genome stored in plasmids or phages
complementary DNA (cDNA)
made from mRNA by “reverse transcripticase”
synthetic DNA
made chemically by a DNA synthesis machine; process for making DNA primers for PCR reactions
restriction enzymes
cuts DNA at specific sequences, usually palindromes
palindrome
a sequence of nucleotides that reads the same forward and backward (i.e. OTTO or ANNA)
PCR (polymerase chain reaction)
makes multiple copies of a piece of DNA enzymatically in the laboratory
PCRs are used to…
clone DNA for recombination
amplify DNA to detectable levels
sequence DNA
diagnose genetic disease
detect pathogens
PCR step 1?
denaturation
PCR step 2?
annealing
PCR step 3?
polymerization
PCR components?
dNTPs
primers
template DNA
heat-stable DNA polymerase
what are the 5 most common cells used in biotechnology?
Escherichia coli
Saccharomyces cerevisiae
plant cells and whole plants
mammalian cells
insect cells
E. coli is used b/c…
easily grown in most conditions
genomics are known
E. coli function
need to eliminate LPS (endotoxin) from products
cells must be lysed to get product
Saccharomyces cerevisiae is used b/c…
easily grown
genomics are known
Saccharomyces cerevisiae function
may express eukaryotic genes easily
plant cells/whole plants are used b/c…
easily grown
may express eukaryotic genes easily
mammalian cells are used b/c…
may express eukaryotic genes easily, although they are harder to grow
insect cells are used b/c…
common alternative if the other cell types cannot be used
BIOTECH THERAPY: subunit vaccines
proteins from the pathogen produced in nonpathogenic organisms to induce production of antibodies
BIOTECH THERAPY: DNA vaccines
nonpathogenic viruses carrying genes for a pathogen’s antigens, which moves a piece of DNA to present to the immune system to produce antibodies
BIOTECH THERAPY: gene therapy
to replace defective or missing genes
BIOTECH THERAPY: gene silencing
“silences” the expression of defective genes
BIOTECH THERAPY: small interfering RNA’s (siRNAs)
bind to mRNA, which is then destroyed by an RNA-induced silencing complex (RISC)
BIOTECH THERAPY: RNA interference (RNAi)
inserts DNA encoding siRNA into a plasmid and transferred into a cell
human genome project
may provide diagnostics and treatments
microbial metagenomics
the study of genetic material directly from environmental samples
shotgun sequencing
sequences small pieces of genomes, which are then assembled by a computer
forensic microbiology
identify pathogens and trace to the source
FORENSIC MICROBIOLOGY: primer for a specific organism will bind to that organism’s DNA and allow it to be…
copied by a heat-stable DNA polymerase
real-time PCR/quantitative PCR (qPCR)
newly made DNA is tagged w/ fluorescent dye; levels can be measured after every PCR cycle
used to quantify the amt. of DNA of a sequence present
reverse-transcription (RT-PCR)
DNA synthesis from RNA using reverse transcripticase
agrobacterium
used to transfer genes to plants
what types of genes is agrobacteria used to transfer?
herbicide resistance
increase the nutrition value of plants
expression of human proteins
gene suppression/silencing
