Biotechnology- the use or alteration of cells or biological molecules ...

vinegaryellowwaterBiotechnology

Oct 23, 2013 (3 years and 5 months ago)

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Biotechnology
-

the use or alteration of cells or biological molecules for specific applications


Chp. 18
-

Genetically Modified Organisms

I.

Intro.

a.

Recombinant DNA Technology
-
Adding foreign genes to bacteria or other single cells

i.

When they reproduce they make
several copies of the foreign DNA

ii.

Fig. 18.3

b.

Transgenic
-

animal with a genetic change in each of its cells

c.

Gene Targeting
-

Adds or deletes specific genes of interest

II.

Recombinant DNA Technology

a.

Making Recomb. DNA Tech requirements

i.

Restriction Enzymes
-

cut do
nor and recipient DNA

ii.

Cloning Vectors
-

DNA to carry the donor DNA

1.

U
se
Plasmids
-

circle of double stranded DNA naturally occurring

(
fig. 18.5&8
)

iii.

recipient cells


insert donor DNA

iv.

Select cells that harbor DNA

v.

Select recombinant cells that contain genes of i
nterest

1.

Create a
Genomic Library
-

bacteria that harbor pieces of genome (HUGE)

a.

Like searching GOOGLE

2.

cDNA Library
-

(complimentary DNA) smaller b/c
only

protein encoding genes

a.

Like searching a scientifically based webpage

vi.

stimulate expression of the foreign

gene


collect and purify protein product

b.

Allows us to look at the functions of genes from complex organisms at the molecular level

III.

Transgenic Organisms

-

Video

a.

Plants

-


insert plasmid into

protoplasts
-

cells with cell wall removed

b.

Animals


DNA is inser
ted into cells using:

i.

Liposomes
-

fatty bubbles that integrate into cell membrane

ii.

Electroporation
-

electricity makes small holes in cell membrane

iii.

Microinjection
-
microscopic needle

iv.

Particle bombardment
-

shoot tiny medal particles into cell with foreign DNA o
n them

v.

Viruses, Retroviruses, and chemicals

c.

Pharming
-

inserting genes into hosts in order to produce
desired proteins and harvesting them

d.

transgenic technology can disrupt normal gene function

IV.

Gene Targeting

a.

Homologous recombination
-

DNA locates similar or

identical sequence and displaces it

b.

“Knocking Out”


stops the function of a gene that the foreign DNA replaced

c.

“Knockin”


genes that have an altered function are swapped in
















Chp. 19
-

Gene Therapy and Genetic Counseling


Gene Therapy
-

repla
cing a malfunctioning gene to alleviate symptoms

by delivering DNA

Genetic Counseling
-

calculating the risk of recurrence of inherited disorders in families, using pedigree charts
and applying the laws of inheritance


I.

Gene Therapy Successes and Setbacks
-

gene therapy doesn’t always work

II.

The Mechanics of Gene Therapy

a.

ex vivo gene therapy



cells are altered outside the body and then infused into the person

b.

in
situ

gene therapy


the health
y

gene plus the DNA that delivers it is injected directly into a
loc
alized and accessible body part. (More invasive


more risk)

c.

in vivo gene therapy
-

the vector is introduced directly into the body (most invasive)

d.

Protein based therapies t
reat the phenotype by replacing a missing protein

e.

Germline gene therapy
-

alters the
DNA of a gamete or fertilized ovum. All resulting cells
changed (not being done in humans)



heritable


f.

Somatic Gene therapy
-

Correct only the somatic cells that an illness affects



not heritable

19.4

g.

Chimeraplasty
-

abnormal genes are not replaced, they
are repaired by inserting DNA and RNA

III.

Genetic
Screening

And Genetic Counseling


Chp. 21
-

Reproductive Technologies


I.

Infertility and Subfertility



Table 21.1

a.

M
ale infertility

often a
deletion of part of the Y chromosome

b.

Female infertility has many ties to
genes (Hormones, structures, pH…)

c.

Many fertility problems

solved using
in vitro fertilization



“fertilization in glass”

(
video
)

II.

Assisted Reproductive Technologies



Table 21.2

a.

P
reimplantation Genetic Diagnosis

(PGD)
-

detects genetic and chromosomal abnorm
alities
before pregnancy starts

i.

remove a cell from the 8 celled embryo leaving 7 which can be successful

ii.

VERY controversial (sex selection…)

b.

Polar body biopsy



genetic test on polar body to infer the genotype of the attached oocyte

i.

analyze the polar body
for mutant alleles

ii.

if it has mutant than you know the oocyte does not have the mutant


Chp. 22
-

The Human Genome Project and Genomics

I.

Genome Sequencing: A continuation of Genetics

a.

Uses


Fig 22.1

b.

Genetic maps have
increas
ed in

level of detail


Fig 22.2

c.

Po
sitional Cloning
-

how does phenotype correspond to causative gene

i.

in contrast to genome pjct. approach which was “sequence now, interpret later”

II.

The Origin of the Idea

a.

Francis Crick


E. coli, “What is true for E. coli is true for the elephant.”

b.

Sanger


m
ethod of cutting and labeling DNA

-

Fig. 22.4

c.

officially began
pjct.
in 1990

III.

Technology Drives the Sequencing Effort

for Genome pjct.

a.

DNA sequencing and computer software to align DNA pieces were essential



Fig. 22.6

b.

Expressed Sequence Tags
-

short pieces
of cDNAs used to locate & tag protein encoding genes

c.

DNA Microarrays
-

DNA embedded on glass

IV.

Genome Information Answers and Raises Questions

a.

What is a gene?

b.

Minimum # of genes

required for life (265
-
350)



Tbl. 22.2

c.

Genome Information will affect you in som
e way in the future