Chapter 21

other methods introducing genes into plant cells

-biolistic gene transfer (gene gun) - microinjection -electroporation

stem cells have 2 common characteristics

-capacity to divide -capacity to differentiate into one or more specialized cell types

sources of insulin

-cows -human cadavers -mainly: recombinant bacteria

inactivate normal mouse gene with CRISPR-CAS

-hetero mice carrying one inactivated copy -hetero mice crossed = 1/4 of offspring homo with inactivated gene -gene knockout

Bacillus thuringiensis toxins

-lethal to catepillars and beetles -harmless to plants and humans -Bt toxins sold in powder form -can be used as foliage spray -toxins paralyze insect's digestive tract

ethical concerns about cloning

-morally wrong threatens basic fabric of parenthood and family -infertile couple who want genetically related child -many countries issued all-out ban (human cloning) -permit limited research in the area (human cloning)

agrocin 84 synthesis

-synthesis and resistance are on a plasmid -research found strains with plasmids have lost ability to be transferred -now used commercially worldwide to prevent crown gall disease

interest in stem cells

1. may help us understand the basic genetic mechanisms that underlie the process of development 2. offer potential to treat human diseases or injuries that cause cell and tissue damage

biological control agents prevent disease in one of two ways:

1. nonpathogens are used to compete effectively against pathogens for nutrients or space 2. microorganism may produce toxins that inhibit other microorganisms or insects, but not the plant

Aging of Cloned Animals

Dolly was genetically older than age indicated -sheep that donated somatic cell to Dolly = 6 years old -when Dolly was born her cells were already 6 years old = shortened life -she had shortened telomeres

A. tumefaciens T DNA can be used for what?

Used as a vector to introduce cloned genes into plants -Ti plasmids need to be moded - selectable marker genes into T DNA -KAN^R commonly used

gene redundancy

a gene knockout with no obvious phenotypic effect

gene kockin

a gene of interest has been inserted into a particular site in the mouse genome

animals can be genetically modified to do what?

add extra proteins to their naturally produced products -ex: extra protein in cattle milk

gene modification (gene editing)

alters the sequence of a gene

electroporation

an electric current is used to create transient pores in the plasma membrane through which DNA can enter

transgenic

an organism that has integrated recombinant DNA into its genome from a different species

mouse model

animal engineered to have gene mutations analogous to human diseases

success in cloning

animals have recently been cloned often like sheep, cows, mice, etc. -telomeres in mice and cattle = correct length

adult stem cells are what?

are super rare - 1 cell in 10,000 in bone marrow is a stem cell -embryonic stem cells and embryonic germ cells can be grown in the laboratory

microorganisms are used to do what?

benefit humans -molecular genetic tools are important to influence these organisms

Agrobacterium radiobacter is an example of what?

biological control agent -bacteria produces agrocin 84, a antibiotic that kills A. tumefaciens

induced pluripotent stem cells (iPS cells)

by injection of four different genes that encode transcription factors

transgenic plants

can be given characteristics that are agriculturally useful -plants highly tolerant of glyphosate -natural herbicide -made to be disease resistant

insulin-dependent diabetes

defect in beta cells -cannot synthesize enough insulin

pluripotent cells

differentiate into almost every cell type, but cant give rise to an entire intact individual

multipotent cells

differentiate into several cell types

reproductive cloning in plants

easy overall -cuttings, expose to hormones

biotransformation

enzymes produced by a microorganism transforms the structure of the toxic pollutant

transgenic plants produce their own insecticide by what?

expressing genes from the naturally occurring bacterium bacillus thuringiensis (Bt)

farming used cloning

farmed use somatic cells from best livestock = genetically homogeneous herds -good agricultural yield -bad as herd can be susceptible to rare diseases

embryonic stem cells (ES cells)

found in the inner cell mass of the blastocyst

genomes of animals can be altered by what?

gene modification or gene addition

Embryonic germ cells (EG cells)

germ-line cells found in the gonads during the fetal stage

totipotent cells

give rise to all cell types Ex: fertilized eggs

insulin

hormone composed of two polypeptide chains, called A and B -regulates several physiological processes, uptake of glucose into fat and muscle cells -produced by beta cells of panceras

Recombinnat Microorganism medicine

insulin, Tissue plasminogen activator, superoxide dismutase. Factor VIII, Renin inhibitor, Erythropeintin

Microinjection

microscopic-sized needles are used to inject DNA into the cells

unipotent cells

only differentiate into one cell type

Genetically modified organisms (GMOs)

organisms that have received genetic material via recombinant DNA technology

Common uses for Microorganisms

production of medicines, food fermentation, biological control, biomediation

biological control

refers to the use of microorganisms or their products to alleviate plant problems -disease or damage from environmental conditions

ethical dilemma for iPS

source of these cells because of ES and EG cells

stem cells

supply cells that construct our bodies from a fertilized egg -can also replenish damaged cells

biotechnology

technologies that involve the use of living organisms, or their products, to benefit humans

gene addition

the addition of a cloned gene into a site in a chromosome of a living cell

reproductive cloning in mammals

thought to have irreversible genetic changes to somatic cells that would make them unfit for cloning -Dolly the sheep 1997

animals can be genetically engineered for what?

tissue transplantation into humans -goal = tissue from pigs can be transplanted into humans with less immunoregjection

gene knockouts are used for what reason?

to understand gene function and human disease -typically done in mice

biodegradation

toxic pollutant is degraded into nontoxic metabolites

bioremediation expanded into what?

treatment of hazardous and refractory wastes associated with chemical and industry activity -petroleum hydrocarbons, etc.

reproductive cloning

two or more genetically identical individuals

biomediation

use of microorganisms to reduce environmental pollutants

xenotransplantation

uses tissues or organs from different species