Biology 1002B Lecture Notes - Lecture 1: Insertional Mutagenesis, Noncoding Dna, Bleomycin
13 Jun 2018
School
Department
Course
Professor
Lecture 1 Outcomes
Relatedness of Chlamydomonas to
plants and animals
- Shares common ancestor with plants
and animals
- Has a flagella (animal trait) and
chloroplasts and is photosynthetic (plant
trait)
- Diverged early from other plants but is
classified as a plant
Relationship between genome size and
protein coding genes
- No relationship because some genomes contain more junk
DNA than others
- Chlamy has a small genome size (20x smaller) relative to
humans but because it has less junk DNA, it has a
proportionately higher number of PCG regions
Chlamydomonas lifecycle.
- Haploid most of the time
- 2 mating types (+/-), caused by some kind of environmental
stress.. nutrient stress (not enough N) it differentiates into 2
types of gametes
Basics of insertional mutagenesis...foreign DNA,
electroporation, plating on agar plates…..
- Insertional Mutagenesis: inserting foreign gene to disrupt the target gene (ex. if codes for
anti-biotic resistance, the new gene will make it resistant)
- Electroporation: zap the mixture with a voltage to open the pores to integrate new DNA into
the cell
- plate mix on the agar plate will ensure that the only the bacteria with the integrated foreign
DNA will grow (ex. agar with antibiotics on it, only resistance bacteria will grow)
- Efficiency: <1%, 0.5% of cells with actually have their genomes disrupted
What is bleomycin, how is it used in the isolation of mutants.
- Bleomycin is an antibiotic, used to isolate mutants because it is added to the agar plate to
which the bacteria containing the foreign DNA is grown so that only the resistant mutants will
survive and grow
What is a genetic screen, why do you need to use one?
- experimental technique used to identify which individuals contain the gene/phenotype of
interest in the mutagenized population
Class 2 & Reading Outcomes
How old is the Earth, and when do we think life developed.
find more resources at oneclass.com
find more resources at oneclass.com
- Earth was formed approximately 4.6 billion years ago
- life may have started as early as 4.0 billion years ago
What are stromatolites
- a type of layered rock that is formed when microorganisms bind particles of sediment
together forming thin sheets
- formed 3.5 billion years ago by cyanobacteria (photosynthetic) (because they used water as
electron donor)
What are the four major developments that need to take place to make a living cell.
1. Abiotic Synthetic: non-biological molecules (sugars, amino acids, etc) need to be
synthesized in the absence of life
2. Heritable Information: information must get transferred to a daughter cell
3. Formation of Cells: cells have a very different internal and external environment
4. Metabolism: energy transformation
Three stages of prebiotic evolution, how much is known about each.
- Geophysical Stage: the composition of the Earth and atmosphere, and how conducive it was
to life
- Chemical Stage: how the building blocks synthesize
- Biological Stage: how is everything organized (unsure how the first cells are formed)
Conditions in the primordial atmosphere, why were they conducive to the development
of complex molecules
- early atmosphere was a reducing atmosphere that you can add electrons to it, enables you
to build molecules that are highly reduced, requires energy to break bonds (lots of lightning)
- A reducing environment is required to form C-H compounds. Any free O2 would prevent this
by immediately oxidizing carbon to CO2 or CO32+
What was the Miller-Urey experiments. What did it show, didn't show.
- Miller-Urey used sparks to mimic lightning, and a condenser so that he could analyze the
gases that were produced
- he was able to produce the building blocks of life (amino acids, sugars, urea, etc) abiotically
in a lab
- didn’t produce polymers… only monomers (ex. amino acids not proteins) therefore didn’t
show how you make polymers
- Miller-Urey experiment gave both chiral structures (racemic 50/50) tf, Miller can’t explain why
biological process are homochiral
What is chirality, why is it important. Homochirality
- same chemical & physical properties but vastly different biological properties
- Homochirality: the specificity of the binding between protein & receptor causes the incorrect
molecules not to bind with the receptors
- having both orientations is selected against because it would require there to be both
receptors (not evolutionary efficient, requires too much complexity)
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Shares common ancestor with plants and animals. Has a flagella (animal trait) and chloroplasts and is photosynthetic (plant trait) Diverged early from other plants but is classified as a plant. Relationship between genome size and protein coding genes. No relationship because some genomes contain more junk. Chlamy has a small genome size (20x smaller) relative to humans but because it has less junk dna, it has a proportionately higher number of pcg regions. 2 mating types (+/-), caused by some kind of environmental stress nutrient stress (not enough n) it differentiates into 2 types of gametes. Basics of insertional mutagenesisforeign dna, electroporation, plating on agar plates Insertional mutagenesis: inserting foreign gene to disrupt the target gene (ex. if codes for anti-biotic resistance, the new gene will make it resistant) Electroporation: zap the mixture with a voltage to open the pores to integrate new dna into the cell.
