BGM1004/L07 Model Eukaryotes Flashcards
What is a model organism?
A well-established experimental biological system
Give 3 characteristics of a good model organism.
Rapid rate of development
Easily manipulated
Short lifespan
Readily available
Large number of offspring per generation
Give the 3 types of model organism.
Genetic
Genomic
Experimental
What is a genetic model organism?
Species amenable to genetic analysis
Give 3 characteristics of a genetic model organism.
Short generation time
Large range of mutants available
Detailed genetic maps
What is a genomic model organism?
Occupies a special position in evolution or have a particular genome size or comparison
What is an experimental model organism?
May not be genetically amenable but have certain other experimental advantages
Why do we need model organisms? (4)
Humans take a long time to mature
Unethical to manipulate human genome
One offspring per cycle
Large in size
What is (possibly) the simplest free-living model organism?
Escherichia coli
What type of cell is E. coli?
Gram negative rod shaped bacterium
Why is E. coli used as a model organism? (3)
Easy to grow
Rapid rate of generation
Easy to manipulate/transform
Give 5 eukaryotic models for genetic analysis.
Yeast
Fruit fly
Worm
Zebra fish
Mouse
How is DNA stored in yeast?
Linear chromosomes within membrane-bound nucleus
How do yeast divide?
Budding or fission
Give an example of a budding yeast used as a eukaryotic model.
Saccharomyces cerevisae
Give an example of a fission yeast used as a eukaryotic model.
Schizosaccharomyces pombe
Give 3 advantages to S. cereviae and S. pombe as eukaryotic models.
Rapid growth rate
Can exist as haploid or diploid
Easily transformable with plasmids
Large mutant collections
What biological properties do yeast share with humans? (4)
Cell division cycle
Gene expression
DNA replication and repair
Signalling pathways
Give 3 advantages to Drosophila melanogaster as a eukaryotic model organism.
Small so large numbers maintainable
Short lifespan
Large number of offspring per cycle
Easy to cross genetics
Huge number of mutants
Many phenotypic markers
How can D. melanogaster be transformed?
P element transposon and other transposons
What allows genetic mapping of D. melanogaster?
Mature larvae produce giant polythene chromosomes
Give 3 contributions from Drosophila genetics.
Cell signalling
Development
Neurological diseases
Give 3 advantages of Caenorhabditis elegans as a eukaryotic model organism.
Small, free-living
Transparent - easy observation
Cheaply maintained
Short lifespan
Two sexes allows genetic crossing
What is the function of siRNAs?
Prevent expression of gene of interest
Give 2 contributions of C. elegans.
Insight into ageing and development
Cell tracking and follow through development
First mutant with increased lifespan
Give 3 advantages to Danio rerio (zebra fish) as a eukaryotic model organism.
Large number of offspring per cycle
Short lifespan
Transparent embryos
Sturdy 1mm embryos are micro-injectable
Mutants via random mutagenesis possible
Knockdown via morpholinos
What is the D. rerio an excellent model for? (4)
Vertebrate development
Neurobiology
Drug discovery and toxicity testing
Diseases including cancer
Give 3 advantages of Mus musculus as eukaryotic model organism.
Short breeding cycle
Large number of offspring per cycle
Manipulation of embryonic stem cells allows transgenic mice
Give 4 diseases that mice are prone to.
Cancers
Blindness
Obesity
Diabetes
Drug addiction
Alcoholism
Aggression
Anxiety
