Model Organism Flashcards
Name 3 examples of non animal models for human disease
Cell free extracts Cell lines Bacteria Eukaryotes Green ALgae/plants Slime molds Fungi
What fungi is used to study cell cycle?
Schizosaccharomyces pombe
What is used to study DNA methylation and protein turnover?
Arabidopsis thaliana
Name the 5 invertebrate animal models for human disease
Mollusc- Aplysia carlifornica Roundworm- Caenorrhabditis elegans Fruitfly- Drosophilia melanogaster Purple sea Urchin- Strongylocentrotus purpuratus Ascidian sea squirt- Ciona intestinalis
What model organism is used to study associative learning?
Aplysia carlifonica
Name 3 examples of vertebrate models for human disease
Zebrafish Medaka African clawed frog Red jungle fowl House mouse Norway rat Rhesus macaque
What is the proper name for budding yeast?
Saccharomyces cerevisiae
Name 3 negatives to model organisms
1- they are domesticated and inbred
2- artificial lab conditions means evolved phenotypes could be missed
3- genetic adaptation to la b conditions
Name 3 examples of genetic adaptations to lab conditions
Non invasive yeast growth
Suppression of mating type switc hing in yeast
Loss of melatonin production in mice
What percentage of human genes identified are shared in eukaryotes?
32%
What is the genome of E.coli?
How many chromosomes
How many Mbase
How many genes
1 chromosome
4.6 Mbase
4500 genes
At 37C what is E.coli doubling time?
20 minutes
When was E.coli last common ancestor with Homo sapiens
2.5BYA
How long is an e.coli?
1-2 uM
Describe the structure of E.coli
Unicellular, no membrane bound organelles
Gram negative
What is the most common aerobe in lower mammalian intestine?
E.coli
Biofuels
Production of proteins
Recombiant DNA
E.coli is used for all of these
OKAY
What discoveries were E.coli used for?
Genetic code Transcription Gene regulation DNA replication Restiction enzymes
What are the 2 limitation of E.coli as a model?
More distantly related than eukaryotic models
Limited phenotypic range
What is the best characterized eukaryote and fungus?
Saccharomycyes cerevisae- budding yeast
Saccharomycyes cerevisae
How many chromosomes
How long is genome in Mbase
How many genes
16 chromosomes
13Mbase genome
6000 genes
What is Saccharomycyes cerevisae life cycle?
1.5-2h
Name 4 benefits of Saccharomyces Cerevisiae
Small, easy to grow, large number of offspring
Haploid and diploid forms
Highly efficient genetic transformation, plasmids
Manipulation of mitochondrial DNA(!)
Name 3 parts of Saccharomyces Cerevisiae life cycle
Mating Sporulation - severe starvation- germination
How long is the Saccharomyces Cerevisiae in um?
6um
When was Saccharomyces Cerevisiae most recent ancestor with humans?
1.5BYA
What were the Saccharomyces cerevisiae nobel discoveries
Cell division cycle (Hartwell 2001)
Telomerase (Szostak 2009)
Vesicular Trafficking (Shekman 2013)
Autophagy (Ohsumi 2016)
What are the 3 limitations to Saccharomyces cerevisiae
as a model organism for humans
More distantly related than animal models
Limited phenotypic range
Essentially unicellular with limited cell signalling
C.elegans
How many chromosomes
How long is genome in Mbase
How many genes
6 chromosomes
100Mbase genomes
20000 genes
How long is a C.elegan life cycle?
3 days
Are C.elegans hemaphrodites?
Which type of reproduction doe they undergo?
Hermaphrodites (XX) and males at low freq. (XO)
Asexual and sexual reproduction
Benefits of C.elegans as a model
Small, easy to grow, large number of offspring
Transparent
Highly stereotypical development & organization
RNAi (including via E. coli expression), genetic manipulation
How longs are C.elegans?
1mm
When was the C.elegans most common ancestor with humans?
900 MYA
We know the lineages of how many somatic cells and neurons in the C.elegan?
ALL 959 somatic cells
302 neurons
Name 4 limitations to C.elegans as a model organism
More distantly related than vertebrate models
Fewer human disease gene homologues than flies or vertebrates
Simpler body plan and brain
More limited phenotypic range
Drosphilia
How many chromosomes
How long is genome in Mbase
How many genes
4 chromosomes
165Mbase genome
14000 genes
How long is the Drosophila life cycle?
10-14 days
How many Drosophila genes have human homologues?
61%
How long are Drosophila?
3mm
When was the Drosophila most recent common ancestor with humans?
900 MYA
What has been fully characterized in Drosophillia?
Brain Morphology
What is different in Drosophila compared to other models?
No cryopreservation
Dani Rerio - fish
How many chromosomes
How long is genome in Mbase
How many genes
25 chromosomes
1.8 Gbase genome
26,000 genes
Do danio reio have sex chromosomes?
NO
sex determining loci and environmental input
How long is a Danio rerio life cycle?
3m
Danio rerio are transparent,
Haploid and gynogenetic diploids can be created
OKAY
How long is a Danio rerio
2.5cm
When was DAnio rerio most recent common ancestor with humans?
450MYA
Name limitations of the Danio Rerio model
More distantly related than mammalian models
Aquatic
Generation time is longer than that of mouse
More expensive than worms or flies
More ethical considerations than flies or worms
High throughput screening is easier in worms and flies
Mus Musculus- mouse
How many chromosomes
How long is genome in Mbase
How many genes
20 chromosomes
2.5Gbase genomes
23,000 genes
How long is the life cycle of a Mus musculus
2years
How long are mus musculus and what is their wight?
7-11 cm
20-25g
How many genes of Mus musculus have human homolgues?
99%
When was Mus musculus most recent common ancestor with humans?
90MYA
Limitations of Mus musculus as a model
Size difference and life span difference with humans
Life style difference with humans (nocturnal, different sensory bias)
Brain is less complex than human brain
More expensive than fish or invertebrates
Limited number of offspring
Embryos are difficult to phenotype in womb
Ethical considerations are more restrictive
Difficult to do high throughput (genetic) screening
