3: genetic model organisms for (cancer) research

Question 1

what are important characteristics of genetic model organisms?

Answer 1

• Simplicity
• genetic toolbox available
• genetic conservation
• versatile

Question 2

why is simplicity good in research?

Answer 2

makes it easier for researchers to manipulate genes and observe the effect it hase on the organism

Question 3

why is genetic toolbox availabilit ygood in research?

Answer 3

gives ability to produce transgenic animals or plants, allows to modif yspecific genes and study their function

Question 4

why is genetic Conservation good in research?

Answer 4

Many similar genes present in different species, can make inference about the gene in other species

Question 5

why is Versatile good in research?

Answer 5

choosen for versatitty and suitability for specific research questions
Unique advantage or disadvantages per model

Question 6

Where refers genotype to?

Answer 6

the complete set of an Individual’s inherited genes
recessive and dominant genes or eventueel mutations

Question 7

Where does the phenotype refer to?

Answer 7

the observatie physical and behavioral traits
result from genotype and environment

Question 8

What is reverse genetics

Answer 8

the process of identifying the gene responsible for a phenotype

Question 9

What is forward genetics?

Answer 9

identifying the phenotype of an organism, working backwards to determine genetic basis of that phenotype

Question 10

what are perturbations (disruption) of gene expression?

Answer 10

DNA-level → knock out
RNA-level → gene knock-down → temporarily

Question 11

how is the transgenic animal model C. elegans made?

Answer 11

• design plasmid with gene of intrest → needs regulatory ellement
• choose a Co - injection marker → for identification like rolling
• prepare the worms → grow to L4 stage
• Injection → plasmid and co - injection Marker
• Screening

Question 12

what is saccharemyges pombe?

Answer 12

fission yeast, unicellular eukaryotic organism

Question 13

features of fission yeast?

Answer 13

• fast grouth rate
• ease of genetic manipulation
• Similarity to higher eukaryotes
• Accessibility to microscopy

Question 14

for what is S. pombe use

Answer 14

to understand basic biological processes as cell division - CDK

Question 15

features of Drosphila Melanogaster as an animal model?

Answer 15

• short generation time
• large number off offspring
• Easy to culture
• Well-studied genome
• simple but complex

Question 16

features of the Zebrafish as an animal model?

Answer 16

• Vertebrate
• circulatory system
• regeneration
• well-developed immune system

Question 17

features of Mouse as an animal model?

Answer 17

• strong homology with humans
• (relative) short lifespan
• Manipulation of the genome

Question 18

what is gene targeting or homologous recombination?

Answer 18

produce knock out mice by inserting artificial DNA into Chromosomes containing nuclei of Es cells
( specifically manipulating a gene in the nucleus of ES cell )

Question 19

What is P53?

Answer 19

tumor_suppressor gene

Question 20

how is intestinal epithelium built up (renewal)?

Answer 20

Every Few days renewed
cells in crypts devide, move ip to the villus, differentiate, shed after life span

Question 21

what is often mutated in colorectal cancer?

Answer 21

APC

Question 22

How does the Wnt signaling cascade work?

Answer 22

Wnt secreted → binds frizzled → binds inactivated Dishevelled → CK1 and Gsk3 bind to LRP and activate it by phosphorylation → APC lets go → Creates stable Beta- catenin → migraties to nucleus → displaces Grucho and Associates with co-activator → transcription Wnt target genes

Question 23

What happens when there is no Wnt-signal?

Answer 23

APC complex gives unstable Beta catenin →proteaseme degrates Beta- catenin → transcription Wnt target genes off