4. VL

Question 1

What do you have to justify when you’re planing an experiment in an animal protocol?

Answer 1

Scientific justification that the project is necessary considering the state of the art.
Scientific justification that there are no alternative methods available
Scientific explanation that expected results of the project are not sufficiently known

Question 2

What do you have to talk about in the animal protocol?

Answer 2

Maintenance conditions and preparation of animals for the experiment,
Detailed practical description of the research plan including methods of anaesthetization and duration,
Description and judgement of the severity and duration of pain or suffering, Ethical justification…

Question 3

An experiment with animals is prohibited in general if…

Answer 3

…experiments related to the development of tobacco

products, detergents or cosmetics

Question 4

An experiment with animals is totally prohibited if…

Answer 4

… it is related to the development and testing of weapons, ammunitions, and related equipment.

Question 5

Henrietta Lacks was treated at Johns Hopkins Hospital against cervical cancer.
What had been the big deal of HeLa cell line?

Answer 5

Without her permission or knowledge, cells were taken from her cervix and an immortal cell line (the HeLa cell line) was produced.
many discoveries with these cells
2013, her genome had been sequenced and published without the knowledge of her family

Question 6

Embryonic Steam Cells (ESC) differentiate themselves to…

Answer 6

Mesoderm (middle layer), Endoderm (inner layer), Ectoderm (external layer)

Question 7

How is the cell fate described in the Waddington‘s epigenetic landscape?

Answer 7

ESC starts with pluripotency –>
Differentation (normal development) –> Cell :)
linage conversion into an other cell (trans-differentiation) —> new cell
Reprogramming to ESC (pluripotency) with different TF

Question 8

How the discovery of inducible pluripotent stem cells (iPSCs) took place? (nuclear transfer)

Answer 8

Oocyte-mediated reprogramming. Differentiation state of the somatic nucleus is erased (gelöscht) after injection into enucleated oocyte (Gurdon, 1962).

Question 9

maybe a treatment with reprogramming factors after myocardial infarction can help the heart getting well again. How can this maybe work?

Answer 9

1. we have an injured heart
2. infect this heart with reprogramming factors
3. cardiac fibroblasts differentiated into cardiac muscle cells

Question 10

What is microcephalic and what is special about it?

Answer 10

it’s when your head is smaller than in other humans. it’s possible to modeling this microcephaly, when you got genetic information from the parents.

Question 11

How can you model giloblastosoma ( one of the most common tumors in human adults)?

Answer 11

start with: human ES cells –> cerebral organoid
(2 ways: transduction modell, transplant modell)
1. Transduction model: oncogene introduction in the cell with Cas9-gRNA, Donor DNA and Electroporation (methode)
the tissue is full of cancer and you can get derived organoid tumor cells
2. transplant model: take a tumor-here co-culture and let it grow on the cells –> patient derived tumor cell

Question 12

How would you create a generation of a cerebral organoid culture system?

Answer 12

let hPSCs grow an agar
taking embryoid bodies and let them grow to neuroectoderm
let the neuroectoderm grow –> neuroepithelium
taking neuroepithelium and them grow in a spinning bioreactor to a cerebral tissue

Question 13

What could you a mini-gut culture system use for?

Answer 13

experimental tool, diagnostic tool, therapeutic tool

Question 14

How can you model a Inter-organ communication?

Answer 14

organ on a chip system - lung and heart on a chip
https://www.youtube.com/watch?v=KQBK4_byRvc
https://www.youtube.com/watch?v=52IL9gemyDw
computer modelling

Question 15

How does the DePick: predicting relevant targets - method work? (working process)

Answer 15

1. take a DePick target De-convolution tool –> searching for hits and identification
2. making a protein target prediction
3. targets will be linked to phenotypic screens

Question 16

how does the DePick analysis work in general?

Answer 16

taking the suppressor compounds together, find out about what (logically) in the next step
you can see how different pathways effect each other

Question 17

what are the general questions in developmental biology?

Answer 17

• How does a single fertilized egg cell give rise to an entire embryo?
• How are different cell types determined?
• What underlies the organization of multiple cell types
into tissues and organs?
• What determines the three-dimensional body?

Question 18

What are the topics of developmental biology?

Answer 18

• How is gene expression regulated that determines the protein content of cells?
• By what mechanisms do proteins determine cell behaviors?
• How do genes provide a generative program for development?
• How is genetic information translated into molecular processes underlying intercellular signaling, cell proliferation, cell differentiation, and cell movement?

Question 19

How does a cell cycle to an adult animal (frog) takes place?

Answer 19

Egg + sperm –> Clevage –> Blastula
Gastrulation, (Gastrula) –> Neurulation (Neurula)
Tail-bud stage embryo –> Organogenesis
free swimming tadpole –> Metamorphosis (Adult)
Fertilisation …

Question 20

The development from a fertilized egg to an embryo is called…

Answer 20

Embryogenesis

Question 21

A historical perspective: Aristotle (384-322 BC) suggested two possibilities of development. Which ones?

Answer 21

a) . Everything is preformed in the embryo and simply gets bigger
b) . New structure arise progessively („epigenesis“ = „upon formation“)

Question 22

What idea of development had August Weismann (1834-1914)?

Answer 22

offspring does not inherit its form from the body (=soma) of the parent but only from the germ cells.
Changes of the body during the lifetime are not being transmitted to the germline.
–> concept of a stem cell.

Question 23

How can you distinct between germ and somatic cells?

Answer 23

Mutations in the somatic cells do not affect germ line.
Mutations in germ cells affects somatic cells and germ line.
Inheritance is through germ cells only. Mutations (red cells) will affect future generations only when they occur within germ cells.

Question 24

What was Weismann‘s theory of nuclear determination`?

Answer 24

Factors within the nucleus are distributed asymmetrically to daughter cells during cleavage and direct their future development

Question 25

2 types of development were considered: Mosaik and regulatory development. What do you know about mosaic development?

Answer 25

Weismann‘s theory of nuclear determination suggested that the fate of each cell was predetermined by factors that it received during cleavage = mosaic development
Roux‘s ablation experiment showed that killing one of the two blastomeres of a frog embryo results in one half of an embryo forming

Question 26

2 types of development were considered: Mosaik and regulatory development. What do you know about regulatory development?

Answer 26

Regulative development generally occurs in early gastrulation when cells are induced to form different structures according to the cell-cell signaling interactions in a specific area of the embryo that lead to the conditional specification of a cell’s fate.
Regulatory development was observed in sea urchin experiments performed by Hans Driesch. This finding apparently contradicted Roux‘s earlier observations in frog embryos. example: monozygotic twins

Question 27

What is the function of the Spemann’s organizer (also called Spemann-Mangold-Organisator), which was discovered by Hans Spemann (1869-1941) and his PhD student Hilde Mangold (1898-1924).

Answer 27

refers in embryology to the oldest and best-known example of an embryonic signal center.
During the development of amphibians(newts, frogs) embryo design (ontogenesis) is controlled from a particular group of cells, that “organizes” the development of all other cells.
is located in the so-called “gray crescent” of the fertilized egg. The dark colored yolk-rich part and the bright yolk-poor part are separated by the gray crescent. These regions are distributed to different cells by the cell divisions during cleavage and blastulation. Those cells that emerge from the gray crescent directly affect the development of the embryo in the dorso-ventral direction and the cell differentiation in its immediate environment by the emission of different signaling proteins.

Question 28

During growth, child is changing …

Answer 28

…shape and proportions as it grows

Question 29

What is the “fate” of a cell?

Answer 29

Fate indicates what a cell will normally develop into if not challenged with another environment (based on its position within the embryo)

Question 30

What is the “determination” of a cell?

Answer 30

Determination refers to a stable internal state of a cell that will not change even when transplanted into another environment

Question 31

When do you call a cell specified?

Answer 31

A cell is specified when it develops into a particular fate even when kept in isolation

Question 32

What means if a cell is “competent”?

Answer 32

A cell that is able to respond to an inducing signal is considered competent.
may be acquired during development by the expression of receptors or formation of gap junctions.

Question 33

Pattern formation can happen by morphogen signaling. A model for that is the The French flag model - what do you know about this model?

Answer 33

Cells can acquire an identity based on positional information. One mechanism by which this is achieved involves morphogens. Morphogens diffuse over several cell diameters and induce different cell fates at different threshold concentrations.

Question 34

Steam cells: imagen we have an unequal distribution of cytoplasmic determinants. What can happen?

Answer 34

The unequal segregation of cytoplasmic determinants during mitosis into the two daughter cells, can cause different fates.