Drosophila proliferation and growth

18 important questions on Drosophila proliferation and growth

What is striking about proliferation in the imaginal discs?

They somehow know to what size they need to grow, no matter what you do, their size does not change without gene mutations

2 theories for the growth size of imaginal discs being always the same

1. Gradient threshold: multiple morphogens together induce proliferation in some but not all cells
2. Cells somehow know how many of them there are

What is a clonal screen

Inducing a KO in an animal, but once they are adult so embryonic lethal is filtered out
  • Higher grades + faster learning
  • Never study anything twice
  • 100% sure, 100% understanding
Discover Study Smart

What organ development is most interesting to research

Eye development, very clear pattern, easy to score. Also easy to see that you could find multiple phenotypes within an animal (one WT and one mutated eye) so differences between individuals do not matter

What is the main component of the fly eye

Ommatidia

How does the eye develop

Disc is connected to antenna disc. Differentiation is from posterior to anterior in a wave, asynchronous. A morphogenetic furrow functions as an organizer, undifferentiated cells undergo apoptosis

What gives fly eyes their colour

R7 neuron is above R8, R7 is red because of pigment protein White (mutant phenotype is white)

What is the substrate of Hippo complex

Yorkie, gets phosphorylated by this complex, has an inhibiting effect because it cannot enter the nucleus and is instead bound by 14-3-3 proteins

What protein does Yorkie interact with

Scalloped. Yorkie is the transcriptional activator, while Scalloped is the TF

What does active Scalloped do

More Diap-1 expression -] apoptosis
More cyclin-E -> cell cycle

By what proteins is Hippo regulated

Merlin and expanded

What are Merlin and Expanded

Tumour suppressors

Molecular function of Merlin and Expanded

Are part of the FERM-tail complex. Protein unfolds, FERM binds to membrane while tail interacts with actin. Active Merlin promotes Warts and Yorkie phosphorylation

How is FERM localized to membrane

By Crumbs, which has a FERM binding motif. It is a transmembrane protein that interacts with FERM intracellular. Is helps with binding Expanded to the membrane.

What happens in Crumbs mtutants

Merlin and Expanded get mislocalized, Hippo complex does not work properly

Intracellular Hippo activation

Through cytoskeleton tension. The less tension, the more proliferation could be needed to fill up gaps. So mechanical regulation

How does mechanical regulation of Hippo work

Ajuba is present at adherens junctions. When tension is high, junction unfolds, exposing a-catenine. This recruits Ajuba and Warts to the membrane, so away from Hippo complex, meaning Yorkie gets active and proliferation starts

One other place where Hippo is active?

Liver size control. Regenerative tissue, so also needs to know when to stop growing

The question on the page originate from the summary of the following study material:

  • A unique study and practice tool
  • Never study anything twice again
  • Get the grades you hope for
  • 100% sure, 100% understanding
Remember faster, study better. Scientifically proven.
Trustpilot Logo