6. VL

Question 1

The visual system of Drosophila is made of…

Answer 1

2 compound eyes:

~800 ommatidia in regular pattern (image formation) + 3 ocelli (lens, few photoreceptors, pigment cells)

Question 2

What are the components on an ommatidium?

Answer 2

~20 cells, with 8 photo- receptor (R) cells in characteristic pattern
bristle, cornea, pseudocone, cone cells, rhabdomere, photoreceptor, cone cell process, photoreceptor, cone cells, cone cell pedicel, axon, basal lamina

Question 3

The photoreceptor cells are…

Answer 3

…epithelial cells

Question 4

Some facts about the rhapdomer?

Answer 4

~ 30,000 microvilli
= light or waveguide, trapping axially directed light
contains rhodopsin (~1000/microvillus) & the phototransduction machinery
100-μm-long rhabdomere is made up of toothbrush-like stacks of membrane called microvilli.

Question 5

Major research topics on the Drosophila compound eye are…

Answer 5

• Organogenesis
• Signaltransduction
• Development of apico-basal cell polarity
• Developmentofplanarcellpolarity
• Phototransduction cascade
• Loss-of-function mutations