Losing sight and visionHow does the eye work?

What is retinitis pigmentosa?

Bioinformatics: life in the computer – basic variant

Seeing

What can we see?

How many tints do you see?

1

1

2

2

3 4

4 4

4 65 5

Spiral or separate circles?

How does the eye work?

Cone and rod cells

Bar and rod cells

Test:• Keep the paper strip close to your eyes.

With the orange dot in the middleLook with both eyes at the orange dot.

• Close your right eye. Now look with your left eye at the red dot.

• Move the paper strip slowly away from you. Keep looking with your left eye at the red dot!

• What do you see?The middle dot appears on a given in your view. But now it is grey! Only when you the paperstrip further away it suddenly flashes on orange.

?

Zooming inFrom organism to molecule

In (almost) every cell DNA is located

DNA is the blueprint of a protein.

The shape and function of proteins are responsible for the the function of organels and cells.

The cells determine how the tissue works, how the organ functions and ultimately how the entire organism is alive.

Retinitis PigmentosaRP is an eye disease in which the cone cells (the cells that display

contrast) are damaged. Most RP-patients complain about night blindness which can transcend into total blindness.Bron: erfelijkheid.nl

Practical

Lets get to work!• Log in on the computer.• Go to this website:

www.bioinformaticaindeklas.nl/lesmateriaal/rp/rp.html• Click on ‘Start practical’ in the menu• Follow the instructions on the screen• Write down your answers on the answersheet.

• Compare genes• Find mutations• Alter the 3D stucture of a protein

What are we going to do?

Functioning of the eye

Retinal is activated by light.Active retinal procedes a signal to the brain

Sight!

Functioning of the eye

sight!

Due to some mutations in rhodopsine, retinal does not have enough space to bend.Therefore no signal can be transferred to the brain

Retinal in rhodopsine

Retinal in rhodopsine

This is the inactive retinal.During activation of retinal the molecule becomes straight.

The helices alter their conformation by bending slightly

Mutations in rhodopsine: Ser186Pro, Ala292Glu en Lys296Glu

296296296296

292292292292

186186186186

Mutations in rhodopsine: Met207Arg

Conclusion

Is it still possible to activate retinal?

Does the unborn child have Retinitis Pigmentosa?

Statement

Retinitis Pigmentosa becomes really disturbingwhen you turn older (35+).

Do you want to know in this stage your life if you are a carrier of this disease?

And how about knowing susceptibility for cancer?