the parallel visual world of an insect
DESCRIPTION
THE PARALLEL VISUAL WORLD OF AN INSECT. Gregor Belušič, Peter Stušek. University of Ljubljana, Biotechnical Faculty, Department of Biology. OWL FLY – INTERESTING ANIMAL FROM. THE ASPEST OF VISION. bipartite eye. ABSORBTION CHARACTERISTICS OF RHODOPSIN AND METARHODOPSIN. triggering of - PowerPoint PPT PresentationTRANSCRIPT
THE PARALLEL VISUAL WORLD OF AN INSECT
Gregor Belušič, Peter StušekUniversity of Ljubljana, Biotechnical Faculty, Department of Biology
300
1.0
1.5
EEmax
0.5
0400 500 600 nm300
1.0
1.5
EEmax
0.5
0400 500 600 nm
R1.0
1.5
EEmax
0.5
0400 500 600 nm
R1.0
1.5
EEmax
0.5
0400 500 600 nm
R
300
1.0
1.5
EEmax
0.5
0400 500 600 nm
R
300
1.0
1.5
EEmax
0.5
0400 500 600 nm
ABSORBTION CHARACTERISTICS OFRHODOPSIN AND METARHODOPSIN
R
300
1.0
1.5
EEmax
0.5
0400 500 600 nm
M
R
300
1.0
1.5
EEmax
0.5
0400 500 600 nm
MMM
exclusive sensitivity in UV
triggering ofsignalling cascade
11E-31E-41E-51E-6
I/Imax
20
15
10
5
0
Intensity curve of a photoreceptor from the VL eye
Hill functionV
Vmax
= In
In
In
slope: n=1.25dynamic range=2 log units
0,10,01
mV
STEEP RESPONSE FUCTION OF UV RECEPTOR
narrow dinamicrange
light intensity
receptorresponse
activation ofsignallingcascade
VISUAL PIGMENT CYCLE
(protein)
(rhodopsin) (active rhodopsin)
Inactivation of metarhodopsin accomplished by arrestin (arr)
high affinitylow affinity
CONCLUSIONS
1. The bipartite eye of owl-fly (Ascalaphus macaronius) is developed for catching the preys against the sky.
2. In order to accomplish this job the visual cells are exclusive sensitive to UV light to lover the ambiguous background of the sky and to enhance the visual contrast.
3. The visual cells operate at high light level therefore they pushed to the “edge” of sufficient arrestin content which is elevated.
4. Using UV light by just a part of the eye ot the whole eye is probbably the general strategy for the animals (dragon flies, drones, may flies...) whose life depends on cathing the preys or mates against the sky .
ABSORBTION CHARACTERISTICS OFRHODOPSIN AND METARHODOPSIN
RR
M
300
1.0
1.5
EEmax
0.5
0400 500 600 nm
RR
M
300
1.0
1.5
EEmax
0.5
0400 500 600 nm
RR
M
300
1.0
1.5
EEmax
0.5
0400 500 600 nm
RR
M
300
1.0
1.5
EEmax
0.5
0400 500 600 nm
RR
M
300
1.0
1.5
EEmax
0.5
0400 500 600 nm
RR
M
300
1.0
1.5
EEmax
0.5
0400 500 600 nm
RR
M
300
1.0
1.5
EEmax
0.5
0400 500 600 nm
RR
M
300
1.0
1.5
EEmax
0.5
0400 500 600 nm
triggers thesignalling cascade
adaptingpulse, 30s 460 nm, 30s
400 nm
395 nm
390 nm
385 nm
380 nm
16%
25%
35%
47%
55%
wavelength metarhodopsin
R
300
1.0
EEmax
0.5
0400
R
300
1.0
EEmax
0.5
0400
PDA AT DIFFERENT
FORMATION OF SUPERPOSITION IMAGES
object
superimposedpictures onrhabdome
clear cone
chrystallinecone
RR
M
1,0
1,5
EEmax
0,5
0400 500 600 nm
M
R
RR
M
1,0
1,5
EEmax
0,5
0400 500 600 nm
M
R
RR
M
1,0
1,5
EEmax
0,5
0400 500 600 nm
M
R
RR
M
1,0
1,5
EEmax
0,5
0400 500 600 nm
M
R
EFFECT OF FOTORECONVERSION
RR
M
3 0 0
1 ,0
1 ,5
EE m a x
0 ,5
04 0 0 5 0 0 6 0 0 n m
R
R
M a
3 0 0
1 ,0
1 ,5
EE m a x
0 ,5
04 0 0 5 0 0 6 0 0 n m
R
R
M i-A rr
3 0 0
1 ,0
1 ,5
EE m a x
0 ,5
04 0 0 5 0 0 6 0 0 n m
R i-arrR
M a
3 0 0
1 ,0
1 ,5
EE m a x
0 ,5
04 0 0 5 0 0 6 0 0 n m
A rr
activ atio n o fs ig na ling cascade
U V
b lueligh t
h
h
SKY RADIANCE
200 300 400 500 600 700 800 900 1000
rela
tive
qua
ntum
num
ber,
Qre
l
above atmosphere
wavelangth (nm)
Earth surfacethe region ofsensitivity of DF eye of L. macaronius