magistrsko delo
Jošt Prevc (Author), Marko Kreft (Reviewer), Gregor Belušič (Mentor)

Abstract

Gospica (Argynnis paphia, Linnaeus 1758) je metulj gozdne krajine iz družine pisančkov (Nymphalidae). Z elektrofiziološkimi, anatomskimi in optičnimi metodami smo raziskali in primerjali mrežnico obeh spolov. Z mikroelektrodami smo izmerili spektralno in polarizacijsko občutljivost fotoreceptorjev ter na poltankih rezinah izmerili absorbanco zaščitnih in filtrskih pigmentov. Tako kot pri ostalih pisančkih se v posameznem omatidiju nahaja 9 fotoreceptorjev (R1–9). Receptorja R1 in 2 sta občutljiva na UV (λmax = 335 nm) in modro (λmax = 435 nm); pri samcih sta občutljiva tudi na zeleno svetlobo (λmax ⡈ 535 nm). Celice R3–8 imajo maksimalno občutljivost v zelenem (λmax = 545 nm) in pri samcih tudi v oranžnem (λmax = 575 nm) delu spektra. Bazalna celica R9 ima vrh občutljivosti premaknjen v rdeč (λmax = 615 nm) del spektra. Občutljivost R9 smo lahko izmerili le s selektivno adaptacijo zeleno občutljivih fotoreceptorjev z rdečo oponenco. Fotoreceptorji namreč med seboj tvorijo inhibitorne sinapse in s tem zožijo spektralno občutljivost, kar izboljša ločljivost barvnega vida. Odkrili smo, da se pri obeh spolih pojavljata oponentna para UV+G– in B+G–, medtem ko imajo samci še tri dodatne pare B+G+, B+Y– in G+R–. V ventralnem delu mrežnice samcev smo odkrili tudi celice, ki najverjetneje koekspresirajo modri in zeleni opsin in tvorijo oponentni par B+G+R–. Na histoloških preparatih smo pokazali, da se pri obeh spolih v distalnem delu mrežnice vseh omatidijev nahajajo rdeči filtrski pigmenti (RFP). Pri samcih se RFP v nekaterih omatidijih nahajajo tudi v proksimalnem delu mrežnice, ki spektralno filtrirajo svetlobo v proksimalni mrežnici in tako premaknejo vrh občutljivosti R9 v rdeč del spektra. Samice imajo trikromatski barvni vid, pri samcih pa predpostavljamo, da sistem RFP in funkcionalnega receptorja R9 ustvari dodaten rdeč kanal in s tem fiziološko osnovo za tetrakromatski vid.

Keywords

gospica;barvni vid;sestavljene oči;omatidij;fotoreceptor;pigment;magistrska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [J. Prevc ]
UDC: 591
COBISS: 138674435 Link will open in a new window
Views: 39
Downloads: 12
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: English
Secondary title: Color vision in the silver-washed fritillary (Argynnis paphia, Lepidoptera: Nymphalidae)
Secondary abstract: The Silver-washed fritillary (Argynnis paphia, Linnaeus 1758) is a woodland butterfly from the family Nymphalidae. Using electrophysiological, anatomical and optical methods, we examined and compared the retina of both sexes. We measured the spectral and polarization sensitivity of photoreceptors with microelectrodes and measured the absorbance of screening and filtering pigments in semi-thin sections. Each ommatidium has 9 photoreceptors (R1–9). Receptors R1 and 2 are sensitive to UV (λmax = 335 nm) or blue (λmax = 435 nm); in males also to green (λmax = 535 nm) light. R3–8 have maximum sensitivity in the green (λmax = 545 nm), in males also in the orange (λmax = 575 nm). The basal cell R9 has a sensitivity peak red shifted to 615 nm. The sensitivity of R9 could only be measured by selective adaptation of green-sensitive photoreceptors with red opponency. Namely, the photoreceptors form mutual inhibitory synapses and thereby narrow their spectral sensitivity, which improves the resolution of color vision. In both sexes the opponent receptor pairs UV+G– and B+G– occur, while males have three additional pairs B+G+, B+Y– and G+R–. In the ventral part of the male retina, we found cells that most likely co-express blue and green opsin and form the opponent pair B+G+R–. In histological preparations, we showed that red screening pigments (RSP) are found in the distal part of the retina of all ommatidia in both sexes. In males however, RSP in some ommatidia that are located in the proximal retina spectrally filter the light incident in the proximal retina and thus shift the R9 sensitivity peak to the red part of the spectrum. Females have trichromatic color vision, but in males we assume that the system of RSP and functional receptor R9 creates an additional red channel and thus the physiological basis for tetrachromatic vision.
Secondary keywords: Silver-washed fritillary;colour vision;compound eyes;ommatidium;photoreceptor;pigment;master thesis;Metulji;Univerzitetna in visokošolska dela;
Type (COBISS): Master's thesis/paper
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za biologijo
Pages: 1 spletni vir (1 datoteka PDF (X, 49 str., [1] str. pril.))
ID: 17632290