20.500.12556/RUL-138488 Fiziološke in anatomske značilnosti mrežnice zlatookega obada Physiological and anatomical properties of deerfly retina Zlatooki obadi (Chrysops sp.) se v veliki meri zanašajo na vid. Samice ga uporabljajo predvsem za iskanje plena in iskanje vodnih teles, ki jih potrebujejo za razmnoževanje. Vid poddružine Chrysopsinae še ni podrobno raziskan, zato smo ga analizirali z mikroskopskimi in elektrofiziološkimi tehnikami. Mrežnica zlatookih obadov je občutljiva pretežno na modro svetlobo in ne na zeleno, kot je pogosto pri mlajših taksonomskih skupinah iz družine obadov (fam. Tabanidae). Pri perifernih fotoreceptorjih je bila polarizacijska občutljivost redka, opazili pa smo jo pri centralnem fotoreceptorju, zato sklepamo, da je vloga prvih zaznava gibanja in slednjih polarizacije svetlobe. Fluorescenca fotoreceptorjev kaže, da v mrežnici najdemo dva tipa omatidijev – pale in yellow. Ta dva tipa sovpadata z orientacijo rabdomer R7, ki so pri pale receptorjih vodoravne, pri yellow pa navpične (vzporedne z dorzoventralno osjo oči). Oba tipa omatidijev sta naključno razporejena po mrežnici. Kornea zlatookih obadov je značilne kovinsko zelene barve s temnimi lisami. Predpostavljali smo, da njena obarvanost vpliva na zaznavo svetlobe, a smo to hipotezo ovrgli, saj tovrstnega vpliva nismo uspeli zaznati z elektrofiziološkimi meritvami. Prav tako obarvanost kornee ni povezana s celično sestavo mrežnice, saj sta oba tipa omatidijev razporejena neodvisno od barve kornee. Obarvana kornea torej nima optične vloge, ni povezana z ustrojem mrežnice, in ima verjetno signalno vlogo pri vidni komunikaciji. Deerflies (Chrysops sp). strongly rely on vision. Females use it primarily to search for prey and water bodies they need for reproduction. The species of the Chrysopsinae subfamily have not yet been studied in detail, so we analysed it with microscopic and electrophysiological techniques. The retina of deerflies is sensitive mainly to blue light and not to green, as is often the case with younger taxonomic groups from the horsefly family (fam. Tabanidae). Polarization sensitivity was rare in peripheral photoreceptors, but was observed in the central photoreceptor, so we conclude that the role of the former is the perception of motion and the latter the polarization of light. Fluorescence of photoreceptors indicates that two types of ommatidia are found in the retina – pale and yellow. These two types coincide with the orientation of rhabdomere R7, which is horizontal in the pale ommatidial type and vertical (parallel to the dorsoventral eye axis)in yellow. Both types of ommatidia are arranged stochastically in retina. The cornea of deerflies is of characteristic metallic green colour with dark spots. We assumed that its coloration affects the detection of light, but we refuted this hypothesis, as we were unable to detect such an effect with electrophysiological measurements. Also, corneal staining is not related to the cellular composition of the retina, as both types of ommatidia are distributed irrespective of the corneal colour. The stained cornea therefore has no optical role, is not related to the structure of the retina, and probably has a signalling role in visual communication. biologija Chrysops sp. sestavljene oči omatidij obarvanost kornee biology Chrysops sp. compound eyes ommatidium cornea coloration true true false [T. Lončar] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2022-07-23 07:15:03 2022-07-23 07:15:17 2022-09-15 04:16:49 0000-00-00 00:00:00 2022 0 Ljubljana 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 591 205358 120278531 23342.pdf 23342.pdf 1 22226114A4537A0A8234FAA4513033B1 a562c8746a9db4eb64e4e3e3c0af0c788a96e6fe102ea9a776b3f8662ff506da 30986340-0a46-11ed-8aca-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=158851 Biotehniška fakulteta 0 0 0