Svojstva i uloga mukoznog sloja na kutikuli oklopljenih dugoživaca (Tardigrada: Heterotardigrada)

master's thesis

• Title (english): Properties and function of mucous coat on the cuticle of armoured tardigrades (Tardigrada: Heterotardigrada)
• Author: Siniša Habazin
• Mentor: Vesna Svetličić (mentor)
• Mentor: Renata Matoničkin Kepčija (mentor)
• Committee member: Renata Matoničkin Kepčija (predsjednik povjerenstva)
• Committee member: Vlasta Ćosović (član povjerenstva)
• Committee member: Nenad Buzjak (član povjerenstva)
• Committee member: Sandra Radić Brkanac (član povjerenstva)
• Committee member: Mladen Juračić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2014-09-09, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Dugoživci su mikroskopski beskralježnjaci koji nepovoljne uvjete u okolišu, poput isušivanja, preživljavaju ulaskom u reverzibilno ametaboličko stanje kriptobioze. Tijelo im prekriva višeslojna kutikula na čijoj je površini mukozni sloj. Cilj ovog rada bio je odrediti sastav, raspored, morfologiju i nanomehanička svojstva mukoznog sloja na kutikuli oklopljenog dugoživca Echiniscus testudo tehnikama bojenja Alcian-modrilom, koloidnim željezom, Nilskim crvenilom i Coomassie briljant plavim, Ramanovom spektroskopijom, pretražnom elektronskom mikroskopijom i mikroskopijom atomskih sila. Materijal mukoznog sloja, u kojem su dokazani mukopolisaharidi, lipidi i proteini, lokaliziran je pretežno u udubljenjima i zonama pregiba dorzalne kutikule. Mikroskopijom atomskih sila oslikana je površina suhe i hidratizirane kutikule u nativnom stanju te je nađeno da se mukozni sloj, građen od kuglastih struktura, prilikom isušivanja skuplja u nepravilne nakupine. Analizom krivulja ovisnosti sile o udaljenosti dobiveni su podaci o nanomehaničkim svojstvima mukoznog sloja i same kutikule. Na temelju rezultata zaključeno je da mukozni sloj ima zaštitnu ulogu i postavljena je hipoteza prema kojoj on djeluje kao brtvilo tanjih dijelova kutikule smanjujući transpiraciju anhidrobionata.

Abstract (english)

Tardigrades are microscopic invertebrates which inhabit terrestrial, freshwater and marine ecosystems. They survive adverse environmental conditions, e.g. dessication, by entering into reversible ametabolic state called cryptobiosis. Body is covered with multilaminated cuticle overlain by mucous coat. Aim of this research was to determine composition, distribution, morphology and nanomechanical properties of mucous coat on the cuticle of armoured tardigrade Echiniscus testudo using Alcian blue, colloidal iron, Nile red and Coomassie brilliant blue staining techniques, as well as Raman spectroscopy, scanning electron microscopy and atomic force microscopy. Mucous coat was found to be composed of mucopolysaccharides, lipids and proteins. It was localized mostly in dorsal epicuticle flexion zones and depressions. Atomic force microscopy imaging revealed that hydrated mucous coat, composed of globular structures, settles into an irregular aggregations upon drying. According to results obtained, protective role of mucous coat was infered; together with hypotesis according to which mucous coat acts as a sealant for thinner regions of the cuticle, thus reducing transpiration of anhydrobionts.

• Keywords: meiofauna; integument; mikroskopija atomskih sila; elektronska mikroskopija; Ramanova spektroskopija; nanomehanička svojstva
• Keywords (english): meiofauna; integument; atomic force microscopy; electron microscopy; Raman spectroscopy; nanomechanical properties
• Language: croatian
• URN:NBN: urn:nbn:hr:217:657275
• Study programme: Title: Enviromental Sciences; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra struke znanosti o okolišu (magistar/magistra struke znanosti o okolišu)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-04-25 08:54:22