Učinak UVB-zračenja i norflurazona na zelenu hidru (Hydra viridissima Pallas, 1766) i smeđu hidru (Hydra oligactis Pallas, 1766)

master's thesis

• Title (english): Effects of UVB radiation and norflurazon on green hydra (Hydra viridissima Pallas, 1776) and brown hydra (Hydra oligactis Pallas, 1776)
• Author: Ana Matijević
• Mentor: Goran Kovačević (mentor)
• Mentor: Petra Korać (mentor)
• Committee member: Petra Korać (predsjednik povjerenstva)
• Committee member: Božena Mitić (član povjerenstva)
• Committee member: Maja Matulić (član povjerenstva)
• Committee member: Goran Kovačević (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2018-09-28, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Postoje dokumentirana istraživanja o postojanju tumora na tijelu hidri, a ovo je
prvo istraživanje gdje su jedinke hidre izlagane tretmanu UVB-zračenjem i/ili norflurazonu s
namjerom da se izazovu tumori. Jedinke zelene hidre (Hydra viridissima Pallas, 1766) i
jedinke smeđe hidre (Hydra oligactis Pallas, 1766) ili obje vrste zajedno izlagane su
norflurazonu koncentracija 2x10-7 mol/L ili 2x10-6 mol/L. Dio hidri izložen je norflurazonu i
zračen UVB-zračenjem valne dužine 254 nm 2 minute. Drugi dio pokusa je rađen tako da su
hidrama dodane suspenzije slobodnoživuće alge Chlorella vulgaris (CV) i endosimbiotske alge
Mychonastes homosphaera (CZ10) ili obje alge zajedno. Hidre s dodatkom algi su izlagane
norflurazonu i zračene na isti način kao u prvom dijelu pokusa. Pratile su se morfološke
promjene hidri: migracija, odgovor na mehanički podražaj, oblik tijela, oštećenje lovki,
nespolno (pupanje) i spolno razmnožavanje te smrtnost. U eksperimentalnim posudicama s
dodatkom algi pratile su se još boja otopine i prisustvo nakupina algi. Migracija hidri, promjena
oblika tijela pretežno iz relaksiranog u kontrahirani oblik i spolno razmnožavanje bili su prvi
znakovi izbjegavanja štetnog učinka UVB-zračenja ili norflurazona. Histološke promjene
pratile su se svjetlosnim mikroskopom i brojale su se stanice ektoderma, gastroderma,
intersticijske stanice, zimogene stanice i žarne stanice, a mjerena je i debljina mezogleje.
Ugibale su samo zračene jedinke zelene hidre. Pri višoj koncentraciji norflurazona i u svim
zračenim hidrama uočena su velika oštećenja u strukturi tkiva hidri. Zračenje je prouzročilo
izrasline na lovkama i na tijelu hidre ili specifične rašljaste lovke

Abstract (english)

The occurence of tumors on the body of hydra has already been reported in
researches but this is the first study in which the individuals of symbiotic green hydra and nonsymbiotic
brown hydra were exposed to UVB-radiation and /or norflurazon in order to induce
tumors. The individuals of green hydra (Hydra viridissima Pallas, 1766) and brown hydra
(Hydra oligactis Pallas, 1766), either separately or both species together, were treated with
norflurazon in concentrations of 2x10-7 mol/L or 2x10-6 mol/L. A group of hydra was treated
with norflurazon and exposed to UVB-radiation with a wavelenght of 254 nm for 2 minutes.
The second part of the experiment was performed by adding suspensions of free-living algae
Chlorella vulgaris (CV) or endosimbiotic Mychonastes homosphaera (CZ10) and both algae
together. The group of hydra with algae suspension was treated with norflurazon and exposed
to UVB-radiation in the same way as in the first part of the experiment. The following
morphological changes of hydra were observed: migration, response to mechanical stimuli,
body shape, damage to tentacles, asexual (budding) and sexual reproduction, and mortality. The
experimental dishes with algae suspension were monitored for the change of solution color and
the presence of algae blobs. Migration, change of body shape from relaxed to predominantly
contracted, and sexual reproduction were identified as the first evasion signs of the deleterious
effects of UVB-radiation and norflurazon. Histological changes were detected by light
microscope, while ectoderm, gastroderm, interstitial, zymogen and cnidocyte cells were
counted. The thickness of mesoglea was measured. Mortality was present in the individuals of
green hydra that were exposed to UVB-radiation. Severe damage to the structure of hydra tissue
was noted in hydra treated with high concentrations of norflurazon and in all hydra exposed to
UVB-radiation. Radiation caused tissue growths on both tentacles and body of hydra as well as
specific fork-shaped tentacles in hydra.

• Keywords: hidra; UVB-zračenje; norflurazon; simbioza; migracija; morfološke i histološke promjene; izrasline
• Keywords (english): Hydra; UVB-radiation; norflurazon; symbiosis; migration; morphological and histological changes; tissue growth
• Language: croatian
• URN:NBN: urn:nbn:hr:217:536389
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra molekularne biologije (magistar/magistra molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-11-20 11:34:40