Magnetska rezonancija - novi pristup u istraživanju ugroženih morskih školjkaša

Magnetic Resonance Imaging (MRI) is increasingly used in biology and the appearance of such imaging and structural findings devoted to endangered marine bivalves shows the recent keen interest in these research techniques. New imaging techniques are ideal for understanding the normal form of soft structures (e.g. gonad, stomach, digestive gland, muscle, gills), and identifying anatomical positions and landmarks of structures in vivo. Because of its biological importance, endangered bivalve mollusks are the subject of much research in physiology. In terms of protection of species, it seemed necessary to perform a preliminary technological evaluation of the MRI possibilities. Aim of this research was to make a preliminary exploration of the possibilities and limits of MRI for assessing anatomical structures and gonad development of the date mussel, Lithophaga lithophaga L., an endangered bivalve from Adriatic sea. This paper presents a new imaging technique used in comparative morphology, with examples of recent applications, and will present original research demonstrating a use of this technique to investigate morphological structures in endangered species. This report therefore presents the preliminary results on MR imaging of the date mussel. From the obtained images, variations in the volumes of the flesh, digestive gland, gonad and adductor muscle, and the surface of the gills could be measured during growth. Gonad measurement by MRI presents a non-destructive method and therefore makes it possible to assess live individual development as well as to compare live individuals.Magnetska rezonancija (MR) sve se više koristi u istraživanjima na području biologije. Upotreba i implementiranje ove metode u svrhu nedestruktivnog proučavanja anatomije i fiziologije ugroženih vrsta morskih školjkaša daje veliki značaj ovakvim istraživačkim tehnikama. Nove moderne tehnologije omogućavaju bolje razumijevanje građe i oblika mekih struktura (npr. gonade, želudac, probavna žlijezda, mišići, škrge), te prepoznavanje anatomskih odlika i međusobni odnos organa kod živih školjkaša. Zbog svoje biološke važnosti, ugrožene vrste školjkaša predmet su mnogih istraživanja. U okviru zaštite vrsta, potrebno je izvršiti preliminarnu procjenu tehnoloških mogućnosti MR. Cilj ovog istraživanja je napraviti prikaz mogućnosti i ograničenja primjene MR u procjeni anatomskih struktura i razvoju gonada kod prstaca, Lithophaga lithophaga L., zaštićenog školjkaša iz Jadranskog mora. Ovaj rad predstavlja primjenu moderne tehnologije u svrhu istraživanja komparativne anatomije te je, uz dosadašnja saznanja, predstavljen originalan način kako bi se istražile morfološke osobitosti ugroženih vrsta. Ovo izvješće obuhvaća preliminarne MR snimke prstaca. Na dobivenim fotografijama moguće je razlučiti i izračunati indekse mase mišića, funkciju probavne žlijezde, gonada i aduktornih mišića te škrga u različitom razdoblju razvoja školjkaša. Primjenom ove nedestruktivne metode u svrhu mjerenja rasta gonada i spolnog sazrijevanja prstaca moguće je procijeniti individualni razvoj, kao i usporediti pojedine žive jedinke

Evaluation of micronucleus and erythrocytic nuclear abnormalities in Balkan whip snake Hierophis gemonensis. Ecotoxicology 19

Abstract Over recent years, changes of erythrocytic nuclei have been increasingly used to evaluate genotoxic effects of different compounds such as polycyclic aromatic hydrocarbons (benzo-a-pyrene, naphthalene, b-naphthoflavone), heavy metals (cadmium, mercury), textile mill effluent especially in aquatic ecosystem. However, in fish, both micronuclei and erythrocytic nuclear abnormalities also appear spontaneously and their frequency can be seasonally dependent. The aim of the study was to evaluate the frequency of micronuclei (MN), nuclear abnormalities (NA) including vacuolated nuclei (VN) and cytoplasmic vacuoles (CV) in erythrocytes of Balkan whip snake Hierophis gemonensis and establish the level of spontaneous appearance during the annual cycle. Average frequency of NA was 10.89 ± 4.72% while the MN (0.03 ± 0.03%) and VN (0.04 ± 0.08%) were seldom detected. NA significantly positively correlated with MN (r = 0.319; P \ 0.05) and VN (r = 0.363; P \ 0.05). Appearance of CV did not correlate with other measured parameters and average frequency was 11.06 ± 8.33%. Significant seasonal variation was found in NA appearance with the lowest value in spring and the highest in winter. VN increase was observed in autumn. MN and CV levels varied between seasons but not significantly. Considering the biological cycle, frequency of NA, VN, MN and CV recorded in pre-hibernation/ hibernation increased compared to the active phase, but only NA elevation was significant. Although the obtained results showed differences according to sex, statistical analysis of measured parameters showed the same pattern of seasonal variation in both sexes

Evaluation of micronucleus and erythrocytic nuclear abnormalities in Balkan whip snake Hierophis gemonensis

The aim of the study was to evaluate the frequency of micronuclei (MN), nuclear abnormalities (NA) including vacuolated nuclei (VN) and cytoplasmic vacuoles (CV) in erythrocytes of Balkan whip snake Hierophis gemonensis and establish the level of spontaneous appearance during the annual cycle. Average frequency of NA was 10.89 ± 4.72 % while the MN (0.03 ± 0.03 %) and VN(0.04 ± 0.08 %) were seldom detected. NA significantly positively correlated with MN (r = 0.319 ; P < 0.05) and VN (r = 0.363 ; P < 0.05). Appearance of CV did not correlate with other measured parameters and average frequency was 11.06 ± 8.33 %. Significant seasonal variation was found in NA appearance with the lowest value in spring and the highest in winter. VN increase was observed in autumn. MN and CV levels varied between seasons but not significantly. Considering the biological cycle, frequency of NA, VN, MN and CV recorded in pre-hibernation/hibernation increased compared to the active phase, but only NA elevation was significant. Although the obtained results showed differences according to sex, statistical analysis of measured parameters showed the same pattern of seasonal variation in both sexes