Analiza kvaliteta vode reke Jablanice na osnovu zajednice vodenih makroinvertebrata

Cilj rada je da se prikažu rezultati ocene kvaliteta vode reke Jablanice (sliv Kolubare) zasnovane na prisutnoj zajednici vodenih makroinvertebrata. Jablanica je relativno kratka (25 km) desna sastavnica, koja u blizini Valjeva sa Obnicom (leva sastavnica) formira Kolubaru. Kolubara, kao poslednja veća pritoka Save, protiče kroz područje sa izraženim i različitim antropogenim uticajima. Sama Jablanica nastaje spajanjem većeg broja potoka sa obronaka planina Jablanik i Medvednik. U skladu sa zahtevima EU prilikom ocene stanja rečnih sistema neophodno je utvrđivanje referentnih uslova. Da bi se utvrdilo recentno stanje, i usaglašenost sa zahtevima za dostizanje referentnog statusa, izvršeno je ispitivanje ove reke u aprilu 2013. godine na tri lokaliteta gornjeg toka. Kao parametri za ocenu kvaliteta vode, korišćeni su sledeći pokazatelji: ukupan broj taksona, saprobni indeks (SI; Zelinka & Marvan), BMWP i ASPT skorovi, broj taksona grupa Ephemeroptera, Plecoptera and Trichoptera (EPT) i indeks diverziteta (SWI; Shannon-Wiener’s indeks). Zabeležena su ukupno 72 taksona makroinvertebrata. Kao najraznovrsnije grupe izdvajaju se Trichoptera (16 taksona) i Ephemeroptera (15 taksona). U odnosu na saprobnu vrednost, utvrđeno je da je većina prisutnih taksona osetljiva na organsko zagađenje (ksenosaprobni i oligosaprobni organizmi). Dobijene vrednosti praktično svih korišćenih pokazatelja kvaliteta vode, upućuju na veoma dobar status (klasa I), čime su ispunjeni uslovi da se ispitivani deo toka Jablanice može smatrati referentnim stanjem, za potrebe istraživanja sliva Kolubare. Puštanje u rad akumulacije u Rovnima (srednji tok Jablanice) može izmeniti zatečeno stanje, zbog čega je neophodan redovni monitoring

Imaging of glial cell morphology, SOD1 distribution and elemental composition in the brainstem and hippocampus of the ALS hSOD1G93A rat

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting motor and cognitive domains of the CNS. Mutations in the Cu,Zn-superoxide dismutase (SOD1) cause 20% of familial ALS and provoke formation of intracellular aggregates and copper and zinc unbinding, leading to glial activation and neurodegeneration. Therefore, we investigated glial cell morphology, intracellular SOD1 distribution, and elemental composition in the brainstem and hippocampus of the hSOD1G93A transgenic rat model of ALS. Immunostaining for astrocytes, microglia and SOD1 revealed glial proliferation and progressive tissue accumulation of SOD1 in both brain regions of ALS rats starting already at the presymptomatic stage. Glial cell morphology analysis in the brainstem of ALS rats revealed astrocyte activation occurring before diseasesymptoms onset, followed by activation of microglia. Hippocampal ALS astrocytes exhibited an identical reactive profile, while microglial morphology was unchanged. Additionally, ALS brainstem astrocytes demonstrated progressive SOD1 accumulation in the cell body and processes, while microglial SOD1 levels were reduced and its distribution limited to distal cell processes. In the hippocampus both glial cell types exhibited SOD1 accumulation in the cell body. X-ray fluorescence imaging revealed decreased P and increased Ca, Cl, K, Ni, Cu and Zn in the brainstem, and higher levels of Cl, Ni and Cu, but lower levels of Zn in the hippocampus of symptomatic ALS rats. These results bring new insights into the glial response during disease development and progression in motor as well as in non-motor CNS structures, and indicate disturbed tissue elemental homeostasis as a prominent hallmark of disease pathology

Distribution of freshwater sponges in Serbia

As data on the distribution of freshwater sponges (Porifera, Demospongiae, Spongillida) in Serbia are extremely scarce, we investigated the main Serbian rivers and lakes with respect to Porifera occurrence, for which 17 lotic and 11 lentic water bodies were selected. Sponges were found in 11 of 17 rivers (62 specimens in total) and in 3 of 11 lakes/reservoirs (seven specimens in total). Classical morphological spicule analysis was coupled with polymerase chain reaction (PCR) and gene sequencing for species identification. Among the 69 collected specimens, five sponge species of the family Spongillidae have been identified: Ephydana fluviatilis (Linnaeus, 1759), Spongilla lacustris (Linnaeus, 1759), Ephydatia muelleri (Lieberklihn, 1856), Trochospongilla horrida Weltner, 1893, and Eunapius fragilis (Leidy, 1851). The most frequently found sponge in Serbian rivers was E.fluviatilis (45 % of all specimens), while the least frequent was E. fragilis (6% of all specimens). The Tisa river has the highest sponge diversity (four species). In lentic water bodies, only E.fluviatilis (four specimens) and S. lacustris (three specimens) were found. In general, sponges were infrequent and their abundance was low in Serbian fresh waters. While sponges seem to tolerate significant variations of physical and chemical parameters, some optimal values can be established

Simulium reptans (Linnaeus, 1758) and Simulium reptantoides Carlsson, 1962 from the Balkan Peninsula

Simulium reptans (Linnaeus, 1758) and Simulium reptantoides Carlsson, 1962 are two species of the Simulium reptans group whose distribution is unclear because of their confusing taxonomy and systematics. Their genetic variability is well known for populations in northern and central Europe and shows that both species have two forms; however, the genetic variability of these species in southern and eastern Europe is unknown. To identify the status of these two species in southeast Europe, mtDNA was extracted from 19 individuals from 12 localities across the Balkan Peninsula. Phylogenetic analysis confirmed the existence of two species with 7.38–7.94% divergence. Each species was comprised of two clades, with 2.31% and 1.43% interclade divergence for S. reptans and S. reptantoides, respectively. This study revealed the presence of both species across the Balkans and that S. reptans occurs in this area in only one form (S. reptans B), while S. reptantoides is found in two genetic forms (A and B)

The relation between chironomid (Diptera: Chironomidae) assemblages and environmental variables: The Kolubara River case study

Chironomid larvae respond rapidly to environmental changes in aquatic ecosystems, with different species possessing different degrees of tolerance. Consequently, this group is considered an effective and reliable indicator of the ecological status. In this study, the relation between larval chironomid assemblages and environmental variables was examined at two sites on the Kolubara River. The nonparametric Mann-Whitney U test did not confirm significant seasonal differences between samples. Correspondence analysis indicated that the study sites are distinguished by their community composition. Based on forward selection analyses, 5 out of the 28 analyzed water parameters and 3 out of the 22 sediment parameters displayed the highest levels of correlation with chironomid assemblages. Forward selection analysis revealed that inorganic pollutants in the sediment (mercury, nickel and cadmium) exerted the greatest influence on the community. Results of canonical correspondence analysis indicated that the sediment characteristics have a more significant impact on chironomid communities than the analyzed water parameters. Our study confirmed that chironomids and sediment analyzes should be obligatorily included in the monitoring of ecological status, since chironomids are often a dominant component of benthic macroinvertebrate assemblages in freshwater ecosystems, with many species inhabiting the sediment with a proclivity for intake of toxic and persistent pollutants

Ancestral modal Y-STR haplotype shared among Romani and South Indian populations

One of the primary unanswered questions regarding the dispersal of Romani populations concerns the geographical region and/or the Indian caste/tribe that gave rise to the proto-Romani group. To shed light on this matter, 161 Y-chromosomes from Roma, residing in two different provinces of Serbia, were analyzed. Our results indicate that the paternal gene pool of both groups is shaped by several strata, the most prominent of which, H1-M52, comprises almost half of each collection's patrilineages. The high frequency of M52 chromosomes in the two Roma populations examined may suggest that they descend from a single founder that has its origins in the Indian subcontinent. Moreover, when the Y-STR profiles of haplogroup H derived individuals in our Roma populations were compared to those typed in the South Indian emigrants from Malaysia and groups from Madras, Karnataka (Lingayat and Vokkaliga castes) and tribal Soligas, sharing of the two most common haplotypes was observed. These similarities suggest that South India may have been one of the contributors to the proto-Romanis. European genetic signatures (i.e., haplogroups E1b1b1a1b-V13, G2a-P15, I-M258, J2-M172 and R1-M173), on the other hand, were also detected in both groups, but at varying frequencies. The divergent European genetic signals in each collection are likely the result of differential gene flow and/or admixture with the European host populations but may also be attributed to dissimilar endogamous practices following the initial founder effect. Our data also support the notion that a number of haplogroups including G2a-P15, J2a3b-M67(xM92), I-M258 and E1b1b1-M35 were incorporated into the proto-Romani paternal lineages as migrants moved from northern India through Southwestern Asia, the Middle East and/or Anatolia into the Balkans

Simulium reptans (Linnaeus, 1758) and Simulium reptantoides Carlsson, 1962 from the Balkan Peninsula

Simulium reptans (Linnaeus, 1758) and Simulium reptantoides Carlsson, 1962 are two species of the Simulium reptans group whose distribution is unclear because of their confusing taxonomy and systematics. Their genetic variability is well known for populations in northern and central Europe and shows that both species have two forms; however, the genetic variability of these species in southern and eastern Europe is unknown. To identify the status of these two species in southeast Europe, mtDNA was extracted from 19 individuals from 12 localities across the Balkan Peninsula. Phylogenetic analysis confirmed the existence of two species with 7.38–7.94% divergence. Each species was comprised of two clades, with 2.31% and 1.43% interclade divergence for S. reptans and S. reptantoides, respectively. This study revealed the presence of both species across the Balkans and that S. reptans occurs in this area in only one form (S. reptans B), while S. reptantoides is found in two genetic forms (A and B)

The extracellular matrix glycoprotein tenascin-C and matrix metalloproteinases modify cerebellar structural plasticity by exposure to an enriched environment

The importance of the extracellular matrix (ECM) glycoprotein tenascin-C (TnC) and the ECM degrading enzymes, matrix metalloproteinases (MMPs) -2 and -9, in cerebellar histogenesis is well established. This study aimed to examine whether there is a functional relationship between these molecules in regulating structural plasticity of the lateral deep cerebellar nucleus. To this end, starting from postnatal day 21, TnC- or MMP-9-deficient mice were exposed to an enriched environment (EE). We show that 8 weeks of exposure to EE leads to reduced lectin-based staining of perineuronal nets (PNNs), reduction in the size of GABAergic and increase in the number and size of glutamatergic synaptic terminals in wild-type mice. Conversely, TnC-deficient mice showed reduced staining of PNNs compared to wild-type mice maintained under standard conditions, and exposure to EE did not further reduce, but even slightly increased PNN staining. EE did not affect the densities of the two types of synaptic terminals in TnC-deficient mice, while the size of inhibitory, but not excitatory synaptic terminals was increased. In the time frame of 4-8 weeks, MMP-9, but not MMP-2, was observed to influence PNN remodeling and cerebellar synaptic plasticity as revealed by measurement of MMP-9 activity and colocalization with PNNs and synaptic markers. These findings were supported by observations on MMP-9-deficient mice. The present study suggests that TnC contributes to the regulation of structural plasticity in the cerebellum and that interactions between TnC and MMP-9 are likely to be important for these processes to occur

The impact of hyperpolarization-activated cyclic nucleotide-gated (HCN) and voltage-gated potassium KCNQ/Kv7 channels on primary microglia function

BackgroundMicroglia are essential to maintain cell homeostasis in the healthy brain and are activated after brain injury. Upon activation, microglia polarize towards different phenotypes. The course of microglia activation is complex and depends on signals in the surrounding milieu. Recently, it has been suggested that microglia respond to ion currents, as a way of regulating their activity and function.Methods and resultsUnder the hypothesis that HCN and KCNQ/Kv7 channels impact on microglia, we studied primary rat microglia in the presence or absence of specific pharmacological blockade or RNA silencing. Primary microglia expressed the subunits HCN1-4, Kv7.2, Kv7.3, and Kv7.5. The expression of HCN2, as well as Kv7.2 and Kv7.3, varied among different microglia phenotypes. The pharmacological blockade of HCN channels by ZD7288 resulted in cell depolarization with slowly rising intracellular calcium levels, leading to enhanced survival and reduced proliferation rates of resting microglia. Furthermore, ZD7288 treatment, as well as knockdown of HCN2 RNA by small interfering RNA, resulted in an attenuation of later microglia activation—both towards the anti- and pro-inflammatory phenotype. However, HCN channel inhibition enhanced the phagocytic capacity of IL4-stimulated microglia. Blockade of Kv7/KCNQ channel by XE-991 exclusively inhibited the migratory capacity of resting microglia.ConclusionThese observations suggest that the HCN current contributes to various microglia functions and impacts on the course of microglia activation, while the Kv7/KCNQ channels affect microglia migration. Characterizing the role of HCN channels in microglial functioning may offer new therapeutic approaches for targeted modulation of neuroinflammation as a hallmark of various neurological disorders