Abstract
Hybrid taxa from the genus Pelophylax can propagate themselves in a modified way of sexual reproduction called hybridogenesis ensuring the formation of clonal gametes containing the genome ...of only one parental (host) species. Pelophylax grafi from South-Western Europe is a hybrid composed of P. ridibundus and P. perezi genomes and it lives with a host species P. perezi (P-G system). Yet it is unknown, whether non-Mendelian inheritance is fully maintained in such populations. In this study, we characterize P. perezi and P. grafi somatic karyotypes by using comparative genomic hybridization, genomic in situ hybridization, fluorescent in situ hybridization, and actinomycin D-DAPI. Here, we show the homeology of P. perezi and P. grafi somatic karyotypes to other Pelophylax taxa with 2n = 26 and equal contribution of ridibundus and perezi chromosomes in P. grafi which supports F1 hybrid genome constitution as well as a hemiclonal genome inheritance. We show that ridibundus chromosomes have larger regions of interstitial (TTAGGG)n repeats flanking the nucleolus organizing region on chromosome no. 10 and a high quantity of AT pairs in the centromeric regions. In P. perezi, we found species-specific sequences in metaphase chromosomes and marker structures in lampbrush chromosomes. Pericentromeric RrS1 repeat sequence was present in perezi and ridibundus chromosomes, but the blocks were stronger in ridibundus. Various cytogenetic techniques applied to the P-G system provide genome discrimination between ridibundus and perezi chromosomal sets. They could be used in studies of germ-line cells to explain patterns of clonal gametogenesis in P. grafi and broaden the knowledge about reproductive strategies in hybrid animals.
Bioengineered spider silk is a biomaterial that has exquisite mechanical properties, biocompatibility, and biodegradability. Iron oxide nanoparticles can be applied for the detection and analysis of ...biomolecules, target drug delivery, as MRI contrast agents and as therapeutic agents for hyperthermia-based cancer treatments. In this study, we investigated three bioengineered silks, MS1, MS2 and EMS2, and their potential to form a composite material with magnetic iron oxide nanoparticles (IONPs). The presence of IONPs did not impede the self-assembly properties of MS1, MS2, and EMS2 silks, and spheres formed. The EMS2 spheres had the highest content of IONPs, and the presence of magnetite IONPs in these carriers was confirmed by several methods such as SEM, EDXS, SQUID, MIP-OES and zeta potential measurement. The interaction of EMS2 and IONPs did not modify the superparamagnetic properties of the IONPs, but it influenced the secondary structure of the spheres. The composite particles exhibited a more than two-fold higher loading efficiency for doxorubicin than the plain EMS2 spheres. For both the EMS2 and EMS2/IONP spheres, the drug revealed a pH-dependent release profile with advantageous kinetics for carriers made of the composite material. The composite spheres can be potentially applied for a combined cancer treatment via hyperthermia and drug delivery.
The results of a comprehensive study of Pleistocene fish‐bearing localities from the territory of Poland are presented. Fish remains came from lacustrine deposits and cave sites representing a ...time‐span from the late Early Pleistocene until the Early Holocene. Here we present the taxonomic composition and species diversity of all known fish assemblages from Poland. In total, 23 species belonging to 20 genera of eight families were identified. Cyprinids were the most taxonomically diverse, followed by salmonids and percids. Other families were each represented only by a single species. The roach, rudd, bream, pike and perch were the most common components of the Pleistocene fish assemblages of Poland. These assemblages are clearly divided into two groups representing palaeolakes and cave sites. A significant taxonomic similarity is observed between fish assemblages from Poland and those of Chibanian and Late Pleistocene ages from central and eastern Europe. Pleistocene environments and climates of Poland are characterized using a multi‐proxy approach (analysis of stable isotopes, plant macro‐remains, pollen, molluscs and cladocerans). Obtained data allowed us to estimate a number of parameters of Pleistocene water bodies of the Polish Lowland (reservoir type, trophism, oxygen content, depth and water level changes, bottom character, and flow speed). The formation of freshwater fish assemblages was influenced by dynamic changes in the hydrographic network, and climatic changes during the Pleistocene and Holocene. Their development was favoured by the formation of lakes after melting of the ice sheet.
Background and aims
Oxidative stress has been reported to increase with aging. Oxidative stress is also associated with hypertension, and antioxidant treatment has been shown to enhance antioxidant ...defense system. We therefore aimed to analyze the relationship between aging and some markers of oxidative stress in elderly patients with essential hypertension compared with healthy controls.
Material and Methods
Blood was collected from 18 patients with essential hypertension and 21 age- and sex-matched healthy controls aged over 65. Patients were on their usual medications while participating in the study. Oxidative stress parameters were investigated by measuring the concentration of glutathione (GSH) in whole blood and activities of glutathione peroxidase (GPx-1), glutathione reductase (GR), catalase (CAT), and Cu-Zn superoxide dismutase (CuZn SOD, SOD-1) in erythrocytes. GSH, GPx-1, GR, CAT, and CuZn SOD correlations with age were expressed as Pearson product-moment correlation coefficient r. Independent-samples T test was used to compare mean values of parameters between groups.
Results
(1) Among all parameters analyzed herein, the activity of SOD-1 showed the most explicit decrease in relation to age, both in healthy controls and hypertensive subjects with r values of −0.54 (P = 0.05) and −0.68 (P < 0.01), respectively. (2) Age-related changes in parameters of oxidative stress did not differ significantly between groups. (3) Mean activity of SOD-1 was significantly higher (P < 0.05) in elderly hypertensives (2341.7 ± 213.71 U/g Hb) when compared with healthy controls (2199.7 ± 213.66 U/g Hb). (4) Mean GSH level was significantly higher (P < 0.01) in patients (3.1 ± 0.29 mmol/l) than in controls (2.8 ± 0.37 mmol/l). (5) Increased level of GSH in hypertension was followed by significantly (P < 0.01) higher activity of GR in this group when compared with controls (83.4 ± 15.25 and 64.1 ± 9.40 U/g Hb, respectively).
Conclusions
(1) The antioxidant barrier changes in elderly subjects with senescence. (2) CuZn SOD activity is negatively correlated with age and this association is not altered by factors that modulate the enzyme activity, such as hypertension and antihypertensive treatment. (3) Significantly higher concentration of GSH and significantly higher GR activity in patients may suggest a significant role of GSH metabolism in the pathogenesis of hypertension, as well as its contribution to the effect of antihypertensive treatment.
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