Endogenous hormone levels during direct somatic embryogenesis in Medicago falcata

Endogenous indole-3-acetic acid, abscisic acid and cytokinins (zeatin, zeatin riboside, N-isopentenyladenine and N-isopentenyladenosine) were evaluated in initial explants (leaves) of in vitro propagated plants of alfalfa ( Medicago falcata L.) lines varying in embryogenic capacity and during the somatic embryogenesis process. Fast embryo-genic induction was correlated with high IAA and low ABA levels in the initial explants. No significant differences were observed in the cytokinin contents. Our results suggest that a certain hormone balance is necessary to allow the expression of the embryogenic potential. The consistent stages of the direct somatic embryogenesis are also characterized by changes in hormonal levels.     

Cercarial chaetotaxy of Codonocephalus urniger (Rudolphi, 1819) (Trematoda: Diplostomidae)

The chaetotaxy of Codonocephalus urniger (Rudolphi, 1819) cercariae recovered from Lymnaea palustris in a brackish water lake in Bulgaria is described and figured. Comparisons with Diplostomum spathaceum (Rudolphi, 1819) and D. pseudospathaceum Niewiadomska, 1984 cercariae indicate a similar general pattern in the distribution of sensilla but with marked differences in their number and arrangement on the ventral sucker, tail stem and furcae. Data on the chaetotaxy of other diplostomid species are used to reveal the similarities and variations in some complexes within the members of Diplostomidae with known cercarial chaetotaxy.     

Genetic Predisposition and its Heredity in the Context of Increased Prevalence of Dermatophytoses

Mycopathologia - Dermatophytosis is a widespread disease with high prevalence and a substantial economic burden associated with costs of treatment. The pattern of this infectious disease covers a...     

Back from the Brink: The Holocene History of the Carpathian Barbel Barbus carpathicus

As a result of specific adaptations and habitat preferences strongly rheophilic fish species may show high levels of endemism. Many temperate rheophilic fish species were subjected to a series of range contractions during the Pleistocene, and then successfully expanded during the Holocene, colonising previously abandoned areas. The Carpathian barbel (Barbus carpathicus Kotlík, Tsigenopoulos, Ráb et Berrebi 2002) occurs in the montane streams in three basins of the main Central European rivers in the northern part of the Carpathian range. We used genetic variation within 3 mitochondrial and 9 microsatellite loci to determine a pattern of postglacial expansion in B. carpathicus. We found that overall genetic variation within the species is relatively low. Estimate of time to the most recent common ancestor (tMRCA) of mitochondrial sequences falls within the Holocene. The highest levels of genetic variation found in upper reaches of the Tisa river in the Danube basin suggest that glacial refugia were located in the south-eastern part of the species range. Our data suggest that the species crossed different watersheds at least six times as three genetically distinct groups (probably established in different expansion episodes) were found in northern part of the species range. Clines of genetic variation were observed in both the Danube and Vistula basins, which probably resulted from subsequent bottlenecks while colonizing successive habitats (south eastern populations) or due to the admixture of genetically diverse individuals to a previously uniform population (Vistula basin). Therefore, B. carpathicus underwent both demographic breakdowns and expansions during the Holocene, showing its distribution and demography are sensitive to environmental change. Our findings are important in the light of the current human-induced habitats alterations.     

Incidence of Spinal Perineurial (Tarlov) Cysts among East-European Patients

The spinal perineurial cyst (Tarlov) is a dilatation between the perineurium and endoneurium of spinal nerve roots, located at level of the spinal ganglion and filled with cerebrospinal fluid but without communication with the perineurial subarachnoid space. The aim of the study was to evaluate it incidence among East-European patients. The retrospective data collected during various magnetic resonance spinal examinations and stored on the picture archiving and communication system was analyzed for an incidence of perineurial cysts. From among 842 patients that underwent examination, 75 cases perineurial cysts were revealed. In 22 cases single anomalies were found. In remaining 53 cases, multiple uni- or less frequently bilateral changes were noted. The most common position was the sacral canal, particularly the level of S2 and S3. Occasionally, cysts were also visible on the cervical, thoracic and lumbar level. Incidence of sacral perineurial cysts was significantly higher in females than in males. Similar data was found for single and multiple changes despite of their localization. Insignificant changes were seen for patient age and cyst size. Perineurial spinal cysts were the most frequently observed on the sacral level and such changes were more common in females.     

Analysis of Age-Related Global DNA Methylation in Chicken

DNA methylation is an epigenetic modification that plays an important role in the normal development and function of organisms. The level of DNA methylation is species-, tissue-, and organelle-specific, and the methylation pattern is determined during embryogenesis. DNA methylation has also been correlated with age. The aim of this study was to determine the global DNA methylation levels and their correlation with age in the chicken, using a Polish autosexing chicken breed, Polbar. A quantitative technique based on an immunoenzymatic assay was used for global DNA methylation analysis. The results show increased global DNA methylation levels with older Polbar embryos. Global DNA methylation levels decrease with the age of hens in the postembryonic stage. This study expands the current knowledge of the Polbar epigenome and the general knowledge of the function of epigenetic mechanisms in birds.     

Interaction of serum amyloid A with human cystatin C—assessment of amino acid residues crucial for hCC–SAA formation (part II)

Secondary amyloid A (AA) amyloidosis is an important complication of some chronic inflammatory diseases, primarily rheumatoid arthritis (RA). It is a serious, potentially life‐threatening disorder caused by the deposition of AA fibrils, which are derived from the circulatory, acute‐phase‐reactant, serum amyloid A protein (SAA). Recently, a specific interaction between SAA and the ubiquitous inhibitor of cysteine proteases—human cystatin C (hCC)—has been proved. Using a combination of selective proteolytic excision and high‐resolution mass spectrometry, the binding sites in the SAA and hCC sequences were assessed as SAA(86–104) and hCC(96–102), respectively. Here, we report further details concerning the hCC–SAA interaction. With the use of affinity tests and florescent ELISA‐like assays, the amino acid residues crucial for the protein interaction were determined. It was shown that all amino acid residues in the SAA sequence, essential for the formation of the protein complex, are basic ones, which suggests an electrostatic interaction character. The idea is corroborated by the fact that the most important residues in the hCC sequence are Ser‐98 and Tyr‐102; these residues are able to form hydrogen bonds via their hydroxyl groups. The molecular details of hCC–SAA complex formation might be helpful for the design of new compounds modulating the biological role of both proteins. Copyright © 2013 John Wiley & Sons, Ltd.