Effects of Ethanol Exposure During Early Pregnancy in Hyperactive, Inattentive and Impulsive Behaviors and MeCP2 Expression in Rodent Offspring

Prenatal exposure to alcohol has consistently been associated with adverse effects on neurodevelopment, which is collectively called fetal alcohol spectrum disorder (FASD). Increasing evidence suggest that prenatal exposure to alcohol increases the risk of developing attention deficit/hyperactivity disorder-like behavior in human. In this study, we investigated the behavioral effects of prenatal exposure to EtOH in offspring mice and rats focusing on hyperactivity and impulsivity. We also examined changes in dopamine transporter and MeCP2 expression, which may underlie as a key neurobiological and epigenetic determinant in FASD and hyperactive, inattentive and impulsive behaviors. Mouse or rat offspring born from dam exposed to alcohol during pregnancy (EtOH group) showed hyper locomotive activity, attention deficit and impulsivity. EtOH group also showed increased dopamine transporter and norepinephrine transporter level compared to control group in the prefrontal cortex and striatum. Prenatal exposure to EtOH also significantly decreased the expression of MeCP2 in both prefrontal cortex and striatum. These results suggest that prenatal exposure to EtOH induces hyperactive, inattentive and impulsive behaviors in rodent offspring that might be related to global epigenetic changes as well as aberration in catecholamine neurotransmitter transporter system.     

Population genetic analysis and origin discrimination of snow crab (Chionoecetes opilio) using microsatellite markers

Major habitats for the snow crab Chionoecetes opilio are mostly found within the northwest Atlantic and North Pacific Oceans. However, the East Sea populations of C. opilio, along with its relative the red snow crab (C. japonicas), are two of the most important commercial crustacean species for fisheries on the east coast of the Korean Peninsula. The East Sea populations of C. opilio are facing declining resources due to overfishing and global climate change. Thus, an analysis of population structure is necessary for future management. Five Korean and one Russian group of C. opilio were analyzed using nine microsatellite markers that were recently developed using next-generation sequencing. No linkage disequilibrium was found between any pair of loci, indicating that the markers were independent. The number of alleles per locus varied from 4 to 18 with a mean of 12, and allelic richness per locus ranged from 4.0 to 17.1 across all populations with a mean of 9.7. The Hardy–Weinberg equilibrium test revealed significant deviation in three out of nine loci in some populations after sequential Bonferroni correction and all of them had higher expected heterozygosity than observed heterozygosity. Null alleles were presumed in four loci, which explained the homozygosity in three loci. The pairwise fixation index (F _ST ) values among the five Korean snow crab populations did not differ significantly, but all of the pairwise F _ST values between each of the Korean snow crab populations and the Russian snow crab population differed significantly. An UPGMA dendrogram revealed clear separation of the Russian snow crab population from the Korean snow crab populations. Assignment tests based on the allele distribution discriminated between Korean and Russian origins with 93 % accuracy. Therefore, the snow crab populations around the Korean Peninsula need to be managed separately from the populations in Bering Sea in global scale resource management. Also, this information can be used for identification of snow crab origin which is problematic in worldwide crab trade.     

Karyotype analysis of some Minuartia L. (Caryophyllaceae) taxa

Karyotypic characters, mitotic metaphase chromosomes, monoploid idiograms and karyograms of Minuartia anatolica (Boiss.) Woronow var. phrygia (Bornm.) McNeill, Minuartia anatolica (Boiss.) Woronow var. scleranthoides (Boiss. & Noe) McNeill, Minuartia corymbulosa (Boiss. & Balansa) McNeill var. gypsophilloides McNeill and Minuartia aksoyi M.Koç & Hamzao?lu were investigated for the first time. Analysis of somatic metaphases showed that the chromosome numbers and the formulas of these taxa were 2n = 24 = 14m + 6sm + 4st for Minuartia anatolica var. phrygia, 2n = 14 = 6m + 8sm for Minuartia anatolica var. scleranthoides, 2n = 14 = 6m + 4sm + 4st for Minuartia corymbulosa var. gypsophilloides and 2n = 30 = 14m + 10sm + 6st for Minuartia aksoyi. No satellites were observed in the karyotypes of these taxa. Karyotype asymmetry was estimated by many different methods, namely the Stebbins classification, the karyotype asymmetry index (As K %), the total form percent (TF %), the Rec and Syi indices, the intrachromosomal asymmetry index (A1) and interchromosomal asymmetry index (A2), the dispersion index (DI), the degree of asymmetry of karyotype (A index) and the asymmetry index (AI).     

Structural and functional analyses of catalytic domain of GH10 xylanase from Thermoanaerobacterium saccharolyticum JW/SL‐YS485

Xylanases are capable of decomposing xylans, the major components in plant cell wall, and releasing the constituent sugars for further applications. Because xylanase is widely used in various manufacturing processes, high specific activity, and thermostability are desirable. Here, the wild‐type and mutant (E146A and E251A) catalytic domain of xylanase from Thermoanaerobacterium saccharolyticum JW/SL‐YS485 (TsXylA) were expressed in Escherichia coli and purified subsequently. The recombinant protein showed optimal temperature and pH of 75°C and 6.5, respectively, and it remained fully active even after heat treatment at 75°C for 1 h. Furthermore, the crystal structures of apo‐form wild‐type TsXylA and the xylobiose‐, xylotriose‐, and xylotetraose‐bound E146A and E251A mutants were solved by X‐ray diffraction to high resolution (1.32–1.66 Å). The protein forms a classic (β/α)₈ folding of typical GH10 xylanases. The ligands in substrate‐binding groove as well as the interactions between sugars and active‐site residues were clearly elucidated by analyzing the complex structures. According to the structural analyses, TsXylA utilizes a double displacement catalytic machinery to carry out the enzymatic reactions. In conclusion, TsXylA is effective under industrially favored conditions, and our findings provide fundamental knowledge which may contribute to further enhancement of the enzyme performance through molecular engineering. Proteins 2013; 81:1256–1265. © 2013 Wiley Periodicals, Inc.     

Differences in Conformational Behavior of ATA and TAT Sequences in Single Strand DNA Trimer

Abstract

The conformational behavior of single strand (ss) TAT and ATA trimers of DNA have been studied by computational chemistry tools including CICADA software interfaced with AMBER molecular mechanics and dynamics. The Single-Coordinate-Driving (SCD) method has been used in conjunction with molecular dynamics simulated annealing. It has been revealed that the conformational flexibility of each sequence differs substantially from the other one. Four common conformational families have been found for both trimers. These are: helical, reverse-stacked (base 3), half-stacked (base 3), reverse-stacked (base 1). However, the energies of conformers representing the families are different for both the studied systems. An additional conformational family, bulged, has been found for ss(ATA), while ss(TAT) has been found also in half-stacked (base 1) conformation. In general, ss(TAT) exhibits a higher number of low energy conformations while ss(ATA) shows one interesting low energy conformational interconversion between reverse-stacked (A3) family and half-stacked (A3) family. The high conformational variability of the trimers has been confirmed by flexibility analysis and by molecular dynamics simulations, which have also shown the conformational stability of single conformational families. It has been concluded that the methodology used is able to provide a very detailed picture of the conformational space of these molecules.     

Dynamics and Binding Modes of Free cdk2 and its Two Complexes with Inhibitors Studied by Computer Simulations

Abstract

This article presents a molecular dynamics (MD) study of the cdk2 enzyme and its two complexes with the inhibitors isopentenyladenine and roscovitine using the Cornell et al. force field from the AMBER software package. The results show that inserting an inhibitor into the enzyme active site does not considerably change enzyme structure but it seemingly changes the distribution of internal motions. The inhibitor causes differences in the domain motions in free cdk2 and in its complexes. It was found out that repulsion of roscovitine N9 substituent causes conformational change on Lys 33 side chain. Isopentenyladenine forms with Lys 33 side chain terminal amino group a hydrogen bond. It implies that the cavity, where N9 substituent of roscovitine is buried, can adopt larger substituent due to Lys 33 side chain flexibility. The composition of electrostatic and van der Waals interactions between the inhibitor and the enzyme were also calculated along both cdk2/inhibitor MD trajectories together with MM-PB/GBSA analysis. These results show that isopentenyladenine-like inhibitors could be more effective after modifications leading to an increase in their van der Waals contact with the enzyme. We suggest that a way leading to better inhibitors occupying isopentenyladenine binding mode could be: to keep N9 and N7 purine positions free, to keep 3,3-dimethylallylamino group at C6 position, and to add, e.g., benzylamino group at C2 position. The results support the idea that the isopentenyladenine binding mode can be used for cdk2 inhibitors design and that all possibilities to improve this binding mode were not uncovered yet.     

Fecal Influenza in Mammals: Selection of Novel Variants

In aquatic birds, influenza A viruses mainly replicate in the intestinal tract without significantly affecting the health of the host, but in mammals, they replicate in the respiratory tract and often cause disease. Occasionally, influenza viruses have been detected in stool samples of hospitalized patients and in rectal swabs of naturally or experimentally infected mammals. In this study, we compared the biological and molecular differences among four wild-type avian H1N1 influenza viruses and their corresponding fecal and lung isolates in DBA/2J and BALB/cJ mice. All fecal and lung isolates were more pathogenic than the original wild-type viruses, when inoculated into mice of both strains. The increased virulence was associated with the acquisition of genetic mutations. Most of the novel genotypes emerged as PB2^E627K, HA^F128V, HA^F454L, or HA^H300P variations, and double mutations frequently occurred in the same isolate. However, influenza virus strain- and host-specific differences were also observed in terms of selected variants. The avian H1N1 virus of shorebird origin appeared to be unique in its ability to rapidly adapt to BALB/cJ mice via the fecal route, compared to the adaptability of the H1N1 virus of mallard origin. Furthermore, a bimodal distribution in fecal shedding was observed in mice infected with the fecal isolates, while a normal distribution was observed after infection with the lung isolates or wild-type virus. Fecal isolates contained HA mutations that increased the activation pH of the HA protein. We conclude that influenza virus variants that emerge in fecal isolates in mammals might influence viral transmission, adaptation to mammals, and viral ecology or evolution.     

Exogenously applied 20-hydroxyecdysone increases the net photosynthetic rate but does not affect the photosynthetic electron transport or the content of photosynthetic pigments in Tetragonia tetragonioides L.

Phytoecdysteroids are steroid compounds present in many plant species (sometimes in rather large amounts), but their biological role is still far from being clear. We have found that the exogenous application of 20-hydroxyecdysone (20E) to leaves of Tetragonia tetragonioides L. causes stimulation of its net photosynthetic rate (P _N) but does not positively affect the photosynthetic electron transport or the content of photosynthetic pigments. The increase in P _N was observed shortly after 20E treatment and was statistically significant during the 4th and 6th hours after treatment but not later, which could be perhaps caused by a strictly short-term window of opportunity for ecdysteroids to significantly affect photosynthetic processes. To our knowledge, these results are the first to suggest a new potential biological function of phytoecdysteroids—regulation of photosynthesis.     

Galatella anatolica sp. nov. (Asteraceae: Astereae) from Osmaniye,Turkey

Galatella anatolica Hamzao?lu & Budak sp. nov. (Asteraceae), collected from Osmaniye (Turkey) is here described as a new species. It is similar to G. angustissima (Tausch) Novopokr. in general habit. Both have stems with few branches and 1‐veined middle leaves, but are distinguished by involucral features, series of phyllaries, and lengths of disc florets, achenes and pappus.