Calcium hypochlorite on mouse embryonic fibroblast cells (NIH3T3) in vitro cytotoxicity and genotoxicity: MTT and comet assay

Molecular Biology Reports - Antimicrobial irrigation solutions are widely used under clinical settings. Their effect on dental tissue is a subject of recent research, which aims for a safer...     

Efficient Flp-Int HK022 dual RMCE in mammalian cells

Recombinase-mediated cassette exchange, or RMCE, is a clean approach of gene delivery into a desired chromosomal location, as it is able to insert only the required sequences, leaving behind the unwanted ones. RMCE can be mediated by a single site-specific DNA recombinase or by two recombinases with different target specificities (dual RMCE). Recently, using the Flp–Cre recombinase pair, dual RMCE proved to be efficient, provided the relative ratio of the enzymes during the reaction is optimal. In the present report, we analyzed how the efficiency of dual RMCE mediated by the Flp–Int (HK022) pair depends on the variable input of the recombinases—the amount of the recombinase expression vectors added at transfection—and on the order of the addition of these vectors: sequential or simultaneous. We found that both in the sequential and the simultaneous modes, the efficiency of dual RMCE was critically dependent on the absolute and the relative concentrations of the Flp and Int expression vectors. Under optimal conditions, the efficiency of ‘simultaneous’ dual RMCE reached ∼12% of the transfected cells. Our results underline the importance of fine-tuning the reaction conditions for achieving the highest levels of dual RMCE.     

Thermoregulatory behavior and oxygen consumption of Octopus mimus paralarvae: The effect of age

Octopus mimus is an important cephalopod species in the coastal zone of Peru and Chile that is exposed to temperature variations from time to time due to El Niño/Southern Oscillation (ENSO) episodes when surface temperatures can reach 24 °C, 6 °C above typical temperatures in their habitat. The relationships between temperature and food availability are important factors that determine the recruitment of juveniles into the O. mimus population. The present study was to evaluate the relationship between thermoregulatory behavior and the age of paralarvae (summer population) to determine whether changes in this behavior occur during internal yolk consumption, making larvae more vulnerable to environmental temperature change. Oxygen consumption of paralarvae when 1–4 d old was determined to establish if respiration could be used to monitor the physiological changes that occur during yolk consumption. Horizontal thermal selection (17–30 °C), critical thermal maxima (CTMax), minima (CTMin), and oxygen consumption experiments were conducted with fasting paralarvae 1–4 d old at 20 °C. Preferred temperatures were dependent on the age of O. mimus paralarvae. One day old paralarvae selected a temperature 1.1 °C (23·4 °C) higher than 2 – 4 d old paralarvae (22·3 °C). The CTMax of paralarvae increased with age with values of 31·9±1.1 °C in 1-d-olds and 33·4±0.3 to 4-d-olds. CTMin also changed with age with low values in 2-d-old paralarvae (9.1±1·3 °C) and 11·9±0·9 °C in 4-d-old animals. The temperature tolerance range of paralarvae was age-dependent (TTD=difference between CTMax and CTMin) with higher values in 2 and 3 d old paralarvae (25–26 °C) as compared to 1 d old (23·1 °C) and 4 d old animals (22.7 °C). Oxygen consumption was not affected by the age of paralarvae, suggesting that mechanisms exist that compensate their metabloism until at least 4 d of age. The temperature tolerance range of a planktonic paralarvae of octopus species is presented for the first time. This range was dependent on the age of paralarvae, and so rendered the paralarvae more vunerable to a combination of high temperature and food deprivation during first days of life. Results in the present study provide evidence that O. mimus could be under ecological pressure if a climate change causes increased or decreased temperatures into their distribution range.     

Visualization of embolism formation in the xylem of liana stems using neutron radiography

Background and Aims

Cold neutron radiography was applied to directly observe embolism in conduits of liana stems with the aim to evaluate the suitability of this method for studying embolism formation and repair. Potential advantages of this method are a principally non-invasive imaging approach with low energy dose compared with synchrotron X-ray radiation, a good spatial and temporal resolution, and the possibility to observe the entire volume of stem portions with a length of several centimetres at one time.

Methods

Complete and cut stems of Adenia lobata, Aristolochia macrophylla and Parthenocissus tricuspidata were radiographed at the neutron imaging facility CONRAD at the Helmholtz-Zentrum Berlin für Materialien und Energie, with each measurement cycle lasting several hours. Low attenuation gas spaces were separated from the high attenuation (water-containing) plant tissue using image processing.

Key results

Severe cuts into the stem were necessary to induce embolism. The formation and temporal course of an embolism event could then be successfully observed in individual conduits. It was found that complete emptying of a vessel with a diameter of 100 µm required a time interval of 4 min. Furthermore, dehydration of the whole stem section could be monitored via decreasing attenuation of the neutrons.

Conclusions

The results suggest that cold neutron radiography represents a useful tool for studying water relations in plant stems that has the potential to complement other non-invasive methods.     

The relationship between the presence of ADHD and certain candidate gene polymorphisms in a Turkish sample

Due to the high heritability of attention-deficit hyperactivity disorder (ADHD), parents of children with ADHD appear to represent a good sample group for investigating the genetics of the disorder. The aim of this study was to investigate the association between ADHD and six polymorphisms in five candidate genes [5-HT2A (rs6311), NET1 (rs2242447), COMT (rs4818), NTF3 (rs6332), SNAP-25 (rs3746544) and (rs1051312)]. We included 228 parents of children diagnosed with ADHD and 109 healthy parents as the control group. The polymorphisms were genotyped using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) assays and analyzed using the chi-square test and the multinomial logit model. SNAP-25 (rs3746544) polymorphism was associated with loading for ADHD, while 5-HT2A (rs6311) and NET1 (rs2242447) polymorphisms were associated with ADHD. On the other hand, there was no significant association between the SNAP-25 (rs1051312), NTF3 (rs6332), or COMT (rs4818) gene polymorphisms and ADHD.     

Isoflavone synthase (IFS) gene phylogeny in Trifolium species associated with plant isoflavone contents

This study presents the results of the identification and quantification of 12 isoflavones (prunetin, irilone, pseudobaptigenin, glycitein, daidzin, genistin, daidzein, pratensein, puerarin, biochanin A, formononetin and genistein) in 23 species of Trifolium (T. arvense, T. pratense, T. ligusticum, T. striatum, T. lappaceum, T. angustifolium, T. hirtum, T. subterraneum, T. isthmocarpum, T. stellatum, T. mutabile, T. strictum, T. fragiferum, T. alexandrinum, T. tomentosum. T. nigrescens subsp. petrisavii, T. nigrescens, T. glomeratum, T. subterraneum subsp. brachycalycinum, T. cherleri, T. resupinatum, T. campestre and T. repens). Isoflavones were extracted by an MSPD method and analyzed with HPLC coupled with a diode-array detector. The evaluation of molecular phylogeny of the IFS gene and the relation with isoflavone content was also performed. Five species (T. subterraneum subsp. brachycalycinum, T. alexandrinum, T. pratense, T. subterraneum and T. lappaceum) were identified with high levels of biochanin A (431–83 mg/kg), formononetin (72–365 mg/kg) and genistein (9–509 mg/kg), which could be utilized as alternative sources for the nutraceutical industry. Genetic phylogeny for the IFS gene was found in the species studied, with 20 out of 23 species having been divided into two clades, while the remaining three were genetically distant. Based on our results, we confirm the direct correlation between IFS gene polymorphism and isoflavones content in species of Trifolium particularly noted for formononetin. Therefore, the IFS gene can be utilized for screening Trifolium genotypes for formononetin. The relation of the three isoflavones' contents and the molecular phylogeny of plants determined by the IFS sequences, as a screening marker for plants with high isoflavone contents in Trifolium species, are to the best of our knowledge described for the first time.     

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).