Laser chasing behaviour of wild fishes exploited as a tool to compare space use between size,sex and species

The spatial extent of animal movement is a key consideration when designing conservation measures, such as marine protected areas. Methods to assess territory size in the marine environment, however, are labour intensive and/or expensive. Here, we explore a novel method to investigate the spatial ecology of territorial fishes by examining their reactions to an artificial light stimulus. During benthic towed video surveys conducted in Lyme Bay, southwest England, several species of wrasse (Labridae) have frequently been observed pursuing a laser projected onto the seabed. While the motivation behind ‘laser‐chasing’ is unclear, we quantified the spatial aspects of this behaviour by comparing chase distance and chase likelihood between and within species, to determine the potential utility of this method for investigating space use and aggression in wild fishes. Cuckoo wrasse (Labrus mixtus) were significantly more likely to display agonistic behaviour towards the laser than Goldsinny wrasse (Ctenolabrus rupestris). Goldsinny wrasse displayed a positive relationship between total length and chase‐distance, but not Cuckoo wrasse. The observed species differences may relate to behavioural factors affecting the motivation behind ‘laser‐chasing’, which is discussed. Chases by the cuckoo wrasse were significantly longer than those by Goldsinny wrasse, and these chase distances were used to estimate theoretical territory sizes for each species. To our knowledge, this is the first study to explore the spatial aspects of the reactions to an artificial stimulus by wild fishes. The potential to develop the method to directly investigate aspects of territoriality and aggression in wild fishes is discussed, including necessary further refinements and testing. Wild wrasses are increasingly exploited in Europe to provide cleaner fish for salmonid aquaculture, and we encourage the development of methods to inform spatial conservation measures for these ubiquitous and iconic species.     

Targeting human telomeric DNA quadruplex with novel berberrubine derivatives: insights from spectroscopic and docking studies

Study on bioactive molecules, capable of stabilizing G-Quadruplex structures is considered to be a potential strategy for anticancer drug development. Berberrubine (BER) and two of its analogs bearing alkyl phenyl and biphenyl substitutions at 13-position were studied for targeting human telomeric G-quadruplex DNA sequence. The structures of berberrubine and analogs were optimized by density functional theory (DFT) calculations. Time-dependent DFT (B3LYP) calculations were used to establish and understand the nature of the electronic transitions observed in UV–vis spectra of the alkaloid. The interaction of berberrubine and its analogs with human telomeric G-quadruplex DNA sequence 5′-(GGGTTAGGGTTAGGGTTAGGG)-3′ was investigated by biophysical techniques and molecular docking study. Both the analogs were found to exhibit higher binding affinity than natural precursor berberrrubine. 13-phenylpropyl analog (BER1) showed highest affinity [(1.45 ± 0.03) × 10⁵ M^?1], while the affinity of the 13-diphenyl analog (BER2) was lower at (1.03 ± 0.05) × 10⁵ M^?1, and that of BER was (0.98 ± 0.03) × 10⁵ M^?1. Comparative fluorescence quenching studies gave evidence for a stronger stacking interaction of the analog compared to berberrubine. The thiazole orange displacement assay has clearly established that the analogs were more effective in displacing the end stacked dye in comparison to berberrubine. Molecular docking study showed that each alkaloid ligand binds primarily at the G rich regions of hTelo G4 DNA which makes them G specific binder towards hTelo G4 DNA. Isothermal titration calorimetry studies of quadruplex–berberrubine analog interaction revealed an exothermic binding that was favored by both enthalpy and entropy changes in BER in contrast to the analogs where the binding was majorly enthalpy dominated. A 1:1 binding stoichiometry was revealed in all the systems. This study establishes the potentiality of berberrubine analogs as a promising natural product based compounds as G-quadruplex-specific ligands.     

Tick tock,tick tock: Mouse culture and tissue aging captured by an epigenetic clock

Aging is associated with dramatic changes to DNA methylation (DNAm), although the causes and consequences of such alterations are unknown. Our ability to experimentally uncover mechanisms of epigenetic aging will be greatly enhanced by our ability to study and manipulate these changes using in vitro models. However, it remains unclear whether the changes elicited by cells in culture can serve as a model of what is observed in aging tissues in vivo. To test this, we serially passaged mouse embryonic fibroblasts (MEFs) and assessed changes in DNAm at each time point via reduced representation bisulfite sequencing. By developing a measure that tracked cellular aging in vitro, we tested whether it tracked physiological aging in various mouse tissues and whether anti‐aging interventions modulate this measure. Our measure, termed CultureAGE, was shown to strongly increase with age when examined in multiple tissues (liver, lung, kidney, blood, and adipose). As a control, we confirmed that the measure was not a marker of cellular senescence, suggesting that it reflects a distinct yet progressive cellular aging phenomena that can be induced in vitro. Furthermore, we demonstrated slower epigenetic aging in animals undergoing caloric restriction and a resetting of our measure in lung and kidney fibroblasts when re‐programmed to iPSCs. Enrichment and clustering analysis implicated EED and Polycomb group (PcG) factors as potentially important chromatin regulators in translational culture aging phenotypes. Overall, this study supports the concept that physiologically relevant aging changes can be induced in vitro and used to uncover mechanistic insights into epigenetic aging.     

On the use of the variogram in checking for independence in spatial data

The variogram is a standard tool in the analysis of spatial data, and its shape provides useful information on the form of spatial correlation that may be present. However, it is also useful to be able to assess the evidence for the presence of any spatial correlation. A method of doing this, based on an assessment of whether the true function underlying the variogram is constant, is proposed. Nonparametric smoothing of the squared differences of the observed variables, on a suitably transformed scale, is used to estimate variogram shape. A statistic based on a ratio of quadratic forms is proposed and the test is constructed by investigating the distributional properties of this statistic under the assumption of an independent Gaussian process. The power of the test is investigated. Reference bands are proposed as a graphical follow-up. An example is discussed.     

Development of an artificial host egg for in vitro egg laying of Trichogramma galloi and T. pretiosum using plastic membranes

An artificial host egg was developed as a first attempt to improve the techniques for in vitro rearing of Trichogramma galloi Zucchi and T. pretiosum Riley (Hymenoptera, Trichogrammatidae). Plastic membranes (polyethylene, polypropylene and polystyrene) of different thickness were tested for their usefulness in manufacturing artificial eggs, using a thermal system to produce semi-spherical cupules on the plastic surface. These artificial eggs were filled with larval hemolymph of Helicoverpa zea (Boddie) (Lepidoptera, Noctuidae), and the optimal size of the artificial egg and density of females/artificial egg for the highest host acceptance (percentage of artificial eggs with at least one parasitoid egg) as well as the ideal level of parasitism (eggs/artificial egg) were determined. High-density polyethylene 7–8 and 9–10 m thick resulted in the best acceptance and level of parasitization for both parasitoid species. Six females per artificial egg resulted in the best rate of parasitization for these parasitoids, although these data were not different when using 4 or 5 females of T. galloi. The size, shape and surface texture of the artificial eggs were found to provide enough cues to elicit parasitization behavior in Trichogramma females, since no chemical stimulus was provided.     

迁移的鼻咽癌细胞容积激活性氯电流

用膜片钳技术研究了Transwell小室趋化迁移后的鼻咽癌CNE-2Z细胞容积激活性CT电流。47％低渗刺激迁移后的CNE-2Z细胞诱发容积激活性氯电流,与未迁移细胞相比,其特性以及其对氯通道阻断剂的敏感性发生明显的变化,此电流的密度明显高于未迁移细胞,而且该电流几乎完全被氯通道阻断剂adenosine-5'-triphosphate(ATP,10 mmol/L)、5-nitro-2-3-phenylpropylamino benzoic acid(NPPB,100μmol/L)和他莫昔芬(30μmol/L)抑制,其中NPPB和他莫昔芬对迁移细胞的抑制作用明显强于未迁移细胞。迁移后的CNE-2Z细胞容积激活性氯通道对阴离子的通透性为:Br>Cl>I>葡萄糖酸,与未迁移细胞(I>Br>Cl>葡萄糖酸)不同。结果提示,容积激活性氯通道可能参与CNE-2Z细胞的迁移过程。     

Plant cryopreservation: Progress and prospects

Summary Cryopreservation (liquid nitrogen, −196°C) represents the only safe and cost-effective option for long-term conservation of germplasm of non-orthodox seed species, vegetatively propagated species, and of biotechnology products. Classical cryopreservation techniques, which are based on freeze-induced dehydration, are mainly employed for freezing undifferentiated cultures and apices of cold-tolerant species. New cryopreservation techniques, which are based on vitrification of internal solutes, are successfully employed with all explant types, including cells suspensions and calluses, apices, and somatic and zygotic embryos of temperate and tropical species. The development of cryopreservation protocols is significantly more advanced for vegetatively propagated species than for recalcitrant seed species. Even though its routine use is still limited, there are a growing number of examples where cryopreservation is employed on a large scale for different types of materials, including seeds with orthodox and intermediate storage behaviour, dormant buds, pollen, biotechnology products, and apices sampled from in vitro plantlets of vegetatively propagated species. Cryopreservation can also be employed for uses other than germplasm conservation, such as cryoselection, i.e., the selection through freezing of samples with special properties, or cryotherapy, i.e., the elimination of viruses from infected plants through apex cryopreservation. Because of its high potential, it is expected that cryopreservation will become more frequently employed for long-term conservation of plant genetic resources.     

Analysis of telomerase activity and detection of its catalytic subunit,hTERT

The discovery of the enzyme telomerase and its subunits has led to major advances in understanding the mechanisms of cellular proliferation, immortalization, aging, and neoplastic transformation. The expression of telomerase in more than 85% of tumors provides an excellent tool for the diagnosis, prognosis, and treatment of cancer. However, the techniques employed in its detection appear to play a significant role in the interpretation of the results. The telomeric repeat amplification protocol (TRAP assay) has been the standard assay in the detection of telomerase activity and many variations of this technique have been reported. Recent advances in the development of the TRAP assay and the incorporation of techniques that provide a quantitative and qualitative estimate of telomerase activity are assessed in this review. In addition to histological and cytological examination of tissues, distribution patterns of the catalytic subunit of telomerase, hTERT, are frequently used in the prognosis of tumors. The methods involved in the detection of hTERT as a biomarker of cellular transformation are also analyzed.