Is bigger better? The relationship between size and reproduction in female Asian elephants

The limited availability of resources is predicted to impose trade‐offs between growth, reproduction and self‐maintenance in animals. However, although some studies have shown that early reproduction suppresses growth, reproduction positively correlates with size in others. We use detailed records from a large population of semi‐captive elephants in Myanmar to assess the relationships between size (height and weight), reproduction and survival in female Asian elephants, a species characterized by slow, costly life history. Although female height gain during the growth period overlapped little with reproductive onset in the population, there was large variation in age at first reproduction and only 81% of final weight had been reached by peak age of reproduction at the population level (19 years). Those females beginning reproduction early tended to be taller and lighter later in life, although these trends were not significant. We found that taller females were more likely to have reproduced by a given age, but such effects diminished with age, suggesting there may be a size threshold to reproduction which is especially important in young females. Because size was not linked with female survival during reproductive ages, the diminishing effect of height on reproduction with age is unlikely to be due to biased survival of larger females. We conclude that although reproduction may not always impose significant costs on growth, height may be a limiting factor to reproduction in young female Asian elephants, which could have important implications considering their birth rates are low and peak reproduction is young – 19 years in this population.     

Photoanalogues of the Initiation Substrates of the RNA Polymerase II, 5‐Azido‐2‐Nitrobenzoyl Derivatives of the ATP γ‐Amidophosphate: The Possible Photoinduced Degradation of the Functional Group to an N‐Arylhydroxylamine

Photoanlogues of the initiation substrates of the RNA polymerase II, N₃Ar‐ NH(CH₂)_nNHpppA where N₃Ar is 5‐azido‐2‐nitrobenzoyl group (n = 2 or 4) were synthesized, allowing the preparation of photoreactive oligonucleotides in situ by RNA polymerase II for application as photolabels. Photolysis of p‐nitro‐substituted aromatic azide in aqueous medium was investigated. Using the azoxy‐coupling reaction it was possible to determine whether a nitrene or p‐nitrophenyl hydroxylamine azoxy compound is the trappable intermediate that is generated at ambient temperature in aqueous solution.     

The role of the tolerance–fecundity trade‐off in maintaining intraspecific seed trait variation in a widespread dimorphic herb

Coexistence of species with different seed sizes is a long‐standing issue in community ecology, and a trade‐off between fecundity and stress tolerance has been proposed to explain co‐occurrence in heterogeneous environments. Here we tested an intraspecific extension of this model: whether such trade‐off also explains seed trait variation among populations of widespread plants under stress gradients. We collected seeds from 14 populations of Plantago coronopus along the Atlantic coast in North Africa and Europe. This herb presents seed dimorphism, producing large basal seeds with a mucilaginous coat that facilitates water absorption (more stress tolerant), and small apical seeds without coats (less stress tolerant). We analysed variation among populations in number, size and mucilage production of basal and apical seeds, and searched for relationships between local environment and plant size. Populations under higher stress (higher temperature, lower precipitation, lower soil organic matter) had fewer seeds per fruit, higher predominance of basal relative to apical seeds, and larger basal seeds with thicker mucilaginous coats. These results strongly suggest a trade‐off between tolerance and fecundity at the fruit level underpins variation in seed traits among P. coronopus populations. However, seed production per plant showed the opposite pattern to seed production per fruit, and seemed related to plant size and other life‐cycle components, as an additional strategy to cope with environmental variation across the range. The tolerance–fecundity model may constitute, under stress gradients, a broader ecological framework to explain trait variation than the classical seed size–number compromise, although several fecundity levels and traits should be considered to understand the diverse strategies of widespread plants to maximise fitness in each set of local conditions.     

Development of a novel neodymium compound for in vivo fluorescence imaging.

We developed a novel fluorescent probe that contains the neodymium(III) complex moiety and fluorescein moiety. This probe can emit long-lived near-infrared luminescence derived from a Nd ion through excitation of the fluorescein moiety with visible light (lambda(ex) = 488 nm, lambda(em) = 880 nm, lifetime = 2.3 micros). These results indicate the possibility of the probe as a candidate for in vivo fluorescence molecular imaging.     

一种特殊的长寿细胞: 毛竹茎秆纤维细胞

利用显微和细胞化学方法, 对毛竹( Phyllostachys edulis) 茎秆纤维次生壁形成过程中超微结构变化以及ATP 酶、Ca²⁺ -ATP_ase 和酸性磷酸酶的超微细胞化学定位进行了研究。研究发现, 次生壁形成早期,细胞核具有双层核膜, 染色质凝聚, 可见大量的线粒体、粗面内质网和高尔基体等细胞器存在于纤维细胞中; 随后, 双层核膜消失, 细胞器将逐渐解体, 多泡体开始出现在纤维细胞的细胞质; 随着年龄的增加,纤维细胞壁逐渐增厚, 并出现多层结构现象, 而运输小泡、细胞膜、胞间连丝和凝聚的染色质将持续存在。在次生壁形成的整个过程中, ATP 酶、Ca²⁺ -ATP_ase 和酸性磷酸酶在运输小泡、细胞膜、质膜内陷、胞间连丝和凝聚的染色质中将持续存在。结果表明, 毛竹茎秆纤维细胞是一种不同于木本双子叶植物的长寿细胞, 纤维原生质体中ATP 酶和酸性磷酸酶的持续存在与次生壁的持续增厚密切相关。     

The ecology of Maesopsis eminii Engl. in tropical Africa

Maesopsis eminii is referred to as one of the most widely distributed African tree species. However, its occurrence in Africa has never been mapped and little is known as to how this species can sustain in different environments. To gain insight into Maesopsis’ ecology, we (i) made a synthesis of its functional trait data from the literature, (ii) investigated phenological patterns using data on four M. eminii trees from Yangambi, DR Congo, (iii) assessed an empirical provenance trial from Uganda on 600 Maesopsis trees and (iv) synthesized geo‐referenced point location maps of Maesopsis entailing WorldClim precipitation and temperature and FAO soils, rainfall and ecological zones for Africa. We found M. eminii to straddle the equator equidistantly in terms of latitude (10.97°N and 10.98°S) covering five forest types where twenty soil types and variable rainfall regimes support complex plant biodiversity. Maesopsis eminii was, however, largely concentrated in the tropical rainforest ecosystem which contains fertile Orthic Ferralsol soils. More than 97% of the point locations were found where annual precipitation was >1000 mm, and 82% occurred where average annual temperature was 22–28°C. Its functional traits, phenology and provenance trial findings explained its occurrence in Africa.     

A metabolic signature for long life in the Caenorhabditis elegans Mit mutants

Mit mutations that disrupt function of the mitochondrial electron transport chain can, inexplicably, prolong Caenorhabditis elegans lifespan. In this study we use a metabolomics approach to identify an ensemble of mitochondrial‐derived α‐ketoacids and α‐hydroxyacids that are produced by long‐lived Mit mutants but not by other long‐lived mutants or by short‐lived mitochondrial mutants. We show that accumulation of these compounds is dependent on concerted inhibition of three α‐ketoacid dehydrogenases that share dihydrolipoamide dehydrogenase (DLD) as a common subunit, a protein previously linked in humans with increased risk of Alzheimer's disease. When the expression of DLD in wild‐type animals was reduced using RNA interference we observed an unprecedented effect on lifespan – as RNAi dosage was increased lifespan was significantly shortened, but, at higher doses, it was significantly lengthened, suggesting that DLD plays a unique role in modulating length of life. Our findings provide novel insight into the origin of the Mit phenotype.     

Giant Sequoia (Sequoiadendron giganteum) Regeneration in Experimental Canopy Gaps

Restoration of giant sequoia populations is a high priority for managers, but few experimental studies have examined the efficacy of restoration treatments. To inform giant sequoia restoration treatment options, we assessed the response of giant sequoia regeneration (germination, mortality, and growth) to experimental gaps within a native giant sequoia grove. We created experimental gaps, ranging in size from 0.05 to 0.4 ha. Following gap creation, we sowed seeds and planted seedlings along north‐south transects across gaps. Transects were planted on paired burned and unburned substrates. The seed‐sowing treatment did not result in a cohort of established seedlings, although the amount of seeds sowed was far short of the potential amount released during intense fires. Mortality of planted seedlings did not vary with gap size (average 25% mortality). However, there was a distinct relationship between gap size and second year seedling growth. The relationship was best modeled with an asymptotic curve for both burned and unburned substrates. Relative seedling growth more than doubled as gap size increased from 0.05 to 0.2 ha, then increases in growth diminished. Growth rates of giant sequoia seedlings saturated above 70% light availability while increasing linearly with belowground resource availability. Long‐lived pioneer species such as giant sequoia require restoration treatments that involve relatively severe disturbances to facilitate cohort establishment and recruitment.     

Disturbance-Mediated Drift in Tree Functional Groups in Amazonian Forest Fragments

The interactive effects of forest disturbance and fragmentation on tropical tree assemblages remain poorly understood. We examined the effects of forest patch and landscape metrics, and levels of forest disturbance on the patterns of floristic composition and abundance of tree functional groups within 21 forest fragments and two continuous forest sites in southern Brazilian Amazonia. Trees were sampled within 60 (10 × 250 m) plots placed in the core areas of the fragments. Tree assemblage composition and abundance were summarized using nonmetric multidimensional scaling (NMDS). Forest patch size explained 36.2 percent and 30 percent of the variance in the proportion of small-seeded softwood and hardwood stems in the 21 forest patches, respectively. Large fragments retained a higher abundance of hardwood tree species whereas small-seeded softwood trees appear to proliferate rapidly in small disturbed fragments. Generalized linear mixed models showed that time since fragmentation had both positive and negative effects on the density of different functional groups of trees and on the ordination axes describing tree abundance. The composition and abundance of different tree genera were also related to time since fragmentation, distance to the nearest edge, and fire severity, despite the recent post-isolation history of the forest patches surveyed. Both the proliferation of fast-growing pioneer trees and the decline of hardwood trees found in our forest plots have profound consequences on the floristic composition, forest dynamics, carbon storage, and nutrient cycling in Amazonian forest fragments.     

Modification,Biological Evaluation and SAR Studies of Novel 1H‐Pyrazol Derivatives Containing N,N′‐Disubstituted Urea Moiety as Potential Anti‐melanoma Agents

Malignant melanomas are amongst the most aggressive cancers. BRAF Inhibitors have exhibited therapeutic effects against BRAF‐mutant melanoma. In continuation of our earlier studies on anti‐melanoma agents based on 1H‐pyrazole skeleton, two sets of novel compounds that include 1H‐pyrazole‐4‐amines FA 1 – FA13 and corresponding urea derivatives FN 1 – FN13 have been synthesized and evaluated for their BRAF^V600E inhibitory and antiproliferation activities. Compound FN 10 displayed the most potent biological activity against BRAF^V600E (IC₅₀ = 0.066 μm ) and the A375 human melanoma cell line (GI₅₀ = 0.81 μm ), which was comparable to the positive control vemurafenib, and more potent than our previously reported 1H‐pyrazole‐3‐amines and their urea derivatives. The results of SAR studies and molecular docking can guide further optimization and may help to improve potency of these pyrazole‐based anti‐melanoma agents.     

Late Devonian dimpled phosphatic microspherules associated with conodonts are possible otoliths of short‐lived and opportunistic organisms

Dimpled phosphatic microspherules, contradictorily associated with conodonts, are widely distributed in strata ranging in age from the Cambrian to Carboniferous. These microspherules have attracted much attention from palaeobiologists and were suggested to be ‘conodont pearls’, ‘conodont otoliths’ or ‘fish otoliths’ due to their similar chemical composition and co‐occurrence with conodonts or fish teeth. However, these hypotheses are still highly controversial. Here, we report ‘checks’, ‘rhythmic growth patterns’ and ‘sub‐diurnal increments’ from growth annuli of the Late Devonian phosphatic microspherules from South China, on the basis of quantitative microstructure analysis. The annulus width of phosphatic microspherules becomes narrower with increasing radius. These microstructural characteristics of growth annuli are most typical indicators of modern animal otoliths. In addition, a maximum value of about 90 annuli is encountered from all the specimens. We propose that these microspherules are essentially phosphatic otoliths, which might have been secreted by a specific kind of marine organisms with very short lifespans (less than 90 days). Furthermore, the sudden enrichment of phosphatic microspherules in the late Frasnian may represent a biological response of short‐lived animals to ecological crisis such as ocean eutrophication.     

Accumulation of “Old Proteins” and the Critical Need for MS‐based Protein Turnover Measurements in Aging and Longevity

Aging and age‐related diseases are accompanied by proteome remodeling and progressive declines in cellular machinery required to maintain protein homeostasis (proteostasis), such as autophagy, ubiquitin‐mediated degradation, and protein synthesis. While many studies have focused on capturing changes in proteostasis, the identification of proteins that evade these cellular processes has recently emerged as an approach to studying the aging proteome. With advances in proteomic technology, it is possible to monitor protein half‐lives and protein turnover at the level of individual proteins in vivo. For large‐scale studies, these technologies typically include the use of stable isotope labeling coupled with MS and comprehensive assessment of protein turnover rates. Protein turnover studies have revealed groups of highly relevant long‐lived proteins (LLPs), such as the nuclear pore complexes, extracellular matrix proteins, and protein aggregates. Here, the role of LLPs during aging and age‐related diseases and the methods used to identify and quantify their changes are reviewed. The methods available to conduct studies of protein turnover, used in combination with traditional proteomic methods, will enable the field to perform studies in a systems biology context, as changes in proteostasis may not be revealed in studies that solely measure differential protein abundances.     

Use of gaseous 13NH3 administered to intact leaves of Nicotiana tabacum to study changes in nitrogen utilization during defence induction

Nitrogen‐13 (t_1/2 9.97 m), a radioactive isotope of nitrogen, offers unique opportunities to explore plant nitrogen utilization over short time periods. Here we describe a method for administering ¹³N as gaseous ¹³NH₃ to intact leaves of Nicotiana tabacum L. (cv Samsun), and measuring the labelled amino acids using radio high‐performance liquid chromatography (HPLC) on tissue extract. We used this method to study the effects of defence induction on plant nitrogen utilization by applying treatments of methyl jasmonate (MeJA), a potent defence elicitor. MeJA caused a significant increase relative to controls in key [¹³N]amino acids, including serine, glycine and alanine by 4 h post‐treatment, yet had no effect on ¹³NH₃ incorporation, a process that is primarily under the control of the glutamine synthatase/glutamate synthase pathway (GS/GOGAT) in cellular photorespiration. We suggest that the reconfiguration of nitrogen metabolism may reflect induction of non‐photorespiratory sources of nitrogen to better serve the plant's defences.     

Combining hyperspectral imaging and chemometrics to assess and interpret the effects of environmental stressors on zebrafish eye images at tissue level

Changes on an organism by the exposure to environmental stressors may be characterized by hyperspectral images (HSI), which preserve the morphology of biological samples, and suitable chemometric tools. The approach proposed allows assessing and interpreting the effect of contaminant exposure on heterogeneous biological samples monitored by HSI at specific tissue levels. In this work, the model example used consists of the study of the effect of the exposure of chlorpyrifos‐oxon on zebrafish tissues. To assess this effect, unmixing of the biological sample images followed by tissue‐specific classification models based on the unmixed spectral signatures is proposed. Unmixing and classification are performed by multivariate curve resolution‐alternating least squares (MCR‐ALS) and partial least squares‐discriminant analysis (PLS‐DA), respectively. Crucial aspects of the approach are: (1) the simultaneous MCR‐ALS analysis of all images from 1 population to take into account biological variability and provide reliable tissue spectral signatures, and (2) the use of resolved spectral signatures from control and exposed populations obtained from resampling of pixel subsets analyzed by MCR‐ALS multiset analysis as information for the tissue‐specific PLS‐DA classification models. Classification results diagnose the presence of a significant effect and identify the spectral regions at a tissue level responsible for the biological change.      

Engineering fire blight resistance into the apple cultivar ‘Gala’ using the FB_MR5 CC‐NBS‐LRR resistance gene of Malus × robusta 5

The fire blight susceptible apple cultivar Malus × domestica Borkh. cv. ‘Gala’ was transformed with the candidate fire blight resistance gene FB_MR5 originating from the crab apple accession Malus × robusta 5 (Mr5). A total of five different transgenic lines were obtained. All transgenic lines were shown to be stably transformed and originate from different transgenic events. The transgenic lines express the FB_MR5 either driven by the constitutive CaMV 35S promoter and the ocs terminator or by its native promoter and terminator sequences. Phenotyping experiments were performed with Mr5‐virulent and Mr5‐avirulent strains of Erwinia amylovora, the causal agent of fire blight. Significantly less disease symptoms were detected on transgenic lines after inoculation with two different Mr5‐avirulent E. amylovora strains, while significantly more shoot necrosis was observed after inoculation with the Mr5‐virulent mutant strain ZYRKD3_1. The results of these experiments demonstrated the ability of a single gene isolated from the native gene pool of apple to protect a susceptible cultivar from fire blight. Furthermore, this gene is confirmed to be the resistance determinant of Mr5 as the transformed lines undergo the same gene‐for‐gene interaction in the host–pathogen relationship Mr5–E. amylovora.     

Bacterial iturins mediate biocontrol activity of Bacillus sp. against postharvest pear fruit‐rotting fungi

A potential antagonist, Bacillus sp. LYLB4 isolated from pear fruits, was tested for its antifungal activity against postharvest pear pathogens. LYLB4 had a remarkable antifungal effect on Botryosphaeria dothidea. Although it showed a weak inhibition effect on the growth of Rhizopus stolonifer on potato dextrose agar (PDA) plates, LYLB4 almost completely destroyed R. stolonifer during direct contact in potato dextrose broth (PDB). LYLB4 treatment was able to significantly reduce disease incidence (by 68.9% and 100%, respectively) and lesion diameter (by 68.7% and 100%, respectively) of ring rot caused by B. dothidea and soft rot caused by R. stolonifer in pears. LYLB4 also suppressed several other phytopathogens in vitro, suggesting a broad‐spectrum antagonistic activity against fungal pathogens. 16S rRNA and gyrA sequence analysis indicated that LYLB4 is closely related to B. velezensis. Genome mining indicated that LYLB4 had 11 secondary metabolites encoding clusters, but that the surfactin and fengycin gene clusters may not be functional because of a large deletion. Matrix‐assisted laser desorption ionization‐time of flight mass spectra (MALDI‐TOF‐MS) demonstrated that iturins were the major lipopeptides, and that C₁₆/C₁₇ Bacillomycin D synthesis was stimulated when LYLB4 was co‐cultured with B. dothidea compared to the control. Overall, these results demonstrate that the main biocontrol mechanism adopted by LYLB4 could be through the production of toxic metabolites and direct contact with pathogens.     

The dynamics of Brazilian protozoology over the past century

Brazilian scientists have been contributing to the protozoology field for more than 100 years with important discoveries of new species such asTrypanosoma cruzi and Leishmania spp. In this work, we used a Brazilian thesis database (Coordination for the Improvement of Higher Education Personnel) covering the period from 1987-2011 to identify researchers who contributed substantially to protozoology. We selected 248 advisors by filtering to obtain researchers who supervised at least 10 theses. Based on a computational analysis of the thesis databases, we found students who were supervised by these scientists. A computational procedure was developed to determine the advisors’ scientific ancestors using the Lattes Platform. These analyses provided a list of 1,997 researchers who were inspected through Lattes CV examination and allowed the identification of the pioneers of Brazilian protozoology. Moreover, we investigated the areas in which researchers who earned PhDs in protozoology are now working. We found that 68.4% of them are still in protozoology, while 16.7% have migrated to other fields. We observed that support for protozoology by national or international agencies is clearly correlated with the increase of scientists in the field. Finally, we described the academic genealogy of Brazilian protozoology by formalising the “forest” of Brazilian scientists involved in the study of protozoa and their vectors over the past century.     

Long‐lived Snell dwarf mice display increased proteostatic mechanisms that are not dependent on decreased mTORC1 activity

Maintaining proteostasis is thought to be a key factor in slowed aging. In several growth‐restricted models of long‐life, we have shown evidence of increased proteostatic mechanisms, suggesting that proteostasis may be a shared characteristic of slowed aging. The Snell dwarf mouse is generated through the mutation of the Pit‐1 locus causing reductions in multiple hormonal growth factors and mTORC1 signaling. Snell dwarfs are one of the longest lived rodent models of slowed aging. We hypothesized that proteostatic mechanisms would be increased in Snell compared to control (Con) as in other models of slowed aging. Using D₂O, we simultaneously assessed protein synthesis in multiple subcellular fractions along with DNA synthesis in skeletal muscle, heart, and liver over 2 weeks in both sexes. We also assessed mTORC1‐substrate phosphorylation. Skeletal muscle protein synthesis was decreased in all protein fractions of Snell compared to Con, varied by fraction in heart, and was not different between groups in liver. DNA synthesis was lower in Snell skeletal muscle and heart but not in liver when compared to Con. The new protein to new DNA synthesis ratio was increased threefold in Snell skeletal muscle and heart compared to Con. Snell mTORC1‐substrate phosphorylation was decreased only in heart and liver. No effect of sex was seen in this study. Together with our previous investigations in long‐lived models, we provide evidence further supporting proteostasis as a shared characteristic of slowed aging and show that increased proteostatic mechanisms may not necessarily require a decrease in mTORC1.