Selected Natural Materials in History

1 Technology of natural materials Early man used conveniently shaped stones as tools. ＂Workshop＂ areas have been found with large numbers of stones, some showing signs of being worked. However, organic materials like wood will decay under normal wet conditions in the presence of oxygen, so we won＇t find the same sort of evidence for wooden tools. It is safe to assume that early man used sticks as probes and clubs, and maybe even for making some sort of nestlike protection against the elements and predators, since we see chimpanzees and other animals doing this sort of thing. So wood, and ahnost certainly other plant materials such as fibrous leaves, and bone and other materials gleaned from dead animals, would be used from the earliest times. We need to know this in order to establish the idea that Man can be expected to have a long history of the use and manipulation of natural materials. This needs skills in choosing materials for certain uses on the basis of their mechanical properties, whether those properties are to do with the ease of shaping the material or the effectiveness of that material in use. Occasionally the material was chosen simply because it was readily available. If we find that a particular material was always used for a certain job, it＇s reasonable to deduce that Man was exerting materials selection criteria through experience.     

Does defensive posture increase mimetic fidelity of caterpillars with eyespots to their putative snake models？

Organisms often evolve behaviours that increase or reinforce the protection from predators afforded by their morpho- logical defences. For example, mimetic animals may adopt postures or locomotory behaviours that emulate a characteristic fea- ture of their model to increase predator deception. Caterpillars with eyespots are thought to mimic snakes, and when threatened many of these caterpillars adopt a posture that appears to enhance this resemblance. Herein we evaluate the quantitative strength of evidence of behavioural mimicry in the caterpillars of 14 species by comparing how closely a series of putative snake-mimicking caterpillars resemble snakes while at rest and when threatened. Specifically, we quantified the head morphology and eye position of a range of snake species, as well as the shape of the apparent head （i.e. anterior body segments） and position of eyespots in caterpillars resting or in their defensive posture. This allowed us to objectively examine evidence for an increased resemblance to either snakes generally, or to Viperidae snakes specifically, upon adopting the defensive posture. Widening the anterior body segments during the defensive posture typically made caterpillars appear more viper-like as opposed to more snake-like in general. Enhanced resemblance to vipers upon mounting the defensive posture was apparent only from the dorsal view. Laterally, caterpillars more closely resembled snakes in the resting posture and shifting to the defensive posture instead reduced mimetic fidelity, Overall we found evidence for behavioural mimicry in all 14 species examined. We highlight that objectively quantifying mimetic fidelity can help identify key features involved in deception .     

Generalization of predator recognition:Velvet geckos display anti-predator behaviours in response to chemicals from non-dangerous elapid snakes

<正> Many prey species detect chemical cues from predators and modify their behaviours in ways that reduce their risk ofpredation. Theory predicts that prey should modify their anti-predator responses according to the degree of threat posed by thepredator. That is, prey should show the strongest responses to chemicals of highly dangerous prey, but should ignore or respondweakly to chemicals from non-dangerous predators. However, if anti-predator behaviours are not costly, and predators are rarelyencountered, prey may exhibit generalised antipredator behaviours to dangerous and non-dangerous predators. In Australia, mostelapid snakes eat lizards, and are therefore potentially dangerous to lizard prey. Recently, we found that the nocturnal velvetgecko Oedura lesueurii responds to chemicals from dangerous and non-dangerous elapid snakes, suggesting that it displays generalisedanti-predator behaviours to chemicals from elapid snakes. To explore the generality of this result, we videotaped the behaviourof velvet geckos in the presence of chemical cues from two small elapid snakes that rarely consume geckos: the nocturnalgolden-crowned snake Cacophis squamulosus and the diurnal marsh snake Hemiaspis signata. We also videotaped geckos in trialsinvolving unscented cards (controls) and cologne-scented cards (pungency controls). In trials involving Cacophis and Hemiaspischemicals, 50% and 63% of geckos spent long time periods ( 3 min) freezing whilst pressed flat against the substrate, respectively.Over half the geckos tested exhibited anti-predator behaviours (tail waving, tail vibration, running) in response to Cacophis(67%) or Hemiaspis (63%) chemicals. These behaviours were not observed in control or pungency control trials. Our resultssupport the idea that the velvet gecko displays generalised anti-predator responses to chemical cues from elapid snakes.Generalised responses to predator chemicals may be common in prey species that co-occur with multiple, ecologically similar,dangerous predators [Current Zoology 56 (3): 337-342, 2010].     

Color variation in signal crayfish Pacifastacus leniusculus

External coloration in animals depends on the interaction of several different factors including the genetics and epigenetics processes that underlie the color expression,the mechanisms of color perception,and the general mechanisms controlling color evolution and function.Among all,camouflages from predators and conspicuousness are of particular interest because pose animal to choose between opposite adjustment in coloration.The external coloration of crustaceans is mainly due to the accumulation of carotenoids in the exoskeleton and the epidermal layer,and the trade-off between camouflage and communication had led to a variety of responses,involving signal partitioning,spectral sensibility,changing coloration,or signaling behavior.Here,we used digital images to explore intrapopulation variability of the external coloration of Pacifastacus leniusculus among body regions within an individual and between sexes.We found that 1)ventral coloration of claws are more saturated and brilliant than upper parts,2)males express a more saturated and brightness coloration than females,especially on the lower portion of claws,3)color intensity and brightness increases with size differently in different body regions,and 4)brightness is more variable in males than in females.All the above patterns support the hypothesis that color in this species could be the result of a compromise between camouflage from predators and conspicuousness for communication.The results of this study suggest that carotenoid might have something to do with intraspecific communication and perform more complex functions than that of a simple pigment.     

More than mimicry？ Evaluating scope for flicker-fusion as a defensive strategy in coral snake mimics

Coral snakes and their mimics often have brightly colored banded patterns, generally associated with warning colora- tion or mimicry. However, such color patterns have also been hypothesized to aid snakes in escaping predators through a ＂flicker-fusion＂ effect. According to this hypothesis, banded color patterns confuse potential predators when a snake transitions from resting to moving because its bands blur together to form a different color. To produce this motion blur, a moving snake＇s bands must transition faster than the critical flicker-fusion rate at which a predator＇s photoreceptors can refresh. It is unknown if coral snakes or their mimics meet this requirement. We tested this hypothesis by measuring the movement speed and color pat- terns of two coral snake mimics, Lampropeltis triangulum campbelli and L. elapsoides, and comparing the frequency of color transitions to the photoreceptor activity of the avian eye. We found that snakes often produced a motion blur, but moving snakes created a blurring effect more often in darker conditions, such as sunrise, sunset, and nighttime when these snakes are often active. Thus, at least two species of coral snake mimics are capable of achieving flicker-fusion, indicating that their color patterns may confer an additional defense aside from mimicry     

Overexpression of Aurora-A kinase promotes tumor cell proliferation and inhibits apoptosis in esophageal squamous cell carcinoma cell line

Attrora-A kinase, a serine/threonine protein kinase, is a potential oncogene. Amplification and overexpression of Aurora-A have been found in several types of human tumors, including esophageal squamous cell carcinoma （ESCC）. It has been demonstrated that cells overexpressing Attrora-A are more resistant to cisplatin-induced apoptosis. However, the molecular mechanisms mediating these effects remain largely unknown. In this report, we showed that overexpression of Attrora-A through stable transfection of pEGFP-Aurora-A in human ESCC KYSE150 cells significantly promoted cell proliferation and inhibited cisplatin- or UV irradiation-induced apoptosis. Cleavages of caspase-3 and poly （ADPribose） polymerase （PARP） in Attrora-A overexpressing cells were substantially reduced after cisplatin or UV treatment. Furthermore, we found that silencing of endogenous Aurora-A kinase with siRNA substantially enhanced sensitivity to cisplatin- or UV-induced apoptosis in human ESCC EC9706 cells. In parallel, overexpression of Aurora-A potently upregulated the expression of Bcl-2. Moreover, the knockdown of Bcl-2 by siRNA abrogated the Aurora-A＇s effect on inhibiting apoptosis. Taken together, these data provide evidence that Aurora-A overexpression promoting cell proliferation and inhibiting apoptosis, suggesting a novel mechanism that is closely related to malignant phenotype and anti-cancer drugs resistance of ESCC cells.     

The evolution and functional diversification of animal microRNA genes

microRNAs （miRNAs） are an abundant class of-22 nucleotide （nt） regulatory RNAs that are pervasive in higher eukaryotic genomes. In order to fully understand their prominence in genomes, it is necessary to elucidate the molecular mechanisms that can diversify miRNA activities. In this review, we describe some of the many strategies that allow novel miRNA functions to emerge, with particular emphasis on how miRNA genes evolve in animals. These mechanisms include changes in their sequence, processing, or expression pattern; acquisition of miRNA^＊ functionality or antisense processing; and de novo gene birth. The facility and versatility of miRNAs to evolve and change likely underlies how they have become dominant constituents of higher genomes.     

Asymmetry in genitalia is in sync with lateralized mating behavior but not with the lateralization of other behaviors

Asymmetries in bilateral organisms attract a lot of curiosity given that they are conspicuous departures from the norm.They allow the investigation of the integration at different levels of biological organization.Here we study whether and how behavioral and asymmetrical anatomical traits coevolved and work together.We ask if asymmetry is determined locally for each trait or at a whole individual level in a species bearing conspicuous asymmetrical genitalia.Asymmetric genitalia evolved in many species;however,in most cases the direction of asymmetry is fixed.Therefore,it has been rarely determined if there is an association between the direction of asymmetry in genitalia and other traits.In onesided livebearer fish of the genus Jenynsia(Cyprinodontiformes,Anablepidae),the anal fin of males is modified into a gonopodium,an intromittent organ that serves to inseminate females.The gonopodium shows a conspicuous asymmetry,with its tip bending either to the left or the right.By surveying 13 natural populations of Jenynsia lineata,we found that both genital morphs are equally common in wild populations.In a series of experiments in a laboratory population,we discovered asymmetry and lateralization for multiple other traits;yet,the degree of integration varied highly among them.Lateralization in exploratory behavior in response to different stimuli was not associated with genital morphology.Interestingly,the direction of genital asymmetry was positively correlated with sidedness of mating preference and the number of neuromasts in the lateral line.This suggests integration of functionally linked asymmetric traits;however,there is no evidence that asymmetry is determined at the whole individual level in our study species.     

Annotated expressed sequence tags and xenobiotic detoxification in the aphid Myzus persicae （Sulzer）

Aphids （Hemiptera： Aphididae） are phytophagous insects that are important agricultural pests. The enormous negative economic impacts caused by aphids worldwide are well known, and are mostly due to their high multiplication rate and the transmission of phytopathogenic viruses. Aphid management strategies mainly involve chemical treatments which are pollutants and are increasingly inefficient, since aphids have developed multiple insecticide-resistant mechanisms. Among the most economically important species is the green peach aptfid Myzus persicae Sulzer （Aphididae： Macrosiphini）, which is able to colonize a wide range of host plants belonging to many different families, and transmits numerous plant viruses. Because of its large prevalence, M. persicae has been the target of massive insecticide treatments; consequently, it has evolved several insecticide-resistant mechanisms. In this work, a collection of expressed genes from M. persicae is presented in order to identify putative genes involved in xenobiotic detoxification. After cDNA cloning and sequencing, 959 expressed sequence tags （EST） were annotated. Most sequences matched known genes corresponded to metabolism proteins （26%）, ribosomal proteins （ 23 % ） and structural proteins （8%）. Among them, several sequences corresponded to proteins putatively involved in sensing, degradation or detoxification of plant xenobiotic products.     

“Second-generation” stem cells for cardiac repair

Over the last years, stem cell therapy has emerged asan inspiring alternative to restore cardiac function after myocardial infarction. A large body of evidence has been obtained in this field but there is no conclusive data on the efficacy of these treatments. Preclinical studies and early reports in humans have been encouraging and have fostered a rapid clinical translation, but positive results have not been uniformly observed and when present, they have been modest. Several types of stem cells, manufacturing methods and delivery routes have been tested in different clinical settings but direct comparison between them is challenging and hinders further research. Despite enormous achievements, major barriers have been found and many fundamental issues remain to be resolved. A better knowledge of the molecular mechanisms implicated in cardiac development and myocardial regeneration is critically needed to overcome some of these hurdles. Genetic and pharmacological priming together with the discovery of new sources of cells have led to a "second generation" of cell products that holds an encouraging promise in cardiovascular regenerative medicine. In this report, we review recent advances in this field focusing on the new types of stem cells that are currently being tested in human beings and on the novel strategies employed to boost cell performance in order to improve cardiac function and outcomes after myocardial infarction.     

Investigating bee dietary preferences along a gradient of floral resources:how does resource use align with resource availability?

Bee dietary preferences,or the floral resources that they consistently collect,likely impact where a species can persist.For this reason it is likely that bee dietary preferences are dependent upon the composition of the plant community.In this study,we evaluated floral visits and pollen loads of the mining bee,Andrena angustitarsata Viereck,across a 630 km north-south range to understand dietary preferences along a floral resource gradient.Previous research,in a more geographically limited area,suggested this species was an eclectic oligolege on predominantly Apiaceae and in part Rosaceae.In the present study we found the species predominately visited and collected pollen from Apiaceae and Rosaceae,but visited 12 flower families and collected pollen from 32,distinguishing them as generalist foragers.The frequency of Apiaceae pollen on the bees and the species-level specialization index(a measure of visit specialization)were higher in regions with higher Apiaceae abundance.In addition Apiaceae and Rosaceae were the only plant families significantly preferred for pollen collection,regardless of floral abundance.We conclude that across our study region A.angustitarsata has a generalist dietary breadth,but also has dietary preference for Apiaceae and Rosaceae.Our study indicates that while bees may overall make generalist foraging decisions they may still prefer and likely benefit from selecting fewer flower taxa.     

Hard to fly the nest： A study of body condition and plumage quality in house sparrow fledglings

Contrary to the nestling phase, the post-fledging phase has been less studied probably because it is challenging to follow the chicks after they fledge. However, this phase is crucial to consider when focusing on the life cycle of individuals because it is associated with new demands： After leaving the nest, individuals have to find their own food and cope with a new set of previously unknown stressors. In this study, we aimed at better understanding how energetically demanding the post-ftedging period is in house sparrows Passer domesticus by measuring several indices of a fledgling＇s state （body condition, fat and muscle scores and plumage quality）. If the energetic demands of the post-fledging period are greater than those of the adult life, we predicted that fledglings should be in lower condition and should have a plumage of lower quality relative to adults. Supporting this prediction, the condition and the plumage of fledglings differed dramatically from those of adults. Interestingly, this difference disappeared in autumn. Overall, our results suggest that the post-fledging period is probably one of the most energetically demanding of the life cycle in this species. Supporting this idea, the resighting probability of fledglings was lower relative to adults. However, resighting probability depends on many factors （mortality, dispersal, habitat use and behaviours） and future studies are necessary to tease apart their relative importance in determining resighting probability [Current Zoology 60 （4）： 449-459, 2014].     

Recombination-Independent Mechanisms and Pairing of Homologous Chromosomes during Meiosis in Plants

Meiosis is the specialized eukaryotic cell division that permits the halving of ploidy necessary for game- togenesis in sexually reproducing organisms, This involves a single round of DNA replication followed by two successive divisions. To ensure balanced segregation, homologous chromosome pairs must migrate to opposite poles at the first meiotic division and this means that they must recognize and pair with each other beforehand. Although understanding of the mechanisms by which meiotic chromosomes find and pair with their homologs has greatly advanced, it remains far from being fully understood. With some notable exceptions such as male Drosophila, the recognition and physical link- age of homologs at the first meiotic division involves homologous recombination. However, in addition to this, it is clear that many organisms, including plants, have also evolved a series of recombination-independent mechanisms to facili- tate homolog recognition and pairing. These implicate chromosome structure and dynamics, telomeres, centromeres, and, most recently, small RNAs. With a particular focus on plants, we present here an overview of understanding of these early, recombination-independent events that act in the pairing of homologous chromosomes during the first meiotic division,     

Insect host-parasite coevolution in the light of experimental evolution

The many ways parasites can impact their host species have been the focus of intense study using a range of approaches. A particularly promising but under-used method in this context is experimental evolution, because it allows targeted manipulation of known populations exposed to contrasting conditions. The strong potential of applying this method to the study of insect hosts and their associated parasites is demonstrated by the few available long-term experiments where insects have been exposed to parasites. In this review, we summarize these studies, which have delivered valuable insights into the evolution of resistance in response to parasite pressure, the underlying mechanisms, as well as correlated genetic responses. We further assess findings from relevant artificial selection studies in the interrelated contexts of immunity, life history, and reproduction. In addition, we discuss a number of well-studied Tribolium castaneum-Nosema whitei coevolution experiments in more detail and provide suggestions for research. Specifically, we suggest that future experiments should also be performed using nonmodel hosts and should incorporate contrasting experimental conditions, such as population sizes or envi- ronments. Finally, we expect that adding a third partner, for example, a second parasite or symbiont, to a host-parasite system could strongly impact （co）evolutionary dynamics.     

Mechanisms of autophagy and apoptosis: Recent developments in breast cancer cells

Autophagy,the pathway whereby cell components are degraded by lysosomes,is involved in the cell response to environmental stresses,such as nutrient deprivation,hypoxia or exposition to chemotherapeutic agents.Under these conditions,which are reminiscent of certain phases of tumor development,autophagy either promotes cell survival or induces cell death. This strengthens the possibility that autophagy could be an important target in cancer therapy,as has been proposed.Here,we describe the regulation of survival and death by autophagy and apoptosis,especially in cultured breast cancer cells.In particular,we discuss whether autophagy represents an apoptosis-independent process and/or if they share common pathways. We believe that understanding in detail the molecular mechanisms that underlie the relationships between autophagy and apoptosis in breast cancer cells could improve the available treatments for this disease.     

Cytoplasmic dynein: a key player in neurodegenerative and neurodevelopmental diseases

Cytoplasmic dynein is the most important molecular motor driving the movement of a wide range of cargoes towards the minus ends of microtubules.As a molecular motor protein,dynein performs a variety of basic cellular functions including organelle transport and centrosome assembly.In the nervous system,dynein has been demonstrated to be responsible for axonal retrograde transport.Many studies have revealed direct or indirect evidence of dynein in neurodegenerative diseases such as amyotrophic lateral sclerosis,Charcot-Marie-Tooth disease,Alzheimer’s disease,Parkinson’s disease and Huntington’s disease.Among them,a number of mutant proteins involved in various neurodegenerative diseases interact with dynein.Axonal transport disruption is presented as a common feature occurring in neurodegenerative diseases.Dynein heavy chain mutant mice also show features of neurodegenerative diseases.Moreover,defects of dynein-dependent processes such as autophagy or clearance of aggregation-prone proteins are found in most of these diseases.Lines of evidence have also shown that dynein is associated with neurodevelopmental diseases.In this review,we focus on dynein involvement in different neurological diseases and discuss potential underlying mechanisms.     

Special Issue on ＂Metagenomics of Marine Environments＂

We are pleased to announce a special issue on ＂Metagenomics of Marine Environments＂ of the journal Genomics, Proteomics ＆ Bioinformatics （GPB）, aiming to provide a platform for high-quality papers focusing on the topic and we invite submissions for this special issue （to be published in August of 2015）.
With most microbes being difficult or impossible to culture, metagenomic approaches based on culture- independent genomic sequencing provide the first real insight of the magnitude and diversity of microbial life that remains largely uncharted. The first metagenomic study of surface water of the Sargasso Sea revealed roughly 1800 species of microbes found in these samples, with 150 new bacterial species and over 1.2 million new genes. The astounding number of genes found in these samples suggests that microbial life in the ocean is far more abundant and diverse than one would expect.