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showing 10 items of 36149 documents
Identification and expression analysis of theSpodoptera exiguaneuropeptidome under different physiological conditions
2018
Neuropeptides are small signalling molecules acting as neurohormones, neurotransmitters and neuromodulators. Being part of the chemical communication system between cells within an organism, they are involved in the regulation of different aspects of animal physiology and behaviour such as feeding, reproduction, development and locomotion. Transcriptomic data from larval and adult tissues have been obtained and mined to generate a comprehensive neuropeptidome for the polyphagous insect pest Spodoptera exigua. Sixty-three neuropeptides have been identified and described based on their tissue specificity and their regulation in response to different abiotic perturbations. Expression analyses …
Cuticular hydrocarbon profiles differ between ant body parts: implications for communication and our understanding of CHC diffusion.
2020
Abstract Insect cuticular hydrocarbons (CHCs) serve as communication signals and protect against desiccation. They form complex blends of up to 150 different compounds. Due to differences in molecular packing, CHC classes differ in melting point. Communication is especially important in social insects like ants, which use CHCs to communicate within the colony and to recognize nestmates. Nestmate recognition models often assume a homogenous colony odor, where CHCs are collected, mixed, and redistributed in the postpharyngeal gland (PPG). Via diffusion, recognition cues should evenly spread over the body surface. Hence, CHC composition should be similar across body parts and in the PPG. To te…
Behavioural, ecological, and evolutionary aspects of diversity in frog colour patterns
2016
The role of colours and colour patterns in behavioural ecology has been extensively studied in a variety of contexts and taxa, while almost overlooked in many others. For decades anurans have been the focus of research on acoustic signalling due to the prominence of vocalisations in their communication. Much less attention has been paid to the enormous diversity of colours, colour patterns, and other types of putative visual signals exhibited by frogs. With the exception of some anecdotal observations and studies, the link between colour patterns and the behavioural and evolutionary ecology of anurans had not been addressed until approximately two decades ago. Since then, there has been eve…
Pace-of-life in a social insect: behavioral syndromes in ants shift along a climatic gradient
2017
Lay SummaryLinks between behavioral traits can shift with the local climate. We show that behavioral associations with temperature not only occur across, but also within populations. At warmer sites ant colonies increased their exploration and foraging activity, but were less aggressive. Moreover, at these warmer sites, more positive links were found between behaviors within populations compared to colder sites, where more negative links prevailed. Our study suggests that associations between behaviors shift along climatic gradients.
Olive Growing in a Time of Change: From Empiricism to Genomics
2016
Since its beginning, the olive crop has been a long-lived agricultural system in the Mediterranean Basin being well adapted to this area. Traditional olive growing, still prevalent in most producing areas, is characterized by low tree density and rainfed orchards with low yield and manually harvested. The traditional olive growing technology is local, diverse, and empirically based. New high density, irrigated, and mechanically harvested orchards has been progressively planted since the end of World War II. These plantations produce high crops at low costs, but they reduce the diversity of cultivars, increase the demand of inputs and the risk of environment unbalances. The expansion and int…
Recombinant laccase from Pediococcus acidilactici CECT 5930 with ability to degrade tyramine
2017
Biogenic amines degradation by bacterial laccases is little known, so we have cloned and heterologously expressed, in E. coli, a new laccase from Pediococcus acidilactici CECT 5930 (Lpa5930), a lactic acid bacterium commonly found in foods able to degrade tyramine. The recombinant enzyme has been characterized by physical and biochemical assays. Here we report the optimization of expression and purification procedures of this laccase. DNA encoding sequence of laccase from P. acidilactici was amplified by PCR and cloned into the expression plasmid pET28a for induction by isopropyl-β-D-thiogalactoipyranoside. Protein expression was performed in E. coli BL21(DE3) harboring pGro7 plasmid expres…
Sexual selection in a wolf spider: Male drumming activity, body size, and viability
1996
Females are often believed to actively choose highly ornamented males (males with extravagant morphological signals or intense sexual display), and ornaments should be honest signals of male viability. However, this belief is relying only on some pieces of empirical evidence from birds. Our study reports active female choice on sexual display that indicates male viability in spiders. We established trials in which we studied female choice in relation to male courtship drumming activity and body size. Females chose the most actively drumming males as mating partners, but the body size of the males did not seem to be selected. Male drumming activity turned out to be a good predictor of male v…
Mycorrhizal symbiosis primes the accumulation of antiherbivore compounds and enhances herbivore mortality in tomato
2021
Abstract Plant association with arbuscular mycorrhizal fungi (AMF) can increase their ability to overcome multiple stresses, but their impact on plant interactions with herbivorous insects is controversial. Here we show higher mortality of the leaf-chewer Spodoptera exigua when fed on tomato plants colonized by the AMF Funneliformis mosseae, evidencing mycorrhiza-induced resistance. In search of the underlying mechanisms, an untargeted metabolomic analysis through ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS) was performed. The results showed that mycorrhizal symbiosis had a very limited impact on the leaf metabolome in the absence of stress, but significantly m…
Clonal populations of Clavibacter michiganensis subsp michiganensis are responsible for the outbreaks of bacterial canker in greenhouse tomatoes in I…
2015
Clavibacter michiganensis subsp. michiganensis (Cmm) strains, collected in greenhouses from 17 farms during tomato bacterial canker outbreaks occurring between 2005 and 2008 in Sicily, were analysed by a multiphasic approach. Population studies were conducted to investigate the possible sources of inocula. Cmm strains were characterized by PCR assays targeting virulence genes, fingerprinting techniques, metabolic profiles and virulence. These strains were comparatively analysed with Cmm strains isolated in other parts of Italy over a period of 15 years. Chromosomal genes encoding virulence determinants tomA, ppaA, chpC, and the plasmid-encoded genes pat-1 and celA were detected by PCR in al…
Melatonin in the seasonal response of the aphid Acyrthosiphon pisum.
2018
Aphids display life cycles largely determined by the photoperiod. During the warm long-day seasons, most aphid species reproduce by viviparous parthenogenesis. The shortening of the photoperiod in autumn induces a switch to sexual reproduction. Males and sexual females mate to produce overwintering resistant eggs. In addition to this full life cycle (holocycle), there are anholocyclic lineages that do not respond to changes in photoperiod and reproduce continuously by parthenogenesis. The molecular or hormonal events that trigger the seasonal response (i.e., induction of the sexual phenotypes) are still unknown. Although circadian synthesis of melatonin is known to play a key role in verteb…