Laboratoire d’Ethologie Expérimentale et Comparée

Review Panel of the ERS LAM Task Force L ymphangioleiomyomatosis (LAM) is a rare lung disease, which occurs sporadically or in association with the genetic disease tuberous sclerosis complex (TSC) Sporadic LAM affects ,1 in 400,000 adult females; in TSC, LAM occurs in 30-40% of adult females

This chapter contains sections titled: Introduction The Morphological-Anatomical Level: Bones as Skeletons and Organs The Microanatomical Level: Bone Structures and Processes The Histological Level: Bone as a Tissue (Table 2) Cells, Extracellular Matrix and Mineralization Non-Osseous Hard Tissues Evolutionary Trends Subject Index

Nonviral gene transfer into the central nervous system (CNS) offers the prospect of providing safe therapies for neurological disorders and manipulating gene expression for studying neuronal function. However, results reported so far have been disappointing. We show that the cationic polymer polyethylenimine (PEI) provides unprecedentedly high levels of transgene expression in the mature mouse brain. Three different preparations of PEI (25-, 50-, and 800-kD) were compared for their transfection efficiencies in the brains of adult mice. The highest levels of transfection were obtained with the 25-kD polymer. With this preparation, DNA/PEI complexes bearing mean ionic charge ratios closest to neutrality gave the best results. Under such conditions, and using a cytomegalovirus (CMV)-luciferase construction, we obtained up to 0.4 10(6) RLU/microgram DNA (equivalent to 0.4 ng of luciferase), which is close to the values obtained using PEI to transfect neuronal cultures and the more easily transfected newborn mouse brain (10(6) RLU/microgram DNA). Widespread expression (over 6 mm3) of marker (luciferase) or functional genes (bcl2) was obtained in neurons and glia after injection into the cerebral cortex, hippocampus, and hypothalamus. Transgene expression was found more than 3 months post-injection in cortical neurons. No morbidity was observed with any of the preparations used. Thus, PEI, a low-toxicity vector, appears to have potential for fundamental research and genetic therapy of the brain.

Whereas recent investigations have revealed viral, inflammatory, and vascular factors involved in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lung pathogenesis, the pathophysiology of neurological disorders in coronavirus disease 2019 (COVID-19) remains poorly understood. Olfactory and taste dysfunction are common in COVID-19, especially in mildly symptomatic patients. Here, we conducted a virologic, molecular, and cellular study of the olfactory neuroepithelium of seven patients with COVID-19 presenting with acute loss of smell. We report evidence that the olfactory neuroepithelium is a major site of SARS-CoV2 infection with multiple cell types, including olfactory sensory neurons, support cells, and immune cells, becoming infected. SARS-CoV-2 replication in the olfactory neuroepithelium was associated with local inflammation. Furthermore, we showed that SARS-CoV-2 induced acute anosmia and ageusia in golden Syrian hamsters, lasting as long as the virus remained in the olfactory epithelium and the olfactory bulb. Last, olfactory mucosa sampling from patients showing long-term persistence of COVID-19-associated anosmia revealed the presence of virus transcripts and of SARS-CoV-2-infected cells, together with protracted inflammation. SARS-CoV-2 persistence and associated inflammation in the olfactory neuroepithelium may account for prolonged or relapsing symptoms of COVID-19, such as loss of smell, which should be considered for optimal medical management of this disease.

The Dlx5 gene encodes a Distal-less-related DNA-binding homeobox protein first expressed during early embryonic development in anterior regions of the mouse embryo. In later developmental stages, it appears in the branchial arches, the otic and olfactory placodes and their derivatives, in restricted brain regions, in all extending appendages and in all developing bones. We have created a null allele of the mouse Dlx5 gene by replacing exons I and II with the E. coli lacZ gene. Heterozygous mice appear normal. Beta-galactosidase activity in Dlx5+/- embryos and newborn animals reproduces the known pattern of expression of the gene. Homozygous mutants die shortly after birth with a swollen abdomen. They present a complex phenotype characterised by craniofacial abnormalities affecting derivatives of the first four branchial arches, severe malformations of the vestibular organ, a delayed ossification of the roof of the skull and abnormal osteogenesis. No obvious defect was observed in the patterning of limbs and other appendages. The defects observed in Dlx5-/- mutant animals suggest multiple and independent roles of this gene in the patterning of the branchial arches, in the morphogenesis of the vestibular organ and in osteoblast differentiation.

Recently, modern neuroscience has made considerable progress in understanding how the brain perceives, discriminates, and recognizes odorant molecules. This growing knowledge took over when the sense of smell was no longer considered only as a matter for poetry or the perfume industry. Over the last decades, chemical senses captured the attention of scientists who started to investigate the different stages of olfactory pathways. Distinct fields such as genetic, biochemistry, cellular biology, neurophysiology, and behavior have contributed to provide a picture of how odor information is processed in the olfactory system as it moves from the periphery to higher areas of the brain. So far, the combination of these approaches has been most effective at the cellular level, but there are already signs, and even greater hope, that the same is gradually happening at the systems level. This review summarizes the current ideas concerning the cellular mechanisms and organizational strategies used by the olfactory system to process olfactory information. We present findings that exemplified the high degree of olfactory plasticity, with special emphasis on the first central relay of the olfactory system. Recent observations supporting the necessity of such plasticity for adult brain functions are also discussed. Due to space constraints, this review focuses mainly on the olfactory systems of vertebrates, and primarily those of mammals.

Abstract 1 Sex differentiates under genetic control during successive periods. Classical morphological and experimental data have shown the sexual bipotentiality of the developing structures. But, as a matter of fact, several observations indicate that both sexes are not equal or equipotential as to their developmental trends and mechanisms. 2 The developmental analysis of the body sex characteristics reveals a hormonal control. In animal experiments made by the author and by others it has been observed that many structures or systems develop along the feminine type in the absence of testes during several critical developmental stages. These structures include the genital tract, the hypothalamic centres controlling the pituitary function, the nervous structures mediating sex behaviour and possibly other tissues. The ovary is unnecessary for the feminine differentiation of these structures; in males, femaleness has to be repressed and maleness imposed by the testes. 3 The problem of gonadal sex differentiation is re-evaluated; developmental aspects occurring during normal development or in the gonads of freemartins in cattle are examined. During early sexual differentiation of the gonads, testes rapidly differentiate whereas ovaries are first characterized mainly by the fact that they do not become testes. These observations can be interpreted by assuming that in males a signal imposes masculinity on the gonadal primordia which otherwise would slowly become ovaries. 4 It is hypothesized that throughout sexual differentiation in mammals, maleness has to be actively imposed on a system which will become feminine if it escapes this control.

Homologies between vertebrate forebrain subdivisions are still uncertain. In particular the identification of homologs of the mammalian neocortex or the dorsal ventricular ridge (DVR) of birds and reptiles is still a matter of dispute. To get insight about the organization of the primordia of the main telencephalic subdivisions along the anteroposterior axis of the neural tube, a fate map of the dorsal prosencephalon was obtained in avian chimeras at the 8- to 9-somite stage. At this stage, the primordia of the pallium, DVR and striatum were located on the dorsal aspect of the prosencephalon and ordered caudorostrally along the longitudinal axis of the brain. Expression of homeobox-containing genes of the Emx, Dlx and Pax families were used as markers of anteroposterior developmental subdivisions of the forebrain in mouse, chick, turtle and frog. Their expression domains delineated three main telencephalic subdivisions in all species at the onset of neurogenesis: the pallial, intermediate and striatal neuroepithelial domains. The fate of the intermediate subdivisions diverged, however, between species at later stages of development. Homologies between forebrain subdivisions are proposed based on the conservation and divergence of these gene expression patterns.

A major evolutionary transition to eusociality with reproductive division of labor between queens and workers has arisen independently at least 10 times in the ants, bees, and wasps. Pheromones produced by queens are thought to play a key role in regulating this complex social system, but their evolutionary history remains unknown. Here, we identify the first sterility-inducing queen pheromones in a wasp, bumblebee, and desert ant and synthesize existing data on compounds that characterize female fecundity in 64 species of social insects. Our results show that queen pheromones are strikingly conserved across at least three independent origins of eusociality, with wasps, ants, and some bees all appearing to use nonvolatile, saturated hydrocarbons to advertise fecundity and/or suppress worker reproduction. These results suggest that queen pheromones evolved from conserved signals of solitary ancestors.

Variability of mitochondrial DNA (mtDNA) of the honey bee Apis mellifera L. has been investigated by restriction and sequence analyses on a sample of 68 colonies from ten different subspecies. The 19 mtDNA types detected are clustered in three major phylogenetic lineages. These clades correspond well to three groups of populations with distinct geographical distributions: branch A for African subspecies (intermissa, monticola, scutellata, andansonii and capensis), branch C for North Mediterranean subspecies (caucasica, carnica and ligustica) and branch M for the West European populations (mellifera subspecies). These results partially confirm previous hypotheses based on morphometrical and allozymic studies, the main difference concerning North African populations, now assigned to branch A instead of branch M. The pattern of spatial structuring suggests the Middle East as the centre of dispersion of the species, in accordance with the geographic areas of the other species of the same genus. Based on a conservative 2% divergence rate per Myr, the separation of the three branches has been dated at about 1 Myr BP.

The production and biological activity of selected toxic metabolites of fungal biological control agents are reviewed. These metabolites include destruxins, oxalic salts, trichothecenes, zearalenone, fumonisins, fusaric acid and aflatoxin isolated from Metarhizium anisopliae, Beauveria bassiana, Trichoderma spp., Fusarium spp., Alternaria alternata, F. oxysporum and Aspergillus spp., respectively.

Ten microsatellite loci and a partial sequence of the COII mitochondrial gene were used to investigate genetic differentiation in B. terrestris, a bumble bee of interest for its high-value crop pollination. The analysis included eight populations from the European continent, five from Mediterranean islands (six subspecies altogether) and one from Tenerife (initially described as a colour form of B. terrestris but recently considered as a separate species, B. canariensis). Eight of the 10 microsatellite loci displayed high levels of polymorphism in most populations. In B. terrestris populations, the total number of alleles detected per polymorphic locus ranged from 3 to 16, with observed allelic diversity from 3.8 +/- 0.5 to 6.5 +/- 1.4 and average calculated heterozygosities from 0.41 +/- 0.09 to 0.65 +/- 0.07. B. canariensis showed a significantly lower average calculated heterozygosity (0.12 +/- 0.08) and observed allelic diversity (1.5 +/- 0.04) as compared to both continental and island populations of B. terrestris. No significant differentiation was found among populations of B. terrestris from the European continent. In contrast, island populations were all significantly and most of them strongly differentiated from continental populations. B. terrestris mitochondrial DNA is characterized by a low nucleotide diversity: 0.18% +/- 0.07%, 0.20% +/- 0.04% and 0.27% +/- 0.04% for the continental populations, the island populations and all populations together, respectively. The only haplotype found in the Tenerife population differs by a single nucleotide substitution from the most common continental haplotype of B. terrestris. This situation, identical to that of Tyrrhenian islands populations and quite different from that of B. lucorum (15 substitutions between terrestris and lucorum mtDNA) casts doubts on the species status of B. canariensis. The large genetic distance between the Tenerife and B. terrestris populations estimated from microsatellite data result, most probably, from a severe bottleneck in the Canary island population. Microsatellite and mitochondrial DNA data call for the protection of the island populations of B. terrestris against importation of bumble bees of foreign origin which are used as crop pollinators.

A set of 52 (CT)n and 23 (GT)n microsatellites in honeybee, 24 (CT)n and 2 (GT)n microsatellites in bumble-bee (n > 6) have been isolated from partial genomic libraries and sequenced. On average, (CT)n and (GT)n microsatellites occur every 15 kb and 34 kb in honeybee and every 40 kb and 500 kb in bumble-bee, respectively. The prevailing categories are imperfect repeats for (CT)n microsatellites in bumble-bee, and perfect repeats for both (CT)n and (GT)n microsatellites in honey-bee. Comparisons with data available in vertebrates indicate a lower proportion of perfect repeats in bees but length distributions are very similar regardless the phylum. This result extends to insects the concept of an evolutionary conservation for quantitative and qualitative characteristics of (CT)n and (GT)n microsatellites. Many (CT)n and (GT)n repeats are surrounded with various types of microsatellites, revealing an associative distribution of short repeat sequences. As expected, a high level of intrapopulational polymorphism has been found with one tested honeybee microsatellite. Also, flanking regions of this microsatellite are similar enough to allow PCR amplification in several other species of Apis and Bombus.

To establish the sublethal concentrations domain, acute and chronic oral tests were conducted on caged honeybee workers (Apis mellifera L) using imidacloprid and a metabolite, 5-OH-imidacloprid, under laboratory conditions. The latter showed a 48-h oral LD50 value (153 ng per bee) five times higher than that of imidacloprid (30 ng per bee). Chronic feeding tests indicated that the lowest observed effect concentrations (LOEC) of imidacloprid and of 5-OH-imidacloprid on mortality of winter bees were 24 and 120 microg kg(-1) respectively. Behavioural effects of imidacloprid and 5-OH-imidacloprid were studied using the olfactory conditioning of proboscis extension response at two periods of the year. Winter bees surviving chronic treatment with imidacloprid and 5-OH-imidacloprid had reduced learning performances. The LOEC of imidacloprid was lower in summer bees (12 microg kg(-1)) than in winter bees (48 microg kg(-1)), which points to a greater sensitivity of honeybees behaviour in summer bees, compared to winter bees.

Primary and secondary form variants of Xenorhabdus isolated from 21 strains (13 species) of Steinernematidae and Heterorhabditidae were tested for 240 biochemical and physiological characters. Primary form variants, isolated from the infective stage nematodes, could always be distinguished from the secondary by adsorption of neutral red from MacConkey agar. Lecithinase, antibiotic activity and/or adsorption of bromothymol blue were useful for distinguishing the variants of most strains. The variants of all strains also differed for other characteristics but the distinguishing characteristics varied from strain to strain. The importance of including both variants of each strain and of using appropriate methods in the study of Xenorhabdus taxonomy was demonstrated.

Similar microsatellite electromorphs (PCR products of the same size) can arise from independent mutational events. Such alleles are not identical by descent. This phenomenon, termed size homoplasy, was studied by sequencing electromorphs of two microsatellite loci in which the stretch of basic repeats is interrupted by different short (1-2 bp) DNA motifs. The number and position of these interruptions were established for electromorphs from closely and distantly related populations of honeybees and bumblebees. No sequence difference was found when electromorphs came from the same subspecies or from closely related subspecies, suggesting that they were probably identical by descent. In contrast, sequence differences were often detected in distantly related subspecies, showing that size homoplasy frequently occurs at this level of population differentiation. Size homoplasy is increased by limits to free length variation of alleles, a phenomenon that seems to act on interrupted microsatellites when comparing distantly related taxa, that is, honeybee subspecies from different evolutionary lineages. Electromorph sequences suggest that, within the scope of these limits, large mutation events have occurred frequently at both interrupted loci studied. In good agreement with the molecular data, computations based on the observed heterozygosity and number of electromorphs and simulation studies showed that neither locus fits the one-step stepwise mutant model (SMM). We speculate that interrupted microsatellites in general could be characterized by a higher variance in repeat number and consequently a lower homoplasy rate than pure ones. Hence, interrupted microsatellites should be most appropriate for investigating population differentiation and evolutionary relationship between relatively distant populations.

Highly variable microsatellites enabled a precise assessment of the number of queen matings in the colonies of five bumble bee species. Fifteen of the sixteen microsatellites initially cloned from B. terrestris had flanking regions similar enough to allow PCR amplification on the other Bombus species analysed. The microsatellites selected for intracolony study (four per species) were characterized by a high heterozygosity (0.58-0.93) and a large number of alleles (3-18) in the local populations from which the colonies originated. A single male appeared to have inseminated the queens in the colonies of four species, B. terrestris, B. lucorum, B. lapidarius and B. pratorum, which belong to three subgenera, whereas two of the three analysed colonies of B. hypnorum were polyandrous (minimum number of two and four patrilines, respectively).

ABSTRACT Passive movement of the basal (thoracic-coxal) leg joint in the shore crab Carcinus maenas normally elicits a resistance reflex in the promotor and remotor motoneurones. Remotion of the joint excites promotor moto-neurones and promotion excites remotor motoneurones. This reflex behaviour may reverse and become an assistance reflex, where movement of the joint excites the motoneurones innervating the muscle which would assist the passive movement. This reversal of reflex activity appears to be dependent upon the central state of activity of the animal.

The antimicrobial, insecticidal, and hemolytic properties of peptides isolated from the venom of the predatory ant Pachycondyla goeldii, a member of the subfamily Ponerinae, were investigated. Fifteen novel peptides, named ponericins, exhibiting antibacterial and insecticidal properties were purified, and their amino acid sequences were characterized. According to their primary structure similarities, they can be classified into three families: ponericin G, W, and L. Ponericins share high sequence similarities with known peptides: ponericins G with cecropin-like peptides, ponericins W with gaegurins and melittin, and ponericins L with dermaseptins. Ten peptides were synthesized for further analysis. Their antimicrobial activities against Gram-positive and Gram-negative bacteria strains were analyzed together with their insecticidal activities against cricket larvae and their hemolytic activities. Interestingly, within each of the three families, several peptides present differences in their biological activities. The comparison of the structural features of ponericins with those of well-studied peptides suggests that the ponericins may adopt an amphipathic α-helical structure in polar environments, such as cell membranes. In the venom, the estimated peptide concentrations appear to be compatible with an antibacterial activity in vivo. This suggests that in the ant colony, the peptides exhibit a defensive role against microbial pathogens arising from prey introduction and/or ingestion.P82414P82415P82416P82417P82418P82419P82420P82421P82422P82423P82424P82425P82426P82427P82428 The antimicrobial, insecticidal, and hemolytic properties of peptides isolated from the venom of the predatory ant Pachycondyla goeldii, a member of the subfamily Ponerinae, were investigated. Fifteen novel peptides, named ponericins, exhibiting antibacterial and insecticidal properties were purified, and their amino acid sequences were characterized. According to their primary structure similarities, they can be classified into three families: ponericin G, W, and L. Ponericins share high sequence similarities with known peptides: ponericins G with cecropin-like peptides, ponericins W with gaegurins and melittin, and ponericins L with dermaseptins. Ten peptides were synthesized for further analysis. Their antimicrobial activities against Gram-positive and Gram-negative bacteria strains were analyzed together with their insecticidal activities against cricket larvae and their hemolytic activities. Interestingly, within each of the three families, several peptides present differences in their biological activities. The comparison of the structural features of ponericins with those of well-studied peptides suggests that the ponericins may adopt an amphipathic α-helical structure in polar environments, such as cell membranes. In the venom, the estimated peptide concentrations appear to be compatible with an antibacterial activity in vivo. This suggests that in the ant colony, the peptides exhibit a defensive role against microbial pathogens arising from prey introduction and/or ingestion.P82414P82415P82416P82417P82418P82419P82420P82421P82422P82423P82424P82425P82426P82427P82428 high pressure liquid chromatography minimal inhibitory concentration trifluoroethanol Social insects have developed a number of defensive systems that prevent the development of disease within colonies. For example, bee propolis and royal jelly present antimicrobial properties (1Fujiwara S. Imai J. Fujiwara M. Yaeshima T. Kawashima T. Kobayashi K. J. Biol. Chem. 1990; 265: 11333-11337Abstract Full Text PDF PubMed Google Scholar, 2Fernandes A. Lopes C.A.M. Sforcin J.M. Funari S.R.C. J. Venom. Anim. Toxins. 1996; 3: 287-294Crossref Google Scholar), and the fecal pellets of termites inhibit the development of fungal pathogens (3Rosengaus R.B. Guldin M.R. Traniello J.F.A. J. Chem. Ecol. 1998; 24: 1697-1706Crossref Scopus (102) Google Scholar). Within ants, most species possess metapleural glands on the thorax whose secretions, spread over the ants and throughout the nest, have a broad spectrum of antimicrobial action (4Hölldobler B. Engel-Siegel H. Psyche. 1984; 91: 201-224Crossref Scopus (105) Google Scholar, 5Maschwitz U. Koob K. Schildknecht H. J. Insect Physiol. 1970; 16: 387-404Crossref Scopus (107) Google Scholar, 6Veal D.A. Trimble J.E. Beattie A.J. J. Appl. Bacteriol. 1992; 72: 188-194Crossref PubMed Scopus (57) Google Scholar, 7Mackintosh J.A. Flood J.A. Veal D.A. Beattie A.J. Austr. J. Entomol. 1999; 38: 124-126Crossref Scopus (6) Google Scholar). The mandibular gland secretions of some army ant species also have a dual defensive role against both predators and microbial attacks of brood (8Brown C.A. Watkins J.F. Eldridge D.W. J. Kansas Entomol. Soc. 1979; 52: 119-122Google Scholar). If these mechanisms control the proliferation of many bacteria and fungi in the nesting environment, the introduction of pathogens may also arise from alimentation, especially prey. Among ants, predators stricto sensu are overrepresented within the subfamily Ponerinae (9Hölldobler B. Wilson E.O. The Ants. Springer-Verlag, Berlin1990Crossref Google Scholar). Most of these species capture almost every encountered prey using their venom (10Orivel J. Souchal A. Cerdan P. Dejean A. Sociobiology. 2000; 35: 131-140Google Scholar), which contains peptides (and proteins) (9Hölldobler B. Wilson E.O. The Ants. Springer-Verlag, Berlin1990Crossref Google Scholar, 11Blum M.S. Hermann H.R. Bettini S. Arthropod Venoms. Springer-Verlag, Berlin1978: 801-869Crossref Google Scholar, 12Schmidt J.O. Piek T. Venoms of the Hymenoptera: Biochemical, Pharmacological and Behavioural Aspects. Academic Press, London1986: 425-508Crossref Google Scholar). Because these prey are then brought back to the nest immediately after immobilization, their potential infection by bacteria, fungi, or viruses may seriously affect the survival of ant colonies or induce extensive damages because of the high population density combined with the close genetic relationship of the individuals. The antibacterial property of ant venom has only been demonstrated in the fire ant, Solenopsis invicta, in whose venom alkaloids inhibit the growth of both Gram-positive and Gram-negative bacteria and presumably act as a brood antibiotic (12Schmidt J.O. Piek T. Venoms of the Hymenoptera: Biochemical, Pharmacological and Behavioural Aspects. Academic Press, London1986: 425-508Crossref Google Scholar, 13Jouvenaz D.P. Blum M.S. MacConnell J.G. Antimicrob. Agents Chemother. 1972; 2: 291-293Crossref PubMed Scopus (72) Google Scholar). Venoms of the wasp,Vespa crabro, honey bees, and various snakes contain antimicrobial peptides, but their functions have not been investigated (14Oren Z. Shai Y. Biochemistry. 1997; 36: 1826-1835Crossref PubMed Scopus (370) Google Scholar, 15Krishnakumari V. Nagaraj R. J. Peptide Res. 1997; 50: 88-93Crossref PubMed Scopus (62) Google Scholar, 16Juvvadi P. Vunnam S. Merrifield R.B. J. Am. Chem. Soc. 1996; 118: 8989-8997Crossref Scopus (104) Google Scholar, 17Blaylock R.S.M. Toxicon. 2000; 38: 1529-1534Crossref PubMed Scopus (26) Google Scholar). Finally, lycotoxins isolated from spider venom are the only antimicrobial peptides in venom for which a preventive role against infections arising from prey ingestion has been demonstrated (18Yan L. Adams M.E. J. Biol. Chem. 1998; 273: 2059-2066Abstract Full Text Full Text PDF PubMed Scopus (152) Google Scholar). Here we investigate the possible role of the venom of a predatory ant species in the prevention of microbial disease. The antimicrobial, insecticidal, and hemolytic properties of the venom of the arboreal ponerine ant, Pachycondyla goeldii, were studied. In total, 15 novel peptides, named ponericins, were purified, and their primary structures were fully characterized through amino acid sequencing and matrix-assisted laser ionization/desorption time-of-flight mass spectrometry analyses. According to their amino acid sequences, ponericins were classified into three families named ponericin G, W, and L. Ten peptides were synthesized to perform detailed analyses of their biological activities. The relationships of these peptides with known antimicrobial peptides are discussed. Whole venom reservoirs were dissected from P. goeldiiants collected in Petit Saut, French Guiana. After rinsing in water, they were stored at −20 °C until processed. The venom reservoirs were disrupted by ultrasonic waves in a 30% acetonitrile, 0.2% trifluoroacetic acid solution (10 μl/venom reservoir), and empty reservoirs and membranes were discarded by centrifugation. Whole venom was injected into a C18 reversed-phase column (5 μm, particle size; 220 × 2.1-mm column; Vydac), and separations were performed at a flow rate of 200 μl/min. Peptide elution was monitored at 215 nm. Collected fractions were vacuum-dried and tested for biological activity. First, the venom was separated into four fractions with a gradient consisting of 10–80% solvent B (80% acetonitrile in 0.1% trifluoroacetic acid) for 60 min. Solvent A was 0.1% aqueous trifluoroacetic acid. Second, the venom was further purified on the same column with a biphasic gradient of 10–25% solvent B for 10 min and 25–55% solvent B for 75 min to improve the separation of the peptides contained in the active fraction. The purified peptides were analyzed by matrix-assisted laser ionization/desorption time-of-flight (Voyager Elite; PerSeptive Biosystems, Inc., Framingham, MA) mass spectrometry as described by Seon et al. (19Seon A.A. Pierre T.N. Redeker V. Lacombe C. Delfour A. Nicolas P. Amiche M. J. Biol. Chem. 2000; 275: 5934-5940Abstract Full Text Full Text PDF PubMed Scopus (24) Google Scholar). Peptides were sequenced by automated Edman degradation using a Procise pulse-liquid protein sequencer (model 494; PerkinElmer Life Sciences). About 30–60 pmol of peptide were dried and solubilized in 10 μl of 0.1 m ammonium acetate buffer, pH 5.5. Carboxyl-terminal sequences were determined by digestion with carboxypeptidase Y and mass spectrometry analysis of the digestion products as described by Seon et al. (19Seon A.A. Pierre T.N. Redeker V. Lacombe C. Delfour A. Nicolas P. Amiche M. J. Biol. Chem. 2000; 275: 5934-5940Abstract Full Text Full Text PDF PubMed Scopus (24) Google Scholar). Ten peptides were synthesized by Fmoc (N-(9-fluorenyl)methoxycarbonyl) chemistry and purified by Synt:em Peptides and were to the isolated to some ponericin was synthesized in a with the The peptide was and at the the for of for Because and peptides present the same in their sequence for and for together with differences or but have activity the peptide was further analyzed to an of the biological activity of their in the and hemolytic action of 10 peptides from P. at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested each the tested concentration was and the to the of the of at the tested in a For each the tested concentration was and the to the of the of venom and an of each were tested for their antibacterial activity against Gram-negative and Gram-positive activity was determined by the in were with 10 μl of the After at were by the peptides were tested against a of Gram-negative and Gram-positive microbial the and fungi in activity was determined by the A of and with was with a of the at and into in were with μl of the were at °C to the of the inhibitory and for at °C or on the activity was also by the The fungal colonies were into the close to a with the and from growth of the fungal colonies after of was as fungal The minimal inhibitory concentration of the peptides and was determined by liquid and growth on the strains in In the growth the were determined by a from an concentration of by in a buffer, pH activity was performed as described In the liquid growth μl of a of bacteria were to μl of growth was in by an in after at °C or The concentrations tested for each peptide were in the of The are as the concentration at which bacteria and the concentration that growth P. C. P. J. Biol. Chem. Full Text PDF PubMed Google Scholar). B from the from honey bee venom, and from the of the were as control antibiotic peptides in the growth action of ponericins and are as the the concentration tested at which the bacteria and the that growth growth growth action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested melittin, and were as peptides in the growth are as the the concentration tested at which the bacteria and the that growth action was at the concentration tested in a melittin, and were as peptides in the growth A of was with of or in were with μl of the peptide solution and at °C to the of the hemolytic After at and were of each peptide or a of of each of the 10 peptides was solubilized in an peptide were injected into of cricket 10 or P. of an or a dried solution of acetonitrile and trifluoroacetic acid in a The to the of of the larvae after was by analysis A of the Press, Scholar). The were in a using a The four peptides, ponericins and were solubilized in with and trifluoroethanol at at concentrations of and The were and with a a and spectrum was from The and were the same and then from the The structure was from each spectrum using the analysis P. PubMed Scopus Google Scholar). antibacterial of the venom of P. action against both Gram-positive and Gram-negative strains at a of The venom was separated on a reversed-phase into four of which only an antibacterial activity against the of the peptides in demonstrated that of the collected antibacterial properties The active peptides present in were analyzed by matrix-assisted laser ionization/desorption time-of-flight mass or were further studied. In total, 15 peptides were characterized at the of their amino acid sequences using Edman The amino acid sequence was also possible for peptides present in For some of the analyzed peptides, carboxypeptidase Y were to or of the amino acid. The of the with the was as a control for each sequence peptides can be classified into three families to their primary structures The peptides were named ponericins G, W, or L to the most amino acid. Within each most of the peptides share a of sequence with each to or for ponericins G, W, or The sequence similarities were using and Ponericins and present the sequence with the of the ponericin G and W families to for and and from to for were classified in the families because they some sequence features with the further investigate the antibacterial spectrum and insecticidal activity of each 10 of these 15 peptides to from each were synthesized as and Whole venom was active against the tested microbial strains the fungi Among the the most Gram-positive bacteria were B. B. and the most Gram-negative The 10 peptides four of antibacterial action at a concentration of Ponericins and an action to that of venom and were active against the tested bacteria and the The to the peptides and For the of the growth against Gram-positive bacteria were also to those with venom, but at the tested these peptides were active against most of the Gram-negative Within was the only that not affect the The of peptides and was active against most of the Gram-positive strains but against the Gram-negative with the of P. and Finally, ponericin only a of the tested be that of the peptides were against the fungal as for peptides and were for further analyses. member of each peptide a activity spectrum was for which was active against only a Their were determined in both liquid and growth against Gram-positive and Gram-negative strains or by most of the peptides In the liquid growth and a activity against most of the and were In the growth were at the of peptide in a the same of were with a action of peptide against most of the tested the comparison of their in the growth with those of melittin, and as peptides that their antimicrobial activity or for The hemolytic activity of the venom and the 10 peptides was tested on both and at the same concentration as the antimicrobial activity spectrum the were the most Whole venom and three peptides and of both and and were active and hemolytic activity only against The peptides not exhibit hemolytic activity. The insecticidal properties of P. venom were only in C. 10 peptides insecticidal properties against A. were active against and with Among these four peptides, and were the only that P. the of against ants was a possible of these ants against their action injected of the 10 peptides on the and ant of P. of the 10 action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested in a The concentration of each of the 10 peptides from to in the venom The from the growth in which the tested concentrations of each were and that most of the strains were that the antibacterial peptide in concentration to exhibit a antibacterial activity in the and concentration of the 10 synthesized peptides present in venom of P. of peptide venom of of ponericin was from the comparison of with the of the peptide of peptide present in venom was determined by the of the fractions to each peptide to the of a known of The concentration of each peptide was with a of the venom of by the to an The of ponericin was from the comparison of with the of the peptide in a The of peptide present in venom was determined by the of the fractions to each peptide to the of a known of The concentration of each peptide was with a of the venom of by the to an some structural features of the ponericins with known antibacterial peptides for which extensive structural have been we analyzed the of four peptides in and in The four peptides in as as in The for ponericin are as in In water, the are of a or structure with a nm. The in the of a solvent the of water, the of a high with a at and at and nm. The analysis of the in in a over for four peptides This the on the and of antibacterial peptides from ant 15 peptides, named ponericins and from the venom of the ponerine ant P. goeldii, present sequences not in were classified into three families to their primary structure ponericins G, W, and L. the of peptides, ponericins G, of action can be and have a action against the microbial strains and are also and are only active against some Gram-positive bacteria and and present insecticidal Ponericins G share sequence with using a of antimicrobial peptides that have been isolated from only families, and PubMed Scopus Google Scholar). the of the ponericins G the isolated from that can be as cecropin-like those isolated from C. M. J. S. A. P. J. Biol. 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Breast cancer is the most common type of cancer worldwide and one of the major causes of cancer death in women. Epidemiological studies have established a link between night-shift work and increased cancer risk, suggesting that circadian disruption may play a role in carcinogenesis. Here, we aim to shed light on the effect of chronic jetlag (JL) on mammary tumour development. To do this, we use a mouse model of spontaneous mammary tumourigenesis and subject it to chronic circadian disruption. We observe that circadian disruption significantly increases cancer-cell dissemination and lung metastasis. It also enhances the stemness and tumour-initiating potential of tumour cells and creates an immunosuppressive shift in the tumour microenvironment. Finally, our results suggest that the use of a CXCR2 inhibitor could correct the effect of JL on cancer-cell dissemination and metastasis. Altogether, our data provide a conceptual framework to better understand and manage the effects of chronic circadian disruption on breast cancer progression.