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1.
J Chem Ecol ; 51(1): 15, 2025 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-39888559

RESUMO

Cuticular hydrocarbons (CHCs) constitute an important class of chemical compounds present in the cuticular layer of insects, where their main functions are to prevent desiccation of the cuticle and as signals for intraspecific recognition. Studies concerning CHCs have shown a phenotypic flexibility of their composition, depending on environmental factors. However, the way that each of these factors influences this variation remains little explored. The aim of the present study was to evaluate the effects of environmental variations on the cuticular chemical composition of the ant Atta laevigata. Workers from four different colonies nesting in forest edge environments were collected over the course of a year, during the hot and humid and cold and dry seasons. The cuticular compounds were extracted and then analyzed by gas chromatography, revealing that the compounds of this species belonged to the classes of linear alkanes, mono, di and trimethyl alkanes, alkenes and alkadienes. Furthermore, the cuticular profile varied significantly among colonies of this species and between seasons, while intra-season variability was more significant during the hot and humid season. The observed temporal variation indicated that the numbers of compounds and the proportion of different types of CHC can vary according to the period of the year, however with a greater significant variation in colonies in the hot and humid season. These results showed that variations in environmental conditions, especially climate, can have decisive effects in the dynamics of cuticular chemistry.


Assuntos
Formigas , Hidrocarbonetos , Estações do Ano , Animais , Formigas/química , Formigas/fisiologia , Hidrocarbonetos/química , Hidrocarbonetos/análise , Hidrocarbonetos/metabolismo , Alcenos/análise , Alcenos/química , Alcenos/metabolismo , Alcanos/análise , Alcanos/química , Cromatografia Gasosa
2.
Chem Res Toxicol ; 38(1): 91-101, 2025 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-39829240

RESUMO

Acrylonitrile-butadiene-styrene (ABS) is a thermoplastic copolymer commonly used in the electronics, automotive, and construction industries. In the aquatic environment, the formation of microplastics from larger-sized plastic waste occurs naturally, induced by physical, chemical, and biological processes that promote the aging of these particles. Here, we investigated the interactions between the freshwater amphipod Hyalella azteca and ABS microplastics (10-20 µm) (pristine and after accelerated aging) over 7 days of exposure. At the end of the exposure period, we evaluated the ability of H. azteca to fragment the ABS particles, as well as the changes in its oxidative stress biomarkers (SOD, CAT, MDA, and GST) as the result of ABS exposure. H. azteca promoted a significant fragmentation of ABS particles. The ratio of this biofragmentation was more pronounced in pristine particles. Despite the absence of significant changes in the mortality of exposed organisms, alterations in the oxidative stress biomarkers were observed. The results demonstrate the ability of H. azteca to fragment pristine and aged ABS microplastics and, the consequent susceptibility of these organisms to the effects of microplastic exposure.


Assuntos
Anfípodes , Butadienos , Microplásticos , Estresse Oxidativo , Estresse Oxidativo/efeitos dos fármacos , Animais , Anfípodes/efeitos dos fármacos , Anfípodes/metabolismo , Microplásticos/toxicidade , Butadienos/química , Butadienos/toxicidade , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/química , Resinas Acrílicas/química , Resinas Acrílicas/toxicidade , Biomarcadores/metabolismo , Estireno/química , Estireno/toxicidade , Poliestirenos/química , Poliestirenos/toxicidade , Formigas
3.
Oecologia ; 207(1): 8, 2024 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-39653799

RESUMO

Mutualisms may be more or less sensitive to environmental conditions depending on the diversity and responses of the species involved. Ants frequently form mutualistic associations with plants bearing extrafloral nectaries (EFNs): the ants protect the plants from herbivores and receive food resources (i.e., nectar) in return. As ectotherms, ants are strongly influenced by temperature, and temperature shifts can affect ant-plant interactions in ways that often depend on species functional traits. In this study, we explored the influence of EFN size and leaf surface temperature on ant-plant interactions in a Caatinga dry forest in Brazil. We observed the ants visiting 14 EFN-bearing plant species at different times of day over 12 sampling months; we also measured leaf surface temperatures during these periods. We next quantified EFN size for 68 individuals from the 14 plant species. The observational data were used to characterize the heat tolerance of the attendant ant species (i.e., based on levels of foraging activity). We then evaluated the mutualism's degree of functional resilience using two indices: functional redundancy (i.e., the number of ant species interacting with a given plant species) and thermal response diversity (i.e., variability in the heat tolerance of the ant species interacting with a given plant species). We found that leaf surface temperature, but not EFN size, had an influence on mutualism functional resilience. As temperatures increased, both functional redundancy and thermal response diversity decreased. This result implies that warmer global temperatures could heighten the vulnerability of facultative ant-plant mutualisms, regardless of plant traits.


Assuntos
Formigas , Simbiose , Temperatura , Formigas/fisiologia , Animais , Brasil , Néctar de Plantas , Folhas de Planta , Plantas , Mirmecófitas
4.
Zootaxa ; 5461(1): 1-62, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-39646913

RESUMO

We review the taxonomy of the Neotropical species of the genus Pachycondyla. A new species (Pachycondyla beneditoi sp. n.) is described. Ponera pilosa new syn. is synonymized with P. crassinoda, based on a type male. Pachycondyla fuscoatra is redescribed and its distinctness from P. impressa is discussed. Pachycondyla harpax is still a taxonomic problem, with much morphological variation over a wide distribution. Pachycondyla impressa does not occur in Brazil; all previous records are P. fuscoatra or P. beneditoi. The gyne of P. lenkoi is described. Pachycondyla constricticeps new syn. is synonymized with P. striata. A neotype for P. fuscoatra is designated and lectotypes for P. harpax, P. impressa and P. striata are designated. An identification key for the Neotropical species is presented.


Assuntos
Distribuição Animal , Formigas , Tamanho Corporal , Animais , Brasil , Masculino , Formigas/classificação , Formigas/anatomia & histologia , Feminino , Tamanho do Órgão , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento
5.
Zootaxa ; 5523(2): 192-210, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39645943

RESUMO

Pheidole is the richest ant genus in the world. We describe herein three new species from the state of Puebla, Mexico: P. jolalpanensis sp. nov., P. latiscava sp. nov. and P. rojasae sp. nov. Additionally state records and notes are provided for P. lamia Wheeler 1901 and P. polymorpha Wilson 2003 for the Mexican states of Veracruz and Querétaro, respectively. Parts of Wilson's taxonomic keys are modified to allow the identification of the new species.


Assuntos
Distribuição Animal , Estruturas Animais , Formigas , Animais , México , Feminino , Masculino , Formigas/classificação , Formigas/anatomia & histologia , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Tamanho do Órgão , Tamanho Corporal
6.
Zootaxa ; 5477(5): 563-570, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-39646064

RESUMO

Ant attendance or trophobiosis is widely distributed in Auchenorrhyncha and can be defined as a disjunctive association, an interspecific relationship between two symbiotic organisms. Aggregation behavior with or without ant mutualism has been documented for nymphs and adults in a few families of Fulgoromorpha whereas ant-attendance is reported for all planthopper families except for Ricaniidae. Based on field observations of Pharsalus repandus Melichar, 1906, the present work aims to record the first mutualistic interaction of ant-attendance in a species of the family Ricaniidae, report its aggregation behavior, its host plant, and expand its known distribution to the states of Paraná and Minas Gerais. Two ants were attending the planthoppers at the same time, identified as Camponotus (Myrmotrhix) rufipes (Fabricius, 1775) and Camponotus (Myrmobrachys) crassus Mayr, 1862. We noted direct contact and observed the ants employing antennal palpation behavior to stimulate the planthoppers to deliver honeydew.


Assuntos
Distribuição Animal , Formigas , Hemípteros , Animais , Formigas/classificação , Formigas/fisiologia , Brasil , Hemípteros/classificação , Hemípteros/fisiologia , Hemípteros/anatomia & histologia , Feminino , Masculino , Tamanho Corporal , Simbiose , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Tamanho do Órgão , Comportamento Animal
7.
Proc Biol Sci ; 291(2037): 20241097, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39689882

RESUMO

The immune system is crucial for organisms to defend against pathogens. Likewise, analogous immune features evolved against similar pressures at the superorganism scale. Upregulating hygiene to the same fungus pathogen is one assumption for convergent immune mechanisms in social insects, although more evidence of immune memory features remains to be confirmed. Here, we assess immune memory traits at the colony level in the leaf-cutting ant Atta sexdens. We exposed their fungus cultivar to both homologous and heterologous challenges with the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana, as well as the mycoantagonistic fungi Fusarium oxysporum and Trichoderma spirale. By measuring ants' behaviours, we evaluated the capacity of A. sexdens: (i) to enhance their collective hygiene, (ii) speed their hygiene in further infections, (iii) how long this capacity lasts in the colonies and (iv) the degree of specificity to increase hygienic responses. Fungus grooming behaviour was enhanced mostly against entomopathogenic fungi, with a trend of faster reactions during homologous challenges. In general, the capacity to elicit such upregulated actions lasted for up to 30 days, but no longer than 60 days. Overall, colonies exhibited a degree of immune specificity, enhancing hygiene only in response to homologous exposures but decreasing it when infected secondarily with a different fungus, indicating flexible social immunity of A. sexdens after immune challenges.


Assuntos
Formigas , Beauveria , Metarhizium , Animais , Formigas/imunologia , Formigas/microbiologia , Formigas/fisiologia , Metarhizium/fisiologia , Beauveria/fisiologia , Comportamento Social , Fusarium/fisiologia , Memória Imunológica , Trichoderma/fisiologia , Trichoderma/imunologia , Comportamento Animal
8.
Glob Chang Biol ; 30(11): e17598, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39605176

RESUMO

Tropical biodiversity is undergoing unprecedented changes due to the hydrological cycle intensification, characterized by more intense droughts and wet seasons. This raises concerns about the resilience of animal and plant communities to such extremes and the existence of potential refugia-areas theorized to safeguard biological communities from adverse climate impacts. Over 20 years of monitoring in Central Amazonia, we investigated the short-term and long-term effects of hydrological cycle intensification on bird, fish, ant, and palm communities. We explored whether the 'insurance effect' of climate trends (droughts buffered by preceded wet seasons) or 'environmental refugia' (droughts or floods buffered by topographic features) could lessen the impact of climate events on community composition, richness, evenness, and species rank. Pronounced abundance changes were observed among animal species, whereas palm species showed relative temporal stability. Birds and fish were more affected by the immediate and long-term severity of droughts and wet periods, while ants responded primarily to short-term drought impacts. Conversely, palm communities exhibited delayed responses to climate extremes, primarily in long-term comparisons. As expected, the proposed 'insurance effect' mitigates the long-term impacts of extreme climate events on animal and plant community trends. However, less extreme hydrological conditions linked to topographic features did not provide effective 'environmental refugia' for animals or plants during adverse climate conditions. These outcomes underscore the complex and varied biological responses to ongoing climate change, challenging the prevailing assumptions about the efficacy of environmental refugia and highlighting the nuanced resilience of biodiversity in Central Amazonia.


A biodiversidade tropical está passando por mudanças sem precedentes devido à intensificação do ciclo hidrológico, caracterizada por secas mais intensas e estações chuvosas mais severas. Isso gera preocupações sobre a resiliência das comunidades de animais e plantas a esses extremos e a existência de potenciais refúgios ­ áreas teoricamente capazes de proteger as comunidades biológicas dos impactos climáticos adversos. Em mais de 20 anos de monitoramento na Amazônia Central, investigamos os efeitos de curto e longo prazo da intensificação do ciclo hidrológico sobre as comunidades de aves, peixes, formigas e palmeiras. Exploramos se o 'efeito seguro' das tendências climáticas (secas amortecidas por estações chuvosas precedentes) ou 'refúgios ambientais' (secas ou cheias amortecidas por características topográficas) poderiam atenuar o impacto dos eventos climáticos na composição das comunidades, riqueza, equidade e mudança na abundância das espécies. Mudanças pronunciadas na abundância foram observadas entre as espécies animais, enquanto as palmeiras apresentaram relativa estabilidade temporal. Aves e peixes foram mais afetados pela severidade imediata e de longo prazo das secas e períodos chuvosos, enquanto as formigas responderam principalmente aos impactos de secas de curto prazo. Em contrapartida, as palmeiras mostraram respostas atrasadas aos extremos climáticos, principalmente em comparações de longo prazo. Como esperado, o 'efeito seguro' proposto atenua os impactos de longo prazo de eventos climáticos extremos nas tendências das comunidades de animais e plantas. No entanto, condições hidrológicas menos extremas associadas a características topográficas não forneceram refúgios ambientais efetivos para animais ou plantas durante condições climáticas adversas. Esses resultados destacam as respostas biológicas complexas e variadas às mudanças climáticas em curso, desafiando as suposições predominantes sobre a eficácia dos refúgios ambientais e ressaltando a resiliência sutil da biodiversidade na Amazônia Central.


Assuntos
Formigas , Biodiversidade , Aves , Mudança Climática , Peixes , Florestas , Animais , Aves/fisiologia , Formigas/fisiologia , Peixes/fisiologia , Brasil , Secas , Arecaceae/fisiologia , Arecaceae/crescimento & desenvolvimento , Estações do Ano
9.
Science ; 386(6717): 105-110, 2024 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-39361762

RESUMO

Fungus-farming ants cultivate multiple lineages of fungi for food, but, because fungal cultivar relationships are largely unresolved, the history of fungus-ant coevolution remains poorly known. We designed probes targeting >2000 gene regions to generate a dated evolutionary tree for 475 fungi and combined it with a similarly generated tree for 276 ants. We found that fungus-ant agriculture originated ~66 million years ago when the end-of-Cretaceous asteroid impact temporarily interrupted photosynthesis, causing global mass extinctions but favoring the proliferation of fungi. Subsequently, ~27 million years ago, one ancestral fungal cultivar population became domesticated, i.e., obligately mutualistic, when seasonally dry habitats expanded in South America, likely isolating the cultivar population from its free-living, wet forest-dwelling conspecifics. By revealing these and other major transitions in fungus-ant coevolution, our results clarify the historical processes that shaped a model system for nonhuman agriculture.


Assuntos
Formigas , Coevolução Biológica , Fungos , Simbiose , Animais , Agricultura , Formigas/microbiologia , Formigas/genética , Domesticação , Fungos/genética , Fungos/classificação , Fotossíntese , Filogenia , América do Sul
10.
Oecologia ; 206(1-2): 175-186, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39369081

RESUMO

Fire is a major disturbance affecting ecosystems globally, but its impact on mutualisms has received minimal attention. Here, we use a long-term field experiment to investigate the impact of different fire regimes on globally important ant-honeydew and ant-extrafloral nectar (EFN) mutualistic interactions in an Australian tropical savanna. These interactions provide ants with a key energy source, while their plant and hemipteran hosts receive protection services. We examined ant interactions on species of Eucalyptus (lacking EFNs) and Acacia (with EFNs) in three replicate plots each of burning every 2 and 3 years early in the dry season, burning late in the dry season every 2 years, and unburnt for > 25 years. The proportions of plants with ant-honeydew interactions in Acacia (44.6%) and Eucalyptus (36.3%) were double those of Acacia plants with ant-EFN interactions (18.9%). The most common ants, representing 85% of all interactions, were behaviourally dominant species of Oecophylla, Iridomyrmex and Papyrius. Fire promoted the incidence of ant interactions, especially those involving EFNs on Acacia, which occurred on only 3% of plants in unburnt plots compared with 24% in frequently burnt plots. Fire also promoted the relative incidence of behaviourally dominant ants, which are considered the highest quality mutualists. Contrary to expectations, frequent fire did not result in a switching of behaviourally dominant ant partners from forest-adapted Oecophylla to arid-adapted Iridomyrmex. Our findings that frequent fire increases ant interactions mediated by honeydew and extrafloral nectar, and promotes the quality of ant mutualists, have important implications for protective services provided by ants in highly fire-prone ecosystems.


Assuntos
Formigas , Incêndios , Pradaria , Néctar de Plantas , Animais , Formigas/fisiologia , Austrália , Acacia , Simbiose , Eucalyptus , Ecossistema , Clima Tropical
11.
Virulence ; 15(1): 2413329, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39370781

RESUMO

The urgency surrounding Candida auris as a public health threat is highlighted by both the Center for Disease Control (CDC) and World Health Organization (WHO) that categorized this species as a priority fungal pathogen. Given the current limitations of antifungal therapy for C. auris, particularly due to its multiple resistance to the current antifungals, the identification of new drugs is of paramount importance. Some alkaloids abundant in the venom of the red invasive fire ant (Solenopsis invicta), known as solenopsins, have garnered attention as potent inhibitors of bacterial biofilms, and there are no studies demonstrating such effects against fungal pathogens. Thus, we herein investigated the antibiotic efficacy of solenopsin alkaloids against C. auris biofilms and planktonic cells. Both natural and synthetic solenopsins inhibited the growth of C. auris strains from different clades, including fluconazole and amphotericin B-resistant isolates. Such alkaloids also inhibited matrix deposition and altered cellular metabolic activity of C. auris in biofilm conditions. Mechanistically, the alkaloids compromised membrane integrity as measured by propidium iodide uptake in exposed planktonic cells. Additionally, combining the alkaloids with AMB yielded an additive antifungal effect, even against AMB-resistant strains. Finally, both extracted solenopsins and the synthetic analogues demonstrated protective effect in vivo against C. auris infection in the invertebrate model Galleria mellonella. These findings underscore the potent antifungal activities of solenopsins against C. auris and suggest their inclusion in future drug development. Furthermore, exploring derivatives of solenopsins could reveal novel compounds with therapeutic promise.


Assuntos
Alcaloides , Antifúngicos , Formigas , Biofilmes , Candida auris , Testes de Sensibilidade Microbiana , Animais , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida auris/efeitos dos fármacos , Candida auris/genética , Alcaloides/farmacologia , Alcaloides/química , Formigas/microbiologia , Candidíase/microbiologia , Candidíase/tratamento farmacológico , Venenos de Formiga/farmacologia , Venenos de Formiga/química , Formigas Lava-Pés
12.
PeerJ ; 12: e18197, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39469588

RESUMO

Two new species of Myrmozercon, M. serratus sp. nov. and M. spatulatus sp. nov., are described based on adults and deutonymphs collected in association with ants in Mexico. They represent the first records of this genus from the Neotropic s.s. faunal region. Both new species are associated with hosts in the genus Camponotus from the same small area of a coastal lagoon, which share the same nesting habit preferences, providing strong evidence for host specificity. All but one colony of C. atriceps hosted mites, whereas they occurred in only half of the colonies of C. rectangularis. There was a significant positive correlation between the abundance of C. atriceps sexual ants and the abundance of mites. We summarize the known host associations for the genus Myrmozercon and discuss host specificity. Larvae of both mite species were collected on the wings of males and gynes suggesting that egg laying occurs on the hosts reproductive caste. Two hypotheses explaining this observation are discussed, larvae may be phoretic on winged sexuals, favoring mite co-dispersal with hosts, or larvae reside on the alates as a refuge from predation.


Assuntos
Formigas , Especificidade de Hospedeiro , Ácaros , Animais , México , Formigas/fisiologia , Formigas/parasitologia , Ácaros/fisiologia , Ácaros/classificação , Masculino , Feminino , Simpatria , Larva/fisiologia
13.
Neotrop Entomol ; 53(5): 1119-1136, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39259443

RESUMO

We provide updated diagnoses for the senex-, burtoni- and dimorphus-groups of Camponotus (Myrmobrachys). Dichotomous keys for the C. (Myrmobrachys) groups and species of the dimorphus-group, based on type-specimens are provided. Two new species of the dimorphus-group are described, Camponotus cameloides sp. nov. and Camponotus hyalus sp. nov. We classified C. dolabratus and C. lancifer as members of the dimorphus-group and C. crassicornis, C. subcircularis, and C. championi as members of the senex-group. Scanning Electron Microscopy was used to describe the branched pilosity of C. cameloides and this is the first description of it for adult workers of Camponotini tribe.


Assuntos
Formigas , Microscopia Eletrônica de Varredura , Animais , Formigas/classificação , Formigas/anatomia & histologia , Feminino , Masculino
14.
Bull Entomol Res ; 114(4): 571-580, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39308218

RESUMO

Global warming is exposing many organisms to severe thermal conditions and is having impacts at multiple levels of biological organisation, from individuals to species and beyond. Biotic and abiotic factors can influence organismal thermal tolerance, shaping responses to climate change. In eusocial ants, thermal tolerance can be measured at the colony level (among workers within colonies), the population level (among colonies within species), and the community level (among species). We analysed critical thermal maxima (CTmax) across these three levels for ants in a semiarid region of northeastern Brazil. We examined the individual and combined effects of phylogeny, body size (BS), and nesting microhabitat on community-level CTmax and the individual effects of BS on population- and colony-level CTmax. We sampled 1864 workers from 99 ant colonies across 47 species, for which we characterised CTmax, nesting microhabitat, BS, and phylogenetic history. Among species, CTmax ranged from 39.3 to 49.7°C, and community-level differences were best explained by phylogeny and BS. For more than half of the species, CTmax differed significantly among colonies in a way that was not explained by BS. Notably, there was almost as much variability in CTmax within colonies as within the entire community. Monomorphic and polymorphic species exhibited similar levels of CTmax variability within colonies, a pattern not always explained by BS. This vital intra- and inter-colony variability in thermal tolerance is likely allows tropical ant species to better cope with climate change. Our results underscore why ecological research must examine multiple levels of biological organisation.


Assuntos
Formigas , Formigas/fisiologia , Animais , Brasil , Filogenia , Ecossistema , Tamanho Corporal , Termotolerância , Mudança Climática
15.
PLoS One ; 19(9): e0307604, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39226298

RESUMO

Nestmate recognition in ants is regulated through the detection of cuticular hydrocarbons by odorant receptors (ORs) in the antennae. These ORs are crucial for maintaining colony cohesion that allows invasive ant species to dominate colonized environments. In the invasive Argentine ant, Linepithema humile, ORs regulating nestmate recognition are thought to be present in a clade of nine-exon odorant receptors, but the identity of the specific genes remains unknown. We sought to narrow down the list of candidate genes using transcriptomics and phylostratigraphy. Comparative transcriptomic analyses were conducted on the antennae, head, thorax, and legs of Argentine ant workers. We have identified a set of twenty-one nine-exon odorant receptors enriched in the antennae compared to the other tissues, allowing for downstream verification of whether they can detect Argentine ant cuticular hydrocarbons. Further investigation of these ORs could allow us to further understand the mechanisms underlying nestmate recognition and colony cohesion in ants.


Assuntos
Formigas , Filogenia , Receptores Odorantes , Animais , Formigas/genética , Formigas/metabolismo , Receptores Odorantes/genética , Receptores Odorantes/metabolismo , Transcriptoma , Perfilação da Expressão Gênica , Antenas de Artrópodes/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo
16.
Food Chem Toxicol ; 193: 115018, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39307343

RESUMO

The investigation of coffee leaves as a source of bioactive principles represents a relatively unexplored area of research. The study assesses the potential adverse effects of an aqueous acetone extract derived from Coffea arabica var. Oro Azteca leaves. The phenolic composition of the extract was identified and quantified by UPLC-MS/MS, and its acute and repeated-dose effects were evaluated in six-week-old CD-1 mice (n = 11 for acute evaluation and n = 20 female and n = 20 male for repeated-dose evaluation). The extract demonstrated no significant toxicity, maintaining consistent body weight and exhibiting a hepatoprotective effect by reducing ALT levels at a dose of 500 mg/kg. Some hyperactivity was observed at the highest doses, but overall, the extract enhanced the immune response and showed no histological alterations, except for mild inflammation in certain organs. The extract, which contains abundant quinic acid, chlorogenic acid, epicatechin, procyanidin B2, and mangiferin, has been deemed safe for consumption.


Assuntos
Coffea , Extratos Vegetais , Folhas de Planta , Animais , Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade , Extratos Vegetais/química , Coffea/química , Folhas de Planta/química , Camundongos , Feminino , Masculino , Administração Oral , Acetona/química , Peso Corporal/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Espectrometria de Massas em Tandem , Formigas
17.
Sci Rep ; 14(1): 17813, 2024 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-39090121

RESUMO

Over 125 million years of ant-plant interactions have culminated in one of the most intriguing evolutionary outcomes in life history. The myrmecophyte Duroia hirsuta (Rubiaceae) is known for its mutualistic association with the ant Myrmelachista schumanni and several other species, mainly Azteca, in the north-western Amazon. While both ants provide indirect defences to plants, only M. schumanni nests in plant domatia and has the unique behaviour of clearing the surroundings of its host tree from heterospecific plants, potentially increasing resource availability to its host. Using a 12-year survey, we asked how the continuous presence of either only M. schumanni or only Azteca spp. benefits the growth and defence traits of host trees. We found that the continuous presence of M. schumanni improved relative growth rates and leaf shearing resistance of Duroia better than trees with Azteca. However, leaf herbivory, dry matter content, trichome density, and secondary metabolite production were the same in all trees. Survival depended directly on ant association (> 94% of trees died when ants were absent). This study extends our understanding of the long-term effects of strict ant-plant mutualism on host plant traits in the field and reinforces the use of D. hirsuta-M. schumanni as a model system suitable for eco-co-evolutionary research on plant-animal interactions.


Assuntos
Formigas , Mirmecófitas , Folhas de Planta , Rubiaceae , Simbiose , Animais , Formigas/fisiologia , Herbivoria , Mirmecófitas/crescimento & desenvolvimento , Mirmecófitas/fisiologia , Folhas de Planta/crescimento & desenvolvimento , Rubiaceae/crescimento & desenvolvimento , Rubiaceae/fisiologia , Árvores/crescimento & desenvolvimento
18.
Mol Omics ; 20(8): 524-531, 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39162257

RESUMO

The basidiomycete fungus Leucoagaricus gongylophorus is able to grow in the fungus garden of leaf-cutter ants. This mutualistic interaction has driven the evolutionary adaptation of L. gongylophorus, shaping its metabolism to produce enzymes adept at lignocellulosic biomass degradation. In this study, we undertook the comprehensive sequencing, assembly, and functional annotation of the genome of L. gongylophorus strain LEU18496, mutualistic fungus of the Atta mexicana. Our genomic analyses revealed a distinctive bimodal nature to the genome: a predominant region characterized by AT enrichment and low genetic density, alongside a smaller region exhibiting higher GC content and higher genetic density. The presence of transposable elements (TEs) within the AT-enriched region suggests genomic compartmentalization, facilitating differential evolutionary rates. With a gene count of 6748, the assembled genome of L. gongylophorus LEU18496 surpasses previous reports for this fungal species. Inspection of genes associated with central metabolism unveiled a remarkable abundance of carbohydrate-active enzymes (CAZymes) and fungal oxidative lignin enzymes (FOLymes), underscoring their pivotal roles in the life cycle of this fungus.


Assuntos
Genoma Fúngico , Anotação de Sequência Molecular , Simbiose , Simbiose/genética , Animais , Genômica/métodos , Elementos de DNA Transponíveis/genética , Agaricales/genética , Composição de Bases , Filogenia , Formigas/genética , Formigas/microbiologia , Basidiomycota/genética
19.
Braz J Biol ; 84: e284085, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38958299

RESUMO

The current study evaluates the antibacterial activity of Camponotus compressus (Hymenoptera: Formicidae) body crude extracts. The increasing antibiotic resistance of bacteria has prompted the world to turn its attention towards insects in the search for new sources of antibacterial compounds. The body crude extract obtained with different solvents were tested against both Gram positive (Staphylococcus aureus, Bacillus subtilis) and Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae). Standard disc diffusion method was used to perform the activity. The extracts of C. compressus were investigated for their effectiveness against all resistant pathogenic bacteria. Staphylococcus aureus was found to be the most susceptible, exhibiting a high average growth inhibition, while Bacillus subtilis showed a lower average growth inhibition zone. Our findings regarding the inhibitory effect of C. compressus extracts show the presence of a broad-spectrum antibacterial compound. This will be helpful in the search for novel natural antibiotics against robust pathogenic bacterial strains.


Assuntos
Antibacterianos , Formigas , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Testes de Sensibilidade Microbiana , Animais , Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Formigas/efeitos dos fármacos , Misturas Complexas/farmacologia
20.
Pest Manag Sci ; 80(12): 6159-6166, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39082239

RESUMO

BACKGROUND: Managing pest species of eusocial insects, such as leaf-cutting ants, poses significant challenges. Controlling them requires understanding of how toxic plant substrates and ant baits are recognized by foragers, transported to the nest, shared among workers and managed by gardeners cultivating the symbiont fungus garden. Despite this, little is known about how unsuitable resources might impact social interactions within ant colonies. This study aims to investigate whether the provision of a suitable substrate (copperleaf) and a toxic substrate (nasturtium leaves) affects the social network dynamics within colonies of two leaf-cutting ant species: Acromyrmex molestans and Acromyrmex subterraneus. The interactions between castes were recorded and subjected to social network analyses. RESULTS: Initial foraging duration increased for A. subterraneus provided with copperleaf, although no difference was observed for the other species and resource combinations. The social network structure was similar for both species when copperleaf leaves were provided as a substrate. However, notable alterations occurred with nasturtium leaf provision, leading to higher integration of gardeners in interactions and noticeable changes in the generalist worker network centrality, particularly in A. subterraneus. DISCUSSION: The observed changes in social interactions, particularly in A. subterraneus, suggest that increasing gardener interactions with other castes expedites the movement of the substrate within the colony. This maximizes the potential toxic effect on the colony. © 2024 Society of Chemical Industry.


Assuntos
Formigas , Folhas de Planta , Formigas/fisiologia , Animais , Comportamento Social , Estresse Fisiológico
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