-
MicroPublication Biology 2024Ant behavior relies on a collection of natural products, from following trail pheromones during foraging to warding off potential predators. How nervous systems sense...
Ant behavior relies on a collection of natural products, from following trail pheromones during foraging to warding off potential predators. How nervous systems sense these compounds to initiate a behavioral response remains unclear. Here, we used chemotaxis assays to investigate how ant compounds are detected by heterospecific nervous systems. We found that avoid extracts of the pavement ant ( ) and either or ion channels are required for this response. These experiments were conducted in an undergraduate laboratory course, demonstrating that new insights into interspecies interactions can be generated through genuine research experiences in a classroom setting.
PubMed: 38596360
DOI: 10.17912/micropub.biology.001146 -
Veterinary Medicine and Science May 2024The odours of different body parts and structures, such as external genitalia, female urine, ventral tail radix, infraorbital sinus and interdigital sinus, have a strong...
BACKGROUND
The odours of different body parts and structures, such as external genitalia, female urine, ventral tail radix, infraorbital sinus and interdigital sinus, have a strong attractiveness for rams. The sinus interdigitalis is considered an important trail gland for sexual behaviour, as its odour is included in the list of strongly attractive structures for male animals during the breeding season, being important in pheromone production.
OBJECTIVES
In the present study, the effects of sex and breeding season on the morphological and histological structure of the interdigital gland were investigated in Hamdani crossbred sheep (Ovis aries).
METHODS
Sinus interdigitalis glands located on the forelimbs and hind limbs were collected from 10 male and 10 female sheep during both breeding and non-breeding seasons. The gland's position in the forelimbs and hind limbs was determined radiographically. The glands were examined macroscopically, histologically and immunohistochemically in both seasons.
RESULTS
In all animals, the topographic location of the gland between the digits was determined to be distal to the phalanx proximalis and at the level of the phalanx media. The mean weight of the gland in male and female animals was 1.07 ± 0.03 and 1.4 ± 0.11 g, respectively. In general, the results of morphometric measurements were higher during the breeding season, and the increase was more pronounced in female animals. In histological examinations, it was determined that both neck and body parts of the tissues consisted of a structure consisting of a connective tissue capsule at the outermost, dermis, epidermis and lumen underneath. Immunohistochemically staining revealed that oestrogen receptors showed positive immunoreactions only in the intracytoplasmic localization of apocrine sweat glands. In terms of morphological, histological and oestrogen receptors, it was thought that the gland may play a role in sexual communication.
Topics: Male; Sheep; Female; Animals; Seasons; Sheep, Domestic; Receptors, Estrogen
PubMed: 38595037
DOI: 10.1002/vms3.1450 -
Chemical species recognition in an adaptive radiation of Hawaiian spiders (Araneae: Tetragnathidae).Proceedings. Biological Sciences Apr 2024Studies of adaptive radiations have played a central role in our understanding of reproductive isolation. Yet the focus has been on human-biased visual and auditory...
Studies of adaptive radiations have played a central role in our understanding of reproductive isolation. Yet the focus has been on human-biased visual and auditory signals, leaving gaps in our knowledge of other modalities. To date, studies on chemical signals in adaptive radiations have focused on systems with multimodal signalling, making it difficult to isolate the role chemicals play in reproductive isolation. In this study we examine the use of chemical signals in the species recognition and adaptive radiation of Hawaiian spiders by focusing on entire communities of co-occurring species, and conducting behavioural assays in conjunction with chemical analysis of their silks using gas chromatography-mass spectrometry. Male spiders significantly preferred the silk extracts of conspecific mates over those of sympatric heterospecifics. The compounds found in the silk extracts, long chain alkyl methyl ethers, were remarkably species-specific in the combination and quantity. The differences in the profile were greatest between co-occurring species and between closely related sibling species. Lastly, there were significant differences in the chemical profile between two populations of a particular species. These findings provide key insights into the role chemical signals play in the attainment and maintenance of reproductive barriers between closely related co-occurring species.
Topics: Animals; Humans; Male; Spiders; Hawaii; Species Specificity; Reproductive Isolation; Silk
PubMed: 38593845
DOI: 10.1098/rspb.2023.2340 -
BioRxiv : the Preprint Server For... Mar 2024Decisions made over long time scales, such as life cycle decisions, require coordinated interplay between sensory perception and sustained gene expression. The dauer...
Decisions made over long time scales, such as life cycle decisions, require coordinated interplay between sensory perception and sustained gene expression. The dauer (or diapause) exit developmental decision requires sensory integration of population density and food availability to induce an all-or-nothing organismal-wide response, but the mechanism by which this occurs remains unknown. Here, we demonstrate how the ASJ chemosensory neurons, known to be critical for dauer exit, perform sensory integration at both the levels of gene expression and calcium activity. In response to favorable conditions, dauers rapidly produce and secrete the dauer exit-promoting insulin-like peptide INS-6. Expression of in the ASJ neurons integrate population density and food level and can reflect decision commitment since dauers committed to exiting have higher expression levels than those of non-committed dauers. Calcium imaging in dauers reveals that the ASJ neurons are activated by food, and this activity is suppressed by pheromone, indicating that sensory integration also occurs at the level of calcium transients. We find that expression in the ASJ neurons depends on neuronal activity in the ASJs, cGMP signaling, a CaM-kinase pathway, and the pheromone components ascr#8 and ascr#2. We propose a model in which decision commitment to exit the dauer state involves an autoregulatory feedback loop in the ASJ neurons that promotes high INS-6 production and secretion. These results collectively demonstrate how insulin-like peptide signaling helps animals compute long-term decisions by bridging sensory perception to decision execution.
PubMed: 38586049
DOI: 10.1101/2024.03.20.586022 -
Scientific Reports Apr 2024In this work, we identified the trail pheromone of the ant Crematogaster scutellaris. We combined gas chromatography-mass spectrometry analysis of extracts from the hind...
In this work, we identified the trail pheromone of the ant Crematogaster scutellaris. We combined gas chromatography-mass spectrometry analysis of extracts from the hind tibia, the location of the respective glands, with automated trail following assays. The study found tridecan-2-ol to be the strongest discriminator between hind tibia and other body part extracts. Tridecan-2-ol elicited trail-following behaviour at concentrations of 1 ng/µL. A separation of the enantiomers showed responses to (R)-tridecan-2-ol already at 0.001 ng/µL and only at a 1000-fold higher concentration for (S)-tridecan-2-ol, suggesting that only the R enantiomer is used by C. scutellaris in its natural environment. We also found strong behavioural responses to 2-dodecanol, a substance that was not detectable in the hind tibia extract of C. scutellaris, but which has been reported to be the trail pheromone of the related species C. castanea. We discuss the contribution of these results to the 'dissection and reconstruction' of strategies and mechanisms underlying the social organization of ants.
Topics: Animals; Pheromones; Ants; Behavior, Animal; Feeding Behavior
PubMed: 38570567
DOI: 10.1038/s41598-024-58383-2 -
BioMed Research International 2024is lactic acid bacteria that produce bacteriocins. Bacteriocins are antimicrobial peptides or proteins that exhibit activity against closely related bacteria. The aim...
BACKGROUND
is lactic acid bacteria that produce bacteriocins. Bacteriocins are antimicrobial peptides or proteins that exhibit activity against closely related bacteria. The aim of this study was to determine the effect of ATCC 4356 bacteriocin against . We used four different phenotypic methods for antimicrobial activities against two standard strains: methicillin-resistant (MRSA) ATCC 33591 and methicillin-susceptible (MSSA) ATCC 25923. The methods were (1) agar well diffusion, (2) overlay soft agar, (3) paper disk, and (4) modification of punch hole. The ammonium sulfate method was used to concentrate crude bacteriocin, and ultrafiltration and dialysis tubes were used to remove ammonium sulfate from the bacteriocins. Each method was repeated in triplicate.
RESULT
ATCC 4356 showed antimicrobial activity against both MRSA and MSSA standard strains only by the overlay soft agar method and not by the agar well diffusion, punch hole modification, and paper disk methods. No antimicrobial effects were observed in crude bacteriocins concentrated.
CONCLUSION
The growth inhibition of in overlay soft agar method may be due to the production of bacteriocin-like substances. The overlay soft agar method is a qualitative test, so there is a need for further study to optimize the conditions for the production of bacteriocin-like substances in the culture supernatant and precise comparison between the inhibitory activity and pheromone secretion of different strains.
Topics: Humans; Staphylococcus aureus; Bacteriocins; Lactobacillus acidophilus; Methicillin-Resistant Staphylococcus aureus; Agar; Ammonium Sulfate; Staphylococcal Infections; Anti-Infective Agents; Anti-Bacterial Agents
PubMed: 38559901
DOI: 10.1155/2024/4119960 -
Nature Communications Mar 2024Extracellular vesicles (EVs) are integral to numerous biological processes, yet it is unclear how environmental factors or interactions among individuals within a...
Extracellular vesicles (EVs) are integral to numerous biological processes, yet it is unclear how environmental factors or interactions among individuals within a population affect EV-regulated systems. In Caenorhabditis elegans, the evolutionarily conserved large EVs, known as exophers, are part of a maternal somatic tissue resource management system. Consequently, the offspring of individuals exhibiting active exopher biogenesis (exophergenesis) develop faster. Our research focuses on unraveling the complex inter-tissue and social dynamics that govern exophergenesis. We found that ascr#10, the primary male pheromone, enhances exopher production in hermaphrodites, mediated by the G-protein-coupled receptor STR-173 in ASK sensory neurons. In contrast, pheromone produced by other hermaphrodites, ascr#3, diminishes exophergenesis within the population. This process is regulated via the neuropeptides FLP-8 and FLP-21, which originate from the URX and AQR/PQR/URX neurons, respectively. Our results reveal a regulatory network that controls the production of somatic EV by the nervous system in response to social signals.
Topics: Humans; Animals; Male; Caenorhabditis elegans; Pheromones; Caenorhabditis elegans Proteins; Neurons; Extracellular Vesicles
PubMed: 38548742
DOI: 10.1038/s41467-024-47016-x -
Molecules (Basel, Switzerland) Mar 2024The impact of organometallic chemistry on the terpene field only really blossomed in the 1960s and 1970s with the realisation that carbon-carbon bond formation under... (Review)
Review
The impact of organometallic chemistry on the terpene field only really blossomed in the 1960s and 1970s with the realisation that carbon-carbon bond formation under mild conditions could be achieved by using nickel or iron carbonyls as synthetic reagents. Concomitantly, the development of palladium derivatives capable of the controlled coupling of isoprene units attracted the attention of numerous highly talented researchers, including future Nobel laureates. We discuss briefly how early work on the syntheses of simple monoterpenes soon progressed to sesquiterpenes and diterpenes of increasing complexity, such as humulene, flexibilene, vitamin A, or pheromones of commercial value, in particular those used in perfumery (muscone, lavandulol), or grandisol and red scale pheromone as replacements for harmful pesticides. As the field progressed, there has been more emphasis on developing organometallic routes to enantiopure rather than racemic products, as well as gaining precise mechanistic data on the transformations, notably the course of metal-promoted molecular rearrangements that have long been a feature of terpene chemistry. We note the impact of the enormously enhanced analytical techniques, high-field NMR spectroscopy and X-ray crystallography, and their use to re-examine the originally proposed structures of terpenes and their organometallic derivatives. Finally, we highlight the very recent ground-breaking use of the crystalline sponge method to acquire structural data on low-melting or volatile terpenes. The literature cited herein covers the period 1959 to 2023.
PubMed: 38543044
DOI: 10.3390/molecules29061409 -
Animals : An Open Access Journal From... Mar 2024The effects of climate change are becoming more apparent, predominantly concerning the impacts of ocean acidification on calcifying species. Many marine organisms rely...
The effects of climate change are becoming more apparent, predominantly concerning the impacts of ocean acidification on calcifying species. Many marine organisms rely on chemical signals for processes such as foraging for food, predator avoidance, or locating mates. The process of how chemical cues in marine invertebrates function, and how this sensory mode is affected by pH levels, is less researched. We tested the impact of reduced pH (7.6), simulating end-of-the-century predicted average ocean pH, against current oceanic pH conditions (8.2), on the behavioural response of male shore crabs to the female sex pheromone bouquet consisting of Uridine-diphosphate (UDP) and Uridine-triphosphate (UTP). While in current pH conditions (8.2), there was a significant increase in sexual interactions in the presence of female pheromone, males showed reduced sexual behaviours at pH 7.6. The crab weight-pH relationship, in which larger individuals respond more intensely sexually in normal pH (8.2), is reversed for both the initial detection and time to locate the cue. These results indicate that lowered pH alters chemical signalling in also outside the peak reproductive season, which may need to be taken into account when considering the future management of this globally invasive species.
PubMed: 38540046
DOI: 10.3390/ani14060948 -
Insects Mar 2024Quantitative real-time PCR (qRT-PCR) is a widely applied technique for accurately assessing the expression of target genes. In practice, the evaluation of gene...
Quantitative real-time PCR (qRT-PCR) is a widely applied technique for accurately assessing the expression of target genes. In practice, the evaluation of gene expression requires appropriate reference genes. To screen reliable reference genes for evaluating gene expression via qRT-PCR in , a notorious migratory pest across Asia, Africa, Europe, and Australia, we assessed the expression stability of 13 candidate reference genes in using the ΔCt method, BestKeeper, Normfinder, GeNorm, and the web-based comprehensive platform RefFinder. These reference genes include , , , , , , , , , , , , and , which is frequently employed in Lepidoptera insects. Our findings revealed that the performance of the candidate reference gene depended on experimental conditions. Specifically, and were the most suitable for evaluating expression changes across developmental stages, tissues, and adult ages. The optimal reference genes were recommended in specific experiment conditions, for instance, and were recommended for mating status, and were recommended for temperature treatments, and - were recommended for larva diet, and and were recommended for adult diet treatments. Additionally, expression profiles of pheromone-binding protein 2 () and glutathione S-transferase () were used to validate the reference genes. This study provides reference genes for the accurate normalization of qRT-PCR data, laying the groundwork for studying the expression of target genes in .
PubMed: 38535380
DOI: 10.3390/insects15030185