Biology Letters最新文献

{"title":"Absence of supergene-linked determination of wing polymorphism and alternative reproductive strategies in the ant Hypoponera opacior.","authors":"Anna Lenhart, Hugo Darras, Susanne Foitzik","doi":"10.1098/rsbl.2026.0070","DOIUrl":"https://doi.org/10.1098/rsbl.2026.0070","url":null,"abstract":"<p><p>Social insects frequently exhibit intraspecific variation in reproductive strategies, characterized by pronounced differences in the morphology, physiology and behaviour of reproductive individuals and the social organization of the colony. In many ant species, this complex variation is governed by supergenes that control multiple traits, including queen morphology and dispersal behaviour, as well as the number of queens that can coexist within a colony. Here, we investigate the genetic basis of sexual dimorphism in the ant Hypoponera opacior, which produces both winged and wingless morphs in males and queens, each associated with distinct reproductive behaviours and seasonal activity. Using whole-genome resequencing of all morphs, we tested for signatures of supergene architecture. Our analyses revealed no evidence for a supergene or other large genomic rearrangement underlying this morphological and behavioural diversity. These findings suggest that male and queen morph determination in H. opacior is not controlled by a large structural polymorphism and may instead result from phenotypic plasticity, environmentally sensitive developmental switches or polygenic factors. Our study demonstrates that complex social traits in ants can evolve and persist without supergene architectures and underscores the importance of considering alternative genetic and epigenetic mechanisms underlying reproductive polymorphisms.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147761441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sex differences in the enjoyment of enrichment: affective bias testing confirms female rats prefer more playful and less vigorous tickling.","authors":"Catalina Gonzalez, Alistair B Lawrence, Michael Mendl, Emma Robinson, Vincent Bombail, Sarah M Brown","doi":"10.1098/rsbl.2026.0075","DOIUrl":"https://doi.org/10.1098/rsbl.2026.0075","url":null,"abstract":"<p><p>There is increasing interest in positive animal welfare which emphasizes that animals should experience predominantly positive mental states. Positive animal welfare raises challenging biological questions, including how we assess positive experiences. Rat tickling mimics rough and tumble play; it is applied to improve welfare and study positive affect, often using ultrasonic vocalizations (USVs) to assess rats' affective state. Standard tickling protocols involve frequent pinning where the supine rat is vigorously tickled on its belly, which we have argued may not be positive for all rats. Here, using an affective bias test, we show that both sexes experience positive affective states when tickled, but females, unlike males, prefer playful tickling with minimal pinning. This result corresponds with our previous work using USVs to assess rats' affective response to tickling, further validating USV recording as a marker of positive affective states. We believe this to be the first example where a refinement aimed at enhancing positive, rather than minimizing negative, mental states in animals has been independently validated; this should provide a model for similar studies in other species. In rats, this refinement should enhance welfare and more generally demonstrate the importance of considering sex differences when designing welfare interventions.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147688001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental infections with a honey bee virus induce fitness costs in ant colonies.","authors":"Lai Ka Lo, Ashmita Baruah, Robert J Paxton, Yuko Ulrich","doi":"10.1098/rsbl.2025.0779","DOIUrl":"https://doi.org/10.1098/rsbl.2025.0779","url":null,"abstract":"<p><p>Acute bee paralysis virus (ABPV) is a key driver of honey bee colony losses that has been increasingly reported in non-bee hosts. Ants have long been hypothesized to act as viral reservoirs, but most evidence comes from field surveys and experimental tests are still scarce. Here, we combined survival and transmission assays, viral load quantification and viral replication assays following experimental inoculations to test whether the clonal raider ant Ooceraea biroi can harbour and transmit ABPV within its colonies. ABPV-injected immatures and adults showed delayed development and elevated mortality, respectively. Viral replication assays suggested these fitness costs were caused by host responses (e.g. immunopathology) rather than viral replication. Viral particles persisted for days in inoculated ants, and high viral loads were detected in untreated colony members after 1-3 days of cohabitation with ABPV-injected pupae or adults, indicating rapid viral spread. These results show that ants can acquire ABPV, incur fitness costs and pass on the virus within their colonies, suggesting that they may act as incidental viral reservoirs. By maintaining and disseminating honey bee viruses, even without supporting replication, ants may contribute to their environmental persistence and spillover across species.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147687961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Light and drug effects reveal three pathways for nitric oxide modulation of the first visual synaptic relay in the lamina ganglionaris.","authors":"Hugo Alejandro Álvarez, Jorge Cebada, Carmen Grijota-Martínez, Laura Ivón Láscarez-Lagunas, Amira Flores-Urbina","doi":"10.1098/rsbl.2025.0653","DOIUrl":"https://doi.org/10.1098/rsbl.2025.0653","url":null,"abstract":"<p><p>The modulation of synaptic relay mechanisms in the visual pathway remains a significant area of investigation. Here, we explore the role of nitric oxide (NO) in the eyestalks of the Australian blue crayfish Cherax quadricarinatus, focusing on its relationship with light exposure and potential regulatory pathways involving NO promoters and inhibitors. NO levels in the eyestalks were assessed using the Griess technique under various light-dark cycles and different physiological parameters (size, weight and sex) of adult crayfish. We found a light-dependent modulation of NO concentration, with constant light exposure significantly elevating NO levels compared with periods where darkness is involved and a negative trend as darkness increased. Interestingly, size, weight and sex variations showed no discernible impact on NO levels. Moreover, the influence of histamine (a primary neurotransmitter involved in the first visual synaptic relay) and a nitric oxide synthase (NOS) inhibitor, such as NG-nitro-l-arginine methyl ester (l-NAME), or the H2-blocker ranitidine, was investigated. As expected, histamine notably enhanced NO synthesis, whereas NOS inhibitors and H2 blockers led to substantial reductions in nitrite concentrations. The findings point to three possible mechanisms of action: (i) a light-induced release of histamine from retinal photoreceptors that activates postsynaptic receptors in lamina ganglionaris monopolar neurons, inducing NO synthesis and retrograde modulation of the photoreceptor; (ii) a histamine-dependent activation of postsynaptic receptors in monopolar cells that promotes NOS-mediated NO production, which retrogradely recruits lamina interneurons (e.g. GABAergic horizontal/amacrine cells) to mediate lateral inhibition of photoreceptors through GABA and/or ACh; and (iii) a mechanism in which light-induced histamine release activates photoreceptor auto-receptors, leading to NO release from the photoreceptor to cells of the lamina ganglionaris.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147687969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Annuality and C4 photosynthesis co-occur but evolved independently in warm, dry environments.","authors":"Laura Schat, Marc Fradera-Soler, Maria S Vorontsova, Siri Fjellheim, Aelys Muriel Humphreys","doi":"10.1098/rsbl.2025.0829","DOIUrl":"https://doi.org/10.1098/rsbl.2025.0829","url":null,"abstract":"<p><p>Warm, dry environments create living conditions that challenge plant growth, reproduction and survival. Plants in these environments have evolved adaptive strategies to enhance water-use efficiency and ensure reproductive success, two of which are annuality and C4 photosynthesis. However, life history variation is rarely included in large-scale studies of plant diversity, and the extent to which these traits coevolve and are jointly selected for is not known. To address this, we used Pagel's models of independent and correlated evolution for over 4000 species of grasses (Poaceae), while accounting for evolutionary rate heterogeneity and potential type I statistical errors. We found that there are more C4 than C3 annuals and that C4 origins predate evolution of annuality, but no support for correlated evolution between the two traits. Our results indicate that any habitat or trait similarities (e.g. small seeds, fast growth) between annuals and C4 species reflect independent adaptations to similar environmental conditions or are contingent on the two traits themselves, rather than the result of evolutionary or functional links between them. Our results further highlight the importance of appropriate null model specification for testing evolutionary hypotheses across large, old clades.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147687972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Volatilized prallethrin impairs the homing ability of bumblebees.","authors":"Kimmo Kaakinen, Olli Juhana Loukola, Eva-Maria Vaajamo, Marjo Helander","doi":"10.1098/rsbl.2025.0749","DOIUrl":"https://doi.org/10.1098/rsbl.2025.0749","url":null,"abstract":"<p><p>Pollinator decline is one of the most urgent environmental challenges of our time, and pesticide use is considered a major contributing factor. In this study, we investigated whether exposure to volatilized prallethrin, a widely used insecticide, impairs the homing ability of bumblebees. Using a consumer-grade vaporizing device, we exposed foraging bees to field-realistic doses of prallethrin and then tested their ability to return to their colony in a rural area where they were already familiar with the surroundings. Our results show that longer exposure durations reduced the bees' return rates, indicating disrupted navigational ability. However, among those that did return, homing time was not affected by the treatment. While our study only focuses on one key behavioural trait, the findings provide clear evidence of a sublethal effect of a commonly used household insecticide on an essential pollinator species.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147687999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding contest skill to reduce the welfare costs of aggression.","authors":"Lucy Oldham, Gareth Arnott, Mark Briffa, Agnieszka Futro, Jo Donbavand, Alena Kadlecova, Ali Alameer, Manzar Malik, Mhairi Jack, Iona Smith, Mark Brims, Claire Anderson, Simon P Turner","doi":"10.1098/rsbl.2025.0563","DOIUrl":"https://doi.org/10.1098/rsbl.2025.0563","url":null,"abstract":"<p><p>Skill is the ability to do a challenging behaviour well. We examined how contest skill influences contest success, costs and whether skilful behaviour enhances welfare. We measured skill across three domains: accuracy, appropriateness (selecting suitable agonistic tactics when the optimal choice varies) and efficiency, alongside vigour, sex and body weight. Skill was weakly correlated across domains. Winners were heavier relative to their opponent, displayed greater vigour and were more skilful at blocking, but other skill measures did not predict contest win/loss outcome. Appropriate blocking by winners reduced the number of lesions received by reducing exposure to attacks, suggesting it can both reduce costs and improve competitive success, with potential welfare benefits. Losers received more lesions when they adopted appropriate postures after submission; however, this unambiguous submission may have resulted from more costly contests. For winners, being heavy relative to the opponent tended to reduce skin lesions received, but otherwise, having a weight advantage did not reduce contest costs. Fighting with increased vigour led to a considerable increase in contest costs, particularly in losers. Compared to other resource-holding potential traits, skill has moderate effects on winning and injuries but nevertheless modulated energetic costs of fighting.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147687938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Incubation strategy and hatching start time affect the duration of the nestling period in precocial Arctic-breeding sandpipers.","authors":"Thomas Pagnon, François-Xavier Dechaume-Moncharmont, Anders Angerbjörn, Joël Bêty, Julien Bouvet, Glen S Brown, Eric Buchel, Dorothee Ehrich, Léa Etchart, Ivan Fufachev, Jannik Hansen, Richard B Lanctot, Johannes Lang, Christopher J Latty, Nicolas Lecomte, Laura McKinnon, Jérôme Moreau, Jeroen Reneerkens, Sarah T Saalfeld, Brigitte Sabard, Niels M Schmidt, Benoit Sittler, Paul A Smith, Aleksandr Sokolov, Vasiliy Sokolov, Natalia Sokolova, Rob S A van Bemmelen, Glenn Yannic, Loïc Bollache, Olivier Gilg","doi":"10.1098/rsbl.2025.0670","DOIUrl":"https://doi.org/10.1098/rsbl.2025.0670","url":null,"abstract":"<p><p>In bird species with precocial development, i.e. chicks acquire abilities to leave the nest soon after hatching, the nestling period during which parents warm their young in the nest by brooding them is short but critical to breeding success. The duration of the nestling period (DNP) depends on the hatching synchrony of eggs and the speed at which chicks acquire these abilities but may be indirectly affected by parental behaviour and temporal variations in temperature and predation. We assessed the effects of incubation strategy (bi- or uniparental), hatching start time, incubation initiation date and predation risk on the DNP in Arctic-breeding sandpipers. We found that the DNP was longer in biparental species (29.75 ± 8.95 h) compared with uniparental ones (25.82 ± 6.87 h) and was extended in nests where chicks began hatching during the colder 'night' hours. No effect of incubation initiation date or predation pressure was found on the DNP. We suggest that parental investment strategies and constraints related to circadian variations in temperature in chicks drive the DNP in Arctic-breeding sandpipers. These results help us better understand how different species may exhibit different behavioural responses during nesting to impending climate change.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147688020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trans-oceanic kinship in the sperm whale (Physeter macrocephalus).","authors":"Rus Hoelzel, Georgios Gkafas, Daniel Engelhaupt","doi":"10.1098/rsbl.2025.0666","DOIUrl":"https://doi.org/10.1098/rsbl.2025.0666","url":null,"abstract":"<p><p>The question of connectivity and dispersal range in the oceans is important because it informs about evolutionary process and speciation, and for conservation, through the identification of cryptic patterns of diversity. Natural boundaries to dispersal are less obvious in marine compared with terrestrial environments and may include oceanographic factors, potentially affecting the distribution of prey. While some cetacean species show surprisingly strong patterns of population structure despite the lack of obvious physical boundaries to dispersal, others are relatively panmictic. Here we focus on the pattern and potential range of dispersal in the largest of the odontocete (toothed whale) species, the sperm whale, a species that shows weak population structure. We compare kinship within and among populations either side of the North Atlantic, and using whole nuclear genomes, we confirm close kinship between a male sampled in the North Sea and a female offspring pair sampled in the Gulf of Mexico.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147632449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Postmating responses depend on genome background in Drosophila melanogaster strains homoallelic for sex peptide.","authors":"Tanya Verma, Hope Human, Ella Kozun, Alberto Civetta","doi":"10.1098/rsbl.2026.0073","DOIUrl":"https://doi.org/10.1098/rsbl.2026.0073","url":null,"abstract":"<p><p>The phenotypic response of gene alleles can be influenced by environmental conditions and genome background. Although progress has been made focusing on polymorphisms at major-effect genes, our understanding of how genome background modulates phenotypic expression remains limited. To address this, we focus on two female postmating responses-egg laying and remating rate, both primarily triggered by sex peptide (SP) transfer from males-across different genome backgrounds and yeast environments. Using 10 Drosophila melanogaster Drosophila Genetic Reference Panel lines carrying an identical SP allele, we found significant effects of both genome background and yeast on egg laying and remating behaviour. SP expression analysis revealed no significant differences among lines, suggesting that the observed phenotypic variation is not driven by transcriptional regulation of the focal gene. However, a genome-wide association analysis of remating under yeast supplementation identified genetic variants non-randomly distributed across chromosomes and implicated potential effectors to this complex trait. Together, our results highlight how genome background can contribute substantially to phenotypic variation that is commonly ascribed to allelic differences at major regulators of reproductive success.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147632377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}