搜索结果：Journal of insect physiology

Global biodiversity is increasingly threatened by widespread anthropogenic impacts, which have accelerated since the First Industrial Revolution. Lowland rivers rank among the most affected ecosystems, having undergone centuries of hydromorphological modifications. The scarcity of historical data hampers precise assessments of biodiversity loss in these rivers since 1950, a critical threshold when anthropogenic pressures led to unprecedented ecological change. We compiled a comprehensive dataset of records of Ephemeroptera, Plecoptera and Trichoptera collected in time series from nine Czech lowland rivers over the past 140 years. Additionally, we integrated environmental data on water quality and hydroclimatic parameters spanning the last 60 years. Both alpha and gamma diversity declined steadily until the 1980s, followed by a partial recovery at the turn of the millennium due to water quality improvements. However, biodiversity recovery has remained limited in recent decades due to persistent pollution, climate change and potential depletion of the regional species pool. Assemblages are undergoing compositional changes driven by species turnover, rendering a return to their mid-20th-century baseline unlikely. Our results further highlight a dramatic loss of biodiversity already in the first half of the 20th century, which has not been offset by the partial recovery of rivers observed after 1990. Immediate actions are necessary to prevent further biodiversity decline and safeguard the ecosystem services of lowland rivers. Globální biodiverzita je stále více ohrožena velkoplošnými antropogenními vlivy, jejichž dopad výrazně akceleroval od dob první průmyslové revoluce po současnost. Nížinné řeky patří mezi nejvíce postižené ekosystémy, neboť prošly staletími hydromorfologických úprav. Nedostatek historických dat však ztěžuje vyhodnocení ztráty jejich biodiverzity od poloviny 20. století, což je kritický milník, kdy dopady lidské činnosti vedly k bezprecedentním ekologickým změnám. Sestavili jsme časové řady záznamů o výskytu jepic, pošvatek a chrostíků (Ephemeroptera, Plecoptera a Trichoptera) z devíti českých nížinných řek za uplynulých 140 let, které jsme doplnili environmentálními daty o kvalitě vody a hydroklimatických parametrech za posledních 60 let. Alfa i gama diverzita studovaných skupin setrvale klesala až do 80. let 20. století, poté došlo k částečnému zotavení související se zlepšením kvality vody na přelomu tisíciletí. V posledních desetiletích však zůstává zotavování omezené kvůli přetrvávajícímu znečištění, změnám klimatu a ochuzení regionálního souboru druhů. Druhové složení společenstev se mění predevším v důsledku výměny druhů, což činí návrat k jejich původnímu složení z poloviny minulého století nepravděpodobným. Naše výsledky navíc podtrhují dramatickou ztrátu biodiverzity už v první polovině 20. století, kterou však částečné zotavení řek po roce 1990 nedokázalo zmírnit. K zamezení dalšího poklesu biodiverzity a zachování ekosystémových služeb nížinných řek jsou nezbytná okamžitá opatření.

InsectMotion is a Python-based tool for analyzing video recordings of movements or muscle contractions in arthropods. It provides a simple, fast, and automated approach for semi-quantitative motion assessment by measuring "pixel activity", defined as changes in pixel intensity or colour. Unlike many existing methods, it does not require specialized equipment, chemical reagents, or expensive software. The application distinguishes active and inactive pixels within selected regions of interest (ROI) and quantifies their changes over a defined time period. InsectMotion offers two analysis modes: Graphical Analysis and Pixel Activity Analysis, both adaptable to various experimental setups. Graphical Analysis generates time-resolved plots of pixel activity, numerical outputs, and peak analysis. Pixel Activity Analysis produces binary images highlighting active pixel clusters and summary metrics describing active areas. Using immunohistochemistry, we detected calcitonin-like diuretic hormone (Bom-CT-DH) and myoinhibitory peptides (Bom-MIPs) in the innervation of digestive and reproductive organs of Bombyx mori. In vitro assays combined with InsectMotion quantified neuropeptide-induced contractions in these tissues. The tool was also applied on Ixodes ricinus in preliminary movement analyses, indicating its potential applicability beyond lepidopteran models. Our data show that InsectMotion is a reliable and accessible tool for in vitro and in vivo studies in neurobiology and physiology.

Left-right asymmetries in brain features and behavior have long been considered unique to humans. However, they are now also recognized in vertebrates and invertebrates and exhibit similar structural lateralization across different species. For instance, the olfactory behavior and brain asymmetry of eusocial insects are evident at the population level. Certain solitary insects also exhibit behavioral asymmetry at the population level. This study examined the electroantennogram (EAG) responses, behavioral responses, and gene expression of the right and left antennae in adult diamondback moth (DBM), Plutella xylostella (lepidoptera: plutellidae). The results revealed that among the detected genes (GOBP1, GOBP2, PBP, PBP1, and ORCO), only the GOBP1 gene showed expression variance between the left and right antennae of female DBM. Also, the expressions of GOBP1 and GOBP2 in the antennae of female moths were significantly higher than that in male DBM. For male DBM, EAG responses of the left antenna were higher at differentconcentrations of Z-3-hexenol, Z-3-hexenyl acetate and allyl isothiocyanate compared to the right antenna. Marked differences were found in EAG responses between the left and right antennae of male DBM at 0.15 μg•μL-1 allyl isothiocyanate. For female DBM, EAG responses of the right antenna were higher at differentconcentrations of Z-3-hexenyl acetate and allyl isothiocyanate compared to the left antenna, but there was no statistical difference. In an olfactometer bioassay, the choice rates of male DBMs with intact left antennae were significantly higher than that of the control liquid paraffin at 1.0 μg•μL-1. Also, the choice rates of female DBM with left or right antennae to the three tested plant volatiles at 0.15 and 1.0 μg•μL-1 concentrations were significantly higher than those in liquid paraffin. Moreover, the relative choice rates of the right antennae were slightly higher than those of the left antennae in female DBM, but the results were reversed in male DBM. This study contributes to the understanding of behavioral asymmetry of the left and right antennae of DBM and provides a reference for the lateralization of olfactory behavior in other lepidoptera insects.

Harmonia axyridis is a well-known predatory ladybird beetle renowned for its high degree of elytral pattern polymorphism. The black and yellow-red complementary areas of elytra are respectively attributed to the deposition of melanin and carotenoid pigments, while the carotenoid profiles are likely to be affected by the phenotypic plasticity of dark spots. Here, using a goldenrod-colored mutant (named gr) and a melanic mutant (named ml), we examined their elytral carotenoid profiles and compared them with those of the wild type (named wt). Moreover, we determined whether similar changes could be detected from the newly emerged stage (NE) to the 5-day post-emergence stage (PE5). The results showed that the non-oxidative carotenes accounted for over 95% of the total carotenoid pool in all the three morphs. Moreover, identical composition of carotenes was observed at both stages, with (E/Z)-phytoene and γ-carotene comprising the majority (over 70%). However, distinct profiles of carotenes were detected in ml as compared to wt and gr. Additionally, both ml and gr presented several specific xanthophylls compared to wt. Nevertheless, the three morphs showed similar changes in carotenoid composition from stage NE to PE5, i.e. the proportion of light-colored pigment (colorless (E/Z)-phytoene) decreased, while the proportion of colored pigments (lycopene and γ-carotene) increased. Our findings suggested that while different carotenoid profiles were detected in the two body color mutants, both mutants exhibited a conserved strategy for carotenoid allocation to the elytra during post-emergence development. These findings will contribute to a more comprehensive understanding of the carotenoid-based coloration in insects, particularly its correlation with the melanin-based pigmentation.

Silkworm pupae serve as an important source of protein supplementation; however, their high fat content and imbalanced essential amino acid (EAA) profile restrict efficient utilization of protein. Previous studies have demonstrated that dietary probiotic supplementation can modulate host physiology through multiple pathways, thereby enhancing nutrient quality. This study investigated the effects of dietary supplementation with Lactobacillus rhamnosus and Lactobacillus casei on gut microbiota, short-chain fatty acids (SCFAs), fat body transcriptome, and pupal nutrient composition in fifth-instar silkworm larvae. Results showed that both probiotics significantly increased the concentrations of acetic acid, butyric acid, isobutyric acid, and total SCFAs, while also modulating the composition and functional characteristics of the gut microbiota. Notably, probiotic treatment enriched the relative abundance of Bacillota, Enterococcus, and Lactobacillus, while reducing Pseudomonas and Cyanobacteria. Transcriptomic analyses revealed that supplementation of both probiotics modulated the transcription of genes (e.g., BmRad and BmLdlr) associated with key nutrient metabolic pathways, including protein synthesis, fatty acid metabolism, and carbohydrate degradation, in the fat body. Amino acid and proteomic analyses indicated that L. rhamnosus significantly inhibited the degradation of EAAs such as leucine, isoleucine, and lysine, thereby increasing their contents in silkworm pupae. Collectively, these findings lay a theoretical foundation for the application of probiotic strategies to enhance the nutrient quality of silkworm pupae and facilitate the development of high-value silkworm pupae products.

The highlands of the eastern Democratic Republic of the Congo (DRC) are home to critically endangered eastern gorillas (Gorilla beringei). Concerns have been raised that the increased temperatures and extreme weather conditions associated with climate change will lead to an increase in the abundance and distribution of Culicoides-borne diseases. Here, we utilized an integrated morphological and molecular approach to identify Culicoides species in a small but significant collection of Culicoides captured from highland eastern gorilla habitat and surrounding areas and updated the Culicoides spp. reported from the highlands of the eastern DRC. A review of the literature related to Culicoides collections in the DRC was conducted in French and English. Recent worldwide checklists were consulted to rectify synonyms and other discrepancies found in the literature for the region. Fresh Culicoides specimens were collected, wings slide-mounted and remaining carcasses subjected to DNA extraction. A total of 82 Culicoides specimens were collected. From these, 75 high-quality DNA barcodes (658-bp of the mtDNA COI gene) were obtained, belonging to 14 distinct taxa, 11 of which were new records for the DRC, including C. bolitinos Meiswinkel, 1989, C. hortenis Khamala & Kettle, 1971, C. citroneus Carter, Ingram & Macfie, 1920, and C. radiomaculatus Khamala & Kettle, 1971, and seven species new to science (C. sp. nr. citroneus, C. sp. nr. glabripennis 1, C. sp. nr. glabripennis 2, C. sp. nr. kibatiensis 1, C. sp. nr. kibatiensis 2, C. sp. nr. neavei 1 and C. sp. nr. neavei 2), increasing the known Culicoides fauna of the DRC from 20 to 31. The presence of C. imicola Kieffer, 1913, C. enderleini Cornet & Brunhes, 1994 and C. neavei Austin, 1912, was confirmed. The potential health impact of the association of known Culicoides pathogen vectors with endangered gorillas is discussed. Les hauts plateaux de l'est de la République démocratique du Congo (RDC) abritent des gorilles de l'Est (Gorilla beringei), en danger critique d'extinction. Il a été soulevé que l’élévation des températures et la fréquence accrue d’événements météorologiques extrêmes, en lien avec les changements climatiques, pourraient accroître l’abondance et élargir l’aire de répartition des maladies véhiculées par les Culicoides. Dans cette étude, nous avons utilisé une approche intégrée, combinant analyses morphologiques et moléculaires, afin d’identifier les espèces de Culicoides dans une collection de petite taille mais significative de Culicoides capturés dans l'habitat des gorilles de l'Est des hautes terres et les zones environnantes, et de mettre à jour les espèces de Culicoides signalées dans les hautes terres de l'est de la RDC. Une revue de la littérature relative aux collections de Culicoides en RDC a été réalisée en français et en anglais. Des listes des espèces mondiales récentes ont été consultées pour rectifier les synonymes et autres incohérences trouvées dans la littérature régionale. Des spécimens frais de Culicoides ont été collectés, les ailes montées sur lames et les carcasses restantes soumises à une extraction d'ADN. Au total, 82 spécimens de Culicoides ont été collectés. À partir de ceux‐ci, 75 codes‐barres de haute qualité (658 pb du gène COI de l'ADNmt) ont été obtenus, appartenant à 14 taxons distincts ‐ dont 11 représentent de nouveaux signalements pour la RDC, notamment C. bolitinos Meiswinkel, 1989, C. hortensis Khamala et Kettle, 1971, C. citroneus Carter, Ingram et Macfie, 1920, et C. radiomaculatus Khamala et Kettle, 1971, ainsi que 7 espèces nouvelles pour la science (C. sp. nr. citroneus, C. sp. nr. glabripennis 1, C. sp. nr. glabripennis 2, C. sp. nr. kibatiensis 1, C. sp. nr. kibatiensis 2, C. sp. nr. neavei 1 et C. sp. nr. neavei 2) – augmentant la faune connue de Culicoides de la RDC de 20 à 31. La présence de C. imicola Kieffer (1913), C. enderleini Cornet et Brunhes (1994) et C. neavei Austin (1912) a été confirmée. L'étude discute des implications potentielles pour la santé publique et animale de l'association entre certains vecteurs de pathogènes connus du genre Culicoides et les populations de gorilles en voie de disparition.

The rapid expansion of Artificial Light at Night (ALAN), driven by anthropogenic activities, has significantly altered natural environments, affecting several taxa. ALAN is widely recognized as a significant ecological stressor, being detrimental to the behavior, physiology and reproductive fitness of insects, including Orthoptera. Based on the studies retrieved from Scopus and Web of Science, the review attempted to answer the following questions (i) Are the regions with the highest light pollution involved in studying the impact of light pollution on Orthoptera? (ii) What are the traits affected by ALAN-induced light pollution in Orthoptera? The review found that studies were largely restricted to developed nations. Countries with the highest night-time illumination have not yet studied the impact of ALAN on Orthoptera. The effect of light has been studied in only 12 species of Orthoptera, compared to the vast diversity of >29,500 species. This review highlights the physiological traits affected by ALAN such as body size, developmental time, survival rate, reproductive investment, circadian rhythm, and immune response. Behaviors affected by ALAN, such as visual orientation, locomotion, calling behavior, and mate searching, are also highlighted. It emphasizes the critical need for targeted research on their calling behavior, the efficacy of acoustic signals, mate attraction, and reproductive success for understanding the behavioural shifts as a consequence of ALAN. Given that most Orthopteran species rely on acoustic communication for mate attraction and reproductive success, it is imperative to study the impacts of ALAN on their acoustic behavior.

Insects enter diapause in order to avoid adverse environmental conditions. Diapause is a complex physiological process regulated by multiple signaling pathways, and the molecular regulatory mechanisms remain incompletely understood. Notch signaling pathway is evolutionarily conserved and plays diverse roles in insect development, including cell fate determination, organ growth, and tissue patterning. Recent research has demonstrated that Notch signaling is indispensable for both the maintenance and recovery of dauer (a diapause-like state in Caenorhabditis elegans), however, the role of Notch signaling in insect diapause has not been previously documented. In the current study, we therefore investigated the expression pattern of Notch in diapausing and developing pupae of Helicoverpa armigera, aiming to elucidate its potential regulatory mechanism of Notch in pupal diapause. We found that the protein expression of intracellular domain of Notch (NICD, the functional part of Notch) was lower in diapause-destined pupae than that in non-diapause pupae. Inhibiting the NICD expression by LY411575 delayed the development of non-diapause pupae. Furthermore, NICD knockdown (via dsRNA) or pharmacological inhibition downregulated the mitochondrial DNA (mtDNA) levels and mitochondrial activity by regulating the transcription factors c-Myc and TFAM. Consistent with previous findings that diapausing brains have lower mitochondrial activity, we propose that Har-NICD might participate in diapause regulation by modulating mitochondrial activity via the c-Myc-TFAM axis.

The kissing bug Rhodnius prolixus, a primary vector of Chagas disease, serves as a model for understanding insect physiology and vector-pathogen interactions. While the role of male reproductive factors in influencing female fertility is well-established in many insects, little is known about male fertility in R. prolixus. Our study examines the role of two apolipoproteins, RPRC010099 and RPRC015421, in male fertility and their potential function as carriers of eicosanoid hormones. Using RNA interference (RNAi), we silenced the genes for both apolipoproteins in male R. prolixus. The silencing of RPRC010099 led to a significant reduction of ∼60% in the number of eggs laid by mated females, while silencing RPRC015421 resulted in a ∼20% reduction. Further analysis, including molecular docking and enzyme-linked immunosorbent assays (ELISA), confirmed that these proteins are transferred from males to females during copulation and have a high affinity to eicosanoid signaling molecules, such as prostaglandin E2. Our findings demonstrate that RPRC010099 and RPRC015421 are important male fertility factors that promote female oviposition and probably act as carriers for eicosanoids. This work not only identifies a novel reproductive role for apolipoproteins but also contributes to a broader understanding of male-female interactions in insect reproduction.

Silkworm silk is a natural protein fiber composed mainly of fibroin and sericin, with protease inhibitors representing an additional abundant constituent. However, the impact of protease inhibitors on the structure and properties of silk fibers has not yet been studied. In this study, we focused on the Kunitz-type protease inhibitor SPI51, the most abundant protease inhibitors of cocoon. CRISPR/Cas9 editing was used to generate a homozygous mutant of SPI51 (SPI51KO), resulting in premature translation termination at the 33rd amino acid. After knocking out SPI51, the mechanical properties of silk were significantly reduced compared with those of the wild type. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results revealed that this deterioration was associated with significantly reduced β-sheet content and lower crystallinity. Morphological observations showed that the fibroin area of SPI51KO silk was significantly smaller than that in the wild type. Further Western blot analysis showed that fibroin heavy chain (Fib-H), fibroin light chain (Fib-L), and fibrohexamerin (P25) were decreased after knocking out SPI51, which resulted in a reduction of silk fibroin layer and affected structure and mechanical properties. Our results provide valuable insights into the balance between proteases and protease inhibitors in the silk gland and reveal for the first time the roles of the protease inhibitor in silk protein synthesis and the structural and mechanical properties of silk fibers.

Substrate-borne vibrational communication is widespread in insects and spiders, yet its role in host location by bethylid ectoparasitoids remains largely unexplored. In this study, we investigated the responses of Sclerodermus domesticus Klug and Sclerodermus cereicollis Kieffer to vibrations produced by the feeding activity of their natural hosts, the longhorn beetles Hylotrupes bajulus (L.) and Trichoferus holosericeus (Rossi). Vibrations were recorded using a laser Doppler vibrometer and characterised in terms of biting frequency, damping, and spectral composition, revealing two distinct bite types with species-specific frequency profiles. A new tool, vibrational Y-shaped arena, was developed to replicate and deliver vibrations, allowing the testing of parasitoids behaviour. Choice tests demonstrated that S. domesticus was attracted to vibrations from H. bajulus, whereas S. cereicollis preferred vibrations from T. holosericeus. Behavioural observations revealed increased antennal drumming and leg rubbing in the presence of host-produced vibrations, suggesting that these behaviours are associated with vibrational detection. Our results provide the first evidence that bethylid parasitoids can detect and respond to host-emitted vibrations, highlighting the importance of substrate-borne cues in host location. These findings advance our understanding of bethylid sensory ecology and may inform novel strategies for the biological control of xylophagous pests.

Transient receptor potential (TRP) channels play critical roles in responding to external environment and regulating homeostasis in insects. TRPs have been widely investigated for their critical roles in regulating various insect behaviors in recent years, and have become potential molecular targets for insecticides or repellents. In this study, 12 TRP gene were identified and analyzed in the genome of Diaphorina citri, a highly destructive pest that has become a global problem due to its a vector of Candidatus Liberibacter asiaticus (CLas), the principal causal of huanglongbing (HLB). The results showed that the TRP family genes were classified into seven subfamilies in D. citri, including three TRPA subfamily, two TRPV and TRPC subfamily, one TRPN, TRPP, TRPM, and TRPML subfamily. Real-time quantitative polymerase chain reaction (RT-qPCR) experiments revealed widespread expression of TRP channel genes across various developmental stages and tissues of D. citri. The expression levels of DcTRPML, DcTRPL, and DcWtrw genes were significantly different from controls, indicating their important roles in immune responses to CLas infection. To investigate the potential role of TRP genes to temperature change, we detected their expression level under low and high temperature stress. The results reveal that the most of TRP genes' transcriptional level were significantly up-regulated, suggestion their involvement in response to temperature stress in D. citri. Our findings provide important information and resources for developing new approaches to control ACP targeting these important ion channels.

As a notorious rice pest, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) inflicts severe damage owing to its exceptionally high reproductive potential. Previous ovarian transcriptome analyses have revealed that the insect Keratin-associated protein (KAP) gene is potentially implicated in vitelline secretion and eggshell sclerotization, and it holds promise as a novel target for the suppression of pest reproduction. In this study, KAP5-2(LOC111045913, XP_039288177.1) and KAP5-4 (LOC111045916, XP_022187086.1) genes' function were studied by RNA interference technology. The results showed that gene silencing significantly suppressed female fecundity, and the pre-oviposition period extended from 3 days to 4 days. The total number of eggs laid within 10 days was significantly reduced, with only 113.2 and 101.3 eggs in the dsKAP5-2 and dsKAP5-4 groups, respectively, representing decreases of 49.3 % and 56.0 % compared to the control group. In addition, the hatching rates of offspring were significantly reduced by 60.1 % and 63.78 %, with many malformed unhatched eggs remaining. Molecular mechanism studies revealed that silencing KAP genes led to significant downregulation of vitellogenin (Vg) and its receptor (VgR, vitellogenin receptor). Additionally, it affected the expression of key genes in the juvenile hormone (Juvenile Hormone Acid Methyltransferase (JHAMT), Methoprene-tolerant (Met)) and nutrient signaling pathways. This study indicates the critical role of KAP genes in regulating female reproductive processes and embryonic development in N. lugens, thereby providing a theoretical foundation for the rational design of eco-friendly insecticides targeting these KAP genes.

Although temperature is considered the most significant environmental factor influencing the survival, development and fitness of the Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedemann) (Diptera: Teprhitidae), relative humidity also plays a crucial role in determining its performance. Phenotypic plasticity and local adaptation to a variety of climatic regions are known to lead to variation of biological traits among medfly populations. We explored the impact of hydric stress during pupal development on survival and development, as well as on the thermal performance of obtained adults of three geographically isolated C. capitata populations. Medfly pupae from Samar (Israel), Creta and Thessaloniki (Greece), that were reared for few generations in standard laboratory conditions, were exposed immediately after pupation to low (13 ± 2%), moderate (38 ± 2%), standard (56 ± 2%) and high (100%) relative humidity. Weight loss during the pupal stage, pupal developmental duration, survival rate, adult weight and sex ratio, as well as morphometric characteristics of adult size (wings, thorax and head) were recorded. Our results highlight the importance of relative humidity during pupal development. We found that low humidity levels during pupal development increased weight loss, prolonged development and resulted in the emergence of smaller sized adults. Responses to humidity were population specific, as the population originated from the xeric area of Samar had, overall, a better response to low humidity levels compared with those from the more humid areas of Creta and Thessaloniki, indicating greater phenotypic plasticity and suggesting a possible consideration for respective future experimental work.

The fruit fly Drosophila melanogaster is a valuable model for studying cellular and metabolic processes conserved with mammals. Using its embryonic Schneider S2 cell line, a widely employed system for heterologous protein expression, we investigated how cell growth progression and short-term slight temperature changes affect mitochondrial physiology via high-resolution respirometry. We assessed five mitochondrial bioenergetic parameters and two coupling parameters at 2nd (early) and 7th (late) days of culture, and at two temperatures (26°C and 28°C). We observed that culture time is the overwhelming driver of cell density variation, while temperature effect is only modest. Importantly, a modest 2°C increase, combined with progression to the late growth phase, synergistically enhanced basal, OXPHOS, and leak respiration, while only marginally affecting coupling efficiency. Notably, spare and maximal respiratory capacities rose disproportionately with either cell growth or mild temperature increase, suggesting mitochondrial biogenesis and functional remodeling. These findings reveal that minor, short-term temperature shifts can elicit rapid mitochondrial acclimation that enhances bioenergetic capacity and metabolic flexibility without compromising efficiency. Such responses exemplify mitochondrial plasticity to environmental and developmental cues and may inform strategies to modulate mitochondrial physiology across biological and biomedical contexts.

The spermatheca is a specialized organ for sperm storage and is essential for reproductive success, particularly in ants, where queens preserve the viability of stored sperm for over a decade. However, the process of establishing the physiological environment and morphology of the spermatheca that enable long-term sperm storage remains largely unexplored. This study demonstrated that a near-anoxic state crucial for sperm viability and an elevated pH, both key features of the spermathecal environment in mated queens of Crematogaster osakensis, were established by 8 days after eclosion, suggesting that the spermatheca becomes functionally ready for sperm storage well before mating. Subsequently, the near-anoxic condition within the spermatheca is maintained after mating. In contrast, the queen's body was normoxic at eclosion, gradually declined to near-anoxic levels by the mating period, and subsequently recovered to normoxic levels 2 months after the nuptial flight. These findings suggest spatio-temporal regulation of oxygen levels in ant queens. Morphologically, the formation of columnar epithelial cells in the hilar region of the spermathecal reservoir, considered essential for sperm storage, was triggered by nuptial flight, unlike in other ant subfamilies, where they develop during the pupal stage. Because these cells are thought to facilitate waste removal from stored sperm, their formation soon after mating appears to occur at an appropriate time for sperm maintenance. These findings indicate that C. osakensis queens establish their sperm storage environment in two distinct phases: preparation of physiological conditions before mating, followed by the completion of morphological development after mating to support long-term sperm maintenance.

Environmental temperature and humidity fluctuations influence insect survival and adaptation, with relevance to both contemporary pest management and future climate scenarios. The cuticle, as the primary physical barrier against environmental stress, critically determines insect adaptive capacity. Here, we investigated the role of PxPCP, a pupal cuticular protein gene, in environmental adaptation of the diamondback moth Plutella xylostella, a globally distributed pest, using CRISPR/Cas9-mediated gene editing. PxPCP knockout significantly impaired developmental performance and reproductive capacity under high temperature while reducing tolerance to temperature extremes and desiccation stress. Mutants displayed increased cuticular permeability and, unexpectedly, elevated body water content under desiccation, indicating that PxPCP regulates active water homeostasis beyond forming passive physical barriers. Transcriptional analysis revealed that PxPCP deficiency triggered compensatory upregulation of cuticle-related genes, including chitin synthase and cuticular lipid metabolism enzymes; however, these transcriptional compensations failed to fully restore cuticular barrier function. Moreover, PxPCP deletion disrupted expression of water homeostasis-related genes, including downregulation of hygroreception sensors and diuretic hormone signaling components, coupled with dysregulated ion transport and osmoprotectant biosynthesis genes, providing molecular evidence for the observed systemic water balance dysfunction. Collectively, our findings demonstrate that PxPCP plays a pivotal role in environmental adaptation by regulating cuticle formation and water homeostasis, providing a molecular basis for understanding the persistent outbreak success of this pest under climate change. These findings offer novel insights into the molecular mechanisms underlying insect climate adaptation and identify a promising molecular target for developing climate-informed pest management strategies.

Global biomedical and health research is increasingly relying on genomic and computational approaches, largely driven by the increasing volumes of nucleic acid sequencing. Concurrently, epidemiological studies and clinical records are generating enormous amounts of data amenable to disease modeling, machine learning, and artificial intelligence techniques. Bioinformatics and data science expertise is therefore essential for improved population health. Accordingly, in 2012, the US National Institutes of Health (NIH) in partnership with the Wellcome Trust, and with support from the African Society for Human Genetics, initiated the H3Africa (Human Heredity and Health in Africa) consortium. One of its key goals was to build capacity among African scientists to lead research on genetic and environmental contributors to health and disease across the continent. In 2017, the NIH provided funding to support the establishment of four graduate bioinformatics training programs across five African universities. Over seven years, these programs enrolled multiple trainees (n > 270), with >110 earning Master's degrees and >20 completing PhDs in Bioinformatics. It is thus timely to evaluate the outcomes and impact of these programs, particularly regarding graduation rates, career trajectories, and the institutions and research domains their alumni are serving. We also assess employment outcomes and the nature of the research they are enabling (n > 110 peer-reviewed articles). We additionally include the progress and outputs of the programs' instructors, which were partially enabled by program resources, networks, and trainees. Overall, this review paints valuable insights into the pioneering role of NIH extramural support in shaping Africa's biomedical research landscape.

Diapause in many insects is a non-feeding state, yet energetic demands persist. This imbalance between energy in and energy out can be met by two main mechanisms: reduced metabolism, facilitated by decreasing temperatures, and storage of nutrients. In bivoltine insects, some individuals may continue direct development while others may enter diapause. Few studies have compared these two groups prior to the decision to diapause, even though biochemical differences are likely due to accumulation of nutrient stores and molecules involved in metabolic suppression. In Megachile rotundata, offspring oviposited in early summer develop directly to adults, while those oviposited later that summer enter diapause as prepupae. Here we test the hypothesis that prepupae between the two groups have distinct metabolomic signatures that will indicate key differences in energetic status. We collected 12 non-diapause and 15 diapause-destined nests. Two prepupae from each nest were flash frozen and kept in -80°C until extracted. Diapause state of frozen bees was verified by observing whether nestmates developed or underwent diapause. We used an untargeted GC-MS-based approach that identified 57 significant metabolites with the potential to differentiate between diapause-destined and non-diapause prepupae. Altered metabolites included sugars, polyols, intermediates of the tricarboxylic acid (TCA) cycle, and amino acids. Seventeen metabolites (60% carbohydrates) were more abundant in diapause-destined prepupae. Forty metabolites (30% amino acids) were more abundant in non-diapausing prepupae. Several metabolites were previously implicated in diapausing insects. Some metabolites, e.g., putrescine, could be used as a biomarker to identify diapause status of nests, benefitting bee growers and farmers.