Mature Females Research Articles

Repetitive Overuse Injury Causes Entheseal Damage and Palmar Muscle Fibrosis in Older Rats

Overuse injury is a frequent diagnosis in occupational medicine and athletics. Using an established model of upper extremity overuse, we sought to characterize changes occurring in the forepaws and forelimbs of mature female rats (14–18 months of age). Thirty-three rats underwent a 4-week shaping period, before performing a high-repetition low-force (HRLF) task for 12 weeks, with the results being compared to 32 mature controls. HRLF animals showed a reduced grip strength versus controls. ELISAs carried out in the HRLF rats, versus controls, showed elevated levels of IL1-α in tendons, IL1-α and TNF-α in distal bones/entheses, and TNF-α, MIP1-α/CCL3, and CINC-2/CXCL-3 in serum, as well as IL-6 in forelimb muscles and tendons, and IL-10 in serum. HRLF rats had elevated collagen deposition in the forepaw intrinsic muscles (i.e., fibrosis), entheseal microdamage, and articular cartilage degradation versus the control rats. CD68/ED1+ osteoclasts and single-nucleated cells were elevated in distal forelimb metaphyses of the HRLF animals, versus controls. Declines in grip strength correlated with muscle fibrosis, entheseal microdamage, articular cartilage damage, distal bone/enthesis IL1-α, and serum IL-6. These data demonstrate inflammatory and persistent degradative changes in the forearm/forepaw tissues of mature female animals exposed to prolonged repetitive tasks, changes with clinical relevance to work-related overuse injuries in mature human females.

Assessing changes in threatened black rockcod Epinephelus daemelii abundance and length over the past 15 years in New South Wales, Australia.

Ideally, protection of a threatened fish will lead to their recovery in abundance, distribution, and size structure within the population, to a point where they are no longer considered threatened. Monitoring abundance and size is crucial to evaluate this, although low numbers associated with being threatened can strongly constrain the methods used. To assess if population recovery is occurring for the black rockcod Epinephelus daemelii, a large subtropical grouper endemic to shallow reefs in the southwest Pacific, surveys were undertaken across northern New South Wales and Lord Howe Island using roving diver timed counts and diver stereo-video measurements to assess relative abundance and length. Surveys in 2023 were compared with initial baseline data captured in 2009-2011 using the same methods. Relative abundance of E. daemelii at long-term monitoring sites has remained relatively constant or declined since 2010 rather than increasing. Comparisons between 84 broadscale sites in 2009-2011 versus 2023 (117 vs. 69 observed E. daemelii) indicate a recent decline in abundance. Although protected from fishing and spearfishing for over 40 years, the relative abundance of E. daemelii does not appear to be increasing over the past 15 years since monitoring commenced. This is a concerning trend that does not indicate recovery, although an increase in the proportion of mature females in the population from 2010 to 2023 is positive. As E. daemelii is slow growing, long lived, late to mature and still susceptible to incidental capture mortality, more active management may be needed to help assist with the slow recovery of this threatened species.

Morphological characteristics, developmental dynamics, and gene temporal expressions across various development stages of Aphis gossypii sexual female

BackgroundAphis gossypii (Hemiptera: Aphididae) is a worldwide polyphagous phloem-feeding agricultural pest, and it can produce offspring by sexual or asexual reproduction. Compared with dozens of generations by parthenogenesis, sexual reproduction is performed in only one generation within one year, and little is known about the sexual reproduction of A. gossypii. In this study, sexual females of A. gossypii were successfully obtained through a previously established induction platform, and the morphological characteristics, developmental dynamics, and temporal gene expression were examined. Subsequently, signaling pathways potentially involved in regulating the growth, development, and reproduction of sexual females were investigated.ResultsThe morphological observation showed that from the 1st instar nymph to adult, sexual females exhibited a gradually deepened body color, an enlarged body size, longer antennae with a blackened end, and obviously protruding cauda (in adulthood). The anatomy found that the ovaries of sexual females developed rapidly from the 2nd instar nymph, and the embedded oocytes matured in adulthood. In addition, time-course transcriptome analysis revealed that gene expression profiles across the development of sexual females fell into 9 clusters with distinct patterns, in which gene expression levels in clusters 1, 5, and 8 peaked at the 2nd instar nymphal stage with the largest number of up-regulated genes, suggesting that the 2nd instar nymph was an important ovary development period. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that a large number of genes in the sexual female adult were enriched in the TGF-beta signaling pathway and Forkhead box O (FoxO) signaling pathway, highlighting their important role in sexual female adult development and reproduction.ConclusionThe morphological changes of the sexual female at each developmental stage were revealed for the first time. In addition, time-course transcriptomic analyses suggest genes enriched in the TGF-beta signaling pathway and FoxO signaling pathway probably contribute to regulating the development and oocyte maturation of sexual females. Overall, these findings will facilitate the regulating mechanism research in the growth and development of sexual females by providing candidate genes.

“Influence of short-to-continuous and continuous photoperiods combined with elevated temperatures on sexual maturation in lumpfish (Cyclopterus lumpus, L. 1758)”

We tested the photothermal effects on sexual maturation in the broodstock of lumpfish (Cyclopterus lumpus) using short-to-continuous (LDL) and continuous (LL) photoperiods for 24 weeks, with temperature elevation during final maturation in females. The lumpfish sexual maturation was phased differently between the two photoperiods, while temperature elevation enhanced the photoperiod changes. Female gonadosomatic index (GSI), and plasma levels of testosterone (T), 11-ketotestosterone (11-KT) and 17β-estradiol (E2) increased under LDL, and temperature elevation enhanced the sex steroid levels in both photoperiods. While the brain expressions of gnrh2 decreased in females exposed to LDL compared to LL groups, the ovarian expressions of fshr, lhr, vtgr, and cyp19a1 changed significantly at ambient temperatures in LL and LDL groups and at elevated temperature in the LL group. A high proportion of males were sexually mature from the start of the experiment, and a prolonged period with sexually mature males was observed in the ambient temperature LL group. This was revealed by elevated GSI, T, 11-KT, as well as brain expression of gnrh2 at the start of the experiment, with the highest presence of spermatozoa, and pronounced fluctuations in T and 11-KT throughout the experiment with significant changes observed only in LL0T. Brain expressions of gnrh2 and testicular expressions of fshr and lhr declined more rapidly in LDL compared to LL groups. With temperature elevation, gnrh2 expressions were enhanced in both LL and LDL. Despite exposure to different photothermal regimes, gonadal development and selected endocrine factors remained stage-coherent. Ovarian expressions of fshr, lhr, vtgr, cyp19a1 and E2 levels increased up to oocyte maturation and decreased at ovulation, while GSI, T and 11-KT increased until ovulation. Testicular fshr and lhr expressions peaked at spermatocyte stage and decreased subsequently, while plasma levels of T and 11-KT increased until the spermatid stage and decreased at the spermatozoa stage. In this study, we show that while photoperiods phase lumpfish sexual maturation, temperature has an important role in cueing the final stages leading to spawning. Additionally, the gonadal development and endocrine factors remain stage-coherent though at different rates in different photothermal regimes.

Identification and field testing of sex-attractant semiochemicals produced by male deer mice, Peromyscus maniculatus.

Following previous reports that male deer mice, Peromyscus maniculatus, produce chemical signals that attract conspecific females, we analysed and field-tested sex-attractant semiochemicals (message-bearing chemicals) of male deer mice. Field traps baited with urine- and faeces-soiled bedding of male mice captured adult female, but not male, mice, indicating dissemination of sex-attractant semiochemicals from the males' excreta. Analysing excreta headspace volatiles of both males and females by gas chromatography-mass spectrometry revealed that 5-methyl-2-hexanone was male-specific, and that eight other ketones (3-methyl-2-pentanone, 2-hexanone, 4-heptanone, 2-heptanone, 6-methyl-2-heptanone, 3-octanone, 2-octanone, 2-nonanone) were 2.6-5.6 times more abundant in male, than in female, samples. In a field experiment with paired trap boxes, treatment boxes baited with the synthetic ketone lure captured 3.4 times more females (17 : 5) and 1.6 times fewer males (5 : 8) than corresponding unbaited boxes. In a follow-up paired-trap field experiment, treatment boxes baited with both the ketone lure and synthetic testosterone captured 8 times more mature females and 2.3 times more immature females, but 9 times fewer immature males, than control boxes baited only with the ketone lure, all indicating that testosterone is a synergistic sex-attractant semiochemical. As previously shown in house mice, Mus musculus, and brown rats, Rattus norvegicus, sex-attractant semiochemicals of male deer mice comprise both volatile and sex steroid components.

Changes in wing resonance in dried preserved crickets.

Male crickets sing to attract females for mating. Sound is produced by tegminal stridulation, where one wing bears a plectrum and the other a wing vein modified with cuticular teeth. The carrier frequency (fc ) of the call is dictated by the wing resonance and the rate of tooth strikes. Therefore, the fc varies across species due to the size of the vibrating membranes on the wings and/or the speed of tooth strikes. But how well is the resonant frequency (fo ) conserved in dried preserved specimens? This project is designed to investigate the gradual change in cricket wing fo over time and aims to produce equations that help to predict or recover the original natural frequency of wing vibration in dry-preserved crickets and allies. Using laser Doppler vibrometry, we scanned the wings of living specimens to determine their fo . The specimens were then preserved, allowing us to continue measuring the wings fo as they desiccate. We found that after the first week, fo increases steeply, reaching a plateau and stabilizing for the following months. We go on to propose a model that can be used to recover the original fc of the wings of preserved Ensifera that use pure tones for communication. Models were corroborated using preserved specimens previously recorded and mounted in dry collections for more than 10 years.

Passive plasticity and a sex difference in the predictability of mobility.

Behavioural predictability describes the behavioural variability of an individual. Unpredictability can arise from many sources including non-adaptive passive plasticity in which an environmental factor acts directly on the individual to create non-adaptive phenotypic variation. In this study, I use radiotelemetry to field test the hypothesis that Cook Strait giant weta Deinacrida rugosa (Orthoptera: Anostostomatidae) exhibit a sex difference in the predictability of their nightly travel distance due to passive behavioural plasticity. As predicted, I found that male mobility (i.e. nightly travel distance) was less predictable than female mobility. Females travel short and predictable distances each night for food and refuges that are close by and readily available. In contrast, male travel is less predictable because they search for female mates that are stochastically dispersed across the landscape. Therefore, their travel distance can vary considerably across nights.

Sexual maturation of the chub mackerel <I>Scomber colias</I> (Scombridae) in the East-Central Atlantic

Scientific monitoring of pelagic fish stocks in 2004–2005 and 2014–2017 provided information on characteristics of sexual maturation of Atlantic chub mackerel Scomber colias in the coastal waters of the Central-Eastern Atlantic. Based on these results we describe ecological and geographical variability of some biological characteristics of the species. Features of sexual maturation of females and males of the mackerel can be described by a logistic equation obtained in the R programming environment. Fork length, at which 50% of individuals aged 1+ are mature, is 18.4 cm for females and 20.0 cm for males; 100% of individuals are mature at age 3+ with a fork length of 32.3 and 30.8 cm for females and males, respectively. A high proportion of spawning chub mackerel individuals in the Central-Eastern Atlantic have been recorded from February to March and from June to July. Chub mackerel in the coastal waters of this region are similar in life cycle characteristics to the populations of the waters off the Canary Islands and the Madeira Archipelago, but differ from the populations of the waters off mainland Portugal, the Azores, South Africa, and the Bay of Biscay in faster sexual maturation and growth rates.

Two major-effect loci influence interspecific mating in females of the sibling species, Drosophila simulans and D. sechellia.

Secondary contact between incompletely isolated species can produce a wide variety of outcomes. The vinegar flies Drosophila simulans and D. sechellia diverged on islands in the Indian Ocean and are currently separated by partial pre- and postzygotic barriers. The recent discovery of hybridization between D. simulans and D. sechellia in the wild presents an opportunity to monitor the prevalence of alleles that influence hybridization between these sibling species. We therefore sought to identify those loci in females that affect interspecific mating, and we adapted a two-choice assay to capture female mate choice and female attractiveness simultaneously. We used shotgun sequencing to genotype female progeny of reciprocal F1 backcrosses at high resolution and performed QTL analysis. We found two major-effect QTL in both backcrosses, one on either arm of the third chromosome that each account for 32-37% of the difference in phenotype between species. The QTL of both backcrosses overlap and may each be alternate alleles of the same locus. Genotypes at these two loci followed an assortative mating pattern with D. simulans males but not D. sechellia males, which mated most frequently with females that were hybrid at both loci. These data reveal how different allele combinations at two major loci may promote isolation and hybridization in the same species pair. Identification of these QTL is an important step towards understanding how the genetic architecture of mate selection may shape the outcome of secondary contact.

Effects of sex, mating status, and genetic background on circadian behavior in Drosophila.

Circadian rhythms play a crucial role in regulating behavior, physiology, and health. Sexual dimorphism, a widespread phenomenon across species, influences circadian behaviors. Additionally, post-mating physiological changes in females are known to modulate various behaviors, yet their effects on circadian rhythms remain underexplored. Here, using Drosophila melanogaster, a powerful model for studying circadian mechanisms, we systematically assessed the impact of sex and mating status on circadian behavior. We measured circadian period length and rhythm strength in virgin and mated males and females, including females mated to males lacking Sex Peptide (SP), a key mediator of post-mating changes. Across four wild-type and control strains, we found that males consistently exhibited shorter circadian periods than females, regardless of mating status, suggesting that circadian period length is a robust sexually dimorphic trait. In contrast, rhythm strength was influenced by the interaction between sex and mating status, with female mating generally reducing rhythm strength in the presence of SP signaling. Notably, genetic background significantly modulated these effects on rhythm strength. Our findings demonstrate that while circadian period length is a stable sex-specific trait, rhythm strength is shaped by a complex interplay between sex, mating status, and genetic background. This study advances our understanding of how sex and mating influence circadian rhythms in Drosophila and provides a foundation for future research into sexually dimorphic mechanisms underlying human diseases associated with circadian disruptions.

Animal personalities influence male mating behavior and reproductive fitness

Abstract The relationship between individual personality and sexual selection has the potential to provide insights into how variation in personality traits is maintained. However, whether and how individuals with different personality traits have different mating behaviors and the fitness consequences has remained largely unexplored. We tested the hypothesis that male individuals have different mating behavior depending on their personality traits, and that there are fitness effects of personality traits. To do so, we conducted trials to quantify personality traits and observed mating behavior under standardized conditions in the red flour beetle (Tribolium castaneum). We also collected the number of offspring produced by their female mates to assess the association between male personality and their reproductive fitness. We found that male beetles showed consistent inter-individual differences in walking distance, emergence time from shelter and death-feigning time, which likely corresponding to two personality traits of activity and boldness. Although larger males had higher mating success and produced more offspring, some personality traits were also strongly related to mating behavior and reproductive fitness. Males with longer walking distances tended to seek female mates more promptly. Other than the morphological trait of body size, the emergence time from shelter (boldness) also showed a positive relationship with the number of matings and offspring reproduced. Furthermore, we found that the interaction between death-feigning time and walking distance in males influenced the number of matings they obtain, with either shy but active or bold but inactive males achieving more matings. We therefore highlight that alongside morphological traits, certain personality traits can also play a role in affecting mating behaviors and even reproductive fitness in males.

Immunization of male BALB/c and C57BL/6 mice similar modulates chemical signals detected in both chromatographic and behavioral tests

The odor plays a key role in communication between animals and the choice of a mate. The odor of urine of males becomes less attractive to mature females after infection or activation of the immune system. The development of the immune response in the early stages is related with the production of both pro-inflammatory and anti-inflammatory cytokines. To investigate the chemical basis of the observed differences and examine the influence of female interactions with the odor of antigen-treated males, we immunized males of inbred BALB/c (Th1) and C57BL/6 (Th2) mice with hemocyanin (KLH). For females of both tested strains, the attraction of the odor of male urine collected 3 days after immunization was lower compared with the odor of control males. Herewith, BALB/c females sniffed the urine of immunized males less frequently, and C57BL/6 females demonstrated a shorter duration of grooming in olfactory tests with urine of immunized males. The altered response of females to the odor of male urine collected on day 3 after KLH injection matched with antigen-induced modulation of relative levels of volatile organic compounds (VOCs) detected in urine samples by gas chromatography and mass spectroscopy (GC-MS). In males of both strains, after KLH injection, an increase in the content of nonanal, benzothiazole, as well as 2-sec-butyl-4,5-dihydrothiazole, and [1,4,5]-oxadithiepane was shown. At the same time, no compounds were found, the content of which changes in different directions in the urine of males after immunization, depending on the strain of the animal.

Exploring Photoreceptor Gene Expression and Seasonal Physiology in Mediterranean Swordfish (Xiphias gladius).

Mature and immature female swordfish show different gonadal expression patterns of melatonin synthesis-related and opsin genes, indicating that seasonality affects gonadal circadian genes, especially through opsin modulation. The high energy demands of reproduction may cause mature female swordfish to become more susceptible to environmental stressors/changes, potentially affecting their health post-reproduction. The modulation of melatonin and opsin expression may also influence swordfish biology, impacting basal metabolism and stress responses. This study aimed to investigate the hepatic expression patterns of genes involved in melatonin and opsins activity after the reproductive period, comparing mature and immature females. Liver samples of swordfish females, collected from the Central Adriatic Sea, were analyzed to evaluate the expression of a melatonin receptor (mel1b), acetylserotonin O-methyltransferase (asmt), opsins (sws, VA opsin and opsin4), and stress response (sod1, sod2 and hsp4b) genes, while histological analysis focused on hepatic melanomacrophages, melanomacrophage centers, and lipid content. The expression of all genes analyzed did not differ between mature and immature females except for sws, which was significantly downregulated in mature females. The overall health conditions of mature and immature females appeared comparable, as suggested by the histological analysis and the absence of significant differences in the expression of stress response genes. Although the study used a limited number of samples and lacked a comparison between the reproductive and non-reproductive periods, the preliminary results suggest that opsins may play a role in modulating physiological processes beyond reproduction.

Maintaining the physiological stability during artificial spawning of Liza ramada in captivity

In captivity, the physiological condition of mature brood fish has a vital role for a successful artificial spawning. Therefore, the current study aimed to minimize endocrine and metabolic disruptions during routine handling, transportation, and acclimatization during artificial spawning in L. ramada. Here, we determined the impacts of transportation and handling, as well as the acclimation to different salinities on the levels of total thyroxine (T4), triiodothyronine (T3), cortisol, and glucose in the mature L. ramada females. The transportation procedures of cultured mature females of L. ramada without anesthesia induced physiological stress as reflected with a rapid elevation in serum cortisol and glucose concomitant with a decrease in T4 within 3 h. However, the anesthesia protocol and the gradual acclimatization to seawater (24 h) were successful in maintaining baseline concentrations of the measured hormones in mature L. ramada females. The recorded levels of thyroid hormones (T4 and T3) and cortisol proved that 40 mg l−1 of clove oil was superior to anesthetic tricaine methane sulfonate (MS-222). In parallel, clove oil as an anesthetic has a rapid induction time and longer recovery time compared to MS-222 in L. ramada anesthesia. So, the slow acclimation and clove oil anesthesia were crucial during the induction of spawning in L. ramada. Indeed, all injected females were physiologically stable and spawned within the appropriate time consistent with the histological observation of both ovary and liver. Together, these findings recommend that maintaining the physiological stability of broodstock is critical for the successful artificial spawning of mullet.

An assessment of whether age, sex, and reproductive status affect bait uptake by grey squirrels

AbstractThe grey squirrel (Sciurus carolinensis) is an invasive alien species in the United Kingdom (UK). The economic impact of grey squirrels on England and Wales forestry is estimated to be around £37 million ($47 million USD) per year, and the presence of this species has caused the decline of the native red squirrel (Sciurus vulgaris) due to interspecific competition and transmission of diseases. Oral contraceptives, delivered in baits, are being developed to control the number of grey squirrels in the UK. Bait uptake can be affected by many factors that must be understood to develop effective delivery methods. As sexually mature females drive population growth, targeting these females with oral contraceptives should be a priority to maximize the impacts of oral contraceptives on grey squirrel populations. This study investigated whether sex, age, or reproductive status affected bait uptake by grey squirrels. We fitted 138 squirrels with passive integrated transponders (PIT‐tags) in 4 woodland sites in the UK and measured bait uptake using squirrel‐specific bait dispensers (hoppers) fitted with PIT‐tag readers and baited with hazelnut paste and the biomarker rhodamine B for 5 days in 2018 and 2022. Overall, 49% of squirrels consumed bait from the hoppers and bait was most likely to be consumed by reproductively active females. Immature squirrels made more visits per day to hoppers and visited more hoppers per day compared with adults, though the results for immature animals were highly variable. Sex, age, and reproductive status were not found to affect bait uptake in grey squirrels at the density of squirrels (3.9–6.3/ha) and bait hoppers (3/ha) tested in this study. The results confirmed that it should be possible to deliver oral contraceptives equally to different individuals within populations of grey squirrels within a relatively short period. The findings of this study could be used to inform targeted interventions aimed at delivering baits containing contraceptives or vaccines to grey squirrels.

Productive and morphological features of females and calves of domestic deer of the Evenk and Nenets breeds during the calving period

Purpose: to conduct a comparative description of the productive and morphological characteristics of domestic reindeer of the Nenets and Evenki breeds.Materials and methods. Study of the morphological, behavioral and reproductive characteristics of domestic reindeer of the Nenets and Evenki breeds, kept in various natural and climatic conditions of the tundra and northern taiga, during the calving and dairy periods. Experimental data were collected from clinically healthy animals. The research was carried out in accordance with the basic methods of zootechnical research (observation, examination). Their gender (visually) and age were determined (using ear tags and animal registration data, and, if necessary, based on the degree of tooth wear); An assessment of the exterior of the reindeer herd was carried out before the rut to select males and females for mating. Methods of visual assessment, linear measurements of animals, and field chronometry of calving were used.Results. The Evenki breed of deer is distinguished by its large size, height, high load-carrying capacity and endurance when transporting goods and people. It has been established that the dynamics of calving of domestic reindeer of the Evenki breed is identical to the dynamics of calving of Nenets reindeer, but there are some peculiarities. In the tundra zone, calving takes 3—5 days longer, and the initial phase begins (on average) 7-10 days earlier than in the taiga zone. The live weight of Evenki breed calves at birth is 0.8 kg higher than that of Nenets breed calves. The intensity of growth up to 3 months of age is higher in the early, mass and late periods of calving. It has been established that calves of the early calving period exceed in live weight at birth and its growth the calves of the mass period, and those, in turn, exceed the calves of the late calving period. This pattern can be traced up to 6 months of age. Calves of early and mass calving periods, having the potential for rapid growth, find themselves in more favorable nutritional conditions in the first months of life than late calves. This is expressed in the ability to receive green pasture food 15-25 days earlier and be stronger by the time the blood-sucking dipterous insects appear. Early calving Nenets calves are more active at night, since there is still a lot of snow in the tundra zone during this period and the temperature sometimes drops below 0ºC.

Lethal versus surviving sepsis phenotypes displayed a partly differential regional expression of neurotransmitters and inflammation and did not modify the blood–brain barrier permeability in female CLP mice

BackgroundSeptic encephalopathy is frequent but its pathophysiology is enigmatic. We studied expression of neurotransmitters, inflammation and integrity of the blood–brain barrier (BBB) in several brain regions during abdominal sepsis. We compared mice with either lethal or surviving phenotype in the first 4 sepsis days. Mature CD-1 females underwent cecal ligation and puncture (CLP). Body temperature (BT) was measured daily and predicted-to-die (within 24 h) mice (for P-DIE; BT < 28 °C) were sacrificed together (1:1 ratio) with mice predicted-to-survive (P-SUR; BT > 35 °C), and healthy controls (CON). Brains were dissected into neocortex, cerebellum, midbrain, medulla, striatum, hypothalamus and hippocampus.ResultsCLP mice showed an up to threefold rise of serotonin in the hippocampus, 5-hydroxyindoleacetic and homovanillic acid (HVA) in nearly all regions vs. CON. Compared to P-SUR, P-DIE mice showed a 1.7 to twofold rise of HVA (386 ng/g of tissue), dopamine (265 ng/g) and 3,4-Dihydroxyphenylacetic acid (DOPAC; 140 ng/g) in the hippocampus, hypothalamus and medulla (174, 156, 82 ng/g of tissue, respectively). CLP increased expression of TNFα, IL-1β and IL-6 mRNA by several folds in the midbrain, cerebellum and hippocampus versus CON. The same cytokines were further elevated in P-DIE vs P-SUR in the midbrain and cerebellum. Activation of astrocytes and microglia was robust across regions but remained typically phenotype independent. There was a similar influx of sodium fluorescein across the BBB in both P-DIE and P-SUR mice.ConclusionsCompared to survivors, the lethal phenotype induced a stronger deregulation of amine metabolism and cytokine expression in selected brain regions, but the BBB permeability remained similar regardless of the predicted outcome.

Population structure and feeding habits of Carcinoscorpius rotundicauda in the bay environment, Southern Gulf of Thailand

This study presents the first comprehensive assessment of the population structure and feeding habits of Carcinoscorpius rotundicauda in Thailand. Sample collection was conducted using crab gill nets at seven sampling sites characterized by distinct ecosystem attributes in Pattani Bay between February 2019 and March 2020. Our findings indicate the presence of a single Asian horseshoe crab (HSC) species within the bay, with a sex ratio of approximately 1:1 (48.1 % males, 51.9 % females) that did not deviate significantly from parity. Habitat variation within the bay did not influence HSC abundance (P > 0.05) whereas monthly abundance fluctuations were highly significant (P < 0.001), peaking in March and reaching the lowest in September. Positive correlations were observed between HSC abundance and environmental factors including dissolved oxygen, temperature, water pH, water depth, and chlorophyll c concentrations. Linear regression analysis revealed a positive correlation between morphometric characteristics and body weight. However, multiple linear regression analysis indicated a negative relationship between body weight and telson length (TEL) and opisthosoma width (OW) of males, as well as TEL of females. The size at which 50 % of the HSC population reached maturity (L50) was estimated to be 12.2 cm for males and 13.5 cm for females based on prosomal width (PW). The average PW measurements of HSC at different egg stages (1–4) from developing to mature females was 14.4 cm, with corresponding body weights ranging from 224 to 243 g. Females at egg of stages 3 and 4 were found throughout the year, indicating multiple spawning events, particularly prevalent in January-April, and predominantly abundant at stations 1, 2, 5 and 6. HSC primarily consumed bivalves (22.1±21.2 %), followed by fishes (5.9±13.0 %) and crustaceans (2.9±9.0 %) by volumetric contribution (%V). This comprehensive study provides novel insights into the population dynamics and feeding ecology of HSC within Thailand. The findings establish a foundational framework for future research endeavors and offer critical data to inform the management and conservation of their habitats.

Biotic factors as key determinants for ovarian and oothecal developmental plasticity of a tortoise beetle

Ovarian development in r-selected species is a highly dynamic process widely studied in various insect groups. An array of biotic and abiotic factors may influence it. So, the present investigation was to evaluate the impact of a female's age and mating status on the ovarian development, ootheca formation, body colour polymorphism, and fat content of the tortoise beetle, Aspidomorpha miliaris (Fabricius). Females of a certain age and mating status were dissected to demonstrate changes in their ovarioles, lateral oviduct, accessory gland, elytral colour, fat body content, and body size. It was predicted that age or mating status would not affect the ovarian parameters like length and width of ovarioles, lateral oviducts, accessory glands, body size, fat body content, and elytral colour. However, the ootheca-forming modifications would be initiated by ageing and mating. The current study demonstrated the substantial effect of age and mating status on the growth of the accessory glands and ovarioles. On the other hand, fat body contents declined comparatively in multiply-mated females. Besides this, the beetle exhibits elytral colour polymorphism till sexual maturity. An accessory gland was exclusively detected in multiply-mated females. This discovery opens opportunities for further investigation into the precise function of the gland, which is likely involved in the formation of ootheca.

Reproductive Biology of the Invasive Blue Crab Callinectes sapidus in the Thermaikos Gulf (Northwest Aegean Sea, Eastern Mediterranean): Identifying Key Information for an Effective Population Management Policy

The reproductive biology of the invasive blue crab Callinectes sapidus was studied in the Thermaikos Gulf (Northwest Aegean Sea, Eastern Mediterranean). In the two-year survey, 5698 (2897♂/2801♀) crabs were caught with the use of fyke nets. Total sex ratio (♂/♀) reached equality (1.03:1). The female blue crab exhibited a protracted reproductive period. Mature and ovigerous females exhibit short migratory movements from estuarine and inshore waters, where the population mostly congregates (0–3 m), and move to slightly deeper waters (1–3 m) up to 9 m for spawning. A total of 340 ovigerous females were caught. Their number varied both spatially and temporally; they were observed for a 7-month period (April to October) with a clear peak in July–August and at a 3 m depth gradient corresponding to ≈60% of the total number of ovigerous females caught in both years. Size at first sexual maturity (CW50) was estimated at 113.1 mm CW. Average fecundity was ≈790,000 eggs. Experimental trawling showed that inshore waters (&lt;1 m) in the estuaries serve as nursery areas for juveniles. Defining the spatiotemporal and bathymetrical distribution of ovigerous females in any invaded coastal habitat could be considered key information for the implementation of a management policy for the species.