Virgin Females Research Articles

The Sex Dependent and Independent Effects of Dietary Whey Proteins Are Passed from the Mother to the Offspring.

The study assesses the metabolic impact of dietary whey proteins across generations. Virgin females are fed 20% energy whey proteins with 70% energy carbohydrates, which reduces body weight gain and visceral adipose compared to controls fed dietary casein. In contrast, the males are unresponsive. The effect is accentuated in reproductive females that also have reduced plasma levels of glucose. The responsive females have increased cecal levels of pyruvic and lactic acid, suggesting a greater catabolism of carbohydrates in the gut. While the male and female offspring born to mothers on whey proteins continue to reduce body weight gain, the female offspring further decreases the visceral and subcutaneous tissues and increases the gut capacity to breakdown dietary carbohydrates and proteins, whereas the male offspring are able to only decrease the visceral and increase protein catabolism in the gut. The ileum of male mice responded by reducing the gene expression for fibroblast growth factor 15 and increasing the expression of chymotrypsinogen B1. The effect of whey proteins on growth can be passed from the mother to the offspring without a sex preference, whereas the transmission of gut activity and adiposity are dependent on the sex of the offspring.

Female Phalangium opilio use fellatio to compensate sexual avoidance

Sexual conflict arises from differences in reproductive interests between the sexes. We allowed the female harvestman Phalangium opilio to sequentially mate with two different males to examine female sexual receptivity in this species. Virgin females were more sexually receptive than non-virgins. Males exhibited a high interest in repeated copulations with the same female, often engaging in aggressive behaviours such as biting and reversed sexual cannibalism. Fellatio, a behaviour in which females lick the male’s penis, was observed in 44% of trials and was associated with female unwillingness to mate and shorter copulation duration. Fellatio was repeatable, suggesting that it is influenced by individual characteristics or underlying physiological factors. Female lifespan was negatively correlated with the total number of eggs produced, suggesting a trade-off between reproduction and longevity. These findings provide evidence of the appearance of fellatio, a female mating strategy that evolved as compensation of avoiding unwanted sexual intercourse.

Evaluating the Efficacy of the Male Annihilation Technique in Managing Oriental Fruit Fly (Diptera: Tephritidae) Populations through Microscopic Assessment of Female Spermathecae.

The male annihilation technique (MAT) plays a crucial role in the pest management program of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). However, a suitable method for real-time and accurate assessment of MAT's control efficiency has not been established. Laboratory investigations found that motile sperms can be observed clearly under the microscope when the spermathecae dissected from mated females were torn, and no sperms were found in the spermathecae of virgin females. Furthermore, it was confirmed that sperms can be preserved in the spermathecae for more than 50 days once females have mated. Laboratory results also indicated that proportion of mated females decreased from 100% to 2% when the sex ratio (♀:♂) was increased from 1:1 to 100:1. Further observation revealed that there were no significant differences in the superficial area of the ovary or spermatheca between mated females and virgin females. Field investigations revealed that the proportion of mated females (PMF) could reach 81.2% in abandoned mango orchards, whereas the PMF was less than 36.4% in mango orchards where MAT was applied. This indicates that the PMF of the field population can be determined by examining the presence of sperms in the spermathecae. Therefore, we suggest that this method can be used to monitor the control efficiency when MAT is used in the field.

Sperm depletion and mate choice of the crab spider, Ebrechtella tricuspidata (Fahricius)

Abstract Mounting evidence suggests that male sperm may be gradually depleted after consecutive matings, resulting in the decline of female reproductive output in insect species. It is predicted that females may employ adaptive strategies to avoid the sperm-depleted males, such as mating multiply with different males and/or discriminating against previously mated males (MMs). Similarly, males may exhibit adaptive behaviors toward females varying in mating status. However, in spiders with males lacking primary copulatory organs and their pedipalps modified to transfer sperm, there are few studies on male mating potential and previous mating experience on their subsequent mate choice. In this study, we used a polyandrous crab spider, Ebrechtella tricuspidata, a sit-and-wait predator with female-biased sex ratio as a model system to ascertain whether 1) male mating experiences influence female reproductive fitness; 2) females respond differently to males varying in mating status; and 3) males respond differently to females varying in mating status. Our results showed that female fecundity was independent of male mating experiences, but female fertility markedly declined with the increase of male previous mating experiences in the first eggsac. Counter to our predictions, females preferred to choose and mate with the larger males, regardless of their mating status. In contrast, male mating status influenced their mating preference toward females. Virgin males did not show any preference between virgin and mated females; however, MMs were more likely to prefer the virgin females over the mated ones. Overall, our results indicated that female choice depended primarily on male relative size rather than male mating status, whereas male choice depended on female mating status. Depending on the investigation of reproductive dynamics and mate choice in E. tricuspidata, the study will provide valuable insights into the adaptive behaviors of both males and females exhibiting toward mates varying in mating status.

Serotonin suppresses intraspecific aggression in an agrobiont spider, Pardosa pseudoannulata, without affecting predation on insects.

Spiders are an abundant group of natural enemies preying on insect pests in agroecosystem. But their potential in biological control has not been fully realized due to difficult mass production. One hindrance is the intense intraspecific aggression in spiders. Neurotransmitters such as serotonin play important roles in modulating aggression. Here, we investigated the regulatory function of serotonin (5-hydroxytryptamine [5-HT]) signaling in the intraspecific aggression in a wandering spider Pardosa pseudoannulata (Araneae, Lycosidae). The aggression was quantified with 5 escalated aggression behaviors as approach, chasing, lunging, boxing, and biting. Virgin (VG) females exhibited higher aggression levels but less 5-HT content than post-reproductive (PR) females. Systemic increase of 5-HT via 5-HT injection decreased aggression, while decrease of 5-HT via RNA interference (RNAi) of the tryptophan hydroxylase gene, increased aggression. The involvement of the four 5-HT receptors were determined via individual or combined RNAi. Co-RNAi of the three 5-HT1 genes increased overall aggression with decreased incidents of approach, chasing, lunging, and increased biting. RNAi of 5-HT1B decreased approach and increased biting, whereas RNAi of 5-HT1A or 5-HT1C did not affect aggression. RNAi of 5-HT7 decreased approach only. Therefore, different 5-HT receptor types contribute to different aspects of the inhibitory effects of 5-HT on aggression and provide several pharmacological targets for manipulating spider aggression. 5-HT injection did not affect spiders' predation on their insect prey, the brown planthopper Nilaparvata lugens. The findings reveal 1 neuronal mechanism regulating intraspecific aggression in spiders and provide an insight in developing aggression suppression strategies for spider mass rearing.

Factors to Male-Female Sex Approaches and the Identification of Volatiles and Compounds from the Terminalia of Proholopterus chilensis (Blanchard) (Coleoptera: Cerambycidae) Females in Nothofagus obliqua (Mirb.) Oerst. (Nothofagaceae) Forests in Chile.

During the spring-summer seasons between 2019 and 2023, in the localities of Maquehue (La Araucanía Region) and Llifén (Los Ríos Region), we collected 262 virgin Proholopterus chilensis (1 female/2.3 males) specimens emerging from the live trunks of N. obliqua trees, an atypical sex ratio in Cerambycidae, suggesting high male competition for females. Virgin specimens of both sexes were individually placed in panel traps in the field, capturing only males (n = 184) over the field study seasons and only in traps baited with females. This fact preliminarily suggests the P. chilensis females emit possible "volatile or airborne" pheromones (eventually being a long-range sex pheromone), something unusual in Cerambycinae, the subfamily to which it currently belongs, although the taxonomic status of the species is under debate. In Llifén and Santiago (Metropolitan Region), behavioral observations were conducted, which allowed us to define the conditions necessary for male-female encounters that were replicated when carrying out volatile captures (Head Space Dynamic = HSD) and collections of compounds from terminalias excised from females. In field trials, virgin females less than ten days old were more attractive than older ones and attracted males during the night, i.e., between 23:00 and 5:00 AM, when the ambient temperature exceeded 11.6 °C. The aeration of females under the conditions described above and subsequent analysis of extracts by GC-MS allowed the identification of compounds absent in males and the control, including two oxygenated sesquiterpenes, a nitrogenous compound (C20), and a long-chain hydrocarbon (C26). From the terminalia extracts, hentriacontane, heptacosane, and heneicosyl, heptacosyl and docosyl acetates were identified by GC-MS, and their roles are unknown in the development of short-distance sexual behaviors, but they could serve to mark a trail leading the male towards the female in the final stage of approach for courtship/mating. Thus, we proposed the hypothesis that P. chilensis females emit both a long-range and a trail-pheromone, which, if confirmed, would be a rare case in this family. The specific identity of the compounds obtained by HSD, as well as the activities of these chemicals and those obtained from the terminalias, should be evaluated in future behavioral studies, as well as regarding their potential to attract males under field conditions. The current document is the first report on volatiles obtained from aerations and compounds extracted from female terminalia in P. chilensis.

Determination of the Flight Capacity of Tuta absoluta (Lepidoptera: Gelechiidae)1

Abstract Since invading Xinjiang, China in 2017, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), commonly known as the tomato leafminer or the South American tomato pinworm moth, has continuously expanded its scope of devastation. Because flight is a major means by which insects disperse, an insect flight mill was employed to elucidate the physiological boundaries and basic parameters of T. absoluta flight biology. The system was used to measure the average flight distance, flight time, and flight speed of adult male and female T. absoluta of different ages, including 5-d-old (post emergence) adults in different mating states that had received supplementary nutrition (5% honey water). Tests of 12 h of continuous suspension in a flight mill showed that 4 through 7-d-old adults had strong flying ability, but 5-d-old adults were the strongest flyers. The mean (±SEM) flight distance, flight time, and flight speed of 5-d-old females were 1.805 ± 0.040 km, 1.467 ± 0.036 h, and 1.231 ± 0.226 km/h, respectively. The mean (±SEM) flight distance, time, and speed of 5-d-old males were 1.627 ± 0.363 km, 1.950 ± 0.056 h, and 0.834 ± 0.202 km/h, indicating significant differences in flight ability between male and female adults. After feeding on 5% honey water, the flight ability of 5-d-old T. absoluta improved significantly compared with the control. The distance, time, and flight speed of honey-water fed 5-d-old virgin females increased by 16.73%, 8.32%, and 8.37%, compared with the control (fed honey-free water). The flight distance, time, and speed of 5-d-old males increased by 7.87%, 0.56%, and 7.07% respectively, compared with the control. After mating, the distance, time, and flight speed of 5-d-old female adults increased by 11.91%, 0.48%, and 11.29% compared with virgin female adults. However, after 5-d-old males mated, their corresponding flight ability decreased by 11.13%, 3.34%, and 7.34%, compared with virgin male adults. In summary, sex, supplementary nutrition, and mating status all have a significant impact on the flight ability of T. absoluta.

Volatile Sex Pheromone Extraction and Chemoattraction Assay in Caenorhabditis elegans.

Chemical communication is vital in organismal health, reproduction, and overall well-being. Understanding the molecular pathways, neural processes, and computations governing these signals remains an active area of research. The nematode Caenorhabditis elegans provides a powerful model for studying these processes as it produces a volatile sex pheromone. This pheromone is synthesized by virgin females or sperm-depleted hermaphrodites and serves as an attractant for males. This protocol describes a detailed method for isolating the volatile sex pheromone from several C. elegans strains (WT strain N2, daf-22, and fog-2) and C. remanei. We also provide a protocol for quantifying the male chemotaxis response to the volatile sex pheromone. Our analysis utilizes measurements such as chemotaxis index (C.I.), arrival time (A.T.), and a trajectory plot to compare male responses under various conditions accurately. This method allows for robust comparisons between males of different genetic backgrounds or developmental stages. Furthermore, the experimental setup outlined here is adaptable to investigating other chemoattraction chemicals.

A Hypothalamic Circuit that Modulates Feeding and Parenting Behaviors.

Across mammalian species, new mothers undergo considerable behavioral changes to nurture their offspring and meet the caloric demands of milk production1-5. While many neural circuits underlying feeding and parenting behaviors are well characterized6-9, it is unclear how these different circuits interact and adapt during lactation. Here, we characterized the transcriptomic changes in the arcuate nucleus (ARC) and the medial preoptic area (MPOA) of the mouse hypothalamus in response to lactation and hunger. Furthermore, we showed that heightened appetite in lactating mice was accompanied by increased activity of hunger-promoting agouti-related peptide (AgRP) neurons in the ARC. To assess the strength of hunger versus maternal drives, we designed a conflict assay where female mice chose between a food source or a chamber containing pups and nesting material. Although food-deprived lactating mothers prioritized parenting over feeding, hunger reduced the duration and disrupted the sequences of parenting behaviors in both lactating and virgin females. We discovered that ARCAgRP neurons directly inhibit bombesin receptor subtype-3 (BRS3) neurons in the MPOA, a population that governs both parenting and satiety. Selective activation of this ARCAgRP to MPOABRS3 circuit shifted behaviors from parenting to food-seeking. Thus, hypothalamic networks are modulated by physiological states and work antagonistically during the prioritization of competing motivated behaviors.

Oxytocin receptors in the nucleus accumbens shell are necessary for the onset of maternal behavior.

In rodents, oxytocin (Oxt) contributes to the onset of maternal care by shifting the perception of pups from aversive to attractive. Both Oxt receptor knockout (Oxtr -/-) and forebrain-specific Oxtr knockout (FB/FB) dams abandon their first litters, likely due to a failure of the brain to 'switch' to a more maternal state. Whether this behavioral shift is neurochemically similar in virgin females, who can display maternal behaviors when repeatedly exposed to pups, or what neuroanatomical substrate is critical for the onset of maternal care remains unknown. To understand similarities and differences in Oxtr signaling in virgin pup-sensitized Oxtr FB/FB as opposed to post-parturient Oxtr -/- and Oxtr FB/FB dams, maternal behavior (pup-sensitized females only) and immediate early gene activation were assessed. Pup-sensitized Oxtr FB/FB females retrieved pups faster on day one of testing and had reduced c-Fos expression in the dorsal lateral septum as compared to virgin pup-sensitized Oxtr +/+ females. This differs from what was observed in post-parturient Oxtr -/- and Oxtr FB/FB dams, where increased c-Fos expression was observed in the nucleus accumbens (NAcc) shell. Based on these data, we then disrupted Oxtr signaling in the NAcc shell or the posterior paraventricular thalamus (pPVT) (control region) of female Oxtr floxed mice using a Cre recombinase expressing adeno-associated virus. Knockout of the Oxtr only in the NAcc shell prevented the onset of maternal care post-parturient females. Our data suggest that a pup-sensitized brain may differ from a post-parturient brain and that Oxtr signaling in the NAcc shell is critical to the onset of maternal behavior.

Mating behaviour in ageing Teratorhabditis palmarum (Nematoda: Rhabditida)

ABSTRACT Teratorhabditis palmarum Gerber and Giblin-Davis, 1990, a free-living nematode, is able to produce hundreds of thousands of offspring in a short time. Reproduction is the main feature that defines life and, therefore, it plays an important role in determining what kinds of selective parameters play a powerful role in the maturity and evolution of mating systems. In the present study, we estimated the features of mating behaviour of Teratorhabditis using long-time microscopic videography and repeated observations. The mating behaviour of Teratorhabditis could be separated into a series of successive behaviours, including pre-mating (searching and contacting), mating (copulating) and post-mating (enduring). Here, we present the mating behaviour of 2- and 10-day-old virgin males and females. The mean time of the four phases – searching, contacting, copulating and enduring – varied significantly, at 24.6 ± 4.6 min, 36 ± 5.7 min, 31 ± 4.1 min and 10 ± 2.3 min in 2-day-old and 38.2 ± 3.3 min, 44.3 ± 5.0 min, 39 ± 4.3 min and 11 ± 3.2 min in 10-day-old individuals, respectively. Attraction between the sexes was observed, indicating the probable involvement of sex pheromone(s) in mating behaviour. In all age groups of males there was a significant increase in the duration of mating as the females aged. As the mobility of ageing individuals was reduced, this may have directly influenced the durations of the various phases of mating behaviour.

Fake news? The impact of information mismatch on mating behaviour.

Multiple cues are often used for mate choice in complex environments, potentially entailing mismatches in the information conveyed by different sources. We address the consequences of this information mismatch for receivers using the spider mite Tetranychus urticae, in which virgin females are highly valuable mates compared to mated females, given first male sperm precedence. Accordingly, males are known to prefer virgins and distinguish them using cues from the females themselves and that they leave on the substrate. Whereas cues from females are highly reliable, those left on the substrate may not reflect the real female mating status if females move and/or mate. Here, we tested the consequences of such mismatch by exposing males to mated or virgin females on patches previously impregnated with cues deposited by females of either mating status. Male mating attempts were solely affected by substrate cues while female acceptance and the number of mating events were independently affected by both cues. Copulation duration, in contrast, depended mainly on the mating status of the female, with the number of copulations and the total time spent mating being intermediate in environments with mismatched information. We also show that males incur mating costs, reflected in reduced survival in environments with virgin cues. These results suggest that substrate cues left by females are instrumental for males to find their mates. However, in environments with mismatched information, males may pay survival costs without the associated benefit of mating with virgins, or they may lose opportunities to mate with virgins by responding to substrate cues from mated females. The benefit of using multiple cues will then hinge upon the frequency of information mismatch, which itself should vary with the dynamics of populations.

First evidence of sperm remains on penis after mating in Opiliones (Opiliones: Gonyleptidae: Pachyloides thorellii)

Male harvestmen penial armature has a remarkable morphology; however, it is poorly known regarding its functions. We examined the male genitalia of virgin and mated males of the gonyleptid Pachyloides thorellii under Scanning Electron Microscope looking for evidence that the penis could remove sperm from the female ovipositor lumen during mating. Micrographs show sperm agglutinations over and within the microsetae fields in six out of the 12 mated males studied. For the mating experiments we used only virgin females, therefore the sperm found in the penis was in all cases their own sperm. This self-sperm removal could be the extraction of sperm excess in cooperation (or not) with the females. This is the first study to show for the Order Opiliones direct evidence that a male penis contains structures that can effectively remove sperm from the female ovipositor. Further behavioral and morphological studies are needed to confirm the conditions of occurrence and participation of each sex in sperm removal processes in this species.

Reproductive Behaviour of Muga Silk Moth, <i>Antheraea assamensis</i> (Helfer)

Reproductive behaviour including calling, courtship and mating behaviour of muga silk moth, Antheraea assamensis Helfer (Lepidoptera: Saturniidae) has been reported here. Muga silk moths are nocturnal and moth emergence occurs from late evening till midnight. Both male and females are sexually mature by the time of eclosion from cocoon, displaying reproductive behaviour from the first day of emergence. Virgin females start releasing sex pheromone exhibiting characteristic calling behaviour after dusk, 1.5 to 2 hr after emergence. These display simple courtship behaviour of 4-12 min duration and virgin females tend to mate with the first male coming in contact. However, once mated females reject further mating attempts by approaching males by walking away or vigorous wing fluttering. Moths start mating (coupling) on the first night onwards, after 2 to 3 hr of emergence. Mating duration ranged from 10 - 16 hr. Male moths mated with multiple females within 4 days of emergence, but no moths mated more than once in a night. Female moths typically mate only once in their lifetime, but multiple mating with intermittent egg laying by female was observed during summer.

Noradrenergic Regulation of the Medial Prefrontal Cortex Mediates Stress Coping in Postpartum Female Mice.

The prevalence of depression in women increases during the postpartum period. We previously reported that subchronic exposure to social stress decreased passive coping in postpartum female mice. This study aimed to investigate whether noradrenaline regulation might regulate coping styles in mice. We first determined whether a different type of stress, subchronic physical stress, decreases passive coping in postpartum females. Postpartum female, virgin female, and male mice were exposed to subchronic restraint stress (restraint stress for 4h for 5 consecutive days). Subchronic restraint stress decreased passive coping in postpartum females but not in virgin females and males in the forced swim and tail suspension tests. We next examined the neuronal mechanism by which subchronic stress decreases passive coping in postpartum female mice. Neuronal activity and expression of noradrenergic receptors in the medial prefrontal cortex (mPFC) were analyzed using immunohistochemistry and reverse transcription-quantitative polymerase chain reaction, respectively. The mPFC was manipulated using chemogenetics, knockdown, or an α2A adrenergic receptor (AR) antagonist. Immunohistochemistry revealed that subchronic restraint stress increased glutamatergic neuron activation in the mPFC via forced swim stress and decreased α2A AR expression in postpartum females. Chemogenetic activation of glutamatergic neurons in the mPFC, knockdown of α2AAR in the mPFC, and the α2A AR receptor antagonist atipamezole treatment decreased passive coping in postpartum females. Subchronic restraint stress decreased passive coping in postpartum females by increasing glutamatergic neuron activity in the mPFC through α2A AR attenuation. The noradrenergic regulation of the mPFC may be a new target for treating postpartum depression.

Morphometric changes at terminal molt and reproductive capacity in the kelp crab Pugettia ferox Ohtsuchi & Kawamura, 2019 (Decapoda: Brachyura: Majoidea)

Abstract It has been assumed that functional maturity and terminal molt occur simultaneously in majoid crabs. Although this assumption seems to be accurate in females, males of some majoids can mate with females even before their terminal molt. Here we describe the morphometric changes at terminal molt and test the reproductive capacity of pre-terminal molt males in the kelp crab Pugettia feroxOhtsuchi & Kawamura, 2019 (Majoidea, Epialtidae, Epialtinae). We measured the post-pseudorostral carapace length (PCL), claw length (CL), claw height (CH), and pleon (abdomen) width (AW) of crabs to estimate the morphological features distinguishing pre- and post-terminal molt individuals, namely relative claw length (CL/PCL) ≥ 0.660 in males and relative abdominal width (AW/PCL) ≥ 0.487 in females. Males with pre-terminal molt morphological features were observed for behavioral maturity through encounters with mature virgin females under laboratory conditions. More than half of the males copulated with a female and then underwent terminal molt. These females bred clutches, and larvae hatched. These results indicate that pre-terminal molt males of P. ferox can be functionally mature.

New Monoterpenoid as the Sex Pheromone of Spanish Populations of the Longtailed Mealybug Pseudococcus Longispinus (Hemiptera: Pseudococcidae).

Pseudococcus longispinus (Targioni-Tozzetti) (Hemiptera: Coccoidea: Pseudococcidae), a polyphagous and cosmopolitan pest native to Australia, is a highly damaging pest for numerous crops of economic importance. The sex pheromone of this species (2-(1,5,5-trimethylcyclopent-2-en-1-yl)ethyl acetate), currently used for pest monitoring purposes, was not attractive to males in field experiments conducted in Spanish persimmon orchards infested with this mealybug. The virgin and mated female volatile profiles of these P. longispinus populations were studied by the volatile collection of effluvia in Porapak-Q. The resulting extracts were analyzed by gas chromatography coupled to mass spectrometry (GC-MS), revealing a new compound specific to virgin females and different from the previously described sex pheromone. Based on GC-MS data and nuclear magnetic resonance experiments, we envisaged monoterpene 2-(1,5-dimethyl-4-methylenecyclopent-2-en-1-yl)ethyl acetate as the new sex pheromone candidate, which was synthesized and shown to be attractive in the field to P. longispinus males of the Spanish population.

Assessment of radiation-induced sterility, longevity, and reproductive characteristics of the Aedes aegypti (Diptera: Culicidae) strain of Swat: A step towards the implementation of SIT in Pakistan.

Biological approaches for vector mosquito control such as sterile insect technique (SIT) requires sterilization of male mosquitoes through specific radiation doses for sterility induction in males. Under the SIT program, the males used must be compatible with the wild males in vigor, flight and selection of mate. Much of this potential is determined by the diet provided in the larval stages and optimizing the irradiation doses that cause complete sterility but have very minimal effect on the lives of irradiated males. The current study is designed to evaluate gamma radiation doses for inducing sterility in male Aedes aegypti mosquitoes with a genomic background from Pakistan (Swat district) and to assess the effects of radiation exposure on the competency of irradiated males and other life traits of irradiated mosquitoes. Sterilization of 17-hour-old male pupae (groups of 50 pupa/cup in three replicates) of the Ae. aegypti Swat strain was conducted using radiation doses of 30, 60, 70, 90, and 105 gray (Gy) from (Co60) at the Nuclear Institute for Food and Agriculture (NIFA) in Peshawar, Pakistan. Post-irradiated pupae were released in adult cages. Virgin females of the same cohort were released (1:1) to mate with the irradiated males. Mortality, longevity, mating competitiveness of males, and female fecundity were recorded. An average of 71 eggs per female was recorded in control with 86% hatch rate. Individual females mated with a 60 Gy treated males produced 60 ± 0.6 eggs per female with 17% hatch rate, and those mated with 70 Gy males produced 42 ± 0.01 eggs with a nil hatch rate, whereas females mated with males treated with ≥70 Gy doses did not reproduce to next generation. Females in groups of 50 mated with 60, 70 Gy treated males (equal pairs), produced 369±1.3 and 98±0.01 eggs with 15% and zero hatch rate. Significant dose dependent reduction in longevity was observed for >30 Gy doses. The matting competence of irradiated males was about half that of un-irradiated males. Aedes aegypti with a Pakistani genomic background treated with a ≥70 Gy dose of gamma radiation induced complete sterility in males and provided the first- step foundation for SIT application in Pakistan. Further extensive studies are required to optimize the SIT techniques so that fully sterile males with very minor quality changes can be produced on large scales for field trials.

Sex Differences in Kidney Damage in BUF/MnaMcwi Rats

Kidney disease is commonly found in the BUF (Buffalo) strain of rats. It has been observed that male BUF rats show signs of focal glomerulosclerosis (FSGS). They are known to have proteinuria, hypoalbuminemia, and hyperlipidemia as they age. This is preceded by renal macrophage activation and Th2 lymphocyte polarization. There is no prior literature that explores kidney disease in female BUF rats.We previously observed that kidneys in female BUF rats appeared more damaged than their male mates, leading to the hypothesize that the female BUF/MnaMcwi (BUF) breeder rats have greater kidney damage features than male mates. To determine the relationship between sex and function, we collected urine samples using metabolic cages (at 12, 17, and 23 weeks of age), harvested organ tissue (heart left, ventricle, spleen, thymus, and kidneys), and used histopathological examination of formalin-fixed paraffn-embedded kidney samples to determine cortex tubule damage and glomerular area. We expected to see sex differences in relative sizes (mg/g BW) of the thymus, heart left ventricle, kidneys, and spleen. We found that the male BUF rats had larger absolute body weight (g), as expected. We also found that there were no significant sex differences in relative sizes (mg/g BW) of the thymus, heart left ventricle, and spleen. There was a significant sex difference in relative total kidney size (mg/g BW), with the females having larger kidney sizes compared to their body weight. In addition, there was increased microalbumin in the female BUF overnight urine collection that was significantly higher than the male BUF rats. There was no significant sex difference in the microalbumin: creatinine ratio. Finally, we found no significant sex difference in cortex tubular damage between the age-matched BUF rats, but there was a significant difference in glomeruler area (mm 2), with male glomeruler areas being significantly larger. Future studies will be done to replicate the findings and determine if virgin females show the same results. ASPIRE Program (R25HL 168782) Medical College of Wisconsin. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Characterization of core maize volatiles induced by Spodoptera frugiperda that alter the mating-mediated approach-avoidance behaviors of Mythimna separata

The fall armyworm (Spodoptera frugiperda) is an invasive species and a destructive pest of maize, which significantly impacts native species and communities via complex mechanisms like competition for resources. However, the interaction between S. frugiperda and local pests remains unclear. In this study, we determined that Oriental armyworm (Mythimna separata) females with different mating status displayed different approach-avoidance behaviors towards maize which was damaged by S. frugiperda larvae. The virgin M. separata females were repelled, while the mated females were attracted by the S. frugiperda-damaged maize. To further understand the olfactory mechanism of this phenomenon, seven volatiles induced by S. frugiperda in maize were characterized by gas chromatography and mass spectrometry (GC-MS), including trans-2-hexenal, linalool, trans-β-farnesene, cis-3-hexenyl acetate, β-caryophyllene, trans-α-bergamotene, and isopentyl acetate. Additionally, electrophysiological and behavioral assays of the seven compounds were performed using both virgin and mated females of M. separata. We determined that virgin and mated females displayed different responses to the HIPV compounds. Trans-β-farnesene was the core compound for repelling virgin females, and trans-2-hexenal was the key attractant for oviposition in mated female M. separata individuals. These findings help our comprehension of the relationships between maize pests and offer new possibilities for controlling them by olfactory-based strategies.