Male-female Interactions Research Articles

Molecular characterization of Smtdc-1 and Smddc-1 discloses roles as male-competence factors for the sexual maturation of Schistosoma mansoni females.

Schistosomes are the only mammalian flatworms that have evolved separate sexes. A key question of schistosome research is the male-dependent sexual maturation of the female since a constant pairing contact with a male is required for the onset of gonad development in the female. Although this phenomenon is long known, only recently a first peptide-based pheromone of males was identified that contributes to the control of female sexual development. Beyond this, our understanding of the molecular principles inducing the substantial developmental changes in a paired female is stillrudimentary. Previous transcriptomic studies have consistently pointed to neuronal genes being differentially expressed and upregulated in paired males. These genes included Smp_135230 and Smp_171580, both annotated as aromatic-L-amino-acid decarboxylases (DOPA decarboxylases). Here, we characterized both genes and investigated their roles in male-female interaction of S. mansoni. Sequence analyses indicated that Smp_135230 represents an L-tyrosine decarboxylase (Smtdc-1), whereas Smp_171580 represents a DOPA decarboxylase (Smddc-1). By qRT-PCR, we confirmed the male-specific and pairing-dependent expression of both genes with a significant bias toward paired males. RNA-interference experiments showed a strong influence of each gene on gonad differentiation in paired females, which was enhanced by double knockdown. Accordingly, egg production was significantly reduced. By confocal laser scanning microscopy, a failure of oocyte maturation was found in paired knockdown females. Whole-mount in situ hybridization patterns exhibited the tissue-specific occurrence of both genes in particular cells at the ventral surface of the male, the gynecophoral canal, which represents the physical interface of both genders. These cells probably belong to the predicted neuronal cluster 2 of S. mansoni. Our results suggest that Smtdc-1 and Smddc-2 are male-competence factors that are expressed in neuronal cells at the contact zone between the genders as a response of pairing to subsequently control processes of female sexual maturation.

Male-Female Interactions for the Expression of Phenotypic Traits and Behavioral Performance of the Male Giant Freshwater Prawn (Macrobrachium rosenbergii)

Male-Female Interactions for the Expression of Phenotypic Traits and Behavioral Performance of the Male Giant Freshwater Prawn (Macrobrachium rosenbergii)

Males show their best side revisited – Effects of predation pressure on laterality in wild guppies

AbstractThe ability to detect and avoid predators has been suggested as one of the main drivers for behavioral lateralization. This is supported by studies reporting that animals from high‐predation environments are more lateralized than those from low‐predation environments. Some studies, however, have shown no effect of predator regime on lateralization. Lateralized behavior can also be driven by phenotypic asymmetry, where the more attractive side of the body is preferentially displayed during male–female interaction and courtship. The importance of fluctuating asymmetry for mate choice has been highly debated for a number of reasons. Here, we revisited the concepts of predator‐induced behavioral lateralization and phenotypic asymmetry using wild Trinidadian guppies Poecilia reticulata from three different stream systems. Using fish collected from both high‐ and low‐predation environments, we quantified behavioral lateralization in terms of directional turning bias, measured right–left body color asymmetry, and investigated whether a male side‐showing preference was present in male–female interaction trials. We found that guppies were, at best, moderately lateralized on average (across all populations), without any general effect of predator regime. There were some slight stream‐dependent side biases in color asymmetry, but this did not translate into a side‐showing preference in any of the populations in the interaction trials. Some significant observed effects align with previously published results, but these were dependent on stream‐origin and were not repeated across different experiments, complicating interpretation. We conclude that when investigating the effects of predation regime in general, and such effects on behavioral lateralization or fluctuating asymmetry in particular, attention must be focused toward several factors such as experimental assay used and population origin, and broad generalizations from results stemming from experiments including only one population should be avoided.

Thermal Plasticity in Behavioral Traits Mediates Mating and Reproductive Dynamics in an Ectotherm.

AbstractEnvironmental temperatures potentially influence reproductive performance and sexual selection by restricting opportunities for activity. However, explicit tests of the behavioral mechanisms linking thermal variation to mating and reproductive performance are rare. We address this gap in a temperate lizard by combining social network analysis with molecular pedigree reconstruction in a large-scale thermal manipulation experiment. Populations exposed to cool thermal regimes presented fewer high-activity days compared with populations exposed to a warmer regime. While plasticity in thermal activity responses in males masked overall differences in activity levels, prolonged restriction nevertheless affected the timing and consistency of male-female interactions. Females were less capable than males of compensating for lost activity time under cold stress, and less active females in this group were significantly less likely to reproduce. While sex-biased activity suppression appeared to limit male mating rates, this did not correspond to a heightened intensity of sexual selection or shifts in the targets of sexual selection. In many populations facing thermal activity restriction, sexual selection on males may play a limited role relative to other thermal performance traits in facilitating adaptation.

Meeting with a male can lead to stress: Female reaction to a pairing with a partner in Felidae

The aim of this study was to test the hypothesis that the level of sexual dimorphism modulates the effects of male-female social interaction on the female physiological condition in felids. We predicted that: 1 – contacts of females with males in species with low level of sexual dimorphism in body size will not lead to significant changes in the activity of the hypothalamus-pituitary-adrenal axis (female stress); 2 - contacts of females with males in species with a high level of sexual dimorphism can result in significant increase in the cortisol level in females. Our study did not support these hypotheses. Despite the fact that sexual dimorphism influenced partner relationships, changes of the activity of HPA in response to social interaction with a partner appeared to be determined by the biology of the species rather than by the degree of sexual dimorphism. In species with unexpressed sexual dimorphism in body size, females determined the character of relationships in the pair. In species with pronounced sexual dimorphism biased towards males, the pattern of relationships was determined by males. However, meeting a partner led to increased cortisol levels in females not in pairs with pronounced sexual dimorphism, but in pairs with a high frequency of partner interactions. This frequency was determined by the species life history and was probably related to the seasonality of reproduction and the degree of monopolization of the home range.

Men’s Self-Reported and Psychophysiological Affective Responses to Sexual Violence and Their Associations with Rape Myths, Personality, and Sexual Traits: A Preliminary Study

Objective: Despite alarming evidence on sexual violence against women, little is known about men’s emotional responses to rape and how these may be involved in sexual violence dynamics. Accordingly, our aim was to capture how rape scenarios are emotionally appraised. Methods: The current study evaluated men’s (N = 30) self-reported and psychophysiological emotional responses (facial EMG, electrodermal activity) to a rape scene, and contrasted it with their responses to stimuli depicting nonsexual violence and nonviolent male-female interactions. The associations between men’s emotional responses and their endorsement of rape myths, personality, and sexual traits were also examined. Results: Findings revealed that the rape scene resulted in higher negative affect, both subjectively and indexed by increased facial EMG (corrugator activity), than the other two stimuli. Additionally, personality traits of neuroticism, lower agreeableness, lower consciousness, psychopathic tendencies, as well as lower sexual inhibition proneness, were all associated with higher subjective sexual arousal toward rape. Conclusions: Findings add to the literature on the putative emotional processes underpinning the appraisal of sexual violence against women.

The role of intrasexual competition on the evolution of male-male courtship display: a systematic review.

Evidence of male-male courtship display is widespread across the animal kingdom. Yet, its function and evolutionary origin remain unclear. Here, we hypothesise that male-male courtship display evolved in response to selection pressure exerted by intrasexual competition during male-female courtship interactions. Intrasexual competition can be caused by bystander male pressure through eavesdropping and exploiting on displayer male's courtship interactions with females. This bystander pressure can lead to an audience effect by the displayer, who will change their courtship behaviour in the presence of bystanders and display directly towards them, even in the absence of females, as an intimidation strategy. In species where this selection pressure has taken place, we predict that the male courtship display will have a dual function: attract females and deter competitors. Therefore, we expected to find more evidence of bystander-related behaviours in species for which male-male courtship display is linked to intrasexual competition compared to species for which other explanatory hypotheses are more plausible (e.g., mistaken identity or courtship practice). We conducted two systematic reviews to test this hypothesis. First, we conducted a search for studies of species with courtship display between males and of the hypotheses provided to explain this behaviour. Our goal was to identify the species with male-male courtship display and evidence of intrasexual competition. Second, among the species with male-male courtship display, we searched for evidence of bystander-related behaviours, i.e., articles referring to eavesdropping, exploitation, and audience effect during male-female courtship interactions. Our goal was to test whether species with intrasexual competition are also more likely to show bystander-related behaviours. Although most studies reporting male courtship display towards other males do not suggest any explanatory hypothesis for this behaviour, the intrasexual competition hypothesis was largely mentioned and supported by some studies reviewed. Additionally, there is more evidence of eavesdropping and of all three bystander-related behaviours combined in species for which the intrasexual competition hypothesis was suggested. Overall, our review supports the hypothesis that intrasexual competition can play a key role in male courtship display evolution, namely that male-male courtship display may have evolved as a secondary function of male-female courtship interactions via bystander male pressure. However, our review also shows that despite the increasing interest in same-sex sexual behaviours, and male-male courtship display in particular, most studies were found to be merely descriptive, and the hypotheses they suggested to explain courtship display between males mostly speculative. This highlights an important gap in the literature. To clarify both the evolution and the function of male-male courtship display, this behaviour needs to be empirically studied more often. Our review can help advancing this research area, as it makes the 20 species with male-male courtship display for which the intrasexual competition hypothesis was suggested excellent candidates for empirical research.

Introduction: African International Migration to the West: Insights from Canada, Australia and Nigeria

Introduction: African International Migration to the West: Insights from Canada, Australia and Nigeria

Sexual conflict and the evolution of monandry: The case of the damselfly Ischnura hastata (Odonata: Coenagrionidae) in the Galápagos Islands

Abstract Sexual selection favours the evolution and maintenance of polygamy, which is the dominant reproductive strategy in insects. Monogamy can evolve in very short‐lived species due to time constraints. Here we study adult activity and mating behaviour of a population of the damselfly Ischnura hastata, a species rarely seen mating, and which has been suggested to be monandric, in wetlands of Isabela Island, Galápagos. By means of mark‐recapture methods, we estimated that the daily survival rate was low, ranging from 0.385 to 0.876, yielding average life expectancies of mature individuals of only 1.2–3.2 days. Adults showed very low activity before 7:00, indicating that mating does not occur early. The number of male–female interactions and mating attempts was extremely low, with only 44 copulations recorded on over 230 h of observations. Copulations were brief, with a mean duration of 11 min (but only two were observed from the start). Males showed clear preference to attempt to grasp in tandem females of intermediate age (in 94.3% of cases), rather than young (31.3%) or mature females (24.0%). Males were very persistent once a tandem was achieved, retaining females for up to 139 min, but most females resisted and did not copulate. We conclude that females of I. hastata show a very short time window to mate, exactly when they change colour from juvenile to mature, and live only enough to mate once. Short lifespan has selected for female monandry in I. hastata, creating an intense sexual conflict over mating rates.

To investigate the role of rutin on bisphenol-A induced female infertility in rats.

The aim of this study is to see how rutin affects female infertility in rats after exposure to bisphenol-A (BA). Now a day, infertility is a major issue in the health care system. Currently, various chemicals and toxins are exposed to our biological system. Moreover, globally the improvement in reproductive health is alarming in developing and developed countries. The complete understanding and full therapeutic spectrum of natural medicines like citrus fruit-derived phytoconstituent i.e., rutin is not explored yet. However, rutin is contributed to the improvement of vascular health and smooth muscle tissue functions. The proposed research work is designed to explore the role of rutin on bisphenol-A (BA) induced female infertility in rats. BA is a potent endocrine disruptor and it causes female infertility in the rat. The inducer of oocyte maturation with nitric oxide donor i.e., sodium nitroprusside (SNP) was used for female infertility in the rat. The test compound rutin was administered with variable doses for 60 minutes per day for 21 days for this study. The female infertility of rats was assessed by male-female interaction behaviours, and anxiety behaviours were tested on 0, 7, 14, and 21st days. The biomarkers levels i.e., estradiol-17b (E2), follicle-stimulating hormone (FSH) and antimullerian tubulin hormone (AMH), reduced glutathione (GSH), and lipid peroxidation (MDA) levels were estimated at the end of the experimental protocol. The treatment of rutin is ameliorated the BA-associated female reproductive behaviours and biomarkers level. Hence, it may be useful to improve female reproductive health due to its potential multi-targeted actions like hormonal regulation, anti-oxidant, and anti-peroxidative actions.

نزاع العلماء في حكم ملازمة البيت للمرأة المسلمة سلفًا وخلفًا

This research is a comparative and analytical study that focuses on the ruling for a Muslim woman to be confined to her home. The researchers present the differences of opinion among classical and contemporary scholars on the issue, discuss their opinions along with comparison and analysis of the reasoning proffered and explains the intellectually convincing view on the issue. Furthermore, the researchers examine in depth the degrees of veracity and authenticity of aḥādīth of the Prophet (sws) that the scholars adduce in their contestations. In this regard, the researchers have used two approaches: the first is the comparative one and second is an analytical one. The researchers conclude that the opinion of the scholars who say that it is not permissible in Islam for Muslim women to leave their houses, go out for work and travel for their studies, is inauthentic and incorrect. This view is neither proven from the Qur’anic text, nor the Prophetic traditions. Moreover, it is against the common practice of the female companions of the Prophets (sws) at the time of his prophethood. Rather, it is verified that the Qur’anic injunction of staying at home was specific to the wives of the Prophet (sws) and it was imposed on them due to certain specific reasons. Therefore, it would not be appropriate at all to generalize this special directive and extend it to other ordinary Muslim women. It is not related to them. So, according to the intellectually convincing view of the scholars, it is permissible for Muslim women to go out of their houses for their daily life needs and necessities as the female companions of the Prophet used to do at the time of his prophethood. They just need to comply with the etiquette and provisions of the Qur’an. These include guarding the gaze from taking liberty, wearing decent and modest attire and avoiding exhibition of adornments worn on limbs other than the face, hands and feet on the occasions of male-female interaction, as is mentioned in Sūrah al-Nūr.

Analysis of The Story of Your Life From the Perspective of Deconstruction

The growth of Western science fiction steadily slowed down after the last century’s “Golden Age”, but the emergence of Chinese-American science fiction writers has given the genre fresh life. This study investigates the deconstruction of Anti-Logocentrism and binary oppositions in the famous science fiction The Story Of Your Life by Chinese American author Ted Chiang applying Derrida’s deconstructionist theories as a theoretical framework. First, the paper analyses the traditional relationship between the self and others in terms of the attitude toward aliens; the author’s deconstruction of the conventional male-female interaction is then analyzed in light of the work’s depiction of the heroine, and the author’s analysis of the conventional cause-and-effect relationship follows. Based on above, the paper reveals Ted Chiang’s intention to create a just and peaceful society in the book, providing readers with a fresh perspective on how to understand it.

GW4064 Alters Gut Microbiota Composition and Counteracts Autism-Associated Behaviors in BTBR T+tf/J Mice.

Autism spectrum disorder (ASD) is considered a heterogeneous neurodevelopmental disorder characterized by significant social, communication, and behavioral impairments. The gut microbiota is increasingly considered a promising therapeutic target in ASD. Farnesoid X receptor (FXR) has recently been shown to modulate the gut microbiota. We hypothesized that FXR agonist GW4064 could ameliorate behavioral deficits in an animal model for autism: BTBR T+Itpr3tf/J (BTBR) mouse. As expected, administration of GW4064 rescued the sociability of BTBR mice in the three-chamber sociability test and male-female social reciprocal interaction test, while no effects were observed in C57BL/6J mice. We also found that GW4064 administration increased fecal microbial abundance and counteracted the common ASD phenotype of a high Firmicutes to Bacteroidetes ratio in BTBR mice. In addition, GW4064 administration reversed elevated Lactobacillus and decreased Allobaculum content in the fecal matter of BTBR animals. Our findings show that GW4064 administration alleviates social deficits in BTBR mice and modulates selective aspects of the composition of the gut microbiota, suggesting that GW4064 supplementation might prove a potential strategy for improving ASD symptoms.

Ultrasonic vocalizations in laboratory mice: strain, age, and sex differences.

Mice produce ultrasonic vocalizations (USVs) in different social contexts across lifespan. There is ethological evidence that pup USVs elicit maternal retrieval and adult USVs facilitate social interaction with a conspecific. Analysis of mouse vocal and social repertoire across strains, sex and contexts remains not well explored. To address these issues, in inbred (C57BL/6, FVB) and outbred (CD-1) mouse strains, we recorded and evaluated USVs as neonates and during adult social encounters (male-female and female-female social interaction). We showed significant strain differences in the quantitative (call rate and duration of USVs) and qualitative vocal analysis (spectrographic characterization) from early stage to adulthood, in line with specific patterns of social behaviors. Inbred C57BL/6 mice produced a lower number of calls with less internal changes and shorter duration; inbred FVB mice displayed more social behaviors and produced more syllables with repeated internal changes; outbred CD-1 mice had an intermediate profile. Our results suggest specific vocal signatures in each mouse strain, thus helping to better define socio-communicative profiles of mouse strains and to guide the choice of an appropriate strain according to the experimental settings.

KOMPEITO, an Atypical Arabidopsis Rhomboid-Related Gene, Is Required for Callose Accumulation and Pollen Wall Development.

Fertilization is a key event for sexually reproducing plants. Pollen–stigma adhesion, which is the first step in male–female interaction during fertilization, requires proper pollen wall patterning. Callose, which is a β-1.3-glucan, is an essential polysaccharide that is required for pollen development and pollen wall formation. Mutations in CALLOSE SYNTHASE 5 (CalS5) disrupt male meiotic callose accumulation; however, how CalS5 activity and callose synthesis are regulated is not fully understood. In this paper, we report the isolation of a kompeito-1 (kom-1) mutant defective in pollen wall patterning and pollen–stigma adhesion in Arabidopsis thaliana. Callose was not accumulated in kom-1 meiocytes or microspores, which was very similar to the cals5 mutant. The KOM gene encoded a member of a subclass of Rhomboid serine protease proteins that lacked active site residues. KOM was localized to the Golgi apparatus, and both KOM and CalS5 genes were highly expressed in meiocytes. A 220 kDa CalS5 protein was detected in wild-type (Col-0) floral buds but was dramatically reduced in kom-1. These results suggested that KOM was required for CalS5 protein accumulation, leading to the regulation of meiocyte-specific callose accumulation and pollen wall formation.

Social Deficits and Cerebellar Degeneration in Purkinje Cell Scn8a Knockout Mice.

Mutations in the SCN8A gene encoding the voltage-gated sodium channel α-subunit Nav1. 6 have been reported in individuals with epilepsy, intellectual disability and features of autism spectrum disorder. SCN8A is widely expressed in the central nervous system, including the cerebellum. Cerebellar dysfunction has been implicated in autism spectrum disorder. We investigated conditional Scn8a knockout mice under C57BL/6J strain background that specifically lack Scn8a expression in cerebellar Purkinje cells (Scn8aflox/flox, L7Cre+ mice). Cerebellar morphology was analyzed by immunohistochemistry and MR imaging. Mice were subjected to a battery of behavioral tests including the accelerating rotarod, open field, elevated plus maze, light-dark transition box, three chambers, male-female interaction, social olfaction, and water T-maze tests. Patch clamp recordings were used to evaluate evoked action potentials in Purkinje cells. Behavioral phenotyping demonstrated that Scn8aflox/flox, L7Cre+ mice have impaired social interaction, motor learning and reversal learning as well as increased repetitive behavior and anxiety-like behaviors. By 5 months of age, Scn8aflox/flox, L7Cre+ mice began to exhibit cerebellar Purkinje cell loss and reduced molecular thickness. At 9 months of age, Scn8aflox/flox, L7Cre+ mice exhibited decreased cerebellar size and a reduced number of cerebellar Purkinje cells more profoundly, with evidence of additional neurodegeneration in the molecular layer and deep cerebellar nuclei. Purkinje cells in Scn8aflox/flox, L7Cre+ mice exhibited reduced repetitive firing. Taken together, our experiments indicated that loss of Scn8a expression in cerebellar Purkinje cells leads to cerebellar degeneration and several ASD-related behaviors. Our study demonstrated the specific contribution of loss of Scn8a in cerebellar Purkinje cells to behavioral deficits characteristic of ASD. However, it should be noted that our observed effects reported here are specific to the C57BL/6 genome type.

Birds of a feather flock (even more) together: An intergroup relations perspective on how #MeToo‐related media coverage affects the evaluation of prospective corporate directors

AbstractResearch SummaryThis study examines how incumbent director reactions to media coverage of the #MeToo movement have impacted the evaluation of prospective corporate directors. We argue that heightened intergroup anxiety related to male–female interactions leads incumbents to seize on social attributes that bolster category‐based trust in the reliability of prospective directors' interpersonal behavior. We predict that in response to #MeToo coverage, incumbents evaluate board candidates more positively when they share demographic characteristics or have prior social connections, and these effects are strengthened when incumbents socially identify with the firm. Empirical analyses using a longitudinal survey of evaluations of director candidates support these predictions. Our findings suggest how social movements can produce unintended consequences by inadvertently triggering psychological processes that partially offset the anticipated benefits of the movement.Managerial SummaryIncreased coverage of #MeToo has heightened concerns among board members about male–female interactions on the board. Our study finds that as #MeToo coverage increases, incumbent directors evaluate potential board candidates more positively to the extent that they share demographic characteristics, including gender, race, functional background, education and age, or when they are connected through the social network of board appointments. These effects are especially pronounced for incumbents who psychologically identify with the firm, meaning that their self‐concept is aligned with features of the organization. Our study suggests how psychological reactions of corporate directors to #MeToo may inadvertently reduce board diversity and overall board effectiveness, and we call for research‐based interventions to correct this unfortunate side effect of a critically important social justice movement.

Male White-shouldered Fairywrens (Malurus alboscapulatus) elevate androgens greater when courting females than during territorial challenges

Androgens like testosterone mediate suites of physical and behavioral traits across vertebrates, and circulation varies considerably across and within taxa. However, an understanding of the causal factors of variation in circulating testosterone has proven difficult despite decades of research. According to the challenge hypothesis, agonistic interactions between males immediately prior to the breeding season produce the highest levels of testosterone measured during this period. While many studies have provided support for this hypothesis, most species do not respond to male-male competition by elevating testosterone. As a result, a recent revision of the hypothesis (‘challenge hypothesis 2.0’) places male-female interactions as the primary cause of rapid elevations in testosterone circulation in male vertebrates. Here, we offer a test of both iterations of the challenge hypothesis in a tropical bird species. We first illustrate that male White-shouldered Fairywrens (Malurus alboscapulatus) differ by subspecies in plasma androgen concentrations. Then we use a social network approach to find that males of the subspecies with higher androgens are characterized by greater social interaction scores, including more time aggregating to perform sexual displays. Next, we use a controlled experiment to test whether males respond to simulated territorial intrusion and/or courtship competition contexts by elevating androgens. We found that males elevated androgens during territorial intrusions relative to flushed controls, however, males sampled during courtship competitions had greater plasma androgens both relative to controls and males sampled while defending territories. Ultimately, our results are consistent with challenge hypothesis 2.0, as sexual interactions with extra-pair females were associated with greater elevation of androgens than territorial disputes.

Male Pheromones Induce Ovulation in Female Honeycomb Groupers (Epinephelus merra): A Comprehensive Study of Spawning Aggregation Behavior and Ovarian Development.

This study characterizes the spawning phenomena of the honeycomb grouper (Epinephelus merra), which is a lunar-synchronized spawner that spawns a few days after full moon. To elucidate the aggregation characteristics of wild honeycomb groupers, the numbers of males and females at the spawning grounds were counted before and after the full moon. Approximately 20 males were consistently observed at the spawning grounds throughout the study period. Females appeared several days after full moon and rapidly increased in number, peaking four days after full moon (41 individuals). The maturation status of the females aggregating at the spawning grounds was investigated. The gonadosomatic index increased rapidly three days after full moon, and ovulation was confirmed. Individuals with ovulatory eggs were present for three days, after which the number of females at the spawning grounds decreased. Additionally, the role of males in final oocyte maturation (FOM) and ovulation in females during the spawning phase was investigated in captivity. FOM was induced in females reared in water with mature males, suggesting that male pheromones in the water induced FOM via activation of the hypothalamic–pituitary–gonadal axis. This suggests that spawning at the natural spawning grounds was the result of male–female interactions via pheromones.

Male and female developmental temperature modulate post-copulatory interactions in a beetle.

Sexual selection theory has proven to be fundamental to our understanding of the male-female (sperm-egg) interactions that characterise fertilisation. However, sexual selection does not operate in a void and abiotic environmental factors have been shown to modulate the outcome of pre-copularory sexual interactions. Environmental modulation of post-copulatory interactions are particularly likely because the form and function of primary reproductive traits appears to be acutely sensitive to temperature stress. Here we report the effects of developmental temperature on female reproductive architecture and the interaction between male and female developmental temperature on the outcome of sperm competition in the bruchid beetle Callosobruchus maculatus. When females were reared at developmental temperatures above and below typical temperatures the bursa copulatrix (site of spermatophore deposition) were smaller and, were either shorter and broader (high temperatures) or longer and thinner (low temperatures) than those reared at intermediate temperatures. Males and females reared at low developmental temperatures were less likely to mate than those reared at higher temperatures. Where copulation occurred, females reared at the highest temperature copulated for longest, whilst males reared at the lowest temperature spent longer in copula. Male developmental temperature had a significant impact on the outcome of sperm competition: males reared at 17°C were largely unsuccessful in sperm competition against control (27°C) males, although some of the variation in the outcome of sperm competition was a product of the interaction between male and female developmental temperature. Our results demonstrate that male-female interactions that characterise pre- and post-copulatory outcomes are sensitive to developmental temperature and that plasticity in cryptic female preferences could lead to heterogeneous selection on the male reproductive phenotype.