Silk-borne chemicals of spider nuptial gifts elicit female gift acceptance

Chemical communication is important in a reproductive context for conveying information used for mate recognition and/or assessment during courtship and mating. Spider silk is a common vehicle for chemical communication between the sexes. However, despite being well described in females, male silk-borne chemicals remain largely unexplored. Males of the spider Pisaura mirabilis silk-wrap prey (i.e. nuptial gifts) that is offered to females during courtship and eaten by the female during mating. Interestingly, rejected males often add more silk to their gift which leads to successful mating, suggesting the presence of silk-borne chemicals that facilitate female gift acceptance. To test this hypothesis, we offered females standardized gifts covered with male silk that was either washed in solvents or unwashed, respectively, to remove or not any chemically active components. We scored female gift acceptance, and as expected in the case chemicals that mediate female mating behaviour are present in male silk, females were more likely to accept gifts covered with unwashed silk. Our findings suggest that silk-borne chemicals of nuptial gifts prime female responses, potentially signalling male quality or manipulating females into mating beyond their interests given the occurrence of male cheating behaviour via nutritionally worthless gifts in this system.

Sensitivity of The Stripe-Faced Dunnart, Sminthopsis Macroura (Gould 1845), To The Phenyl Pyrazole Insecticide, Fipronil, Toxicological Signs And Implications For Pesticide Risk Assessments In Australia

A lack of toxicity data quantifying responses of Australian native mammals to agricultural pesticides prompted an investigation into the sensitivity of the stripe-faced dunnart, Sminthopsis macroura (Gould 1845) to the insecticide, fipronil (5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinyl pyrazole, CAS No. 120068-37-3). Using the Up-And-Down method for determining acute oral toxicity in mammals, derived by the Organisation for Economic Cooperation and Development (OECD), median lethal dose estimates of 990 mg kg− 1 (95% confidence interval (CI) = 580.7–4770.0 mg kg− 1) and 270.4 mg kg− 1 (95% CI = 0.0 - >20000.0 mg kg− 1) were resolved for male and female S. macroura respectively. The difference between median lethal dose estimates for males and females may have been influenced by the increased age of two female dunnarts. Further modelling of female responses to fipronil doses used the following assumptions: (a) death at 2000 mg kg− 1, (b) survival at 500 mg kg− 1 and (c) a differential response (both survival and death) at 990 mg kg− 1. This modelling revealed median lethal dose estimates for female S. macroura of 669.1 mg kg− 1 (95% CI = 550–990 mg kg− 1; assuming death at 990 mg kg− 1) and 990 mg kg− 1 (95% CI = 544.7–1470 mg kg− 1; assuming survival at 990 mg kg− 1). These median lethal dose estimates are 3–10-fold higher than the only available LD50 value for a similarly sized eutherian mammal, Mus musculus (L. 1758; 94 mg kg− 1) and that available for Rattus norvegicus (Birkenhout 1769; 97 mg kg− 1). Implications for pesticide risk assessments in Australia are discussed.

Experimental sexual selection reveals rapid divergence in male and female reproductive transcriptomes and their interactions

Mating causes substantial changes in females, altering male and female reproductive fitness. Some postmating effects are hypothesized to be at least partially mediated by gene expression changes, driven by postcopulatory sexual selection, which results in population divergence of reproductive proteins that could generate reproductive isolation. However, understanding of the direct role of sexual selection on gene expression divergence along with the subsequent molecular mismatches that could occur between diverging populations is limited. Here, we analyze gene expression divergence following over 150 generations of experimental evolution in which Drosophila pseudoobscura evolved under either elevated polyandry or enforced monogamy. We find that sexual selection rapidly impacted sex-, tissue-, and mating-specific responses, and not always in the predicted direction. Postmating female responses are either unique to each sexual selection treatment or exhibit asymmetric non-congruence, in which monogamy females upregulate and polyandry females downregulate the same genes following mating. This substantial population divergence of gene expression also gives rise to either unique or mismatched gene expression patterns in crosses between treatments. Many of these genes are involved in immune and stress responses, and non-congruent responses are particularly prevalent in the female reproductive tract, the main arena for postcopulatory sexual selection. In summary, we show that sexual selection has pervasive impacts on gene expression divergence acting both differentially between reproductive tissues of the same sex and asymmetrically in postmating female responses, and this divergence is highest in the female reproductive tract, the main arena for postcopulatory sexual selection.

Effect of lockdown on activities of daily living in the built environment and wellbeing

In an effort to arrest the spread of coronavirus (COVID-19) infection, a nationwide lockdown was declared in India in March 2020. To assess how personal built environments affected the citizens in the first few weeks, an explorative online survey was conducted, eliciting responses about work habits before the lockdown, psychological wellbeing, time spent in various activities, characteristics of those who worked from home, and food and sleep patterns. We received 121 (76 male and 45 female) responses with an average age of 35.5 years [max: 70 years, min: 18 years, standard deviation (SD): 12.9 years]. The major difference caused by the lockdown was a reduction in the time taken and distance travelled of the commute to workplaces, which was an average of 30 minutes and 9.5 km, respectively. In terms of diet, subjects who were vegetarian did not experience any difference, unlike those who were non-vegetarians (p < 0.05). The results show an association of the dependent variable of ‘feeling in general’ with predictor variables of ‘energy, pep, vitality’ and ‘feel healthy to work’ during the pandemic, whereas the predictor variables of ‘energy, pep, vitality’, ‘happy and satisfied personal life’, ‘feel healthy to work’ show an association with the dependent variable of ‘feeling in general’ before the lockdown with a significance of p < 0.02 and R2 = 0.51 and R2 = 0.60, respectively. Among those who worked from home in constrained environments, people found spaces and seemed to adapt reasonably well to the built environment with employees showing a preference for working from bedrooms and students for working from ‘sit-out’ (outside) spaces (p < 0.05). There was no change in the quality or quantity of sleep during the lockdown. This study in the early weeks of the lockdown documents the way in which individuals lived through it in terms of the built environment at home.

Nothobranchius furzeri as an emerging model for mate choice: female choice revealed by animations

The African turquoise killifish (Nothobranchius furzeri) is the shortest-lived vertebrate research model. It is also sexually dimorphic, making it suitable for studying sexual selection. We take advantage of a natural tail colour polymorphism in males and investigate female responses to computer animations of males that differ in this phenotype. Our findings indicate that GRZ (Gonarezhou) females prefer animated males with traits specific to their strain (a yellow tail with a black band) compared to males exhibiting traits from another strain of the same species (a red tail). When females were simultaneously shown animations of both males, they spent significantly more time on the side of the tank where the yellow-tailed animation was visible, and significantly more time interacting with the yellow-tailed animation. Given these repeatable responses and the availability of genomic resources, N. furzeri represents an excellent, untapped model for studying the genetic basis of preferences and reproductive behaviours.

Complex sensory environments alter mate choice outcomes

Noise is a common problem in animal communication. We know little, however, about how animals communicate in noise using multimodal signals. Multimodal signals are hypothesized to be favoured by evolution because they increase the efficacy of detection/discrimination in noisy environments. We tested the hypothesis that female túngara frogs’ responses to attractive male advertisement calls are improved in noise when a visual signal component is added to the available choices. We tested this at two levels of decision complexity (two and three choices). In a two-choice test, the presence of noise did not reduce female preferences for attractive calls. The visual component of a calling male, associated with an unattractive call, also did not reduce preference for attractive calls in the absence of noise. In the presence of noise, however, females were more likely to choose an unattractive call coupled with the visual component. In three-choice tests, the presence of noise alone reduced female responses to attractive calls and this was not strongly affected by the presence or absence of visual components. The responses in these experiments fail to support the multimodal signal efficacy hypothesis. Instead, the data suggest that audio-visual perception and cognitive processing, related to mate choice decisions, are dependent on the complexity of the sensory scene.

Gender Dimensions in Disaster and Safety Management

Research shows that disasters affect women more adversely than men especially in developing countries due to differences in socio-cultural customs or physical condition. However, in developed countries, not much difference was found in the percentage of male and female victims of disaster. In South Korea, disasters cause severe damage almost every year, thus the public interest in disaster and safety management is increasing. However, due to insufficient data, it is difficult to analyze whether women suffer more severely than men or not. Therefore, in this study, we reviewed Korea’s disaster management laws and guidelines. In addition, a questionnaire survey was implemented to analyze the level of the public awareness related to disasters and safety management. A total of 489 adults participated in the survey. As a result, it was found that both men and women were not well aware of the possibility of a disaster, and needed to be educated about the locations of shelters and evacuation procedures. Gender analysis showed significant differences in male and female responses concerning some questions. For example, women found it difficult to access disaster and safety management education. Nevertheless, men and women showed similar willingness to participate in disaster and safety management education and training. Therefore, disaster and safety management education programs should be developed and implemented more actively. In addition, it was suggested that sex and age of the victims should be reported and female investigators should be included in the disaster damage investigation team.