Kin selection and male androphilia in Samoan fa'afafine

The Kin Selection Hypothesis for male androphilia posits that genes for male androphilia can be maintained in the population if the fitness costs of not reproducing directly are offset by enhancing inclusive fitness. In theory, androphilic males can increase their inclusive fitness by directing altruistic behavior toward kin, which, in turn, allows kin to increase their reproductive success. Previous research conducted in Western countries has failed to find any support for this hypothesis. The current study tests this basic prediction of the Kin Selection Hypothesis for male androphilia by comparing the altruistic tendencies of androphilic and gynephilic males in the Polynesian nation of Independent Samoa. In Independent Samoa, androphilic males are known locally as fa'afafine. Altruistic tendencies were assessed using a Kin Selection Questionnaire. Comparisons of the altruistic tendencies of fa'afafine and gynephilic men revealed that these two groups did not differ in terms of their overall generosity and allocation of financial resources toward kin, nor did they differ in terms of general neediness or financial resources obtained from kin. Fa'afafine did, however, report greater avuncular tendencies than gynephilic men. Although the greater avuncular tendencies of fa'afafine support the basic prediction of the Kin Selection Hypothesis for male androphilia, further research is needed before one can conclude that these elevated tendencies represent a specially designed adaptation for promoting the fitness of kin. We discuss a number of sociocultural factors that might promote the expression of avuncular tendencies by androphilic males in Independent Samoa. Our results underscore the importance of testing functional hypotheses in evolutionarily appropriate environments.     

Next-generation sequencing analysis of Pardosa pseudoannulata's diet composition in different habitats

Spiders are the most common and predominant predators in terrestrial ecosystems. The predatory behavior of spiders affects the energy flow across the food web within an ecosystem. Traditiaonal methods for analyzing spider diets such as field observation, anatomy and faeces analysis are not suitable for spider experiments due to spiders’ special dietary behavior. The molecular method based on the specific primers of prey DNA seems to be inefficient either in spite of its wide application in diet analysis. As the next-generation sequencing (NGS) technology becomes prevalent in many different areas, several cases of the NGS-based analysis of mammal diets have been published. This study analyzed the diet differences of Pardosa pseudoannulata (Araneae: Lycosidae) in four habitats (a wetland, a tea plantation, an alpine meadow and a paddy field) by using the NGS technology, combined with the DNA barcode method. The results suggested that the Pardosa pseudoannulata feed on a broad range of prey, and 7 orders and 24 families of insects were detected in the four investigated habitats. Moreover, it is found that the diet diversity of Pardosa pseudoannulata is greatly influenced by their living environments and seasons. In a nutshell, this study established an NGS-based methodology for spider diets analysis, and the results provided some basic materials to inform the protection and utilization of the Pardosa pseudoannulata as a potential eco-friendly predator against pests.     

The micronucleus test with mouse peripheral blood on N-methyl-N'-nitro-N-nitrosoguanidine and mitomycin C

The micronucleus test using mouse peripheral blood was conducted with N-methyl-N'-nitro-N-nitro-soguanidine (MNNG) and mitomycin C (MMC) as part of the 5th collaborative study supported by the Environmental Mutagen Society of Japan (CSGMT/MMS · JEMS).Male CD-1 mice were intraperitoneally injected once with 12.5–100 mg/kg of MMC. Peripheral blood was drawn at different intervals after treatment, placed on slides previously coated with acridine orange and the numbers of reticulocytes with micronuclei (MNRETs) were scored.The experiments indicated that the maximum effect of both MNNG and MMC was found about 48 h after treatment, and that the micronucleus test using peripheral blood is useful for the screening of chemicals throughout the experimental period in a single animal.     

Gymnoascus arxii's potential in deteriorating woollen textiles dyed with natural and synthetic dyes

So far, very little is known about microbiological deterioration of dyed woollen textiles. In this paper, the influence of the Gymnoascus arxii fungus on woollen textiles dyed with natural and synthetic dyes was studied. What is more, it was analysed whether the enrichment of the culture medium with additional nutrients has any impact on the deterioration of dyed woollen fabrics caused by a strongly keratinolytic strain. The study was carried out by means of a pure culture method over three different time periods, i.e. 1, 2 and 4 weeks. Within a week, the pure Gymnoascus arxii strain led to a severe deterioration in the mechanical strength of the examined woollen textiles, with the raw fabric being the most severely damaged. After the two-week incubation period, only the fabrics coloured in yellow, i.e. the fabric dyed with natural dye weld, and the synthetic yellow textile as well as the textile dyed with natural dye indigo survived, exclusively on the enriched medium. Solely the weld dyed textile withstood the four-week culture on the nutrient-enriched medium. The conducted studies demonstrated a strong influence of Gymnoascus arxii on dyed fabrics leading to their irreversible destruction. It has been also shown that the presence of nutrients in the substrate that are readily available to microorganism may hinder the development of the Gymnoascus arxii strain and thus, prevent textile deterioration.