Female sticklebacks Gasterosteus aculeatus use self-reference to optimize MHC allele number during mate selection

Theoretical and empirical studies suggest that an optimal resistance to pathogens and parasites requires an optimal number of MHC alleles per individual. Here we argue that three-spined sticklebacks (Gasterosteus aculeatus) achieve this goal by applying a strategy that involves a self-referential process. According to this model, females complement their own set of alleles with a more or less diverse set of male alleles such that the combined diversity reaches an optimum. In previous experiments, we have identified allele counting as a major mate-choice strategy in large populations. The self-referential allele-counting hypothesis predicts that MHC-based mate choice favors dissimilar MHC alleles in small populations facing the risk of inbreeding. Therefore, we conducted an experiment that simulated a small effective population size with low MHC class-II diversity. Our experiments are based on the analysis of MHC class-IIB alleles that explain a major part of the overall MHC diversity in sticklebacks, as determined by mathematical modeling. The results show that females preferred males with dissimilar alleles. Our present and the previous studies (which we reanalyzed with respect to our new predictions) show that irrespective of high or low population diversity faced by female sticklebacks for their mate choice, they use information about their own and their potential mate's MHC polymorphism for optimal complementation of their own set of alleles. From combining the data of the previous and the present experiment we found that female sticklebacks try to achieve an optimum number of MHC class-IIB alleles for their offspring through mate choice. The chosen MHC diversity is close to the most frequent diversity found naturally in individual fish, which in addition have the lowest parasite burden.     

Commercially available garden products as important sources of antibiotic resistance genes—a survey

Environmental Science and Pollution Research - The dissemination of antibiotic resistance genes (ARGs) in the environment contributes to the global rise in antibiotic resistant infections....     

Social laterality in wild beluga whale infants: comparisons between locations, escort conditions, and ages

One of the important aspects of the animal social behavior is the laterality in perception of conspecifics. Spatial laterality in adult–infant interactions is usually revealed in primates as a cradling/holding bias in adults or nipple preference in infants. The origin and function of such biases, however, remain unclear. Here, we investigated spatial laterality in adult–infant pairs in beluga whales from two geographically distinct locations using aerial photography analysis. In addition, behavioral observations on individually identified mother–infant pairs at a belugas’ breeding aggregation were conducted to assess the infants’ age influence on the lateralization in pairs. A general preference of the calves to position themselves to the right of the accompanied adult was found. We failed to reveal any influence of geographical location, presence or relative position of other individuals escorting the adult–infant pair, and position of the calf along the body of the escorting adult. A significant right-sided bias in infants’ position was present in all age classes, but 2–6 months-old belugas were found to be stronger lateralized, than the newborns and 7–18 months-old calves. That may reflect age-related changes in infants’ motor and social behavior. We argue that the revealed laterality is associated with the calves’ left eye–right hemisphere preference in perceiving social stimuli, and we then discuss its possible advantages. Pronounced adult–infant spatial laterality in condition (unlike that seen in primates) when forelimbs do not directly determine subjects’ relative positioning suggests sensory lateralization alone to be the determining factor.     

Material cycle realization by hazardous phosphogypsum waste,ferrous slag,and lime production waste application to produce sustainable construction materials

Journal of Material Cycles and Waste Management - The article presents data from new compositions of construction materials developed from three types of Kazakhstan enterprises’ industrial...     

Removal of a red dye using noncommercial peroxidase extracted from rice bran

The present study investigates the application of a noncommercial peroxidase enzyme, which was extracted from rice bran, to decolorize wastewater that was simulating effluent from a textile manufacturer using a red dye in its coloration process.     

Toxicity of mixtures of perfluorooctane sulphonic acid with chlorinated chemicals and lipid regulators

The toxicological interaction of perfluorooctane sulphonic acid (PFOS) with the chlorinated pollutants triclosan and 2,4,6-trichlorophenol and the lipid regulators gemfibrozil and bezafibrate was evaluated using the combination index-isobologram equation. The endpoint for bioassays was the growth rate inhibition of the green alga Pseudokirchneriella subcapitata. The results showed that most of the binary combinations assayed exhibited antagonism at all effect levels. The addition of a third component induced a less antagonistic or even synergistic behaviour. This was particularly marked for the ternary mixture of triclosan and 2,4,6-trichlorophenol with PFOS, for which synergism was very strong at all effect levels, with a combination index as low as 0.034 ± 0.002 at EC₅₀ for the mixture. The results obtained indicate that the evaluation of mixture toxicity from single component data using the concentration addition approach could severely underestimate combined toxicity.