Wild yellow dung fly females may not select sperm based on dung pat microclimate but could nevertheless benefit from polyandry

Molecular techniques have substantially improved our knowledge of postcopulatory sexual selection. Nevertheless, studies examining sperm utilization in natural populations of nonsocial insects are rare, support for sperm selection (biased use of stored sperm, e.g. to match offspring genotypes to prevailing environmental conditions) is elusive, and its relevance within natural populations unknown. We performed an oviposition site choice experiment in the field where female yellow dung flies Scathophaga stercoraria could deposit eggs into three different microenvironments on a dung pat (the east-west ridge, north- or south-exposed side), and genotyped the offspring and sperm remaining in storage after oviposition. Females exhibited plasticity in the number of eggs deposited according to pat age. Additionally, temperature strongly influenced egg placement: the warmer the temperature, the higher the proportion of eggs laid into the north-exposed side of dung. The number of ejaculates in storage differed amongst spermathecae, and females stored sperm from more males than fathered their offspring (2.11 sires vs. 2.84 males within sperm stores). Mean last male paternity was 83.4%, roughly matching previous laboratory estimates. Importantly, we found no evidence that females selectively lay eggs of different genotypes, by biasing paternity towards certain males, depending on offspring's microclimate. Thus, while we show female choice over number of eggs and where these are deposited, there was no evidence for sperm selection. We further revealed positive effects of multiple mating on total number of offspring and proportion of offspring emerging from the dung. We argue that the integration of field studies and laboratory experiments is essential to promote our understanding of polyandry and cryptic female choic

Comparative evidence supports a role for reproductive allocation in the evolution of female ornament diversity

1. Sexually selected ornaments are highly variable, even among closely related species, and the ultimate causes of variation in ornament evolution are unclear, including in rare cases of female ornament expression. One hypothesis is that differences across species in female reproductive allocation may help to explain patterns of female ornament expression among insects with nuptial gifts. 2. Dance flies (Diptera: Empididae: Empidinae) vary considerably among species in the presence and extravagance of female ornaments, which probably evolved through female contests for mates. In most dance flies, adult females appear to acquire all their dietary protein from nuptial gifts provided by males during mating. The importance of nuptial feeding on egg development is not yet known. 3. To test the prediction that the presence of female ornaments reflects differences in the degree to which females rely on nuptial feeding for egg development, egg development was examined in wild females of two species, one ornamented and the other unornamented. An ageing technique based on cuticular bands was validated, which permitted a regression of egg size on adult age. 4. We found that egg development depended on mating status in the ornamented species alone, meaning the eggs of unmated females of the ornamented species did not develop. This contrast across species is consistent with expectations that females of different species vary in their dependence on nuptial gifts for egg development. 5. These findings provide preliminary support for the hypothesis that differences in reproductive allocation mediate the intensity of female contests for nuptial gifts

Mate choice for genetic quality when environments vary: suggestions for empirical progress

Mate choice for good-genes remains one of the most controversial evolutionary processes ever proposed. This is partly because strong directional choice should theoretically deplete the genetic variation that explains the evolution of this type of female mating preference (the so-called lek paradox). Moreover, good-genes benefits are generally assumed to be too small to outweigh opposing direct selection on females. Here, we review recent progress in the study of mate choice for genetic quality, focussing particularly on the potential for genotype by environment interactions (GEIs) to rescue additive genetic variation for quality, and thereby resolve the lek paradox. We raise five questions that we think will stimulate empirical progress in this field, and suggest directions for research in each area: (1) How is condition-dependence affected by environmental variation? (2) How important are GEIs for maintaining additive genetic variance in condition? (3) How much do GEIs reduce the signalling value of male condition? (4) How does GEI affect the multivariate version of the lek paradox? (5) Have mating biases for high-condition males evolved because of indirect benefits

Sexual selection on multiple female ornaments in dance flies

Sex-specific ornaments typically occur in males, but they can also develop in females. While there are several models concerning the evolution of male-specific ornaments, it is not clear how, or under what circumstances, those models apply to female-specific ornament evolution. Here, we present a manipulative field experiment that explores the theoretical ‘trait space’ of multiple female-specific ornaments to study how these unusual traits evolved. We measured the attractiveness of two female-specific ornaments (pinnate leg scales and inflatable abdominal sacs) in the dance fly Rhamphomyia longicauda in a wild mating swarm. We found significant directional preferences for larger ornaments of both types; however, variation in one of the ornaments (abdominal sacs) was almost three times more effective at improving attractiveness. The abdominal ornament was consistently effective in increasing attractiveness to males regardless of leg ornament expression, while leg ornament size was only effective if abdominal ornaments were very small. These results are consistent with predictions from a sexual conflict model of ornament expression in supporting the probable role of deception in the evolution of female-specific ornaments among dance flies. Sexual conflict can be an important force in generating elaborate sex-specific ornaments in females as well as males

Phosphorylation of specific sets of tau isoforms reflects different neurofibrillary degeneration processes

AbstractTau proteins are the basic components of filaments that accumulate within neurons during neurofibrillary degeneration, a degenerating process with disease-specific phenotypes. This specificity is likely to be sustained by both phosphorylation state and isoform content of tau aggregates that form neuronal inclusions. In the present study, characterization of tau isoforms involved in neurofibrillary degeneration in Alzheimer's disease, Pick's disease, corticobasal degeneration and progressive supra-nuclear palsy was performed. Both analyses by immunoblotting using specific tau antibodies and cell transfection by tau isoform cDNAs allowed us to demonstrate the aggregation of (1) the six hyperphosphorylated tau isoforms in Alzheimer's disease, (2) tau isoforms without exon 10-encoding sequence in Pick's disease and (3) hyperphosphorylated exon 10-tau isoforms in corticobasal degeneration and progressive supranuclear palsy. Thus, neurofibrillary degeneration phenotypes are likely to be related to the phosphorylation of different combinations of tau isoforms (with and/or without exon 10-encoding sequence) in subpopulations of neurons

Oecanthus nigricornis (Orthoptera: Gryllidae) as the first known host of Stylogaster neglecta (Diptera: Conopidae)

The conopid fly Stylogaster neglecta Williston (Diptera: Conopidae) is a parasitoid with no known host. We report this species as the first recorded dipteran parasitoid of Oecanthus nigricornis Walker (Orthoptera: Gryllidae) (black-horned tree crickets). We reared field-collected O. nigricornis juveniles over several months in 2017 and found that larval S. neglecta emerged from them during late July into August. We estimated the incubation period for S. neglecta larvae to be around 30 days based on the length of time it took for them to emerge from the host and pupate (subsequently all hosts died). We documented several cases of multiple parasitism. In 2018, we dissected O. nigricornis sampled from four sites across southern Ontario, Canada and upstate New York, United States of America and found that the percentage of juvenile O. nigricornis parasitised ranged 2–39%. Further sampling will be necessary to determine whether this variation represents consistent population differences or between-year variation in parasitism

Sperm competition in yellow dung flies: No consistent effect of sperm size

The male competition for fertilization that results from female multiple mating promotes the evolution of increased sperm numbers and can impact sperm morphology, with theory predicting that longer sperm can at times be advantageous during sperm competition. If so, males with longer sperm should sire more offspring than competitors with shorter sperm. Few studies have directly tested this prediction, and findings are inconsistent. Here we assessed whether longer sperm provide a competitive advantage in the yellow dung fly (Scathophaga stercoraria; Diptera: Scathophagidae). Initially, we let brothers with different temperature-mediated mean sperm lengths compete – thus minimizing confounding effects of genetic background – and found no clear advantage of longer sperm. We then used flies from lines subjected to bidirectional selection on phenoloxidase activity that had shown correlated evolutionary responses in sperm and female spermathecal duct lengths. This experiment also yielded no main effect of sperm size on siring success. Instead, there was a trend for a shorter-sperm advantage, but only when competing in females with longer spermathecal ducts. Our data corroborated many previously reported findings (last-male precedence, effects of copula duration and body size), suggesting our failure to find sperm size effects is not inherently due to our experimental protocols. We conclude that longer sperm are not competitively superior in yellow dung flies under most circumstances, and that, consistent with previous work, in this species competitive fertilization success is primarily determined by the relative numbers of sperm competing

Competition for access to mates predicts female-specific ornamentation and male investment in relative testis size

Sexually selected ornaments are highly variable and the factors that drive variation in ornament expression are not always clear. Rare instances of female‐specific ornament evolution (such as in some dance fly species) are particularly puzzling. While some evidence suggests that such rare instances represent straightforward reversals of sexual selection intensity, the distinct nature of trade‐offs between ornaments and offspring pose special constraints in females. To examine whether competition for access to mates generally favours heightened ornament expression, we built a phylogeny and conducted a comparative analysis of Empidinae dance fly taxa that display female‐specific ornaments. We show that species with more female‐biased operational sex ratios in lek‐like mating swarms have greater female ornamentation, and in taxa with more ornate females, male relative testis investment is increased. These findings support the hypothesis that ornament diversity in dance flies depends on female receptivity to mates, which is associated with contests for nutritious nuptial gifts provided by males. Moreover, our results suggest that increases in female receptivity lead to higher levels of sperm competition among males. The incidence of both heightened pre‐mating sexual selection on females and post‐mating selection on males contradicts assertions that sex‐roles are straightforwardly reversed in dance flies

Schizophrénie, approche spécialisée et continuité de soins. Le programme spécifique d’intervention Premier-Épisode de l’Hôtel-Dieu de Lévis

La schizophrénie est une maladie complexe à caractère évolutif. Reposant sur un cadre conceptuel d'orientation cognitive, le programme spécifique d'intervention Premier épisode de l'Hôtel-Dieu de Lévis fournit une évaluation complète et standardisée au plan individuel et familial. Puis sont rendues disponibles différentes modalités de traitement, selon une approche individuelle (psycho-éducation, psychothérapie) et de groupe (intervention psychologique au plan cognitif ou Integrated Psychological Therapy, de Brenner). L'intervention psycho-éducative familiale est également offerte aux familles. Les structures et la démarche décrites s'harmonisent avec celles qui étaient en place avant la création du programme, ce qui offre une continuité de soins. Le cadre conceptuel sous-jacent et les modalités du fonctionnement du programme sont aussi présentés.Schizophrenia is a complex illness with an evolutive character. Based on a conceptual framework of cognitive orientation, the specific intervention program First Episode of Hôtel-Dieu in Lévis includes a complete and standardized assessment to an individualized and family plan. Different methods of treatment acording to an individualized approach (psyhco-education, psychotherapy) as well as group therapy (psychological intervention at the cognitive level or Brenner's Integrated psychological therapy) are then proposed. Psycho-education intervention for families is also offered. Structures and different steps described here, harmonize with those already in place before the program's creation thus offering a continuity in care. The underlying conceptual framework and the different methods of functioning of the program are also presented.La esquizofrenia es una enfermedad compleja da caracter evolu-tivo. El programa especifico de intervention Primer episodio de Hôtel-Dieu de Lévis que reposa en un marco conceptual de orientaciôn cognoscitiva, ofrece una evaluaciôn compléta y estandarizada a nivel individual y familiar. Ademâs se ofrecen diferentes modalidades de tratamiento, segûn un enfoque individual (psicoeducaciôn, psicoterapia) y de grupo (intervenciôn psicolôgica a nivel cognoscitivo o Integrated psychological therapy, de Brenner). Igualmente se le ofrece a las fami-lias, la Intervenciôn psioeducativa familiar. Las estructuras y los pasos a seguir que se describen se armonizan a las que ya existian antes de la creation del programa, Io que ofrece una continuidad de tratamiento. Son presentados, el marco conceptual subyacente y las modalidades del fucionamiento des programa

The impact of uncertainty on cooperation intent in a conservation conflict

1. Stakeholder cooperation can be vital in managing conservation conflicts. Laboratory experiments show cooperation is less likely in the presence of uncertainty. Much less is known about how stakeholders in real‐life conservation conflicts respond to different types of uncertainty. 2. We tested the effects of different sources of uncertainty on cooperative behaviour using a framed field experiment and interviews. The experiment compared a baseline scenario of perfect certainty with scenarios including either: (a) scientific uncertainty about the effectiveness of a conflict‐reduction intervention; (b) administrative uncertainty about intervention funding; or (c) political uncertainty about the extent of community support. We applied these scenarios to a conservation conflict in the Outer Hebrides, Scotland, involving the management of geese to simultaneously meet both conservation and farming objectives. We asked 149 crofters (small‐scale farmers) if they would commit to cooperate with others by helping fund a goose management plan given the three sources of uncertainty. 3. On average, intention to cooperate was highest (99%) in scenarios without uncertainty, and lowest under administrative uncertainty (77%). Scientific uncertainty and political uncertainty both had less of an effect, with over 95% of crofters predicted to be willing to cooperate in these scenarios. Crofters who indicated concern for other crofters suffering the impact of geese were more likely to cooperate. The longer an individual had been a crofter, the less likely they were to cooperate. 4. Synthesis and applications. Crofters’ intention to cooperate is high but lessened by uncertainty, especially over the commitment from other stakeholders such as government, to cooperate on goose management. Existing cooperation on goose management may be at risk if uncertainty is not reduced outright or commitments between parties are not strengthened. This has wide applicability, supporting the need for researchers and government advisers to: (a) determine how uncertainty will impact intention of stakeholders to cooperate; and (b) take steps (such as uncertainty reduction, communication or acceptance) to reduce the negative impact of uncertainty on cooperation