Evolution of female colours in birds: The role of female cost of reproduction and paternal care

Female ornamentation is frequently observed in animal species and is sometimes found as more evolutionary labile than male ornamentation. A complex array of factors may explain its presence and variation. Here we assessed the role of female cost of reproduction and paternal care. Both factors have been pinpointed as important by theoretical studies but have not been investigated yet in details at the interspecific level. We worked on 133 species of North temperate Passeriformes bird species for which both the clutch volume - here taken as the proxy of female cost of reproduction - and amount of paternal care are relatively well known. Using spectrometry, we measured the whole-body coloured plumage patches and quantified three metrics corresponding to brightness (i.e. achromatic component), colour chromaticity (i.e. intensity) and colour volume (i.e. diversity). We found a strong association between male and female colour metrics. Controlling for this association, we found additional small but detectable effects of both cost of reproduction and paternal care. First, females of species with more paternal care were slightly brighter. Second, the interaction between the level of paternal care and egg volume was correlated with female colour intensity: females with more paternal care were more chromatic, with this association mostly present when their investment in reproduction was low. Together these results suggest that female cost of reproduction and paternal care are part of the multiple factors explaining variation of female coloration, besides the strong covariation between male and female coloration.

Functional Imaging in Olfactory Disorders

Purpose of Review

The aim was to synthesize key findings regarding the use of functional MRI (fMRI) to assess olfactory dysfunction (OD), and thus, to evaluate whether fMRI could be a reliable clinical diagnostic tool.

Recent Findings

In response to olfactory stimulation, patients with quantitative OD display reduced activation in olfactory-related brain regions but also stronger activation in non-olfactory brain areas. Parosmic patients also seem to show both weaker and higher brain signals. As to trigeminal chemosensory system, fMRI suggests that central processing may be declined in patients with OD. Functional connectivity studies report a possible correlation between altered neuronal connections within brain networks and olfactory performances.

Summary

fMRI emerges as a valuable and promising objective method in OD evaluation. Yet, its high inter-individual variability still precludes its routine clinical use for diagnostic purpose. Future research should focus on optimizing stimulation paradigms and analysis methods.

Are behaviour and stress-related phenotypes in urban birds adaptive?

Urbanisation is a world‐wide phenomenon converting natural habitats into new artificial ones. Environmental conditions associated with urbanisation represent great challenges for wildlife. Behaviour and stress tolerance are considered of major importance in the adaptation to novel urban habitats and numerous studies already reported behavioural and stress response phenotypes associated with urbanisation, often suggesting they represented adaptations, while rarely demonstrating it.

The main goal of this study was to test the adaptive nature of urban shifts in behavioural and stress‐related traits, and by adaptive we mean phenotypic change favouring traits in the same direction as selection.

Using 7 years of monitoring of urban and forest great tits, we first tested for differences in exploratory behaviour, aggressiveness and breath rate, between both habitats. Second, we performed habitat‐specific analyses of selection on the three former traits using (a) reproductive success and (b) survival estimated via capture–mark–recapture models, as fitness estimates, to determine whether shifts in these behavioural and stress‐related traits were aligned with patterns of ongoing selection.

We found that urban birds displayed higher exploratory behaviour and aggressiveness, and higher breath rate, compared to forest birds. Selection analyses overall revealed that these shifts were not adaptive and could even be maladaptive. In particular, higher handling aggression and higher breath rate in urban birds was associated with lower fitness. Higher exploration scores were correlated with lower survival in both habitats, but higher reproductive success only in forest males. Overall, differences in patterns of selection between habitats were not consistent with the phenotypic divergence observed.

Taken together, these results highlight that phenotypic shifts observed in cities do not necessarily result from new selection pressures and could be maladaptive. We hypothesise that divergences in behavioural traits for urban birds could result from the filtering of individuals settling in cities. We thus encourage urban evolutionary scientists to further explore the adaptive potential of behavioural traits measured in urban habitats (a) by replicating this type of study in multiple cities and species, (b) by implementing studies focusing on immigrant phenotypes and (c) by measuring selection at multiple life stages.

Epigenetics and the city: Non-parallel DNA methylation modifications across pairs of urban-forest Great tit populations

Identifying the molecular mechanisms involved in rapid adaptation to novel environments and determining their predictability are central questions in evolutionary biology and pressing issues due to rapid global changes. Complementary to genetic responses to selection, faster epigenetic variations such as modifications of DNA methylation may play a substantial role in rapid adaptation. In the context of rampant urbanization, joint examinations of genomic and epigenomic mechanisms are still lacking. Here, we investigated genomic (SNP) and epigenomic (CpG methylation) responses to urban life in a passerine bird, the Great tit (Parus major). To test whether urban evolution is predictable (i.e. parallel) or involves mostly nonparallel molecular processes among cities, we analysed both SNP and CpG methylation variations across three distinct pairs of city and forest Great tit populations in Europe. Our analyses reveal a polygenic response to urban life, with both many genes putatively under weak divergent selection and multiple differentially methylated regions (DMRs) between forest and city great tits. DMRs mainly overlapped transcription start sites and promotor regions, suggesting their importance in modulating gene expression. Both genomic and epigenomic outliers were found in genomic regions enriched for genes with biological functions related to the nervous system, immunity, or behavioural, hormonal and stress responses. Interestingly, comparisons across the three pairs of city-forest populations suggested little parallelism in both genetic and epigenetic responses. Our results confirm, at both the genetic and epigenetic levels, hypotheses of polygenic and largely nonparallel mechanisms of rapid adaptation in novel environments such as urbanized areas.

Connecting the data landscape of long-term ecological studies: The SPI-Birds data hub

The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long-term studies of birds, we have created the SPI-Birds Network and Database (www.spibirds.org)-a large-scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI-Birds has recruited over 120 members, and currently hosts data on almost 1.5 million individual birds collected in 80 populations over 2,000 cumulative years, and counting. SPI-Birds acts as a data hub and a catalogue of studied populations. It prevents data loss, secures easy data finding, use and integration and thus facilitates collaboration and synthesis. We provide community-derived data and meta-data standards and improve data integrity guided by the principles of Findable, Accessible, Interoperable and Reusable (FAIR), and aligned with the existing metadata languages (e.g. ecological meta-data language). The encouraging community involvement stems from SPI-Bird's decentralized approach: research groups retain full control over data use and their way of data management, while SPI-Birds creates tailored pipelines to convert each unique data format into a standard format. We outline the lessons learned, so that other communities (e.g. those working on other taxa) can adapt our successful model. Creating community-specific hubs (such as ours, COMADRE for animal demography, etc.) will aid much-needed large-scale ecological data integration.

Microelimination or Not? The Changing Epidemiology of Human Immunodeficiency Virus-Hepatitis C Virus Coinfection in France 2012–2018

Background

The arrival of highly effective, well-tolerated, direct-acting antiviral agents (DAA) led to a dramatic decrease in hepatitis C virus (HCV) prevalence. Human immunodeficiency virus (HIV)-HCV–coinfected patients are deemed a priority population for HCV elimination, while a rise in recently acquired HCV infections in men who have sex with men (MSM) has been described. We describe the variations in HIV-HCV epidemiology in the French Dat’AIDS cohort.

Methods

This was a retrospective analysis of a prospective cohort of persons living with HIV (PLWH) from 2012 to 2018. We determined HCV prevalence, HCV incidence, proportion of viremic patients, treatment uptake, and mortality rate in the full cohort and by HIV risk factors.

Results

From 2012 to 2018, 50 861 PLWH with a known HCV status were followed up. During the period, HCV prevalence decreased from 15.4% to 13.5%. HCV prevalence among new HIV cases increased from 1.9% to 3.5% in MSM but remained stable in other groups. Recently acquired HCV incidence increased from 0.36/100 person-years to 1.25/100 person-years in MSM. The proportion of viremic patients decreased from 67.0% to 8.9%. MSM became the first group of viremic patients in 2018 (37.9%). Recently acquired hepatitis represented 59.2% of viremic MSM in 2018. DAA treatment uptake increased from 11.4% to 61.5%. More treatments were initiated in MSM in 2018 (41.2%) than in intravenous drug users (35.6%). In MSM, treatment at the acute phase represented 30.0% of treatments in 2018.

Conclusions

A major shift in HCV epidemiology was observed in PLWH in France from 2012 to 2018, leading to a unique situation in which the major group of HCV transmission in 2018 was MSM.

Clinical Trials Registration. NCT02898987.

Examining the link between relaxed predation and bird coloration on islands

Insular ecosystems share analogous ecological conditions, leading to patterns of convergent evolution that are collectively termed as the 'island syndrome'. In birds, part of this syndrome is a tendency for a duller plumage, possibly as a result of relaxed sexual selection. Despite this global pattern, some insular species display a more colourful plumage than their mainland relatives, but why this occurs has remained unexplained. Here, we examine the hypothesis that these cases of increased plumage coloration on islands could arise through a relaxation of predation pressure. We used comparative analyses to investigate whether average insular richness of raptors of suitable mass influences the plumage colourfulness and brightness across 110 pairs of insular endemic species and their closest mainland relatives. As predicted, we find a likely negative relationship between insular coloration and insular predation while controlling for mainland predation and coloration, suggesting that species were more likely to become more colourful as the number of insular predators decreased. By contrast, plumage brightness was not influenced by predation pressure. Relaxation from predation, together with drift, might thus be a key mechanism of species phenotypic responses to insularity.

Eggshell coloration indicates female condition during egg-laying: a field experiment in blue tits

Several selection pressures may explain the evolution of avian eggshell coloration patterns. In cavity-nesting species, there are two main non-exclusive hypotheses. The sexually selected eggshell colour hypothesis proposes that eggshell coloration is a sexually selected signal of female and offspring quality used by males that influences paternal care or future re-mating decisions. The structural function hypothesis proposes that pigments help strengthen the eggshell and are present at higher levels and at the blunt end of the egg when females face calcium shortages. We tested whether eggshell coloration (brown spots on a white ground colour) in blue tits (Cyanistes caeruleus) could reliably indicate female condition at laying by forcing females to produce two consecutive clutches, thus increasing their reproductive costs. Three measures of eggshell coloration – the area covered by spots as well as white ground UV-chroma and brightness – changed between clutches; the fourth measure, spot distribution, did not. The changes were more dramatic in young and lower-quality females. All the measures varied with female quality (i.e. body condition and/or laying date). Overall, higher-quality females produced more colourful (larger, more concentrated spotted surface area; higher UV-chroma) and less bright (i.e. putatively more pigmented) eggshells, a result that is generally in line with past research. We found a clear empirical link between eggshell coloration and female condition in blue tits, an important step in determining whether eggshell coloration is a sexual signal, but which does not exclude a potential concomitant structural function.

oXiris® Use in Septic Shock: Experience of Two French Centres

BACKGROUND

Sepsis is a dysregulated host response to an infection and can result in organ dysfunctions and death. Extracorporeal blood purification techniques aim to improve the prognosis of these patients by modulating the unbalanced immune response. This study reports our experience with the use of the oXiris® membrane for septic shock patients requiring continuous renal replacement therapy (CRRT).

SUMMARY

Thirty-one patients were diagnosed with septic shock and underwent CRRT with the oXiris® membrane between 2014 and 2019. We compared the observed hospital mortality with that predicted by the Simplified Acute Physiology Score II (SAPS II). Change in the Sequential Organ Failure Assessment (SOFA) score and of the main clinical and biological parameters over time were analyzed. Hospital mortality was lower than predicted for the most severe patients (60 vs. 91% for the [74-87] SAPS II quartile and 70 vs. 98% for the [87-163] SAPS II quartile, p < 0.02). There was no significant improvement in the SOFA score from 0h to 48 h. An 88% relative decrease in norepinephrine infusion was observed (median at 0 h was 1.69 [0.52-2.45] µg/kg/min; at 48 h it was 0.20 [0.09-1.14] µg/kg/min, p = 0.002). Lactataemia and pH were significantly improved over time. Patients with intra-abdominal sepsis as well as those with Gram-negative bacilli (GNB) infections seemed to benefit the most from the therapy. Key Messages: CRRT with the oXiris® haemofilter resulted in higher observed survival than predicted by a severity score (SAPS II) for the most severe patients. Haemodynamic status and lactataemia appeared to improve, especially in intra-abdominal sepsis and GNB infections.

Dynamic predictions of long-term kidney graft failure: an information tool promoting patient-centred care

Background

Informing kidney transplant recipients of their prognosis and disease progression is of primary importance in a patient-centred vision of care. By participating in decisions from the outset, transplant recipients may be more adherent to complex medical regimens due to their enhanced understanding.

Methods

We proposed to include repeated measurements of serum creatinine (SCr), in addition to baseline characteristics, in order to obtain dynamic predictions of the graft failure risk that could be updated continuously during patient follow-up. Adult recipients from the French Données Informatisées et VAlidées en Transplantation (DIVAT) cohort transplanted for the first or second time from a heart-beating or living donor and alive with a functioning graft at 1 year post-transplantation were included.

Results

The model was composed of six baseline parameters, in addition to the SCr evolution. We validated the dynamic predictions by evaluating both discrimination and calibration accuracy. The area under the receiver operating characteristic curve varied from 0.72 to 0.76 for prediction times at 1 and 6 years post-transplantation, respectively, while calibration plots showed correct accuracy. We also provided an online application tool (https://shiny.idbc.fr/DynPG).

Conclusion

We have created a tool that, for the first time in kidney transplantation, predicts graft failure risk both at an individual patient level and dynamically. We believe that this tool would encourage willing patients into participative medicine.

Urban versus forest ecotypes are not explained by divergent reproductive selection

Increasing urbanization offers a unique opportunity to study adaptive responses to rapid environmental change. Numerous studies have demonstrated phenotypic divergence between urban and rural organisms. However, comparing the direction and magnitude of natural selection between these environments has rarely been attempted. Using seven years of monitoring of great tits (Parus major) breeding in nest-boxes across the city of Montpellier and in a nearby oak forest, we find phenotypic divergence in four morphological and two life-history traits between urban and forest birds. We then measure reproductive selection on these traits, and compare selection between the habitats. Urban birds had significantly smaller morphological features than their rural counterparts, with a shorter tarsus, lower body mass, and smaller wing and tail lengths relative to their overall body size. While urban female tarsus length was under stabilizing selection, and forest males show positive selection for tarsus length and negative selection for body mass, selection gradients were significantly divergent between habitats only for body mass. Urban great tits also had earlier laying dates and smaller clutches. Surprisingly, we found selection for earlier laying date in the forest but not in the city. Conversely, we detected no linear selection on clutch size in the forest, but positive selection on clutch size in the urban habitat. Overall, these results do not support the hypothesis that contemporary reproductive selection explains differences in morphology and life history between urban- and forest-breeding great tits. We discuss how further experimental approaches will help confirm whether the observed divergence is maladaptive while identifying the environmental drivers behind it.

Disentangling drivers of reproductive performance in urban great tits: a food supplementation experiment

Worldwide urban expansion induces degradation of the natural environment, resulting in new constraints in terms of breeding sites, anthropogenic disturbances as well as food resources. The alteration of resource abundance and type may induce non-adaptive investments in reproduction from urban dwellers. Food availability and quality have been identified as potential drivers of the decline in passerine body mass and fledging success in urbanized landscapes, particularly if birds misinterpret cues of food abundance used to adjust their reproductive investment. In a previous study, we demonstrated in urban great tits, Parus major, that highly preferred larger cavities have larger clutches with lower breeding success, leading to a maladaptive breeding investment. Previous studies also showed that urban great tits are smaller or thinner than rural ones, both at nestling and adult stages. Here, we present the results of a food-supplementation experiment to examine whether food resources mediate this maladaptive breeding investment and constrain the reproductive performance of this urban bird population. We predicted higher performance in food-supplemented broods, especially in larger cavities, and stronger effects of the supplementation in more artificialized territories. Surprisingly, we found that food-supplemented nestlings and their parents had lower body mass and condition, especially in areas with more pedestrians. Supplementation was also associated with lower nestling survival until fledging in places that presented lower levels of naturalness, independently of cavity size. This work highlights a lack of knowledge on avian feeding behaviour in cities, a key element for understanding how breeding performance is affected by human presence and habitat naturalness.

Assortative mating by colored ornaments in blue tits: space and time matter

Assortative mating is a potential outcome of sexual selection, and estimating its level is important to better understand local adaptation and underlying trait evolution. However, assortative mating studies frequently base their conclusions on small numbers of individuals sampled over short periods of time and limited spatial scales even though spatiotemporal variation is common. Here, we characterized assortative mating patterns over 10 years in four populations of the blue tit (Cyanistes caeruleus), a passerine bird. We focused on two plumage ornaments-the blue crown and the yellow breast patch. Based on data for 1,657 pairs of birds, we found large interannual variation: assortative mating varied from positive to negative. To determine whether there was nonetheless a general trend in the data, we ran a within-study meta-analysis. It revealed that assortative mating was moderately positive for both ornaments. It also showed that mating patterns differed among populations and especially between two neighboring populations that displayed phenotypic divergence. Our results therefore underscore that long-term studies are needed to draw broad conclusions about mating patterns in natural populations. They also call for studying the potential role of assortative mating in local adaptation and evolution of ornaments in both sexes.

Peripheral venous catheter insertion simulation training: A randomized controlled trial comparing performance after instructor-led teaching versus peer-assisted learning

INTRODUCTION

Peripheral venous catheter insertion is a procedural skill that every medical student should master. Training is often limited to a small number of students and is poorly evaluated. The objective of this study was to evaluate the performance of peer-assisted learning in comparison to instructor-led teaching for peripheral venous catheter insertion training.

METHODS

Students were randomized to the control group attending a traditional instructor-led training session (slideshow and demonstration by an anesthetist instructor, followed by training on a procedural simulator) or to the test group attending a peer-assisted training session (slideshow and demonstration video-recorded by the same instructor, followed by training on a procedural simulator). The primary endpoint was the performance of peripheral venous catheter insertion, assessed on procedural simulator one week later by blinded experts using a standardized 20-item grid. Students self-evaluated their confidence levels using a numeric 10-point scale.

RESULTS

Eighty-six students were included, 73 of whom attended the assessment session. The median performance score was 12/20 [8-15] in the instructor-led teaching group versus 13/20 [11-15] in the peer-assisted learning group (P=0.430). Confidence levels improved significantly after the assessment session and were significantly higher in the peer-assisted learning group (7.6/10 [7.0-8.0] versus 7.0/10 [5.0-8.0], P=0.026).

CONCLUSION

Peer-assisted learning is effective for peripheral venous catheter insertion training and can be as effective as instructor-led teaching. Given the large number of students to train, this finding is important for optimizing the cost-effectiveness of peripheral venous catheter insertion training.

Interspecific variation in the relationship between clutch size, laying date and intensity of urbanization in four species of hole-nesting birds

The increase in size of human populations in urban and agricultural areas has resulted in considerable habitat conversion globally. Such anthropogenic areas have specific environmental characteristics, which influence the physiology, life history, and population dynamics of plants and animals. For example, the date of bud burst is advanced in urban compared to nearby natural areas. In some birds, breeding success is determined by synchrony between timing of breeding and peak food abundance. Pertinently, caterpillars are an important food source for the nestlings of many bird species, and their abundance is influenced by environmental factors such as temperature and date of bud burst. Higher temperatures and advanced date of bud burst in urban areas could advance peak caterpillar abundance and thus affect breeding phenology of birds. In order to test whether laying date advance and clutch sizes decrease with the intensity of urbanization, we analyzed the timing of breeding and clutch size in relation to intensity of urbanization as a measure of human impact in 199 nest box plots across Europe, North Africa, and the Middle East (i.e., the Western Palearctic) for four species of hole‐nesters: blue tits (Cyanistes caeruleus), great tits (Parus major), collared flycatchers (Ficedula albicollis), and pied flycatchers (Ficedula hypoleuca). Meanwhile, we estimated the intensity of urbanization as the density of buildings surrounding study plots measured on orthophotographs. For the four study species, the intensity of urbanization was not correlated with laying date. Clutch size in blue and great tits does not seem affected by the intensity of urbanization, while in collared and pied flycatchers it decreased with increasing intensity of urbanization. This is the first large‐scale study showing a species‐specific major correlation between intensity of urbanization and the ecology of breeding. The underlying mechanisms for the relationships between life history and urbanization remain to be determined. We propose that effects of food abundance or quality, temperature, noise, pollution, or disturbance by humans may on their own or in combination affect laying date and/or clutch size.

Disruptive viability selection on a black plumage trait associated with dominance

Traits used in communication, such as colour signals, are expected to have positive consequences for reproductive success, but their associations with survival are little understood. Previous studies have mainly investigated linear relationships between signals and survival, but both hump-shaped and U-shaped relationships can also be predicted, depending on the main costs involved in trait expression. Furthermore, few studies have taken the plasticity of signals into account in viability selection analyses. The relationship between signal expression and survival is of particular interest in melanin-based traits, because their main costs are still debated. Here, we first determined the main factors explaining variability in a melanin-based trait linked to dominance: the bib size of a colonial bird, the sociable weaver Philetairus socius. We then used these analyses to obtain a measure representative of the individual mean expression of bib size. Finally, we used capture-recapture models to study how survival varied in relation to bib size. Variation in bib size was strongly affected by year and moderately affected by age, body condition and colony size. In addition, individuals bearing small and large bibs had higher survival than those with intermediate bibs, and this U-shaped relationship between survival and bib size appeared to be more pronounced in some years than others. These results constitute a rare example of disruptive viability selection, and point towards the potential importance of social costs incurred by the dominance signalling function of badges of status.

The intensity threshold of colour vision in a passerine bird, the blue tit (Cyanistes caeruleus)

Many vertebrates use colour vision for vital behaviour but their visual performance in dim light is largely unknown. The light intensity threshold of colour vision is known only for humans, horses and two parrot species. Here, we first explore this threshold in a passerine bird, the blue tit (Cyanistes caeruleus). Using classic conditioning of colour cues to food rewards in three individuals, we find a threshold ranging from 0.05 to 0.2 cd m(-2). Results are comparable to the two previously tested bird species. For tits, nest light conditions probably exceed that threshold, at least after sunrise. These results shed new light on the lively debate questioning the visual performance of cavity nesters and the evolutionary significance of egg and chick coloration. Although this needs further investigation, it is possible that blue tits exploit both colour and brightness cues when viewing their eggs, chicks or conspecifics in their nests.

Variation in clutch size in relation to nest size in birds

Nests are structures built to support and protect eggs and/or offspring from predators, parasites, and adverse weather conditions. Nests are mainly constructed prior to egg laying, meaning that parent birds must make decisions about nest site choice and nest building behavior before the start of egg-laying. Parent birds should be selected to choose nest sites and to build optimally sized nests, yet our current understanding of clutch size-nest size relationships is limited to small-scale studies performed over short time periods. Here, we quantified the relationship between clutch size and nest size, using an exhaustive database of 116 slope estimates based on 17,472 nests of 21 species of hole and non-hole-nesting birds. There was a significant, positive relationship between clutch size and the base area of the nest box or the nest, and this relationship did not differ significantly between open nesting and hole-nesting species. The slope of the relationship showed significant intraspecific and interspecific heterogeneity among four species of secondary hole-nesting species, but also among all 116 slope estimates. The estimated relationship between clutch size and nest box base area in study sites with more than a single size of nest box was not significantly different from the relationship using studies with only a single size of nest box. The slope of the relationship between clutch size and nest base area in different species of birds was significantly negatively related to minimum base area, and less so to maximum base area in a given study. These findings are consistent with the hypothesis that bird species have a general reaction norm reflecting the relationship between nest size and clutch size. Further, they suggest that scientists may influence the clutch size decisions of hole-nesting birds through the provisioning of nest boxes of varying sizes.

Females tend to prefer genetically similar mates in an island population of house sparrows

BACKGROUND

It is often proposed that females should select genetically dissimilar mates to maximize offspring genetic diversity and avoid inbreeding. Several recent studies have provided mixed evidence, however, and in some instances females seem to prefer genetically similar males. A preference for genetically similar mates can be adaptive if outbreeding depression is more harmful than inbreeding depression or if females gain inclusive fitness benefits by mating with close kin. Here, we investigated genetic compatibility and mating patterns in an insular population of house sparrow (Passer domesticus), over a three-year period, using 12 microsatellite markers and one major histocompability complex (MHC) class I gene. Given the small population size and the distance from the mainland, we expected a reduced gene flow in this insular population and we predicted that females would show mating preferences for genetically dissimilar mates.

RESULTS

Contrary to our expectation, we found that offspring were less genetically diverse (multi-locus heterozygosity) than expected under a random mating, suggesting that females tended to mate with genetically similar males. We found high levels of extra-pair paternity, and offspring sired by extra-pair males had a better fledging success than those sired by the social male. Again, unexpectedly, females tended to be more closely related to extra-pair mates than to their social mates. Our results did not depend on the type of genetic marker used, since microsatellites and MHC genes provided similar results, and we found only little evidence for MHC-dependent mating patterns.

CONCLUSIONS

These results are in agreement with the idea that mating with genetically similar mates can either avoid the disruption of co-adapted genes or confer a benefit in terms of kin selection.

Eggshell spottiness reflects maternally transferred antibodies in blue tits

Blue-green and brown-spotted eggshells in birds have been proposed as sexual signals of female physiological condition and egg quality, reflecting maternal investment in the egg. Testing this hypothesis requires linking eggshell coloration to egg content, which is lacking for brown protoporphyrin-based pigmentation. As protoporphyrins can induce oxidative stress, and a large amount in eggshells should indicate either high female and egg quality if it reflects the female's high oxidative tolerance, or conversely poor quality if it reflects female physiological stress. Different studies supported either predictions but are difficult to compare given the methodological differences in eggshell-spottiness measurements. Using the blue tit Cyanistes caeruleus as a model species, we aimed at disentangling both predictions in testing if brown-spotted eggshell could reflect the quality of maternal investment in antibodies and carotenoids in the egg, and at improving between-study comparisons in correlating several common measurements of eggshell coloration (spectral and digital measures, spotted surface, pigmentation indices). We found that these color variables were weakly correlated highlighting the need for comparable quantitative measurements between studies and for multivariate regressions incorporating several eggshell-color characteristics. When evaluating the potential signaling function of brown-spotted eggshells, we thus searched for the brown eggshell-color variables that best predicted the maternal transfer of antibodies and carotenoids to egg yolks. We also tested the effects of several parental traits and breeding parameters potentially affecting this transfer. While eggshell coloration did not relate to yolk carotenoids, the eggs with larger and less evenly-distributed spots had higher antibody concentrations, suggesting that both the quantity and distribution of brown pigments reflected the transfer of maternal immune compounds in egg yolks. As yolk antibody concentrations were also positively related to key proxies of maternal quality (egg volume, number, yellow feather brightness, tarsus length), eggshells with larger spots concentrated at their broad pole may indicate higher-quality eggs.

Control of the estrous cycle in guinea-pig (Cavia porcellus)

The aim of this work was to look for a simple method to obtain synchronized ovulation in guinea pigs under farming conditions while respecting animal welfare. The luteolytic activity of three different prostaglandins F2alpha (PGF2α) analogs (D-cloprostenol, D,L-cloprostenol and luprostiol) and a daily treatment with oral progestagen (altrenogest) was tested successively at different stages of the estrous cycle on the same group of females during a period of 8 mo. The estrous cycle length was not modified by the administration of PGF2α analogs, whatever the stage of the estrous cycle when the treatment was initiated. Our results led us to reject the use of PGF2α analog to induce practical synchronization of the estrus in this species. In females (n = 29), given 15 days with altrenogest (0.1 mL po once a day), ovulation occurred 4.43 ± 0.13 days after the end of the treatment. Altrenogest treatment was followed by mating. No negative impacts of the treatment on the pregnancy rates, delivery rates and litter sizes were observed. This standard method of guinea-pig estrus synchronization is less stressful for the animals compared to techniques using progesterone tubing.

115 FIRST SUCCESSFUL PREGNANCY AFTER EMBRYO TRANSFER INTO SYNCHRONIZED FEMALES IN GUINEA PIG (CAVIA PORCELLUS)

The guinea pig (Cavia porcellus) has been used as a laboratory animal since the late 18th century and still remains essential in many research areas. It also plays an important role in the Andes societies as a source of protein for many low-income highlanders and as part of rituals and traditional medicines. Thus, the conservation of genetic diversity is a long-term issue that must be considered. To establish an embryo cryobank, it is necessary to develop a method of embryo transfer. Up to now no pregnancies after surgical embryo transfer into synchronized females have been reported in guinea pigs. The aim of this work was to design a standard embryo transfer method in this species. Eight normally cycling female guinea pigs from the Maria-Marcela Farm (Puente Piedra, Peru), weighing from 1 to 1.5 kg, were used in this study. Females were housed under farming conditions and fed on commercial pellets and tap water ad libitum. Three donor females were superovulated using 15 IU of human menopausal gonadotrophin (hMG, Massone®, Buenos Aires, Argentina) and mated as soon as the vagina opened. Copulatory plug was observed and vaginal smears were taken to guarantee successful mating. Thirty-eight embryos were collected between Days 3.5 and 4.5 after ovulation at the morula and early blastocyst stages. Five recipient females were synchronized by a daily 0.1-mL dose of altrenogest (Regumate® Equine, Intervet, France) per os by means of a syringe for 15 days. Two embryos were transferred into each uterine horn by laparotomy at Day 3.5 and 4.5 after ovulation. Two types of pipettes were tested for embryo transfer: pulled glass pipettes approximately 0.3 mm in diameter in 2 female recipients and plastic open pulled straws (OPS, Minitüb®, Germany) in 3 recipients. Pregnancy diagnosis was detected by observation of no return to oestrus at Day 16 and confirmed by ultrasonography. None of the 3 OPS-transferred females were pregnant. One of the 2 pulled glass pipette–transferred females was diagnosed as pregnant and delivered 2 stillbirths (one per uterine horn). There were no postsurgical complications and the females undergoing embryo transfer returned to normal reproduction. We demonstrated that a classic surgical embryo transfer method is possible under field conditions to obtain pregnancy in this species. We suggest further studies using glass pipettes, which allow a more precise embryo deposition. Future experiments will incorporate the transfer of frozen-thawed embryos on a larger scale.

Functional consequences of chronic ENT inflammation on the development of hearing and communicative abilities

Hearing processing and communication abilities development may be influenced by chronic inflammation of the airways in children, especially in case of otitis media and/or adenotonsillar hypertrophy. The present review summarizes the influence of adenotonsillar hypertrophy on speech abilities as well as the consequences of otitis media, with a particular focus on peripheral and central hearing, on the development of language, attention, and memory skills.

Female plumage coloration is sensitive to the cost of reproduction. An experiment in blue tits

1. A growing number of studies suggest that female ornaments are linked to maternal quality and influence male mate choice. These findings challenge the traditional male-biased view of sexual selection and the hypothesis that female ornaments are the outcome of a genetic correlation with male ornaments. To further test the hypothesis that female traits have a function, it is now essential to investigate their honesty and to determine how signalling and reproduction interact in females. If female traits are honest indicators of quality, then they are likely to have a specific signalling function. 2. We investigated whether carry-over effects of reproduction might ensure the honesty of plumage colour signalling of a bird species with conspicuous UV-blue and yellow coloration, the blue tit Cyanistes caeruleus. Reproductive effort was manipulated by removing clutches, thereby forcing both sexes to reproduce twice and to raise chicks later in the breeding season when food is less abundant. In the year following this manipulation, we investigated the change in plumage in experimental and control males and females. The change was measured in the two putative feather ornaments, the UV-blue cap and the yellow breast, and another feather trait probably less likely to be sexually selected: the wing length. We also tested whether higher-quality females had their coloration less affected by the experiment. 3. We found that control but not manipulated males and females increased their signal towards UV. In addition, in the manipulated group, females that were able to lay more eggs had their UV-blue coloration less affected by the treatment. For yellow coloration, we found that manipulated yearlings but not manipulated adults decreased their yellow chroma in comparison with control. Lastly, our results show that the condition of the manipulated females tended to be positively correlated with yellow chroma. 4. These results show that the trade-offs between reproduction and signalling can ensure the honesty of conspicuous plumage traits in female and male blue tits. In addition, they suggest that female traits have the potential to evolve under sexual selection in this and other bird species.

Can eggs in a cavity be a female secondary sexual signal? Male nest visits and modelling of egg visual discrimination in blue tits

Eggshell colouration is thought to function as a female-specific secondary sexual trait. While tests of this idea are rapidly accumulating in cavity-nesting birds, some fundamental underlying assumptions remain rarely investigated: namely, can males see eggshell coloration and perceive colour differences between the eggs of different females? We tested these two key assumptions in a natural population of blue tits (Cyanistes caeruleus). Using transponders, we tracked male nest visits and found that all males visited their nest-boxes while eggs were present and often visually accessible. Interestingly, some males also visited neighbouring nests. We then tested whether birds could detect eggshell coloration using models of avian colour vision; models were performed with and without limitations on visual performance owing to dim light. Both models found that differences in eggshell brightness were often easier to discriminate than differences in colour; there was more contrast in white eggshell background between clutches than within and its contrast against nest background was repeatable within clutches, suggesting these features could act as signals. Yet, the detectability of these contrasts depended entirely on model assumptions of visual limitations. Consequently, we need a better understanding of underlying visual mechanisms in dim-light environments and behavioural discrimination experiments before confirming the signalling potential of eggshell coloration.

Estimating and visualizing fitness surfaces using mark-recapture data

Understanding how selection operates on a set of phenotypic traits is central to evolutionary biology. Often, it requires estimating survival (or other fitness-related life-history traits) which can be difficult to obtain for natural populations because individuals cannot be exhaustively followed. To cope with this issue of imperfect detection, we advocate the use of mark-recapture data and we provide a general framework for both the estimation of linear and nonlinear selection gradients and the visualization of fitness surfaces. To quantify the strength of selection, the standard second-order polynomial regression method is integrated in mark-recapture models. To visualize the form of selection, we use splines to display selection acting on multivariate phenotypes in the most flexible way. We employ Markov chain Monte Carlo sampling in a Bayesian framework to estimate model parameters, assessing traits relevance and calculating the optimal amount of smoothing. We illustrate our approach using data from a wild population of Common blackbirds (Turdus merula) to investigate survival in relation to morphological traits, and provide evidence for correlational selection using the new methodology. Overall, the framework we propose will help in exploring the full potential of mark-recapture data to study natural selection.

[CT guided neurolysis of the sphenopalatine ganglion for management of refractory trigeminal neuralgia]

The authors present the case of a patient with recurrent trigeminal neuralgia, refractory to medical treatment and ablation of the trigeminal ganglion, who underwent three separate CT guided injections for pterygopalatine ganglion ablation over a two year period. Ablation of the pterygopalatine ganglion may be an effective technique for pain management in patients suffering from atypical facial pain syndrome, cluster headache, or neuritis. The technique used for CT guided ablation using alcohol or radiofrequency is described. The advantages and pitfalls of this technique are reviewed.

[Symptomatic venous congestion of the brain stem after embolization for dural fistula of the cavernous sinus]

We report the case of a 60-year old woman presenting, 3 days after arterial embolization of a dural arteriovenous fistula, with diplopia and gait disturbance in relation with right oculomotor nerve palsy and cerebellar dysfunction. On T2 weighted MR images, several hyperintense areas appeared in the pons and the midbrain. After one month, clinical symptoms and diffuse hyperintense areas resolved spontaneously, as the patient was treated by anti-vitamin K. This complication probably corresponds to reversible pontine venous congestion caused by poor venous drainage of the dural arteriovenous fistula.

Differential influence of Pomphorhynchus laevis (Acanthocephala) on the behaviour of native and invader gammarid species

Although various species of acanthocephalan parasites can increase the vulnerability of their amphipod intermediate hosts to predation, particularly by altering their photophobic behaviour, their influence on the structure of amphipod communities and the success of invader species has so far received little attention. We compared the prevalence and behavioural influence of a fish acanthocephalan parasite, Pomphorhynchus laevis, in two species of amphipods, Gammarus pulex and Gammarus roeseli in sympatry in the river Ouche (Burgundy, eastern France). There, G. pulex is a resident species, whereas G. roeseli is a recent coloniser. Both uninfected G. pulex and G. roeseli were strongly photophobic. although less so in the invading species. However, there was no significant difference in reaction to light between infected and uninfected G. roeseli, whereas infected G. pulex were strongly photophilic. We discuss our results in relation to the parasite's ability to manipulate invading host species, the possibility that resistant individuals have been selected during the invasion process, and the role that acanthocephalan parasites can play in shaping the structure of amphipod communities.

Plasma serotonin level after 1 day of fluoxetine treatment: a biological predictor for antidepressant response?

RATIONALE

Antidepressant treatments present a delayed onset of action.

OBJECTIVE

The present study investigated whether plasma or serum serotonin, 5-hydroxytryptamine (5-HT), could predict clinical improvement.

METHODS

Biological parameters were determined after a 4-week drug-free period (day 0) and 1, 14 and 28 days after the beginning of the treatment with fluoxetine 20 mg daily in depressed patients. Clinical evaluations were assessed on days 0, 14 and 28.

RESULTS

One day after a single dose, the mean values of plasma 5-HT (5.4 +/- 2.6 nmol/l) and serum 5-HT (484 +/- 215 nmol/l) were not statistically different from basal mean values (4.5 +/- 2.5 nmol/l and 523 +/- 263 nmol/l, respectively). The repeated treatment significantly reduced serum 5-HT to 34% (P = 0.002) and 17% (P = 0.0004) of pretreatment values after 14 and 28 days of treatment, respectively; plasma 5-HT was also reduced significantly to 28% and 15% of pretreatment values (P < 0.05 in both cases). At day 28, four of the eight patients responded by showing a reduction in MADRS score of at least 50% of the baseline score. No correlation was found between pretreatment values of serum or plasma 5-HT and clinical evolution, even if a tendency (P < 0.07) to lower serum 5-HT pretreatment values was observed in responders. Plasma 5-HT after 1 day of treatment was significantly different between responders and non-responders: the plasma 5-HT concentration in responders was 3.4 +/- 1.7 nmol/l versus 7.4 +/- 1.6 nmol/l in non-responders (P = 0.02). Moreover, plasma 5-HT levels after 1 day of treatment were positively correlated to the final MADRS score (r = +0.89, n = 8, P = 0.003) and inversely correlated to its change from the initial score (r = -0.76, n = 8, P = 0.02).

CONCLUSION

These preliminary data show that fluoxetine and norfluoxetine might influence 5-HT peripheral venous blood parameters and that plasma 5-HT after 1 day of treatment might be a biological predictor for antidepressant response.

Masc2, a gene from Ascobolus encoding a protein with a DNA-methyltransferase activity in vitro, is dispensable for in vivo methylation

We have shown previously that masc1, a gene encoding a putative C5-DNA-methyltransferase (MTase), was necessary for the de novo 'Methylation Induced Premeiotically' (MIP) process and sexual reproduction in Ascobolus, whereas it was dispensable for maintenance methylation. A second MTase gene from Ascobolus, masc2, encodes a protein, Masc2, which possesses the large amino-terminal part characteristic of eukaryotic maintenance MTases. In vitro assays have shown that Masc2 displays a methylation activity, suggesting that it might be the MTase responsible for maintenance methylation. To check its function in vivo, we engineered a disruption of the masc2 gene. The resulting mutant strains did not exhibit any particular phenotype during either vegetative growth or sexual reproduction. Neither the masc2 mutation nor the double masc1 masc2 mutation had any detectable effect upon the maintenance of the pre-existing methylation of single gene copies previously subjected to MIP, natural retroelement-like repeats and tandemly repeated rDNA. The masc2 mutation did not alter either MIP or the other de novo methylation process that operates in vegetatives cells. Nor did it impair the meiotic process of methylation transfer. These results suggest that at least a third MTase gene responsible for maintenance and vegetative de novo methylation is present in Ascobolus.

An in vivo and in vitro structure-function analysis of the Saccharomyces cerevisiae U3A snoRNP: protein-RNA contacts and base-pair interaction with the pre-ribosomal RNA

The structure and accessibility of the S. cerevisiae U3A snoRNA was studied in semi-purified U3A snoRNPs using both chemical and enzymatic probes and in vivo using DMS as the probe. The results obtained show that S. cerevisiae U3A snoRNA is composed of a short 5' domain with two stem-loop structures containing the phylogenetically conserved boxes A' and A and a large cruciform 3' domain containing boxes B, C, C' and D. A precise identification of RNA-protein contacts is provided. Protection by proteins in the snoRNP and in vivo are nearly identical and were exclusively found in the 3' domain. There are two distinct protein anchoring sites: (i), box C' and its surrounding region, this site probably includes box D, (ii) the boxes B and C pair and the bases of stem-loop 2 and 4. Box C' is wrapped by the proteins. RNA-protein interactions are more loose at the level of boxes C and D and a box C and D interaction is preserved in the snoRNP. In accord with this location of the protein binding sites, an in vivo mutational analysis showed that box C' is important for U3A snoRNA accumulation, whereas mutations in the 5' domain have little effect on RNA stability. Our in vivo probing experiments strongly suggest that, in exponentially growing cells, most of the U3A snoRNA molecules are involved in the 10-bp interaction with the 5'-ETS region and in two of the interactions recently proposed with 18S rRNA sequences. Our experimental study leads to a slightly revised version of the model of interaction proposed by J. Hughes. Single-stranded segments linking the heterologous helices are highly sensitive to DMS in vivo and their functional importance was tested by a mutational analysis.

Prevention of bleomycin-induced pulmonary fibrosis after adenovirus-mediated transfer of the bacterial bleomycin resistance gene

A serious limitation in the use of the DNA-cleaving, antitumoral-antibiotic, bleomycin during chemotherapy is pulmonary toxicity. Lung injury induced by bleomycin is characterized by an increased deposition of interstitial extracellular matrix proteins in the alveolar wall that compromises respiratory function. Several drugs have been tested in animal models to prevent the pulmonary toxicity of bleomycin, but have not led to a useful clinical treatment because of their adverse effects on other tissues. We have shown that transgenic mice expressing Streptoalloteichus hindustanus (Sh) ble bleomycin resistance protein in pulmonary epithelial cells in the lungs are protected against bleomycin-induced toxicity in lungs. In the present study, we used intranasal administration by adenovirus-mediated gene transfer of the bleomycin resistance Sh ble gene to mouse lung for prevention of bleomycin-induced pulmonary fibrosis. We constructed recombinant adenoviruses Ad.CMVble and Ad.RSVble harboring the bleomycin resistance Sh ble gene under the control of the cytomegalovirus early promoter and the Rous sarcoma virus early promoter, respectively. Transgene expression was detected in epithelia of conducting airways and alveolar septa by immunostaining with a rabbit polyclonal antibody directed against the bleomycin resistance protein and persisted for the duration of drug treatment; i.e., up to 17 d. No toxic effect was seen in adenovirus-treated mice. Pretreatment of mice with Ad.CMVble or Ad.RSVble completely prevented collagen deposition 42-133 d after bleomycin treatment, as measured by lung OH-proline content. Histologic studies indicated that there was little or no lung injury in the adenovirus/bleomycin-treated mice compared with the bleomycin-treated mice. These observations may lead to new approaches for the prevention of bleomycin-induced pulmonary fibrosis.

Secondary structure of the yeast Saccharomyces cerevisiae pre-U3A snoRNA and its implication for splicing efficiency

The Saccharomyces cerevisiae U3 snoRNA genes contain long spliceosomal introns with noncanonical branch site sequences. By using chemical and enzymatic methods to probe the RNA secondary structure and site-directed mutagenesis, we established the complete secondary structure of the U3A snoRNA precursor. This is the first determination of the complete secondary structure of an RNA spliced in a spliceosome. The peculiar cruciform structure of the U3A snoRNA 3'-terminal region is formed in the precursor RNA and the conserved Boxes B and C are accessible for binding the U3 snoRNP proteins. The intron forms a highly folded structure with a long central stem-loop structure that brings the 5' box and the branch site together. This is in agreement with the idea that secondary structure interactions are necessary for efficient splicing of long introns in yeast. The 3' splice site is in a bulged loop and the branch site sequence is single-stranded. Surprisingly, the 5' splice site is involved in a 6-base pair interaction. We used in vitro splicing experiments to show that, despite a noncanonical branch site sequence and a base paired 5' splice site, transcripts that mimic the authentic pre-U3A snoRNA are spliced very efficiently in vitro. Sequestering the 5' splice site in a more stable structure had a negative effect on splicing, which was partially compensated by converting the branch site sequence into a canonical sequence. Analysis of spliceosomal complex formation revealed a cumulative negative effect of a base pair interaction at the 5' splice site and of a deviation to the consensus sequence at the branch site on the efficiency of spliceosome formation in vitro.