Fitness Traits Research Articles

Feeding partridges with organic or conventional grain triggers cascading effects in life-history traits.

Farmland birds are declining across Europe and North America and the research of factors behind is the subject of extensive researches. Agricultural intensification is now recognized as a major factor governing the loss of biodiversity with strong evidence that pesticides induced direct bird mortality at a high dose. However, less attention has been given to the long-term effects of chronic exposure to low dose of pesticides. Here, we used an experimental procedure in which grey partridges were fed with untreated grains obtained from either organic (no pesticide) or conventional agriculture (with pesticide) for 26 weeks, thus strictly mimicking wild birds foraging on fields. We then examined a suite of life-history traits (ecophysiological and behavioural) that may ultimately, influence population dynamics. We show for the first time that ingesting low pesticide doses over a long period has long-term consequences on several major physiological pathways without inducing differential mortality. Compared to control partridges, birds exposed to chronic doses i) had less developed carotenoid-based ornaments due to lower concentrations of plasmatic carotenoids, ii) had higher activated immune system, iii) showed signs of physiological stress inducing a higher intestinal parasitic load, iv) had higher behavioural activity and body condition and v) showed lower breeding investment. Our results are consistent with a hormetic effect, in which exposure to a low dose of a chemical agent may induce a positive response, but our results also indicate that breeding adults may show impaired fitness traits bearing population consequences through reduced breeding investment or productivity. Given the current scale of use of pesticides in agrosystems, we suggest that such shifts in life-history traits may have a negative long-term impact on wild bird populations across agrosystems. We stress that long-term effects should no longer be ignored in pesticide risk assessment, where currently, only short-term effects are taken into account.

The distribution of runs of homozygosity in the genome of river and swamp buffaloes reveals a history of adaptation, migration and crossbred events

BackgroundWater buffalo is one of the most important livestock species in the world. Two types of water buffalo exist: river buffalo (Bubalus bubalis bubalis) and swamp buffalo (Bubalus bubalis carabanensis). The buffalo genome has been recently sequenced, and thus a new 90 K single nucleotide polymorphism (SNP) bead chip has been developed. In this study, we investigated the genomic population structure and the level of inbreeding of 185 river and 153 swamp buffaloes using runs of homozygosity (ROH). Analyses were carried out jointly and separately for the two buffalo types.ResultsThe SNP bead chip detected in swamp about one-third of the SNPs identified in the river type. In total, 18,116 ROH were detected in the combined data set (17,784 SNPs), and 16,251 of these were unique. ROH were present in both buffalo types mostly detected (~ 59%) in swamp buffalo. The number of ROH per animal was larger and genomic inbreeding was higher in swamp than river buffalo. In the separated datasets (46,891 and 17,690 SNPs for river and swamp type, respectively), 19,760 and 10,581 ROH were found in river and swamp, respectively. The genes that map to the ROH islands are associated with the adaptation to the environment, fitness traits and reproduction.ConclusionsAnalysis of ROH features in the genome of the two water buffalo types allowed their genomic characterization and highlighted differences between buffalo types and between breeds. A large ROH island on chromosome 2 was shared between river and swamp buffaloes and contained genes that are involved in environmental adaptation and reproduction.

Maternal reproductive output and F1 hybrid fitness may influence contact zone dynamics.

The outcome of secondary contact between divergent lineages or species may be influenced by both the reproductive traits of parental species and the fitness of offspring; however, their relative contributions have rarely been evaluated, particularly in longer-lived vertebrate species. We performed pure and reciprocal laboratory crosses between Ctenophorus decresii (tawny dragon) and C.modestus (swift dragon) to examine how parental reproductive traits and ecologically relevant offspring fitness traits may explain contact zone dynamics in the wild. The two species meet in a contact zone of post-F1 hybrids with asymmetric backcrossing and predominantly C.modestus mtDNA haplotypes. We found no evidence for reduced parental fecundity or offspring fitness for F1 hybrid crosses. However, maternal reproductive strategy differed between species, irrespective of the species of their mate. Ctenophorus modestus females had higher fecundity and produced more and larger clutches with lower embryonic mortality. Parental species also influenced sex ratios and offspring traits, with C.modestus ♀×C.decresii ♂ hybrids exhibiting higher trait values for more fitness measures (growth rate, sprint speed, bite force) than offspring from all other pairings. Together, these patterns are consistent with the prevalence of C.modestus mtDNA in the contact zone, and asymmetric backcrossing likely reflects fitness effects that manifest in the F2 generation. Our results highlight how parental species can influence multiple offspring traits in different ways, which together may combine to influence offspring fitness and shape contact zone dynamics.

Influence of maternal weight, age, larval feeding and their interactions on the hatchery outcomes of an Indian major carp (Labeo rohita, Hamilton 1822)

Broodstocks’ size (weight or length), age and larval feeding are crucial in the production of good quality gametes and larvae in any fish. Therefore, this study was conducted with two experiments to understand 1) effects of maternal weight and age, and 2) effects of maternal weight, age, larval feeding and their interactions on egg and larval traits using the Indian major carp (Labeo rohita). In both experiments, females were divided into two size groups based on their body weights (‘large’ and ‘small’) to obtain eggs and larvae. In experiment-1, parameters of egg quality such as egg weight, egg number, egg diameter, egg area and hatching rate were assessed, and larvae were reared up to two weeks with optimum feeds to evaluate their traits such as deformation rate, survival rate, total length and body area. In experiment-2, only the three-day old larvae were randomly assigned into two feeding regimes (‘everyday’ and ‘every other day’) up to two weeks to assess their fitness. The results revealed that egg weight, hatching rate, larval total length, body area increased significantly (P <0.05) and hatchling deformation rate decreased significantly (P <0.05) with the increase of female age, whereas only egg weight was linearly related to female weight (R2 = 0.47, P <0.05) in experiment-1. The experiment-2 showed that everyday fed larvae had significantly (P <0.05) higher survival rate, total length and body area than those fed every other day. The dietary treatment found no significant effects of maternal age, weight and their interactions with larval feeding. Thus, the study showed that maternal body weight, age and larval feeding may influence some traits of egg and larval fitness. The overall findings suggest that maternal weight, age and regular larval feeding must be considered to produce good quality of gametes and larvae for sustainable production of this species.

The seesaw of diet restriction and lifespan: lessons from Drosophila studies.

Diet restriction (DR) studies undergo the implementation of reduced single or multiple component/s of the fly food without causing malnutrition. The question of how and why DR modifies the fate of lifespan in fruit flies Drosophila melanogaster has prompted us to emphasize by attending the control food composition first. Certain concentrations of DR food do not always confer an extended lifespan, rather it enables the flies to achieve their normal lifespan, which was probably reduced by the control food per se (having toxic effect caused due to the excess levels of dietary components). However, the current paradigm of DR studies has elicited its benefits and losses via trade-offs in the organismal traits and have highlighted the need for a common diet, but have not claimed the tested diets as balanced. So, the DR effect on lifespan and other fitness traits cannot be justified only based on varying control food across labs and hence, the approach of DR studies has to be revisited and a balanced diet has to be formulated. The current article discusses the need for a balanced diet, the traits to be considered before designing a diet, and certain problems in the existing synthetic medium. Therefore, based on the control food composition, the validity of lifespan extension conferred by these nutrient restricted diets need to be accounted for.

Fluctuating Asymmetry and Sexual Dimorphism in Human Facial Morphology: A Multi-Variate Study.

Fluctuating asymmetry is often used as an indicator of developmental instability, and is proposed as a signal of genetic quality. The display of prominent masculine phenotypic features, which are a direct result of high androgen levels, is also believed to be a sign of genetic quality, as these hormones may act as immunosuppressants. Fluctuating asymmetry and masculinity are therefore expected to covary. However, there is lack of strong evidence in the literature regarding this hypothesis. In this study, we examined a large dataset of high-density 3D facial scans of 1260 adults (630 males and 630 females). We mapped a high-density 3D facial mask onto the facial scans in order to obtain a high number of quasi-landmarks on the faces. Multi-dimensional measures of fluctuating asymmetry were extracted from the landmarks using Principal Component Analysis, and masculinity/femininity scores were obtained for each face using Partial Least Squares. The possible correlation between these two qualities was then examined using Pearson's coefficient and Canonical Correlation Analysis. We found no correlation between fluctuating asymmetry and masculinity in men. However, a weak but significant correlation was found between average fluctuating asymmetry and masculinity in women, in which feminine faces had higher levels of fluctuating asymmetry on average. This correlation could possibly point to genetic quality as an underlying mechanism for both asymmetry and masculinity; however, it might also be driven by other fitness or life history traits, such as fertility. Our results question the idea that fluctuating asymmetry and masculinity should be (more strongly) correlated in men, which is in line with the recent literature. Future studies should possibly focus more on the evolutionary relevance of the observed correlation in women.

A time-lagged association between the gut microbiome, nestling weight and nestling survival in wild great tits.

Natal body mass is a key predictor of viability and fitness in many animals. While variation in body mass and therefore juvenile viability may be explained by genetic and environmental factors, emerging evidence points to the gut microbiota as an important factor influencing host health. The gut microbiota is known to change during development, but it remains unclear whether the microbiome predicts fitness, and if it does, at which developmental stage it affects fitness traits. We collected data on two traits associated with fitness in wild nestling great tits Parus major: weight and survival to fledging. We characterised the gut microbiome using 16S rRNA sequencing from nestling faeces and investigated temporal associations between the gut microbiome and fitness traits across development at Day-8 (D8) and Day-15 (D15) post-hatching. We also explored whether particular microbial taxa were 'indicator species' that reflected whether nestlings survived or not. There was no link between mass and microbial diversity on D8 or D15. However, we detected a time-lagged relationship where weight at D15 was negatively associated with the microbial diversity at D8, controlling for weight at D8, therefore reflecting relative weight gain over the intervening period. Indicator species analysis revealed that specificity values were high and fidelity values were low, suggesting that indicator taxa were primarily detected within either the survived or not survived groups, but not always detected in birds that either survived or died. Therefore these indicator taxa may be sufficient, but not necessary for determining either survival or mortality, perhaps owing to functional overlap in microbiota. We highlight that measuring microbiome-fitness relationships at just one time point may be misleading, especially early in life. Instead, microbial-host fitness effects may be best investigated longitudinally to detect critical development windows for key microbiota and host traits associated with neonatal weight. Our findings should inform future hypothesis testing to pinpoint which features of the gut microbial community impact on host fitness, and when during development this occurs. Such confirmatory research will shed light on population level processes and could have the potential to support conservation.

High prevalence and variable fitness of fluoroquinolone-resistant avian pathogenic Escherichia coli isolated from chickens in Korea

ABSTRACT Colibacillosis caused by avian pathogenic Escherichia coli (APEC) is the most common bacterial disease in poultry, resulting in significant economic losses. Resistance to fluoroquinolones has been found to be high in APEC worldwide, which has increased concerns about risks to human health as well as poultry production. In the present study, we determined the prevalence, genetic traits, and fitness traits of fluoroquinolone-resistant APEC isolated from chickens in Korea using a total of 286 APEC isolates collected between 2014 and 2017. The APEC isolates were highly resistant to nalidixic acid (86.0%), ampicillin (71.7%), tetracycline (69.6%), and sulfisoxazole (61.2%), and 132 (46.2%) of the isolates were resistant to both enrofloxacin and ciprofloxacin. These fluoroquinolone-resistant isolates showed eight mutation combinations including single- or double-point mutations in the gyrA, parC, or parE genes. The isolates with double mutations (codons 83 and 87) in gyrA and additional mutations in parC and parE showed high-level fluoroquinolone resistance (minimum inhibitory concentrations, 16–128 µg/ml). The isolates fell into four phylogenetic groups, and groups A (47/132, 35.6%) and B1 (47/132, 36.4%) were the most predominant. Nine isolates (6.8%) belonged to group B2 and included major lineages of extraintestinal pathogenic E. coli, sequence type (ST) 95 (n = 3) and ST69 (n = 2). The isolates varied in their virulence-associated gene content, biofilm formation, and intramacrophage survival. Overall, fluoroquinolone-resistant APEC in poultry poses a potential risk to public health and represents a highly diverse group of the resistant bacteria that varied in their genetic and fitness traits.

Environmental and genetic influences on fitness-related traits in a hatchery coho salmon population

Many natural and managed organisms will require substantial functional genetic variation to respond to selection in the face of rapid environmental change. Pacific salmon have experienced strong fluctuations in critical fitness traits over the past five decades. We examined genetic and phenotypic variability over three generations in a pedigreed hatchery population of coho salmon (Oncorhynchus kisutch) by monitoring seven fitness-related traits. Three-year-old adult return numbers varied more than fivefold, and jack (2-year-old males) numbers varied 13-fold. Body sizes of Inch Creek coho salmon decreased consistently such that fish were only 40.7% as heavy in 2015 as in 2006, and female reproductive traits also decreased. During the study period, the majority of families produced returning adult progeny, and effective population size was relatively constant. Heritability estimates for phenotypic traits were significantly greater than zero except for condition factor, and the estimated heritability for jacking was 0.42. The Inch Creek coho salmon population harbours substantial heritability for fitness and reproductive traits and thus likely retains substantial capacity for adaptation despite many years of hatchery propagation.

Arabidopsis cell wall composition determines disease resistance specificity and fitness

Plant cell walls are complex structures subject to dynamic remodeling in response to developmental and environmental cues and play essential functions in disease resistance responses. We tested the specific contribution of plant cell walls to immunity by determining the susceptibility of a set of Arabidopsis cell wall mutants (cwm) to pathogens with different parasitic styles: a vascular bacterium, a necrotrophic fungus, and a biotrophic oomycete. Remarkably, most cwm mutants tested (29/34; 85.3%) showed alterations in their resistance responses to at least one of these pathogens in comparison to wild-type plants, illustrating the relevance of wall composition in determining disease-resistance phenotypes. We found that the enhanced resistance of cwm plants to the necrotrophic and vascular pathogens negatively impacted cwm fitness traits, such as biomass and seed yield. Enhanced resistance of cwm plants is not only mediated by canonical immune pathways, like those modulated by phytohormones or microbe-associated molecular patterns, which are not deregulated in the cwm tested. Pectin-enriched wall fractions isolated from cwm plants triggered immune responses in wild-type plants, suggesting that wall-mediated defensive pathways might contribute to cwm resistance. Cell walls of cwm plants show a high diversity of composition alterations as revealed by glycome profiling that detect specific wall carbohydrate moieties. Mathematical analysis of glycome profiling data identified correlations between the amounts of specific wall carbohydrate moieties and disease resistance phenotypes of cwm plants. These data support the relevant and specific function of plant wall composition in plant immune response modulation and in balancing disease resistance/development trade-offs.

Multiple life-stage inbreeding depression impacts demography and extinction risk in an extinct-in-the-wild species

Inbreeding can depress individuals’ fitness traits and reduce population viability. However, studies that directly translate inbreeding depression on fitness traits into consequences for population viability, and further, into consequences for management choices, are lacking. Here, we estimated impacts of inbreeding depression (B, lethal equivalents) across life-history stages for an extinct-in-the-wild species, the sihek (Guam kingfisher, Todiramphus cinnamominus). We then projected population growth under different management alternatives with our B estimates incorporated, as well as without inbreeding depression (B = 0) or with a conventional default B. We found that inbreeding depression severely impacted multiple life-history stages, and directly translated into an effect on population viability under management alternatives. Simulations including our B estimates indicated rapid population decline, whereas projections without inbreeding depression or with default B suggested very gradual population decline. Further, our results demonstrate that incorporation of B across life-history stages can influence management decisions, as projections with our B estimates suggested a need to switch to increased breeding management to avoid species extinction and support wild releases. Our results demonstrate that magnitude of B across life-history stages can translate into demographic consequences, such that incorporation of multiple life-stage B into population models can be important for informed conservation management decision-making.

Implementation of an Economic Lifetime Net Merit for the Dual-Purpose German Black Pied Cattle Breed

Recently, a Total Merit Index (RZ€) has been developed for German Holstein dairy cattle on the basis of margin in Euro. Our aim was to adjust this lifetime net merit for the dual-purpose German Black Pied cattle breed (DSN) accounting for beef production in addition to milk performance and fitness traits. We used the estimated breeding values of DSN sires and developed a breeding value for carcass weight and quality. Furthermore, we adjusted the German Holstein marginal profits per standard deviation, which are used to calculate the estimated breeding values, to DSN-specific values. The DSN Net Merit is the sum of the three sub-indices DSN Net Milk, DSN Net Fitness, and DSN Net Beef, which contribute to the DSN Net Merit with 52.84%, 43.43%, and 3.73%, respectively. The DSN Net Merit that was calculated for 33 DSN sires ranged between EUR −1114 and +709. The DSN Net Merit strongly correlates with the Total Merit Index. The implementation of the DSN Net Merit is useful for selection and mating decisions. Especially, the sub-index DSN Net Beef, which does not correlate with existing breeding values, can be used to maintain the dual-purpose character of DSN while modestly improving milk yield. The approach can be easily adapted to other dual-purpose breeds.

Effect of Inbreeding Coefficient on Growth and Fitness Traits in a Closed Flock of Corriedale Sheep

Background: The corriedale sheep breed was imported into J and K during sixties for use in improvement of local sheep and are maintained at Mountain Research Station of Sheep and Goat, SKUAST- K. The animals over the years were allowed to mate within the selected animals of the flock as there was hardy any fresh importation of exotic animals from last 49 years due to which closed flock population was established within the farm. This has led to apprehensions over the loss of genetic diversity through years.Methods: The present study was to undertaken to evaluate the performance of Corriedale sheep under temperate climate and to estimate the inbreeding coefficient and its effect on growth and fitness traits of Corriedale sheep maintained at Mountain Research Centre for Sheep and Goat (MRCSG), F.V.Sc and A.H, SKUAST-K Shuhama, Kashmir. The information on performance and pedigree spanning over a period of 49 years (1969-2017) was collected and utilized for the study. The traits studied were birth weight (BW), weaning weight (WW), 6 months weight (6MW), 9 months weight (9MW) and 12 months weight (12MW) age at first lambing (AFL), litter size (LS), total lambs born per ewe (TLB) and survival rate (SR). Result: The averages estimates for BW, WW, 6MW, 9MW, 12MW, AFL, LS, TLB and SR were 3.72±0.01 kg, 13.31±0.07 kg, 18.65±0.05kg, 22.15±0.04 kg, 25.84±0.06 kg 807.20±4.34 days, 1.08±0.00, 4.83±0.03 and 80.76±1.98, respectively. The overall inbreeding coefficient (F) and proportion of population inbred (per cent) for Corriedale sheep were 18.3 and 43.3, respectively. The increased inbreeding coefficient had negative impact and highly significant (p less than 0.01) on all the traits under study except LS. The increased inbreeding coefficient (F) also had a negative impact on all the traits under study. With increase in the level of inbreeding there was a decrease in total body weight traits, lambs born per ewe and survival rate where as age at first lambing was increasing with the increase. he results indicated as decrease of 0.25 kg, 1.45 kg, 5.04 kg, 5.53 kg and 5.48 kg in body weight of the animals at birth, weaning weight, six months, nine months and twelve months from 1969-2017. To overcome the negative impact of inbreeding coefficient in the flock introduction of genetic variability through importation of Corriedale germplasm into the farm is highly recommended.

Effects of Wolbachia infection on fitness-related traits in Drosophila melanogaster

Wolbachia is an intracellular symbiont that infects a large number of arthropod species, ensuring its success in populations by influencing host reproduction. The wMel strain in Drosophila melanogaster does not cause any strong modifications of sexual reproduction. Consequently, it is not clear how the high infection rates of the bacterium in populations of this species are maintained. The wMel strain is classified into two groups of genotypes - wMel and wMelCS. The wMel genotype is ubiquitous in populations, while wMelCS is rare. In this study, we analyzed fitness-related traits in isofemale lines from the unique natural population from Uman (Central Ukraine), in which we observed preservation of the rare wMelCS genotype despite the fluctuations of infection rates between years. We analyzed these effects of Wolbachia genotype and host genetic background on important fitness parameters such as sensitivity to cold and oxidative stress, female fecundity and lifespan. We found that, in the studied population, Wolbachia had an impact on fitness traits only in certain Drosophila genotypes. Positive effects were manifested in the alterations of fecundity, but at the cost of reduced lifespan and resistance to stress. Based on these findings, we conclude that the effect of bacteria on fitness and stress related traits is context-dependent and is modified by the host genotype, at least in the lines established from the Uman population.

Larval food provisions affect developmental time, body size and vitellogenin titers of Scaptotrigona pectoralis gynes (Hymenoptera: Meliponini)

Body size has frequently been discussed as related to reproductive success. Stingless bees show remarkable variation in body size among and within sexes and castes, but very little is known about the proximate causes and the consequences of such variation in these highly eusocial bees. In this study, we evaluated the effect of different amounts of food provided to the larvae on developmental time, body size, abdominal mass, and vitellogenin (Vg) hemolymph titers of gynes of the stingless bee Scaptotrigona pectoralis, a species with trophic caste determination. Our results provide empirical evidence of a significant effect of the quantity of larval food on the duration of development, body size, and traits of reproductive fitness. We discuss proximate causes that may explain gyne size variation in stingless bees. We see this as an initial step towards understanding the adaptive significance and ultimate causes of this phenomenon in highly eusocial bees.

Current Orthopaedic Residency Letters of Recommendation Are Not Biased by Gender of Applicant.

Background:Letters of recommendation (LORs) are highly influential in the residency selection process. Differences in language and length of LORs by gender have been demonstrated for applicants applying to surgical residencies and fellowships. This had yet to be studied in orthopaedic surgery. Given the gender disparity in the field, we sought to investigate the impact of gender on orthopaedic residency applicant LORs. We hypothesized that differences in length and language would be present for women applicants as compared to men.Methods:LORs for 2019 to 2020 applicants who applied to a single academic institution were selected for review. Female and male applicants were matched by medical school attended and United States Medical Licensing Examination Step 1 score. LORs were analyzed using both qualitative and quantitative analyses. Letters were evaluated for their word count, presence of language terms, and frequency of language terms. A similar subgroup language analysis was performed for standardized LORs (SLORs).Results:Six hundred fifty-six applicants met the initial screening criteria—126 women and 530 men. After matching, 71 female applicants were paired with 111 male applicants. Word count was, on average, longer for female applicants. LORs for female applicants were more likely to contain language terms that characterized their ability, achievement, participation in athletics, awards received, fit, leadership, and personality traits. Of these terms, ability and participation in athletics were also found more frequently in LORs written for women. In addition, language characterizing technical skills was found more frequently in LORs of female applicants. Similar codes were found to be statistically significant in the SLOR subgroup analysis.Conclusion:This study highlights that current orthopaedic surgery residency LORs do not appear to be biased by applicant gender. LORs were longer for female applicants and described them more positively. Future female orthopaedic residency applicants should be assured that current female candidates are applying with at least similar if not greater subjective qualifications to their male counterparts based on the findings of this study.

Barrier therapies supporting the biology of the mucosal barrier-medical devices for common clinical mucosal disorders.

Recently mucosal barrier therapies have been either CE marked or licensed by Food and Drug Administration (FDA) as medical devices. A barrier therapy (BT) uses a physical non-drug mode of action as its sole mechanism to manage a clinical syndrome. A BT is verified as technically or biologically safe having efficacy that has been proven by valid clinical trials. However, it remains unclear what anatomical portions of the mucosa are physically engaged by any given BT. Therefore, this article clarifies the physical basis for clinical efficacy of any given mucosal BT's. Current regulatory classification of medical devices is defined. More importantly, the biology of mucosal barrier is detailed by structure, compartmental elements and function. A live-function or cross-sectional anatomical perspective of the mucosa is provided. A cross-sectional anatomical perspective of the mucosa is provided in order to highlight the physical point of contact for any given mucosal BT's. Five traits of an effective mucosal BT are proposed to assess traits of fitness for any given BT. A BT is either classical, possessing four to five traits, or non-classical, possessing three or fewer traits. Among 16 commercially available mucosal BT's which share nine distinct formulations, most are non-classical BT while two (alginate and polymeric sucralfate) are classical mucosal BT's.

Early-life fitness trait variation among divergent European and North American farmed and Newfoundland wild Atlantic salmon populations

It has long been clear that interbreeding between domesticated and wild Atlantic salmon can lead to negative fitness consequences for native populations. Few studies, however, have examined these consequences at critical early life stages, particularly in the context of distinct geographical and ancestral relationships among populations as well domestication selection. In Newfoundland (NF), Canada, while the majority of aquaculture sites use the North American (NA) Saint John River strain, site-specific permission has been granted to farm a strain of European origin (EO). We designed a common-garden experiment to compare fitness-related traits (e.g. development time, survival, size and growth) at different early-life stages (eye development, hatch and yolk absorption) among EO and NA farmed, 2 NF wild and F1hybrid groups. Significant differences (p &lt; 0.001) were observed in development time, survival, growth and energy conversion among farmed, F1hybrid and wild populations. While pure populations (farmed and wild) differed amongst one another, we found few differences in fitness-related traits between F1hybrids and their maternal wild/farmed strains. This suggests that the early-life fitness consequences of F1hybridization will be largely manifested through the action of maternal effects. Additionally, significant associations between the maternal effects of egg size and alevin development time, size, survival, growth, condition and energy conversion efficiency were found. These findings suggest that early-life fitness-related trait differences among farmed, wild and their related F1hybrids are generated by the geographic and ancestral relationship and maternal effects of egg size and less so by domestication selection.

Multifaceted Insights on Fusarium Head Blight in Small Grains in Pennsylvania

Fusarium head blight (FHB) is a serious disease of small-grain cereals that causes economic losses due to both yield reduction and mycotoxin contamination worldwide. To optimize the regional management of the disease, knowledge of risk factors associated with FHB outbreaks and mycotoxin accumulation are essential steps. Therefore, a 2-year survey was conducted during the summers of 2018 and 2019, in which naturally FHB-affected spikes from different hosts were collected across the major cereal-producing regions of Pennsylvania (South, Central, and North). FHB severity (%) data were recorded from each field. Furthermore, a collection of 307 Fusarium graminearum isolates was used to investigate specific components of the pathogen biology, such as the composition of the trichothecene genotype, saprophytic and pathogenic fitness, and sensitivity to triazole-based fungicides. Our results confirm that FHB is an important disease in Pennsylvania, and the risk of disease epidemics may be impacted by both the year and the location. Overall, the regional population of F. graminearum causing FHB in Pennsylvania is the 15ADON genotype. Based on in vitro and in vivo experiments, F. graminearum populations obtained from three distinct small-grain management regions could not be differentiated for the majority of fitness traits examined. All isolates were sensitive to tebuconazole and metconazole fungicides in vitro. Overall, this new knowledge can help shed light on the relative importance of FHB epidemics in Pennsylvania and provide directions for monitoring the sustainability of the integrated strategies used to manage FHB and mycotoxin accumulation.

Telomere length in relation to colour polymorphism across life stages in the tawny owl

Telomere erosion has been proposed to be tightly associated with senescence, environmental stressors and life history trade‐offs. How telomere dynamics vary across life stages and especially in relation to (heritable) phenotypic traits is still unclear. The tawny owl Strix aluco display a highly heritable melanin‐based colour polymorphism, a grey and a brown morph, linked to several fitness traits including morph‐specific telomere dynamics. As adults, brown tawny owls have shorter relative telomere length (RTL) and exhibit faster telomere shortening rate than grey owls. Here we test if these morph‐specific telomere dynamics emerge already during growth, or if they are induced only in adult life through differential physiological costs associated with the life history of the morphs. We analysed RTL from 287 tawny owl offspring and 81 first breeding adults to evaluate at what life stage morph‐specific patterns emerge. We found no differences in RTL between the two morphs during the nestling period nor at the first breeding attempt. Sex, brood size or size rank in the nest did not affect offspring RTL. Among first‐breeders, females had shorter telomeres than males suggesting a sampling‐time dependent difference in reproductive costs between sexes, due to the prominent sex roles in tawny owls in the early nestling period. The probability to return to breed after the first breeding attempt was not affected by RTL, sex or colour morph. The lack of morph‐specific difference in RTL among nestlings and first breeders suggests that previously observed morph‐specific differences in RTL dynamics in adults emerge at the onset of the breeding career and is likely due to different physiological profiles and life‐history strategies adopted by adults. We conclude that different telomere dynamics and senescence patterns among highly heritable phenotypes (colour morphs) are likely to be a result of differential costs of reproduction and self‐maintenance.