| 1. |
- Watson, Hannah, et al.
(author)
-
Thermoregulatory costs of the innate immune response are modulated by winter food availability in a small passerine
- 2023
-
In: Journal of Animal Ecology. - 0021-8790. ; 92:5, s. 1065-1074
-
Journal article (peer-reviewed)abstract
- In winter, a challenge to the immune system could pose a major energetic trade-off for small endotherms, whereby increasing body temperature (Tb; i.e. eliciting fever) may be beneficial to fight off invading pathogens yet incur a cost for vital energy-saving mechanisms. Having previously shown that the availability and acquisition of energy, through manipulation of food predictability, influences the depth of rest-phase hypothermia in a wild bird in winter, we expected that the nocturnal thermoregulatory component of the acute-phase immune response would also be modulated by food availability. By manipulating winter food availability in the wild for great tits Parus major, we created an area offering a “predictable” and constant supply of food at feeding stations, while an unmanipulated area was subject to naturally “unpredictable” food. Birds were subject to an immune challenge shortly after dusk, and the thermoregulatory response was quantified via continuous recording of nocturnal Tb, using subcutaneous thermo-sensitive transponders. In response to immune challenge, all birds increased Tb above the level maintained prior to immune challenge (i.e. baseline). However, birds experiencing a naturally unpredictable food supply elevated Tb more than birds subject to predictable food resources, during the period of expected peak response and for the duration of the night. Furthermore, “unpredictable-food” females took longer to return to their baseline Tb. Assuming baseline nocturnal Tb reflects an individual's optimum, based on their available energy budget, the metabolic cost of eliciting an acute-phase response for “unpredictable-food” birds was more than double that of “predictable-food” birds. The absence of differences in absolute Tb during the peak response could support the idea of an optimal Tb for immune system activation. Alternatively, “predictable-food” birds could have acquired tolerance to endotoxin as a result of using feeding stations, thus affording them reduced costs associated with a smaller Tb increase. These findings shed new light on the trade-offs associated with food acquisition, thermoregulation and immune function in small-bodied endotherms. This knowledge is of increasing importance, given the predicted elevated pathogen risks associated with changes in climate and anthropogenic activities.
|
|
| 2. |
- Aastrup, Christian, et al.
(author)
-
Size and immune function as predictors of predation risk in nestling and newly fledged jackdaws
- 2023
-
In: Animal Behaviour. - : Elsevier BV. - 0003-3472. ; 198, s. 73-84
-
Journal article (peer-reviewed)abstract
- Prey choice by predators may be based on the potential prey's condition, for example resulting in substandard individuals running a higher risk of being predated. Over 5 years, we studied young jackdaws, Corvus monedula, to determine whether size and innate baseline immune function may predict predation risk by goshawks, Accipiter gentilis, during the nestling and early fledging phases. We measured body mass, wing length, tarsus length and four innate immune indices two to four times when nestlings were 12–29 days old. To determine which individuals had been predated during the nestling phase and shortly after fledging, we searched for metal rings of the jackdaws in the only goshawk territory close to the jackdaw colony. Nestling mortality before 12 days of age was entirely due to starvation, whereas between 12 days of age and fledging, mortality was mainly due to predation. Nestlings with smaller size (mass, wing, tarsus) and low lysis titre and haptoglobin concentrations were at a higher risk of being predated before fledging. Directly after fledging, individuals with short wings were preferentially predated, with no effects of body mass, tarsus length or any of the four immune indices measured at day 29 (i.e. shortly before fledging). That lower immune function and smaller size predict predation risk in nestlings may reflect that these individuals are of poor quality and/or lag behind in development. We hypothesize that hunger makes these nestlings sit closest to the entrance hole and hence become the first to be predated. For fledglings, our results suggest that poor flight ability makes individuals with short wings the easiest targets for avian predators.
|
|
| 3. |
- Alyamani, Manar, et al.
(author)
-
Alkaline sphingomyelinase (NPP7) impacts the homeostasis of intestinal T lymphocyte populations
- 2023
-
In: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 13
-
Journal article (peer-reviewed)abstract
- Background and aim: Alkaline sphingomyelinase (NPP7) is expressed by intestinal epithelial cells and is crucial for the digestion of dietary sphingomyelin. NPP7 also inactivates proinflammatory mediators including platelet-activating factor and lysophosphatidylcholine. The aim of this study was to examine a potential role for NPP7 in the homeostasis of the intestinal immune system. Methods: We quantified the numbers of B-lymphocytes, plasma cells, T-lymphocytes including regulatory T-lymphocytes (Tregs), natural killer cells, dendritic cells, macrophages, and neutrophils, in the small and large intestines, the mesenteric lymph nodes and the spleens of heterozygous and homozygous NPP7 knockout (KO) and wildtype (WT) mice. Tissues were examined by immunohistochemistry and stainings quantified using computerized image analysis. Results: The numbers of both small and large intestinal CD3ε+, CD4+, and CD8α+ T-lymphocytes were significantly higher in NPP7 KO compared to WT mice (with a dose-response relationship in the large intestine), whereas Treg numbers were unchanged, and dendritic cell numbers reduced. In contrast, the numbers of CD3ε+ and CD4+ T-lymphocytes in mesenteric lymph nodes were significantly reduced in NPP7 KO mice, while no differences were observed in spleens. The numbers of B-lymphocytes, plasma cells, natural killer cells, macrophages, and neutrophils were similar between genotypes. Conclusion: NPP7 contributes to the regulation of dendritic cell and T-lymphocyte numbers in mesenteric lymph nodes and both the small and large intestines, thus playing a role in the homeostasis of gut immunity. Although it is likely that the downstream effects of NPP7 activity involve the sphingomyelin metabolites ceramide and spingosine-1-phosphate, the exact mechanisms behind this regulatory function of NPP7 need to be addressed in future studies.
|
|
| 4. |
- Andreasson, Fredrik, et al.
(author)
-
Variation in breeding phenology in response to climate change in two passerine species
- 2023
-
In: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 201:1, s. 279-285
-
Journal article (peer-reviewed)abstract
- Increasingly warmer springs have caused phenological shifts in both plants and animals. In birds, it is well established that mean laying date has advanced to match the earlier food peak. We know less about changes in the distribution of egg-laying dates within a population and the environmental variables that determine this variation. This could be an important component of how populations respond to climate change. We, therefore, used laying date and environmental data from 39 years (1983–2021) to determine how climate change affected laying date variation in blue tits (Cyanistes caeruleus) and marsh tits (Poecile palustris), two sympatric passerines with different life histories. Both species advanced mean laying date (0.19–0.24 days per year) and mean laying date showed a negative relationship with maximum spring temperature in both blue and marsh tits. In springs with no clear temperature increase during the critical time window (the time-window in which mean laying date was most sensitive to temperature) start of breeding in blue tits was distributed over a longer part of the season. However, there was no such pattern in marsh tits. Our findings suggest that temperature change, and not necessarily absolute temperature, can shape the variation in breeding phenology in a species-specific manner, possibly linked to variation in life-history strategies. This is an important consideration when predicting how climate change affects timing of breeding within a population.
|
|
| 5. |
- Baltazar-Soares, Miguel, et al.
(author)
-
Bringing to light nuclear-mitochondrial insertions in the genomes of nocturnal predatory birds
- 2023
-
In: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 181
-
Journal article (peer-reviewed)abstract
- Mito-nuclear insertions, or NUMTs, relate to genetic material of mitochondrial origin that have been transferred to the nuclear DNA molecule. The increasing amounts of genomic data currently being produced presents an opportunity to investigate this type of patterns in genome evolution of non-model organisms. Identifying NUMTs across a range of closely related taxa allows one to generalize patterns of insertion and maintenance in autosomes, which is ultimately relevant to the understanding of genome biology and evolution. Here we collected existing pairwise genome-mitogenome data of the order Strigiformes, a group that includes all the nocturnal bird predators. We identified NUMTs by applying percent similarity thresholds after blasting mitochondrial genomes against nuclear genome assemblies. We identified NUMTs in all genomes with numbers ranging from 4 in Bubo bubo to 24 in Ciccaba nigrolineata. Statistical analyses revealed NUMT size to negatively correlate with NUMT's sequence similarity to with original mtDNA region. Lastly, characterizing these nuclear insertions of mitochondrial origin in a comparative genomics framework produced variable phylogenetic patterns, suggesting in some cases that insertions might pre-date speciation events within Strigiformes.
|
|
| 6. |
- Broggi, Juli, et al.
(author)
-
Individual response in body mass and basal metabolism to the risks of predation and starvation in passerines
- 2023
-
In: The Journal of experimental biology. - : The Company of Biologists. - 1477-9145 .- 0022-0949. ; 226:2
-
Journal article (peer-reviewed)abstract
- Wintering energy management in small passerines has focused on the adaptive regulation of the daily acquisition of energy reserves within a starvation-predation trade-off framework. However, the possibility that the energetic cost of living, i.e. basal metabolic rate (BMR), is being modulated as part of the management energy strategy has been largely neglected. Here, we addressed this possibility by experimentally exposing captive great tits (Parus major) during winter to two consecutive treatments of increased starvation and predation risk for each individual bird. Body mass and BMR were measured prior to and after each week-long treatment. We predicted that birds should be lighter but with a higher metabolic capacity (higher BMR) as a response to increased predation risk, and that birds should increase internal reserves while reducing their cost of living (lower BMR) when exposed to increased starvation risk. Wintering great tits kept a constant body mass independently of a week-long predation or starvation treatment. However, great tits reduced the cost of living (lower BMR) when exposed to the starvation treatment, while BMR remained unaffected by the predation treatment. Energy management in wintering small birds partly relies on BMR regulation, which challenges the current theoretical framework based on body mass regulation.
|
|
| 7. |
- Dijkstra, Esmee A., et al.
(author)
-
Locoregional Failure During and After Short-course Radiotherapy Followed by Chemotherapy and Surgery Compared With Long-course Chemoradiotherapy and Surgery
- 2023
-
In: Annals of Surgery. - : Lippincott Williams & Wilkins. - 0003-4932 .- 1528-1140. ; 278:4, s. E766-E772
-
Journal article (peer-reviewed)abstract
- Objective:To analyze risk and patterns of locoregional failure (LRF) in patients of the RAPIDO trial at 5 years.Background:Multimodality treatment improves local control in rectal cancer. Total neoadjuvant treatment (TNT) aims to improve systemic control while local control is maintained. At 3 years, LRF rate was comparable between TNT and chemoradiotherapy in the RAPIDO trial.Methods:A total of 920 patients were randomized between an experimental (EXP, short-course radiotherapy, chemotherapy, and surgery) and a standard-care group (STD, chemoradiotherapy, surgery, and optional postoperative chemotherapy). LRFs, including early LRF (no resection except for organ preservation/R2 resection) and locoregional recurrence (LRR) after an R0/R1 resection, were analyzed.Results:Totally, 460 EXP and 446 STD patients were eligible. At 5.6 years (median follow-up), LRF was detected in 54/460 (12%) and 36/446 (8%) patients in the EXP and STD groups, respectively (P=0.07), in which EXP patients were more often treated with 3-dimensional-conformed radiotherapy (P=0.029). In the EXP group, LRR was detected more often [44/431 (10%) vs. 26/428 (6%); P=0.027], with more often a breached mesorectum (9/44 (21%) vs. 1/26 (4); P=0.048). The EXP treatment, enlarged lateral lymph nodes, positive circumferential resection margin, tumor deposits, and node positivity at pathology were the significant predictors for developing LRR. Location of the LRRs was similar between groups. Overall survival after LRF was comparable [hazard ratio: 0.76 (95% CI, 0.46-1.26); P=0.29].Conclusions:The EXP treatment was associated with an increased risk of LRR, whereas the reduction in disease-related treatment failure and distant metastases remained after 5 years. Further refinement of the TNT in rectal cancer is mandated.
|
|
| 8. |
- Kjellberg Jensen, Johan, et al.
(author)
-
Quantifying the influence of urban biotic and abiotic environmental factors on great tit nestling physiology
- 2023
-
In: Science of the Total Environment. - : Elsevier B.V.. - 0048-9697 .- 1879-1026. ; 859
-
Journal article (peer-reviewed)abstract
- There is a long history of avian studies investigating the impacts of urbanization. While differences in several life-history traits have been documented, either between urban and rural populations or across generalized urbanization gradients, a detailed understanding of which specific environmental variables cause these phenotypic differences is still lacking. Here, we quantified several local environmental variables coupled to urbanization (air pollution, tree composition, ambient temperature, and artificial light at night [ALAN]) within territories of breeding great tits (Parus major). We linked the environmental variables to physiological measures of the nestlings (circulating fatty acid composition [FA], antioxidant capacity and an oxidative damage marker [malondialdehyde; MDA]), to garner a mechanistic understanding of the impact of urbanization. We found that the antioxidant capacity of nestlings decreased with higher numbers of oak trees and levels of PM2.5 (airborne particulate matter with a diameter < 2.5 μm). Furthermore, the ratio of ω6:ω3 polyunsaturated FAs, important for immune function, was positively correlated with PM2.5 concentration, while being negatively associated with ambient temperature and number of non-native trees in the territory. Body mass and wing length both increased with the number of local oak trees. We also show, through a principal component analysis, that while the environmental variables fall into an urbanization gradient, this gradient is insufficient to explain the observed physiological responses. Therefore, accounting for individual environmental variables in parallel, and thus allowing for interactions between these, is crucial to fully understand of the urban ecosystem. © 2022 The Authors
|
|
| 9. |
- Lamers, Koosje P., et al.
(author)
-
Adaptation to climate change through dispersal and inherited timing in an avian migrant
- 2023
-
In: Nature Ecology and Evolution. - 2397-334X. ; 7:11, s. 1869-1877
-
Journal article (peer-reviewed)abstract
- Many organisms fail to adjust their phenology sufficiently to climate change. Studies have concentrated on adaptive responses within localities, but little is known about how latitudinal dispersal enhances evolutionary potential. Rapid adaptation is expected if dispersers from lower latitudes have improved synchrony to northern conditions, thereby gain fitness and introduce genotypes on which selection acts. Here we provide experimental evidence that dispersal in an avian migrant enables rapid evolutionary adaptation. We translocated Dutch female pied flycatchers (Ficedula hypoleuca) and eggs to Sweden, where breeding phenology is ~15 days later. Translocated females bred earlier, and their fitness was 2.5 times higher than local Swedish flycatchers. We show that between-population variation in timing traits is highly heritable, and hence immigration of southern genotypes promotes the necessary evolutionary response. We conclude that studies on adaptation to large-scale environmental change should not just focus on plasticity and evolution based on standing genetic variation but should also include phenotype–habitat matching through dispersal as a viable route to adjust.
|
|
| 10. |
- Nagel, Johanna, et al.
(author)
-
Reduced risk of serious pneumococcal infections up to 10 years after a dose of pneumococcal conjugate vaccine in established arthritis.
- 2023
-
In: Vaccine. - : Elsevier BV. - 1873-2518 .- 0264-410X. ; 41:2, s. 504-510
-
Journal article (peer-reviewed)abstract
- Background: To examine rates of serious pneumococcal infections up to 10 years after vaccination with 7-valent conjugated pneumococcal vaccine (PCV7) in patients with arthritis compared to non-vaccinated arthritis patients.Methods: In total, 595 adult arthritis patients (rheumatoid arthritis; RA = 342, 80 % women and spondylarthropathy; SpA = 253, 45 % women) received one dose of PCV7. Mean age/disease duration were 62/16 and 51/14 years, respectively. For each patient, 4 matched reference subjects were identified. At vaccination, 420 patients received bDMARDs (anti-TNF = 330, tocilizumab = 15, abatacept = 18, anakinra = 1, rituximab = 56). Methotrexate was given as monotherapy (n = 86) or in combination with bDMARD (n = 220). 89 SpA patients received NSAIDs without DMARD. The Skåne Healthcare Register was searched for ICD-10 diagnostic codes for pneumococcal infections (pneumonia, lower respiratory tract infection, septicemia, meningitis, septic arthritis) between January 2000 and December 2018. Frequency of infections after vs before vaccination were calculated (relative risks). Relative risk ratio (RRR) and relative risk reduction (1-RRR) were calculated comparing patients vs non-vaccinated references. Kaplan-Meier and Cox regression were used to investigate time to first event and predictors of infections.Results: Among vaccinated RA and SpA patients, there was a significant relative risk reduction of pneumonia and all serious infections; 53% and 46%, respectively. There was no significant difference in time to first pneumonia or all serious infections after vaccination between patients and references. Higher age, RA diagnosis and concomitant prednisolone were associated with infections.Conclusion: One dose of pneumococcal conjugate vaccine may decrease risk of serious pneumococcal infection up to 10 years in patients with arthritis receiving immunomodulating treatment.
|
|
