Biology subjects

Fossen, E. I. F.

Publications and source records attributed to Fossen, E. I. F..

3 recordsLinked to original sources

bioRxiv2026

A systematic review and meta-analysis of risk factors for Leishmania infection in dogs in Europe

BackgroundIdentifying risk factors for Leishmania infection in dogs is essential for understanding disease epidemiology and informing control and targeted prevention. This systematic review and meta-analysis examined these risk factors across endemic and non-endemic regions of Europe. MethodsInclusion criteria included studies that quantified the association between Leishmania infection (both asymptomatic infection and canine leishmaniosis) and risk factors among European dogs. Non-peer reviewed grey literature and studies that focus only on prevention were excluded. The search included all records indexed in PubMed up to 17th March 2026. Risk of bias was assessed using the ROBINS-E tool. Random-effects multilevel models were used for meta-analysis, and sensitivity analyses were conducted to assess robustness. ResultsOf the 46 studies included, 94% were cross-sectional and 76% assessed seroprevalence. Studies were primarily conducted in Southern Europe (Spain 35%, Portugal 17%, Italy 17%, and Greece 11%). There was considerable evidence of an association between increasing age and infection (OR = 1.15 [95% CI: 1.10, 1.21] per year). Five additional factors showed some evidence of association: male sex (OR = 1.17 [1.01, 1.36]), higher body weight (OR = 1.06 [1.02, 1.09] per kg), outdoor housing (OR = 1.84 [1.26, 2.69]), outdoor sleeping (OR = 2.50 [1.52, 4.09]), and neuter status showing higher odds in neutered dogs (OR = 2.22 [1.37, 3.61]). Other potential risk factors, with weak or no clear evidence, included fur length, coat color, breed, utilization (e.g. pet or hunting), urbanicity, care setting, clinical signs, cohabitation, co-infection, sand fly density, land cover, home features, owner perception and knowledge of the disease, travel history and origin of dog, and area-level socioeconomic deprivation. Over 75% of analytical units were assessed as having a high risk of bias, with the remaining assessed as moderate risk. Inadequate handling of confounders was the primary source of bias risk. ConclusionsThe results highlight key risk factors to consider in future research and for improving prevention and disease control, with most identified factors likely acting as proxies of exposure to sand fly bites. Future studies should ensure adequate control for confounding, while causal inference would be strengthened by conducting longitudinal cohort studies.

zoology↗

bioRxiv2023

Evolution during uncorrelated environmental fluctuations: bet-hedging or phenotypic plasticity?

Evolution in fluctuating environments is predicted to disfavor specialization and instead select for alternative strategies, such as phenotypic plasticity or possibly bet-hedging, depending on the accuracy of environmental cues and type of fluctuations. While these two alternatives are often contrasted in theoretical studies, their evolution are seldom studied together in empirical work. We used experimental evolution in the nematode worm Caenorhabditis remanei to simultaneously study the evolution of plasticity and bet-hedging in environments differing only in their temperature variability. We exposed worms for 30 generations to either fluctuating or slowly increasing temperature, these two environments had the same average temperature over evolutionary time. After experimental evolution, we scored size at sexual maturity and fitness in full siblings reared in two different temperatures, optimal 20{degrees}C and mildly stressful 25{degrees}C. Experimental evolution in the fluctuating environment resulted in the evolution of increased body size plasticity but not increased bet-hedging, compared to evolution in the slowly changing environment. Plasticity followed the temperature size rule as size decreased with increasing temperature and this plastic response was adaptive. In addition, we documented substantial standing genetic variation in body size, which represents a potential for further evolutionary change.

evolutionary biology↗

bioRxiv2019

Do genetic differences in growth thermal reaction norms maintain genetic variation in timing of diapause induction?

O_LIAn optimal timing for diapause induction through the sexual production of dormant propagules is expected in populations of annual organisms. Yet, experimental work typically finds high within-population genetic variation in the sexual production of such propagules. Thus, high genetic variation in timing for diapause induction should be a common feature of annual organisms. C_LIO_LIHere, we hypothesize that genetic variation in the propensity to produce diapause propagules, Pd, is maintained by a genotype-by-environment interaction in growth performance, where fast-growing genotypes within an environment should delay diapause relative to slow-growing genotypes. From this, we derive two predictions. First, if there is ecological crossover in growth performance, the genetic correlation of Pd between environments should be negative. Second, the correlation between absolute plasticities of growth and Pd should be negative. C_LIO_LIWe tested these predictions by quantifying ephippia production in genotypes of a population of the facultative sexual cladoceran Daphnia magna at two temperatures. The population biomass at the onset of ephippia production was used as a measure of Pd, whereas somatic growth rate was used to quantify growth. Plasticity for both measurements was derived from thermal reaction norms. C_LIO_LIOur results did not support either prediction, as neither the genetic correlation of Pd between environments, nor the correlation between absolute plasticity of growth and Pd were found to be significant. C_LIO_LIOur results suggest that genetic variation in the timing of diapause is not maintained by genetic differences in thermal growth reaction norms. We propose as an alternative hypothesis that if there is across year variation in how stochastically the environment deteriorates, fluctuating selection may favor genotypes with different Pd between years. C_LI

evolutionary biology↗