For example, chronic self-propagating inflammation may contribute to the inflammation now widely considered to be one of the causes of senescence (Franceschi et al. For example, in the mammalian gut, Firmicutes produce short-chain fatty acids (SCFAs) that generally prevent inflammation, while Bacteroidetes have more pro-inflammatory effects (Skillington et al. 2021). In young and healthy humans, there is a balance in the abundance of the major bacterial phyla, but this may shift led to a higher proportion of Bacteroidetes to Firmicutes in older people, leading to a pro-inflammatory state (Claesson et al. 2011; Skillington et al. 2021).
This is in line with the idea of the One Health concept, which assumes that human health is closely linked to animal health and the state of the entire ecosystem (Prata et al. 2022). Despite the great diversity and ecological importance of birds (Oliveros et al. 2019), the study of GM in birds has lagged far behind that of mammals (Sun et al. 2022). Furthermore, avian gastrointestinal tract (GIT) has undergone several physiological and anatomical adaptations given active flight (Caviedes-Vidal et al. 2007; Mcwhorter, Caviedes-Vidal and Karasov 2009).
The proportion of the main bacterial species in birds also differs significantly from that in mammals (Hird et al. 2015; Grond et al. 2018). Third, I investigated physiological aging and inflammation in the great tit (Parus major), a model sparrow bird for eco-evolutionary research. To investigate whether plasma testosterone levels change with age and whether testosterone levels affect various traits associated with large tit condition (contribution XIII).
Both melanin and carotenoid-based plumage decorations are condition-dependent traits that also serve as fair signals in sexual selection in birds (e.g., Albrecht et al. 2009; Svobodová et al. 2013; Guindre-Parker and Love 2014), including the great tit.
Results and discussion
Akinyemi et al. 2020), which revealed a rather diverse microbiota in egg contents and embryo gut, but largely neglected potential environmental contaminants, our results showed only negligible microbial communities in great tit egg contents and embryo gut samples. But how to find a needle in a haystack among thousands of immune genes. Tit TLR variability was of a similar order to other avian and rodent TLR studies (Alcaide and Edwards 2011; Fornůsková et al.
Following this paper, since most TLR research in non-model bird species has focused on populations with bottlenecks and depleted genetic variation (e.g. Grueber et al. 2013; Gonzalez-Quevedo et al. 2015; Vlček et al. 2022), in paper IX we investigated intra- and interspecific variation in three TLR genes (TLR1A, TLR3, T LR4) in eleven species of terns. doves and finches with large effective population sizes. In Paper XII, we also demonstrated gene loss of cannabinoid receptor 2 (CNR2), an important neuroimmune regulator, due to chromosomal rearrangements in parrots.
According to our predictions, we revealed that the experimentally induced peripheral inflammation propagated to the brain in the parrots, but not in the zebra finch. All this suggests that CNR2 gene loss could explain why parrots are more susceptible to neuroimmune diseases (Rinder et al. 2009; Staeheli, Rinder, and Kaspers 2010) and infection-induced behavioral disorders (Rubinstein and Lightfoot 2012; Speer 2014). Until recently, senescence in molecular physiological properties was poorly documented in longitudinal studies of free-living birds (see reviews by Stier et al.
In paper XIII, we assessed inter-annual stability and age-related changes in plasma testosterone levels in 49 repeatedly captured big tits. Since testosterone regulates multiple condition-related traits, including ornamental expression (Duckworth, Mendonça, and Hill 2004; Galván, Díaz, and Sanz 2010; Vinkler and Albrecht 2010) and generally has an immunosuppressive effect (Foo et al. 2017), we also tested for its yellow breast in sexually selected stripes and yellow breast and sexually selected stripes. 6; In paper XIV, we compared lifelong patterns of different pro-inflammatory properties: (i) chronic inflammation measured as leukotriene B4 levels (LTB4) and (ii) acute inflammation measured as cellular oxidative burst after in vitro LPS challenge in 54 repeatedly captured large tits.
LTB4 is a pro-inflammatory lipid regulator that is elevated in various age-related chronic inflammatory diseases in humans (He et al. 2020). While we found that LTB4 levels also increased linearly with age in large chicks, this provides the first evidence that chicks can suffer from inflammation like humans (Franceschi et al. In contrast to previous studies (Bauerová et al. 2017), there was no association between heavy metals and anemia-like conditions.
Conclusion
In paper XV we evaluated the longitudinal accumulation of four heavy metals (Zn, Pb, Cd, As) in blood and their possible effects on health-related hematological traits in 185 recaptured large tits. Contrary to our predictions, we found weak age-related changes in blood only for Pb with the highest levels occurring in infants and older elderly individuals and not for other heavy metals. However, we found that TWBC were positively correlated with all three levels of heavy metals assessed, suggesting that their toxicity may increase leukocyte proliferation (Dumonceaux and Harrison 1994; Jones 2015).
Our results show that bird blood can be used for actual monitoring of heavy metals, even if the age is unknown. The conceptual framework developed for immune gene categorization (paper VII), together with our newly described state-of-the-art methodological pipeline that identifies putative functional variation based on adaptive convergence (paper VIII), can be applied to systematically search for functional SNVs in antiparasitic resistance in immune genes across much better MHC genomes. Indeed, our review of innate immunity TLRs (letters VIII - IX) and RLRs (letters X - XI) in mice revealed that they are highly variable, subject to positive selection, and that many SNVs appear to be functionally important for pathogen recognition but still await functional verification by in vitro mutagenesis.
The surprising losses of several MDA5 and RIG-I genes in different clades of birds opened the way for a functional understanding of such an event. Our reported pseudogenization of CNR2 in parrots (contribution XII) could explain why parrots are more susceptible to various psychological and neuroimmune disorders triggered by inflammation. And more importantly, given the advanced cognitive abilities of parrots, this could suggest that captive parrots could serve as a promising biomedical model for studying various behavioral syndromes associated with inflammation.
Using a longitudinally monitored population of free-living big tit, we have provided strong evidence for physiological aging and immunosenescence in multiple traits (papers XIII - XV and Tesicky et. al., in preparation). In contrast, male testosterone and cellular oxidative burst levels were polynomially dependent on age, corresponding to hormonal senescence and immunosenescence. All of this suggests that small passerine birds seem to age like humans and laboratory mammals, despite numerous adaptations for longevity.
While the observed aging in some traits may be a passive consequence of physiological decline without functional limitations, its decline in other traits may be driven by excessive costs to maintain them, followed by active diversion from energetically expensive traits (Letters 2018; Gaillard and Lemaître 2020).
Li, T., Těšický, M., Melepat, B., Divín, D., Veetil, N.K., Vinkler, M.: Adaptive evolution of inflammasom-related genes in amniotic vertebrates. Hraníček, J., Kreisinger, J., Vinkler, M.: Poháněči střevní mikrobioty u divočáků: zdravotní účinky a kontaminace těžkými kovy. Divín, D., Goméz Samblas, M., Kuttiyarthu Veetil, N., Voukali, E., Swiderska, Z., Krajzingrová, K., Těšický, M., Beneš, M., Elleder, D., Vinkler, M.: Inflammation loss of papouščí geny.
Těšický, M., Velová, H., Novotný, M., Kreisinger, J., Beneš, V., Vinkler, M.: Detekce adaptivní konvergence v imunitních genech: lekce z Toll-like receptorů v prsech. Bauerová, P., Krajzingrová, T., Těšický, M., Velová, H., Hraníček, J., Musil, S., Svobodová, J., Albrecht, T., Vinkler, M.: Bioakumulace těžkých kovů v krvi a její účinky na parametry zdravotního stavu u dlouhodobě sledované městské populace vačnatců, 2 dny ZochPa. Těšický, M., Tomášek, O., Krajzingrová, T., Velová, H., Svobodová, J., Bauerová, P., Pinkasová, H., Albrecht, T., Vinkler, M.: Vliv stárnutí na imunitu, antioxidační enzymy a markery oxidativního stresu u velkých prsou (Parus).
Těšický M., Tomášek, O., Syslová, K., Krajzingrová, T., Velová, H., Svobodová, J., Bauerová, P., Pinkasová, H., Albrecht, T., Vinkler, M.: Fyziologické aspekty stárnutí v Rusku). Těšický, M., Velová, H., Novotný, M., Kreisinger, J., Vinkler, M.: Pozitivní selekce a konvergentní evoluce tvarují molekulární fenotypové rysy vrozených imunitních receptorů u koček (Paridae). Kubovčiak, J., Kropáčková, L., Albrecht, T., Těšický, M., Martin, J.F., Kreisinger, J.: Analýza holobiontních asociací mezi hostitelem a střevní mikrobiotou v přechodných procesech.
Těšický, M., Velová, H., Svobodová, J., Bauerová, P., Krajzingrová, T., Tomášek, O., Pechmanová, H., Albrecht, T., Vinkler, M.: Biologie stárnutí a imunosenescence u sýkor koňadry (Parus major). Kubovčiak, J., Kropáčková, L., Albrecht, T., Těšický, M., Martin, JF, Kreisinger, J.: Analýza predikcí konceptu holobionta ve vztahu mikrobiota-hostitel u pěvců. Těšický, M., Velová, H., Reifová, R., Vinkler, M.: Different species yet the same alleles: shared polymorphism in innate imunitní receptors in the tit family.
Kubovčiak, J., Kropáčková, L., Albrecht, T., Těšický, M., Martin, J.F., Kreisinger, J.: Interspecifická variace gastrointestinální mikrobioty u pěvců na úrovni bakteriálních genů. Těšický, M., Vinkler, M., Reifová, R., Velová, H.: Sdílená variabilita vybraných receptorů vrozené imunity u sýkorek (Paridae), The Zoological days, Brno, Česká republika 2017 (přednáška; česky) 9. Kubovčiak, J., Lěšický, M.š. -F., Kreisinger, J.: Hostitelská fylogeneze vysvětluje variace střevního mikrobiomu u volně žijících pěvců.
