Mechanizmy výběru partnera u hýla rudého Carpodacus erythrinus: test hypotézy dobrých a komplementárních genů

Master's esis, 2007 Michal Vinkler 3 I ABSTRACT Within the contemporary theory on the sexual selection there are two main competing hypotheses concerning the female indirect benefits arising from the mate choice. The 'Good genes' hypothesis assumes that the female tends to gain for her progeny some generally beneficial alleles through mating with an appropriate male. On the other hand the 'Complementary genes' hypothesis supposes that the mate choice is governed by the female effort to obtain for her offspring the most fitting parental haplotypes. This thesis aimed to provide evidence for discrimination between these two hypotheses in scarlet rosefinch. Three principal aspects of the sexual selection were concerned: (1) the reliability of male ornamentation as an indicator of individual's quality; (2) the associations between parental traits and offspring health indicators and (3) the effect of paternity on offspring heterozygosity and immune responsiveness in mixed- paternity broods. The results indicate that male ornamentation is a reliable signal of individual's health which may be used by females in their mate choice. The ornamentation does not reflect male's heterozygosity. Moreover, the social father's ornamental plumage hue and saturation are good predictors of nestlings'health and immune...Michal Vinkler 5 ABSTRAKT Mechanizmy výběru partnera u hýla rudého Carpodacus erythrinus: test hypotézy dobrých a komplementárních genů: Teorie pohlavního výběru v současné době poskytuje dvě zásadní hypotézy snažící se vysvětlit nepřímé výhody, které může samice volbou vhodného sexuálního partnera získat. Hypotéza "dobrých genů" předpokládá, že samice volí svého partnera na základě znaků indikujících přítomnost určitých, v danou dobu vhodných alel, které může samec svým potomkům předat. Hypotéza "komplementárních genů" naopak tvrdí, že si samice vybírá takového partnera, který nese genotyp co nejkomplementárnější k jejímu vlastnímu. Cílem této práce bylo nashromáždit u modelového druhu hýla rudého data, na jejichž základě by bylo možno rozhodnout mezi platnostmi obou hypotéz. Studovány byly tři hlavní aspekty pohlavního výběru: 1) spolehlivost samčího zbarvení jako indikátoru kvality samce; 2) vztahy mezi znaky rodičů a indikátory zdravotního stavu u jejich potomků; 3) vliv paternity na heterozygotnost a imunitní odpovídavost u mláďat ve hnízdech se smíšenou paternitou. Výsledky této studie ukazují, že samčí ornament představuje u tohoto druhu spolehlivý signál vypovídající o zdraví jeho nositele. Ornamentace není podmíněna celkovou heterozygotností jedince. Dále bylo zjištěno, že různé složky barvy...Department of ZoologyKatedra zoologieFaculty of SciencePřírodovědecká fakult

Understanding the evolution of immune genes in jawed vertebrates

Driven by co-evolution with pathogens, host immunity continuously adapts to optimize defence against pathogens within a given environment. Recent advances in genetics, genomics and transcriptomics have enabled a more detailed investigation into how immunogenetic variation shapes the diversity of immune responses seen across domestic and wild animal species. However, a deeper understanding of the diverse molecular mechanisms that shape immunity within and among species is still needed to gain insight into—and generate evolutionary hypotheses on—the ultimate drivers of immunological differences. Here, we discuss current advances in our understanding of molecular evolution underpinning jawed vertebrate immunity. First, we introduce the immunome concept, a framework for characterizing genes involved in immune defence from a comparative perspective, then we outline how immune genes of interest can be identified. Second, we focus on how different selection modes are observed acting across groups of immune genes and propose hypotheses to explain these differences. We then provide an overview of the approaches used so far to study the evolutionary heterogeneity of immune genes on macro and microevolutionary scales. Finally, we discuss some of the current evidence as to how specific pathogens affect the evolution of different groups of immune genes. This review results from the collective discussion on the current key challenges in evolutionary immunology conducted at the ESEB 2021 Online Satellite Symposium: Molecular evolution of the vertebrate immune system, from the lab to natural populations.Biotechnology and Biological Sciences Research CouncilGrant/Award Number: BB/K004468/1, BB/M011224/1, BB/ N023803/1 and BB/V000756/1Department for Environment, Food and Rural AffairsUK Government, Grant/ Award Number: OD0221Deutsche Forschungsgemeinschaft, Grant/ Award Number: 437857095Grantová Agentura České Republiky, Grant/Award Number: 19-20152YGrantová Agentura, Univerzita Karlova, Grant/Award Number: 646119H2020 European Research Council, Grant/Award Number: ERC-2019- StG- 853272- PALAEOFARMUniversity of Oxford, Grant/Award Number: 0005172; Ministerstvo Školství, Mládeže a TělovýchovyGrant/Award Number: SVV 260684/2023; Ministerstvo Zemědělství, Grant/Award Number: MZE-RO0723National Institutes of Health, Grant/Award Number: 1R01AI123659-01A1; Univerzita Karlova v PrazeGrant/Award Number: START/SCI/113 with reg. no. CZ.02.2.69/0.0/0.0/19_; Vetenskapsrådet, Grant/Award Number: 2020-0428

Trans-Species Polymorphism in Immune Genes: General Pattern or MHC-Restricted Phenomenon?

Immunity exhibits extraordinarily high levels of variation. Evolution of the immune system in response to host-pathogen interactions in particular ecological contexts appears to be frequently associated with diversifying selection increasing the genetic variability. Many studies have documented that immunologically relevant polymorphism observed today may be tens of millions years old and may predate the emergence of present species. This pattern can be explained by the concept of trans-species polymorphism (TSP) predicting the maintenance and sharing of favourable functionally important alleles of immune-related genes between species due to ongoing balancing selection. Despite the generality of this concept explaining the long-lasting adaptive variation inherited from ancestors, current research in TSP has vastly focused only on major histocompatibility complex (MHC). In this review we summarise the evidence available on TSP in human and animal immune genes to reveal that TSP is not a MHCspecific evolutionary pattern. Further research should clearly pay more attention to the investigation of TSP in innate immune genes and especially pattern recognition receptors which are promising candidates for this type of evolution. More effort should also be made to distinguish TSP from convergent evolution and adaptive introgression. Identification of balanced TSP variants may represent an accurate approach in evolutionary medicine to recognise disease-resistance alleles

Understanding the evolution of immune genes in jawed vertebrates

Driven by co-evolution with pathogens, host immunity continuously adapts to optimize defence against pathogens within a given environment. Recent advances in genetics, genomics and transcriptomics have enabled a more detailed investigation into how immunogenetic variation shapes the diversity of immune responses seen across domestic and wild animal species. However, a deeper understanding of the diverse molecular mechanisms that shape immunity within and among species is still needed to gain insight into-and generate evolutionary hypotheses on-the ultimate drivers of immunological differences. Here, we discuss current advances in our understanding of molecular evolution underpinning jawed vertebrate immunity. First, we introduce the immunome concept, a framework for characterizing genes involved in immune defence from a comparative perspective, then we outline how immune genes of interest can be identified. Second, we focus on how different selection modes are observed acting across groups of immune genes and propose hypotheses to explain these differences. We then provide an overview of the approaches used so far to study the evolutionary heterogeneity of immune genes on macro and microevolutionary scales. Finally, we discuss some of the current evidence as to how specific pathogens affect the evolution of different groups of immune genes. This review results from the collective discussion on the current key challenges in evolutionary immunology conducted at the ESEB 2021 Online Satellite Symposium: Molecular evolution of the vertebrate immune system, from the lab to natural populations

Toll-like receptor evolution in birds: gene duplication, pseudogenisation and diversifying selection

Toll-like receptors (TLRs) are key sensor molecules in vertebrates triggering initial phases of immune responses to pathogens. The avian TLR family typically consists of ten receptors, each adapted to distinct ligands. To understand the complex evolutionary history of each avian TLR, we analysed all members of the TLR family in the whole genome assemblies and target sequence data of 63 bird species covering all major avian clades. Our results indicate that gene duplication events most probably occurred in TLR1 before synapsids diversified from sauropsids. Unlike mammals, ssRNA-recognising TLR7 has duplicated independently in several avian taxa, while flagellin-sensing TLR5 has pseudogenised multiple times in bird phylogeny. Our analysis revealed stronger positive, diversifying selection acting in TLR5 and the three-domain TLRs (TLR10 [TLR1A], TLR1 [TLR1B], TLR2A, TLR2B, TLR4) that face the extracellular space and bind complex ligands than in single-domain TLR15 and endosomal TLRs (TLR3, TLR7, TLR21). In total, 84 out of 306 positively selected sites were predicted to harbour substitutions dramatically changing the amino acid physicochemical properties. Furthermore, 105 positively selected sites were located in the known functionally-relevant TLR regions. We found evidence for convergent evolution acting between birds and mammals at 54 of these sites. Our comparative study provides a comprehensive insight into the evolution of avian TLR genetic variability. Besides describing the history of avian TLR gene gain and gene loss, we also identified candidate positions in the receptors that have been likely shaped by direct molecular host-pathogen co-evolutionary interactions and most probably play key functional roles in birds

Mechanizmy výběru partnera u hýla rudého Carpodacus erythrinus: test hypotézy dobrých a komplementárních genů

Katedra zoologieDepartment of ZoologyPřírodovědecká fakultaFaculty of Scienc

Vliv stavu a funkce imunitního systému na pohlavní výběr u ptáků

Evolution is a most fascinating feature of all living things in our world. The means of organismal evolution are diverse, comprising mainly of natural and sexual selection. Both of these phenomena may contribute to evolutionary adaptations in health and disease. The questions of immunity impact on the process of sexual selection and sexual selection for increased anti-parasite resistance are wide issues of the present research in natural sciences. Their clarification requires multidisciplinarily-based investigation combining a variety of partial results into a single united paradigm. My co-workers and I have chosen several specific issues to study, in order to fill some of the important gaps of the current knowledge. We proposed the Carotenoid maintenance handicap hypothesis to point out that optimisation instead of maximisation of the carotenoid intake and ornamental display may be physiologically convenient for the individual. In Scarlet rosefinch (Carpodacus erythrinus) we confirmed the role of the carotenoid-based ornamental colouration in the process of sexual selection and investigated several partial aspects of the association between immunogenetics, immune function, health and the ornament expression and mate choice. In Zebra finch (Taeniopygia guttata) we have shown that the present way of..