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Association between louse abundance and MHC II supertypes in Galápagos mockingbirds
VLČEK, Jakub
In this thesis I describe association between abundance of ectoparasitic lice and supertypes of major histocompatibility complex in mockingbirds of Galápagos islands. I report a significant association between several supertypes and the lice abundance. Lice abundance was correlated also with heterocyte to lymphocyte ratio, an immunogenetic index reflecting rate of immune stress. This scientific contribution is valuable, because ectoparasite abundance in birds was rarely contrasted to MHC and other immune indices.
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Conservation genetics of Galápagos mockingbirds: from immune genes to genomes
VLČEK, Jakub
In this thesis I have dealt with the population genetic processes of mockingbirds in the Galápagos Islands ( Mimus ) in relation to the limited island area, from the perspective of two types of immune genes and the genome-wide approach. The thesis starts with an introduction to population genetic concepts relevant to conservation genetics followed by description of immune genes: the major histocompatibility complex (MHC) and the Toll-like receptors (TLR). In the final part of the introduction, I address how genetic drift, selection and inbreeding shape genome-wide genetic patterns in small populations. The introduction is followed by four chapters, beginning with an examination of MHCII polymorphism in populations of mockingbirds in the Galápagos Islands. The study of the relationship between MHCII and the abundance of ectoparasites is the content of the second chapter. The third chapter shows how polymorphism of TLRs is shaped by interaction of genetic drift and natural selection. The last chapter deals with the effects of limited island size on inbreeding and genetic load, supported by inferences of the past demography of mockingbirds. The thesis concludes with a summary of the results and their potential implications in the field of conservation genetics.
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Perception of individual variation in body odour in human adults
Fialová, Jitka ; Havlíček, Jan (advisor) ; Schaal, Benoist (referee) ; Stopka, Pavel (referee)
The thesis consists of two parts. The first part introduces the topic of human chemical communication and reviews current evidence on individual variation in human body odour and its perception. This part is framed by sexual selection theory. In the first chapter, the concept of the theory of communication is introduced followed by a discussion on the specifics of chemical communication. Next, the formation of individually specific body odour signatures with reference to skin glands, their volatile products and the subsequent metabolization by skin microflora is described. The next chapters are dedicated to selected interindividual body odour cues such as sex and kin recognition, genetic compatibility in genes of Major Histocompatibility Complex, and health and reproductive status in a mate choice context. Furthermore, interactions between perfumes and body odours are discussed. Finally, methods of body odour sampling are introduced and a rationale behind presenting individual samples or body odour blends is discussed. The second part is comprised of six scientific papers, specifically three reviews and three empirical studies. Review papers summarize factors affecting human body odour quality with emphasis on diet and affective states. The first text shows that human body odours contain cues to...
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Changes in preferences for heterozygosity in MHC genes across the menstrual cycle
Ptáčková, Kateřina ; Havlíček, Jan (advisor) ; Janotová, Kateřina (referee)
5 Abstract Products of major histocompatibility complex (MHC) plays key role in immune system of vertebrates. Prior studies on different vertebrate species show, that heterozygosity in MHC genes is linked to more efficient immune system and preferred in mate choice. Results of human studies are ambivalent, which can be due to the effect of some modulating factors like reproductive status. Therefore, our aim was to test heterozygosity related preferences in faces, odor and voice across menstrual cycle. Our sample consisted of 51 men and 52 women, from which 23 used hormonal contraception and 29 had natural cycle. They were genotyped in -A, -B and -DR alleles. All odor stimuli, face photos and voice records were rated on seven-point scale in both follicular and luteal phase. Repeated measures ANOVA was used for the analysis. Changes in ratings across the menstrual cycle and heterozygosity were most discernible on voice ratings. Voices of homozygous males were rated more attractive than voices of heterozygous males especially in follicular phase. Similar shift to higher ratings in follicular phase was manifested in ratings of homozygous male faces, but the difference between homozygous males and heterozygous males was not significant. Women with natural cycle also rated voices higher in their follicular phase...
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Perception of individual variation in body odour in human adults
Fialová, Jitka ; Havlíček, Jan (advisor) ; Schaal, Benoist (referee) ; Stopka, Pavel (referee)
The thesis consists of two parts. The first part introduces the topic of human chemical communication and reviews current evidence on individual variation in human body odour and its perception. This part is framed by sexual selection theory. In the first chapter, the concept of the theory of communication is introduced followed by a discussion on the specifics of chemical communication. Next, the formation of individually specific body odour signatures with reference to skin glands, their volatile products and the subsequent metabolization by skin microflora is described. The next chapters are dedicated to selected interindividual body odour cues such as sex and kin recognition, genetic compatibility in genes of Major Histocompatibility Complex, and health and reproductive status in a mate choice context. Furthermore, interactions between perfumes and body odours are discussed. Finally, methods of body odour sampling are introduced and a rationale behind presenting individual samples or body odour blends is discussed. The second part is comprised of six scientific papers, specifically three reviews and three empirical studies. Review papers summarize factors affecting human body odour quality with emphasis on diet and affective states. The first text shows that human body odours contain cues to...
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Vztah atraktivity a MHC: Role menstruačního cyklu a partnerského statusu.
Vávrová, Kateřina ; Havlíček, Jan (advisor) ; Flegr, Jaroslav (referee)
Extremely polymorphic genes of major histocompatibility complex (MHC) play a significant role in the function of immune system by recognizing heterogeneous particles, mainly pathogenic origin. Previous research on various vertebrate species indicates that MHC influences individual body odour and mate choice preferences. Many individuals tend to prefer MHC dissimilar partner so that warrants them an offspring resistant against wider spectrum of infections. Research on MHC-related mate preferences in humans, however, is inconclusive to date. Several studies indicate that women not taking hormonal contraceptives prefer the smell of MHC dissimilar partners while other studies have not come to this conclusion. This can be caused by the absence of potentially influencing factors like the menstrual cycle phase. The aim of this study was to test MHC-similarity mate choice preferences in odour, facial and vocal modalities. In particular, we focused on a potential effect of hormonal contraception. Furtermore, we tested preferential shifts across the menstrual cycle by comparing women's preferences in the follicular and the luteal phase in pill and non-pill users. A group of 52 women in different phases of their menstrual cycle rated odour samples, photos and vocal recordings taken from 51 men. All...
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Changes in preferences for heterozygosity in MHC genes across the menstrual cycle
Ptáčková, Kateřina ; Havlíček, Jan (advisor) ; Janotová, Kateřina (referee)
5 Abstract Products of major histocompatibility complex (MHC) plays key role in immune system of vertebrates. Prior studies on different vertebrate species show, that heterozygosity in MHC genes is linked to more efficient immune system and preferred in mate choice. Results of human studies are ambivalent, which can be due to the effect of some modulating factors like reproductive status. Therefore, our aim was to test heterozygosity related preferences in faces, odor and voice across menstrual cycle. Our sample consisted of 51 men and 52 women, from which 23 used hormonal contraception and 29 had natural cycle. They were genotyped in -A, -B and -DR alleles. All odor stimuli, face photos and voice records were rated on seven-point scale in both follicular and luteal phase. Repeated measures ANOVA was used for the analysis. Changes in ratings across the menstrual cycle and heterozygosity were most discernible on voice ratings. Voices of homozygous males were rated more attractive than voices of heterozygous males especially in follicular phase. Similar shift to higher ratings in follicular phase was manifested in ratings of homozygous male faces, but the difference between homozygous males and heterozygous males was not significant. Women with natural cycle also rated voices higher in their follicular phase...
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