抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

So far in this course we have dealt entirely with the evolution of characters that are controlled by simple Mendelian inheritance at a single locus. There are notes on the course website about gametic disequilibrium and how allele frequencies change at two loci simultaneously, but we didn’t discuss them. In every example we’ve considered we’ve imagined that we could understand something about evolution by examining the evolution of a single gene. That’s the domain of classical population genetics. For the next few weeks we’re going to be exploring a field that’s actually older than classical population genetics, although the approach we’ll be taking to it involves the use of population genetic machinery. If you know a little about the history of evolutionary biology, you may know that after the rediscovery of Mendel’s work in 1900 there was a heated debate between the “biometricians” (e.g., Galton and Pearson) and the “Mendelians” (e.g., de Vries, Correns, Bateson, and Morgan). Biometricians asserted that the really important variation in evolution didn’t follow Mendelian rules. Height, weight, skin color, and similar traits seemed to

Human biochemical genetics

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Modern Applied Statistics With S

1. Introduction and Overview. 2. Detecting Influential Observations and Outliers. 3. Detecting and Assessing Collinearity. 4. Applications and Remedies. 5. Research Issues and Directions for Extensions. Bibliography. Author Index. Subject Index.

Regression Diagnostics: Identifying Influential Data and Sources of Collinearity

Male bed bugs pierce females through the body wall and inseminate directly into the body cavity. It has previously been shown that such traumatic insemination carries costs for females, and sexual conflict regarding the mode of insemination should thus propel male-female coevolution. Since males accumulate sexually antagonistic adaptations, females should evolve counter-adaptations that efficiently abate the costs to females of sexual interactions. Yet, unambiguous experimental evidence for female counter-adaptations is lacking. In bed bugs, the spermalege (a highly modified region of the abdomen where the male usually pierces the female) may represent a female counter-adaptation. We assess the female costs of traumatic insemination by varying the rate of insemination on the one hand, and the rate and mode of piercing trauma to females on the other. Our results show that female mating costs are not extreme-elevated mating rate shortened female lifespan but had no significant effect on lifetime egg production. More importantly, additional abdominal piercing in the spermalege had no effect on females whereas even a very low rate of such piercing outside the spermalege reduced female lifetime egg production by 50%. Thus, females are well counter-adapted to the intrusive mode of insemination exhibited by male bed bugs and the costs of elevated mating are comparable with those in other insects, as predicted by theory. We therefore demonstrate that the spermalege efficiently reduces the direct costs of piercing trauma to females, and hence provide experimental evidence for a female counter-adaptation to a sexually antagonistic male trait.

Costly traumatic insemination and a female counter-adaptation in bed bugs

Animal mitogenomes are generally thought of as being economic and optimized for rapid replication and transcription. We use long-read sequencing technology to assemble the remarkable mitogenomes of ...

The Evolution of Dark Matter in the Mitogenome of Seed Beetles

Extreme cost of male riding behaviour for juvenile females of the Zeus bug

Theory predicts that the ability of selection and recombination to purge mutation load is enhanced if selection against deleterious genetic variants operates more strongly in males than females. However, direct empirical support for this tenet is limited, in part because traditional quantitative genetic approaches allow dominance and intermediate-frequency polymorphisms to obscure the effects of the many rare and partially recessive deleterious alleles that make up the main part of a population's mutation load. Here, we exposed the partially recessive genetic load of a population of Callosobruchus maculatus seed beetles via successive generations of inbreeding, and quantified its effects by measuring heterosis-the increase in fitness experienced when masking the effects of deleterious alleles by heterozygosity-in a fully factorial sex-specific diallel cross among 16 inbred strains. Competitive lifetime reproductive success (i.e., fitness) was measured in male and female outcrossed F1s as well as inbred parental "selfs," and we estimated the 4 × 4 male-female inbred-outbred genetic covariance matrix for fitness using Bayesian Markov chain Monte Carlo simulations of a custom-made general linear mixed effects model. We found that heterosis estimated independently in males and females was highly genetically correlated among strains, and that heterosis was strongly negatively genetically correlated to outbred male, but not female, fitness. This suggests that genetic variation for fitness in males, but not in females, reflects the amount of (partially) recessive deleterious alleles segregating at mutation-selection balance in this population. The population's mutation load therefore has greater potential to be purged via selection in males. These findings contribute to our understanding of the prevalence of sexual reproduction in nature and the maintenance of genetic variation in fitness-related traits.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/evl3.239

Selection in males purges the mutation load on female fitness.

Female remating behaviour is a key mating system parameter that is predicted to evolve according to the net effect of remating on female fitness. In many taxa, females commonly resist male remating attempts because of the costs of mating. Here, we use replicated populations of the seed beetle Acanthoscelides obtectus selected for either early or late life reproduction and show that ‘Early’ and ‘Late’ females evolved different age-specific rates of remating. Early females were more likely to remate with control males as they aged, while Late females were more resistant to remating later in life. Thus, female remating rate decreases with age when direct selection on late-life fitness is operating and increases when such selection is relaxed. Our findings not only demonstrate that female resistance to remating can evolve rapidly, but also that such evolution is in accordance with the genetic interests of females.

/pdf/ageing-and-the-evolution-of-female-resistance-to-remating-in-124vloxw5d.pdf

Göran Arnqvist

Papers

Costly traumatic insemination and a female counter-adaptation in bed bugs

The Evolution of Dark Matter in the Mitogenome of Seed Beetles

Extreme cost of male riding behaviour for juvenile females of the Zeus bug

Selection in males purges the mutation load on female fitness.

Ageing and the evolution of female resistance to remating in seed beetles