This study describes a compact method for determining joint probabilities of identity-by-state (IBS) within and between loci in populations evolving under genetic drift, crossing-over, mutation, and regular inbreeding (partial self-fertilization). Analogues of classical indices of associations among loci arise as functions of these joint identities. This coalescence-based analysis indicates that multi-locus associations reflect simultaneous coalescence events across loci. Measures of association depend on genetic diversity rather than allelic frequencies, as do linkage disequilibrium and its relatives. Scaled indices designed to show monotonic dependence on rates of crossing-over, inbreeding, and mutation may prove useful for interpreting patterns of genome-scale variation.

The ability to self-fertilize often varies among closely related hermaphroditic plant species, though, variation can also exist within species. In the North American Arabidopsis lyrata, the shift from self-incompatibility (SI) to selfing established in multiple regions independently, mostly since recent postglacial range expansion. This has made the species an ideal model for the investigation of the genomic underpinnings of the breakdown of SI and its population genetic consequences. By comparing nearby selfing and outcrossing populations across the entire species\' geographic distribution, we investigated variation at the self-incompatibility (S-)locus and across the genome. Furthermore, a diallel crossing experiment on one mixed-mating population was performed to gain insight in the genetics of mating system variation. We confirmed that the breakdown of SI had evolved in several S-locus backgrounds. The diallel suggested the involvement of binuclearly expressed parental genes with dominance relations. Though, the population-level genome-wide association study did not single out clear-cut candidate genes but several regions with one near the S-locus. On the implication side, selfing as compared to outcrossing populations had less than half of the genomic diversity, while the number of runs of homozygosity and their length scaled with the degree of inbreeding. The results highlight that mating system shifts to selfing, its genetic underpinning and the likely negative genomic consequences for evolutionary potential can be strongly interlinked with past range dynamics.

Mating systems, influenced by the social and ecological environment and individual attributes, are fundamental components of animal social organisation, impacting behaviour, animal distribution, ecosystem processes, individual reproductive success, and population dynamics. Bats are of particular interest for studies of mating systems as they are thought to exhibit a greater diversity in mating systems than any other mammalian order, and thus make great models for improving our fundamental understanding of causes and consequences of social organisation. Here, we review the current knowledge of bat mating systems. Our analyses show that research on bat mating systems has not kept pace with research on bats in general and that traditional typologies do not accommodate the mating system of several species. Therefore, we propose an alternative, functional framework to categorise mating systems of bats and by extension of other taxa. We argue that mating systems can be classified according to a male reproductive skew continuum, with an increasing skew from monogamy to true lekking. We include an additional category of lek-like mating system along the continuum to account for previous trans-categorical cases that have the appearance of resource defence but are functionally akin to a lek. The new framework has a total of seven categories: promiscuity, monogamy, female defence polygyny, resource defence polygyny, a lek-like mating system, exploded classical lek, and clustered classical lek. Applying this framework to bats reveals that lek mating systems are more prevalent in bats than previously recognised. It is our aim that this review and the proposed framework provide a greater understanding of bat mating systems particularly and provoke research into the factors that shape mating systems across animal taxa more generally.

Self-fertile Caenorhabditis nematodes carry a surprising number of Medea elements, alleles that act in heterozygous mothers and cause death or developmental delay in offspring that don\'t inherit them. At some loci, both alleles in a cross operate as independent Medeas, affecting all the homozygous progeny of a selfing heterozygote. The genomic coincidence of Medea elements and ancient, deeply coalescing haplotypes, which pepper the otherwise homogeneous genomes of these animals, raises questions about how these apparent gene-drive elements persist for long periods of time. Here I investigate how mating system affects the evolution of Medeas, and their paternal-effect counterparts, peels. Despite an intuition that antagonistic alleles should induce balancing selection by killing homozygotes, models show that, under partial selfing, antagonistic elements experience positive frequency dependence: the common allele drives the rare one extinct, even if the rare one is more penetrant. Analytical results for the threshold frequency required for one allele to invade a population show that a very weakly penetrant allele, one whose effects would escape laboratory detection, could nevertheless prevent a much more penetrant allele from invading under high rates of selfing. Ubiquitous weak antagonistic Medeas and peels could then act as localized barriers to gene flow between populations, generating genomic islands of deep coalescence. Analysis of gene expression data, however, suggest that this cannot be the whole story. A complementary explanation is that ordinary ecological balancing selection generates ancient haplotypes on which Medeas can evolve, while high homozygosity in these selfers minimizes the role of gene drive in their evolution.

Inbreeding depression (ID) is a major selective force during mating system evolution primarily contributed by highly to partially recessive deleterious mutations. Theories suggest that transient genetic association with fitness alleles can be important in affecting the evolution of alleles that modify the selfing rate during its sweep. Nevertheless, empirical tests often focus on the pre-existing genetic association between selfing rate and ID maintained under mutation-selection balance. Therefore, how this standing genetic association is affected by key factors and its impacts on the evolution of selfing remain unclear. I show that as the selection coefficient of deleterious mutations increases, the association between selfing rate and ID declines from positive to negative. These results predict that association between selfing and ID tends to be negative in populations with low selfing rates, while positive in highly selfing populations. Using population genetic and quantitative genetic models, I show that standing genetic associations between selfing rate and fitness alleles can significantly impact the evolution of the mean selfing rate of a population. I present better metrics of population-level ID, which can be calculated based on the correlation coefficient between individual selfing rate and the fitness of selfed and outcrossed offspring.

OBJECTIVE: Evolution of cross-pollination efficiency depends on the genetic variation of flower traits, the pollen vector, and flower trait matching between pollen donors and recipients. Trait matching has been almost unexplored among nonheterostylous species, and we examined whether the match of anther length in pollen donors and stigma length in pollen recipients influences the efficiency of cross-pollination. To explore potential constraints for evolutionary response, we also quantified genetic variation and covariation among sepal length, petal length and width, stamen length, style length, and herkogamy.
METHODS: We created 58 experimental arrays of Turnera velutina that varied in the extent of mismatch in the position of anthers and stigmas between single-flowered plants. Genetic variation and correlations among flower traits were estimated under greenhouse conditions.
RESULTS: Style length, but not herkogamy, influenced the efficiency of cross-pollination. Plants with stamen length that matched the style length of other plants were more efficient pollen donors, whereas those with the style protruding above the stamens of other plants were more efficient pollen recipients. Significant broad-sense heritability (0.22 > hB 2 < 0.42) and moderate genetic correlations (0.33 > r < 0.85) among floral traits were detected.
CONCLUSIONS: Our results demonstrated that anther-stigma mismatch between flowers contributed to variation in the efficiency of cross-pollination. The genetic correlations between stamen length and other floral traits suggests that any change in cross-pollination efficiency would be driven by changes in style rather than in stamen length.

The neurohormones oxytocin (OT) and arginine vasopressin (AVP) are involved in social behaviors and psychiatric conditions. However, more research on nonhuman primates with complex social behaviors is needed. We studied two closely-related primate species with divergent social and mating systems; hamadryas baboons (Papio hamadryas, n=38 individuals) and anubis baboons (Papio anubis, n=46). We measured OT in cerebrospinal fluid (CSF, n=75), plasma (n=81) and urine (n=77), and AVP in CSF (n=45), and we collected over 250 hours of focal behavioral observations. Using Bayesian multivariate models, we found no clear species difference in hormone levels; the strongest support was for hamadryas having higher CSF OT levels than anubis (posterior probability [PP] for females = 0.75, males = 0.84). Looking at nine specific behaviors, OT was associated with affiliative behaviors (approach, proximity, grooming, PP ∼ 0.85 - 1.00), albeit inconsistently across sources of measurement (CSF, plasma, and urine, which were uncorrelated with each other). Most behaviors had low repeatability (R ∼ 0 - 0.2), i.e. they did not exhibit stable between-individual differences (or \"personality\"), and different behaviors did not neatly coalesce into higher-order factors (or \"behavioral syndromes\"), which cautions against the use of aggregate behavioral measures and highlights the need to establish stable behavioral profiles when testing associations with baseline hormone levels. In sum, we found some associations between peptides and social behavior, but also many null results, OT levels from different sources were uncorrelated, and our behavioral measures did not indicate clear individual differences in sociability.

More than 80% of the world\'s populations are at risk of vector-borne diseases, with mosquito-borne diseases as a significant global public health problem. Mosquito populations control is critical to interrupting the transmission of mosquito-borne diseases. This review summarizes the physical attributes, smell, vision, touch, and hearing of mosquitoes to unravel the preferences of female mosquitoes, and describes the mechanisms underlying the best male mating by female mosquitoes, so as to provide new insights into management of mosquito-borne diseases.
［摘要］ 全球80%以上的人口面临病媒传播疾病风险, 其中蚊媒传染病是全球核心公共卫生问题之一。阻止蚊媒传染 病传播的关键是控制蚊虫。本文从蚊虫体型、嗅觉、视觉、触觉和听觉等方面阐述雌蚊的择偶偏好, 探究雌蚊选择最佳雄配的机制, 为蚊媒传染病的控制提供新思路。.

Studies of reproductive biology and resources availability to floral visitors by plant species are important to understand the plant-pollinator interactions that drive species adaptation. We aim to understand the relationship between reproduction mechanisms of Deuterocohnia meziana (Bromeliaceae) and pollinators. The species occurs in Bolivia and Paraguay, and it is the only species of the genus found in Brazil, where it is restricted to ironstone outcrops. These areas are currently threatened by the iron mining industry. Additionally, they face risks from fire occurrence and grazing by cattle. We analyzed the floral biology, reproductive system, phenology, and pollination ecology of a natural population of Deuterocohnia meziana, from ironstone outcrops in Brazil. The species exhibits diurnal anthesis, with stigma receptive throughout anthesis, and 77% of pollen viability. Deuterocohnia meziana produces relatively large amounts of nectar, especially early in the morning (32.8 ± 9.4 μl), with a mean sugar concentration of 23.5 (± 3.2) ºBrix. It is self-incompatible with a peak flowering occurring in August (dry season), although flowers are observed continuously throughout the year. The species exhibits two types of inflorescences, young and mature, among which an average of 13.1 and 3.6 flowers open per day, respectively. Hummingbirds and bees are the effective pollinators, although butterflies and ants also visit D. meziana flowers. The species is reliant on exogenous pollen and pollinators for fruit set. The continuous conservation of D. meziana populations and their communities is essential for preserving plant-pollinator mutualism and the floral community adapted to ironstone outcrops.

Runs of homozygosity (ROHs) are indicative of elevated homozygosity and inbreeding due to mating of closely related individuals. Self-fertilization can be a major source of inbreeding which elevates genome-wide homozygosity and thus should also create long ROHs. While ROHs are frequently used to understand inbreeding in the context of conservation and selective breeding, as well as for consanguinity of populations and their demographic history, it remains unclear how ROH characteristics are altered by selfing and if this confounds expected signatures of inbreeding due to demographic change. Using simulations, we study the impact of the mode of reproduction and demographic history on ROHs. We apply random forests to identify unique characteristics of ROHs, indicative of different sources of inbreeding. We pinpoint distinct features of ROHs that can be used to better characterize the type of inbreeding the population was subjected to and to predict outcrossing rates and complex demographic histories. Using additional simulations and four empirical datasets, two from highly selfing species and two from mixed-maters, we predict the selfing rate and validate our estimations. We find that self-fertilization rates are successfully identified even with complex demography. Population genetic summary statistics improve algorithm accuracy particularly in the presence of additional inbreeding, e.g. from population bottlenecks. Our findings highlight the importance of ROHs in disentangling confounding factors related to various sources of inbreeding and demonstrate situations where such sources cannot be differentiated. Additionally, our random forest models provide a novel tool to the community for inferring selfing rates using genomic data.