| 1. |
- Abbott, Jessica K., et al.
(författare)
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Sex chromosome evolution : Historical insights and future perspectives
- 2017
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Ingår i: Proceedings of the Royal Society B: Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 284:1854
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Forskningsöversikt (refereegranskat)abstract
- Many separate-sexed organisms have sex chromosomes controlling sex determination. Sex chromosomes often have reduced recombination, specialized (frequently sex-specific) gene content, dosage compensation and heteromorphic size. Research on sex determination and sex chromosome evolution has increased over the past decade and is today a very active field. However, some areas within the field have not received as much attention as others.We therefore believe that a historic overviewof key findings and empirical discoveries will put current thinking into context and help us better understand where to go next. Here, we present a timeline of important conceptual and analytical models, as well as empirical studies that have advanced the field and changed our understanding of the evolution of sex chromosomes. Finally, we highlight gaps in our knowledge so far and propose some specific areas within the field that we recommend a greater focus on in the future, including the role of ecology in sex chromosome evolution and newmultilocus models of sex chromosome divergence.
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| 2. |
- Jansson, Samuel, et al.
(författare)
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Correlation of mosquito wing-beat harmonics to aid in species classification and flight heading assessment
- 2019
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Ingår i: Novel Biophotonics Techniques and Applications V. - : SPIE. - 1605-7422 .- 2410-9045. - 9781510628434 ; 20:60
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Konferensbidrag (refereegranskat)abstract
- Surveying disease vectors is currently excessively laborious for continuous and widespread monitoring. Wing beat modulation spectroscopy gives opportunity for species and sex recognition in electronic traps or mosquito target classification in lidar. We used a polarimetric dual-wavelength-band laboratory system to record kHz modulated backscattered light from insects. The system operates in the near and short-wave infrared at 808 nm and 1550 nm and retrieves both co- and depolarized light. Here we give clues on the harmonic content and covariance of four mosquito species and fruit flies. Further, we interpret the interdependence of harmonic strengths when insects transit the probe volume with random heading direction and provide correlation matrices for coherent and incoherent light. Using the obtained parameters, we demonstrate that species that are difficult to distinguish with microscope can be classified with high accuracy. The results are valuable for understanding wingbeat harmonics in relation to heading and valuable for optimal sensor design for disease vector surveillance.
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| 3. |
- Liotta, Melissa N, et al.
(författare)
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Tactical dimorphism : the interplay between body shape and mating behaviour in the swordtail Xiphophorus multilineatus (Cyprinodontiformes: Poeciliidae)
- 2019
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Ingår i: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066 .- 1095-8312. ; 127:2, s. 337-350
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Tidskriftsartikel (refereegranskat)abstract
- Alternative reproductive tactics (ARTs) are characterized by dimorphism for reproductive phenotypes (i.e. tactical dimorphism). Tactical dimorphism often evolves as a response to differing phenotypic optima for a shared reproductive trait between members of the same sex in a species. We characterized dimorphism for body shape between ARTs in the swordtail fish Xiphophorus multilineatus and investigated the relationship between body shape and mating behaviours. Xiphophorus multilineatus possesses two ARTs, a courter male that uses only courtship to attract females, and a sneaker male that is contextually plastic and uses both courtship and force copulatory sneak chases. We found that courter and sneaker males are dimorphic for body shape; however, we did not detect a significant difference in the allometric relationship between body shape and size. Additionally, we found that more fusiform sneaker males were more likely to use sneak-chase behaviour in the absence of a competitor. These results suggest that the ARTs in X. multilineatus have different phenotypic optima for body shape and that a fusiform body shape might be more optimal for sneak-chase behaviour. Understanding tactical dimorphism in this species will allow us to explore further how the ARTs evolved and the potential for intralocus tactical conflict to constrain the evolution of each ART from reaching their respective optima.
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| 4. |
- Olito, Colin, et al.
(författare)
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The interaction between sex-specific selection and local adaptation in species without separate sexes
- 2018
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Ingår i: Philosophical Transactions of the Royal Society B: Biological Sciences. - : The Royal Society. - 1471-2970 .- 0962-8436. ; 373:1757
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Tidskriftsartikel (refereegranskat)abstract
- Local adaptation in hermaphrodite species can be based on a variety of fitness components, including survival, as well as both female and male sex-functions within individuals. When selection via female and male fitness components varies spatially (e.g. due to environmental heterogeneity), local adaptation will depend, in part, on variation in selection through each fitness component, and the extent to which genetic trade-offs between sex-functions maintain genetic variation necessary for adaptation. Local adaptation will also depend on the hermaphrodite mating system because self-fertilization alters several key factors influencing selection and the maintenance of genetic variance underlying trade-offs between the sex-functions (sexually antagonistic polymorphism). As a first step to guide intuition regarding sex-specific adaptation in hermaphrodites, we develop a simple theoretical model incorporating the essential features of hermaphrodite mating and adaptation in a spatially heterogeneous environment, and explore the interaction between sex-specific selection, self-fertilization and local adaptation. Our results suggest that opportunities for sex-specific local adaptation in hermaphrodites depend strongly on the extent of self-fertilization and inbreeding depression. Using our model as a conceptual framework, we provide a broad overview of the literature on sex-specific selection and local adaptation in hermaphroditic plants and animals, emphasizing promising future directions in light of our theoretical predictions.
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| 5. |
- Ponnikas, Suvi, et al.
(författare)
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Why Do Sex Chromosomes Stop Recombining?
- 2018
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Ingår i: Trends in Genetics. - : Elsevier BV. - 0168-9525. ; 34:7, s. 492-503
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Tidskriftsartikel (refereegranskat)abstract
- It is commonly assumed that sex chromosomes evolve recombination suppression because selection favours linkage between sex-determining and sexually antagonistic genes. However, although the role of sexual antagonism during sex chromosome evolution has attained strong support from theory, experimental and observational evidence is rare or equivocal. Here, we highlight alternative, often neglected, hypotheses for recombination suppression on sex chromosomes, which invoke meiotic drive, heterozygote advantage, and genetic drift, respectively. We contrast the hypotheses, the situations when they are likely to be of importance, and outline why it is surprisingly difficult to test them. Lastly, we discuss future research directions (including modelling, population genomics, comparative approaches, and experiments) to disentangle the different hypotheses of sex chromosome evolution.
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