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- Bouffet-Halle, Alix, et al.
(författare)
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Characterisation and cross-amplification of sex-specific genetic markers in Australasian Egerniinae lizards and their implications for understanding the evolution of sex determination and social complexity
- 2022
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Ingår i: Australian Journal of Zoology. - 0004-959X. ; 69:2, s. 33-40
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Tidskriftsartikel (refereegranskat)abstract
- Sex is a pervasive factor that underpins functional phenotypic variation across a range of traits. Although sex can usually be distinguished morphologically, in some species this is not possible. The development of genetic markers for sex identification is, thus, key if we are to incorporate sex into an understanding of ecological or evolutionary process. Here we develop genetic markers for the identification of sex within an iconic Australian lizard group, the Egernia group, which is notable for its complex social behaviour. We used restriction-site associated DNA sequencing to characterise sex-specific genetic sequences for a key member of the group, Liopholis whitii, and designed primers for four of these putative sex-specific sequences. These primers amplified across some, but not all, species of the group. Our results provided several important insights. They suggest conservatism of a XX/XY sex determination system within the group as well as sex-specific genomic regions that appear independent of the conserved genomic regions identified in other skink species. More broadly, the development of sex markers for the Egernia group opens up a range of potential research questions related to the role that sex plays in the mediation of social behaviour and, through this, the emergence and stability of social life.
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| 2. |
- Modig, Kristofer, et al.
(författare)
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Water dynamics in the large cavity of three lipid-binding proteins monitored by 17O magnetic relaxation dispersion.
- 2003
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Ingår i: Journal of Molecular Biology. - 1089-8638. ; 332:4, s. 965-977
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Tidskriftsartikel (refereegranskat)abstract
- Intracellular lipid-binding proteins contain a large binding cavity filled with water molecules. The role played by these water molecules in ligand binding is not well understood, but their energetic and dynamic properties must be important for protein function. Here, we use the magnetic relaxation dispersion (MRD) of the water 17O resonance to investigate the water molecules in the binding cavity of three different lipid-binding proteins: heart fatty acid-binding protein (H-FABP), ileal lipid-binding protein (I-LBP) and intestinal fatty acid-binding protein (I-FABP). Whereas about half of the crystallographically visible water molecules appear to be expelled by the ligand, we find that ligand binding actually increases the number of water molecules within the cavity. At 300 K, the water molecules in the cavity exchange positions on a time-scale of about 1 ns and exchange with external water on longer time-scales (0.01–1 s). Exchange of water molecules among hydration sites within the cavity should be strongly coupled to ligand motion. Whereas a recent MD simulation indicates that the structure of the cavity water resembles a bulk water droplet, the present MRD results show that its dynamics is more than two orders of magnitude slower than in the bulk. These findings may have significant implications for the strength, specificity and kinetics of lipid binding.
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