27 research outputs found
The role of body size on the outcome of mating interactions in Drosophila melanogaster
Sexual selection is the process by which some individuals produce more and/or better quality offspring than others because they are better at securing mates. While this may be accomplished by defeating same-sex rivals (intrasexual selection), individuals of one sex (typically females) may also “decide” on the suitability of individuals of the opposite sex (typically males), resulting in intersexual selection on attractive traits. While a great deal of scrutiny has focused on how sexual selection influences male display traits, much less scrutiny has been directed toward the factors underlying female preference, including genetic variation, as well as the extent to which both sexes are involved in mate choice.
In Drosophila melanogaster, a model species for the study of sexual selection, previous studies have examined the role of body size variation in a single sex on the behaviours and outcomes related to courtship and copulation. However, few studies have simultaneously varied both male and female body size. In my first study (Chapter 2), I experimentally paired male and female flies from across a wide spectrum of body size phenotypes and quantified several behavioural traits: time to courtship initiation, length of courtship and length of copulation. I found that absolute body size differences affected length of courtship and that relative body size differences affected time to courtship initiation.
While Chapter 2 demonstrated how mate choice may be expressed within a single generation of individuals, whether individual preference variation in females had a genetic component had yet to be determined experimentally. In my second study (Chapter 3), I investigated if female body size preference had a genetic component by directly selecting on female preference over multiple generations. Using artificial selection, I “penalized” females that mated with males of certain body sizes over 20 generations and observed several significant differences in female preference behaviour. In all treatments, females tended to associate significantly more with males of body sizes different from those they were artificially selected against.
These results not only suggest that body size in both sexes can significantly influence female preference behaviours, but that body size may be a trait possessing significant genetic variation with the potential to be strongly shaped by sexual selection
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Proceedings of the 13th annual conference of INEBRIA
CITATION: Watson, R., et al. 2016. Proceedings of the 13th annual conference of INEBRIA. Addiction Science & Clinical Practice, 11:13, doi:10.1186/s13722-016-0062-9.The original publication is available at https://ascpjournal.biomedcentral.comENGLISH SUMMARY : Meeting abstracts.https://ascpjournal.biomedcentral.com/articles/10.1186/s13722-016-0062-9Publisher's versio
Regulation of Angiogenesis by Aminoacyl-tRNA Synthetases
In addition to their canonical roles in translation the aminoacyl-tRNA synthetases (ARSs) have developed secondary functions over the course of evolution. Many of these activities are associated with cellular survival and nutritional stress responses essential for homeostatic processes in higher eukaryotes. In particular, six ARSs and one associated factor have documented functions in angiogenesis. However, despite their connection to this process, the ARSs are mechanistically distinct and exhibit a range of positive or negative effects on aspects of endothelial cell migration, proliferation, and survival. This variability is achieved through the appearance of appended domains and interplay with inflammatory pathways not found in prokaryotic systems. Complete knowledge of the non-canonical functions of ARSs is necessary to understand the mechanisms underlying the physiological regulation of angiogenesis
A picornavirus protein interacts with Ran-GTPase and disrupts nucleocytoplasmic transport
Active nucleocytoplasmic transport of protein and RNA in eukaryotes depends on the Ran-GTPase system to regulate cargo–receptor interactions. Several viruses, including the RNA picornaviruses, encode factors that alter nuclear transport with the aim of suppressing synthesis of antiviral factors and promoting viral replication. Picornaviruses in the cardiovirus genus express a unique 67-aa Leader protein (L), known to alter the subcellular distribution of IFN regulatory proteins targeted to the nucleus. We report here that L binds directly to Ran and blocks nuclear export of new mRNAs. In Xenopus egg extracts, recombinant L also inhibits mitotic spindle assembly, a RanGTP function crucial to cell-cycle progression. We propose that L inhibits nucleocytoplasmic transport during infection by disrupting the RanGDP/GTP gradient. This inhibition triggers an efflux of nuclear proteins necessary for viral replication and causes IFN suppression. To our knowledge, L is the first viral picornaviral protein to interact directly with Ran and modulate the Ran-dependent nucleocytoplasmic pathway
A T42A Ran Mutation: Differential Interactions with Effectors and Regulators, and Defect in Nuclear Protein Import
Integrated Reporting in Municipally Owned Corporations: A Case Study in Italy
Municipally owned corporations (MOCs) are autonomous organisations owned by municipalities that are used to produce or deliver local public services outside of the local bureaucracy. Profit maximisation is not the primary goal of MOCs, since they are also required to achieve other objectives, such as social outcomes, innovation, and employment. The integrated report, due to its structure, could provide a holistic perspective of an MOC’s performance. This chapter aims to elucidate the trends in the literature about MOCs’ accountability and the implementation of an integrated reporting system. Using a case study analysis, the results of the research demonstrate how the International Integrated Reporting Council’s framework is useful to pursue accountability policies and the benefits derived from the implementation of integrated reporting