Evolution of precopulatory and post-copulatory strategies of inbreeding avoidance and associated polyandry

Acknowledgments This work was funded by a European Research Council Starting Grant to JMR. Computer simulations were performed using the Maxwell Computing Cluster at the University of Aberdeen. We thank Matthew E. Wolak and two anonymous reviewers for very helpful comments.Peer reviewedPublisher PD

Identification and characterization of a novel microsomal enzyme involved in cardiolipin synthesis and remodeling

Cardiolipin (CL) is a specialized dimeric phospholipid predominantly found in the inner mitochondrial membrane in eukaryotes. Following de novo synthesis, the acyl chains of CL are remodeled in a manner that is tissue- and enzyme-specific, and can also be regulated by dietary intervention. This process is important for health. An incorrect CL fatty acyl profile is associated with serious disorders ranging from Barth Syndrome (BTHS), to Parkinson’s disease, heart, disease, and some cancers. To date, four highly specific enzymes have been implicated in this process. In this work, I report the biochemical and cellular characterization of a novel 25 kDa microsomal protein with a putative role in the synthesis and remodeling of CL. Of interest, this protein is highly abundant in cardiac and neural tissue, both of which contain the highest concentration of CL. In vitro evidence from crude lysates from HEK-293 overexpressing cells, and reticulocyte lysates, suggested that this enzyme functions as a phosphatidylcholine (PC): monolysocardiolipin (MLCL) transacylase in the synthesis of CL. The second objective of this thesis was to investigate the effects of the overexpression of this enzyme on cellular phospholipid content and composition in vivo, and related effects on mitochondrial physiology. As compared to controls, HEK-293 cells overexpressing this enzyme had an ~62% higher content of CL as compared to controls, but no significant increases in any other major phospholipid classes. Interestingly, mitochondrial respiration was impaired in these cells, although mitochondrial DNA content was not different, indicating that total mitochondria had not decreased. Overexpression of this enzyme in HEK-293 cells significantly up-regulated the mRNA expression of multiple genes involved in phospholipid biosynthesis, suggesting that it may also indirectly alter CL metabolism through cell signaling that could target transcriptional regulation. This enzyme has been previously demonstrated to synthesize small bioactive molecules that play roles in myriad biological pathways. However, treatment of cells with these the three most abundant species of these small bioactive molecules did not significantly increase CL content in HEK-293 cells. This suggested either that these bioactive molecules do not play a significant role in modulating the CL biosynthetic effects of this new enzyme, or that other species of the small bioactive molecules may be involved in mediating the induction of phospholipid metabolizing genes in HEK-293 cells overexpressing the novel enzyme. The final objective of this thesis was to assess the ability of one of the most abundant small bioactive molecules in modulating CL content and composition in a model of cellular CL deficiency. This work was performed in parallel with the studies in the second objective examining the ability of these small bioactive molecules to alter CL in HEK-293 cells, and therefore, the negative results of that work did not inform the choice of which species of bioactive molecule was tested. Cultured B-lymphocytes from individuals with Barth Syndrome (BTHS) were utilized as a study model. BTHS is a rare, X-linked genetic disorder that stems from mutations in Tafazzin, a CL fatty acid remodeling enzyme. Due to their inability to remodel the fatty acyl chains on CL following de novo synthesis, patients with BTHS have decreased CL content, which leads to a disease state, including heart failure, growth delay, and cyclic neutropenia. B-lymphocytes from BTHS patients treated with 1 M of an abundant species of these bioactive molecules exhibited a partial rescue of characteristic growth and CL deficiencies. This was surprising, given that: 1) the same species of bioactive molecule did not increase CL content in HEK-293 cells, and 2) that a final collaborative characterization study found that HEK-293 cells overexpressing the novel enzyme had significantly decreased content of this particular species of bioactive molecule. Of interest, that study also found that overexpression of this new enzyme may raise levels of a less abundant species of bioactive molecule, strongly suggesting that future studies should examine this species of bioactive molecule in the context of both CL synthesis and BTHS treatment. Thus, this novel enzyme is a microsomal PC:MLCL transacylase that increases CL in cells. study of this enzyme and its downstream bioactive molecules may provide novel therapeutic targets for disorders of CL metabolism

Functional characterization of murine 1-acylglycerol-3-phosphate O-acyltransferase 4 (AGPAT4)

The human genome project has allowed for the rapid identification of a large number of protein families based on similarities in their genetic sequences. The acyl-glycerol phosphate acyltransferase (AGPAT) family of enzymes have been largely identified through sequence homology, with eleven isoforms identified in both mice and humans. Interestingly, very little work has been done on the characterization of AGPAT isoform 4. In the present study, I report the functional characterization of AGPAT4 as a lysophosphatidic acid acyltransferase. Although AGPAT4 is present in most tissues, I have found that it is abundant in multiple brain regions including olfactory bulbs, hippocampus, cerebellum, cortex, and brain stem, and is detectable in both primary neurons and glial cells. In assays performed in vitro, AGPAT4 significantly increased the incorporation of [14C]oleoyl-CoA into phosphatidic acid using lysophosphatidic acid as an acyl acceptor. AGPAT4 did not display significant acyltransferase activity with lysophosphatidylcholine, lysophosphatidylethanolamine, lysophosphatidylserine, lysophosphatidylinositol, lysophosphatidylglycerol, monolysocardiolipin or dilysocardiolipin acyl acceptors. Overexpressing AGPAT4 in Sf9 cells increased the total phosphatidylinositol content, but did not significantly affect levels of other glycerophospholipids, including phosphatidic acid. Analysis of the fatty acyl profile of PA from AGPAT4-overexpressing cells indicated increased individual saturated fatty acids, particularly lauric acid (C 12:0), and arachidic acid (C 20:0). AGPAT4 localized predominately to the mitochondria, and was also regulated during embryogenesis, and in varying metabolic states. In summary, this thesis has characterized AGPAT4 as a lysophosphatidic acid acyltransferase with a potential role in mitochondrial function

Quantifying inbreeding avoidance through extra-pair reproduction

© 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.Peer reviewedPublisher PD

When Disclosure is Involuntary: Empowering Users with Control to Reduce Concerns

Modern organizations must carefully balance the practice of gathering large amounts of valuable data from individuals with the associated ethical considerations and potential negative public image inherent in breaches of privacy. As it becomes increasingly commonplace for many types of information to be collected without individuals\u27 knowledge or consent, managers and researchers alike can benefit from understanding how individuals react to such involuntary disclosures, and how these reactions can impact evaluations of the data-collecting organizations. This research develops and empirically tests a theoretical model that shows how empowering individuals with a sense of control over their personal information can help mitigate privacy concerns following an invasion of privacy. Using a controlled experiment with 94 participants, we show that increasing control can reduce privacy concerns and significantly influence individuals\u27 attitudes toward the organization that has committed a privacy invasion. We discuss theoretical and practical implications of our work

Vector competence of Aedes aegypti, Culex tarsalis, and Culex quinquefasciatus from California for Zika virus.

Zika virus (ZIKV) has emerged since 2013 as a significant global human health threat following outbreaks in the Pacific Islands and rapid spread throughout South and Central America. Severe congenital and neurological sequelae have been linked to ZIKV infections. Assessing the ability of common mosquito species to transmit ZIKV and characterizing variation in mosquito transmission of different ZIKV strains is important for estimating regional outbreak potential and for prioritizing local mosquito control strategies for Aedes and Culex species. In this study, we evaluated the laboratory vector competence of Aedes aegypti, Culex quinquefasciatus, and Culex tarsalis that originated in areas of California where ZIKV cases in travelers since 2015 were frequent. We compared infection, dissemination, and transmission rates by measuring ZIKV RNA levels in cohorts of mosquitoes that ingested blood meals from type I interferon-deficient mice infected with either a Puerto Rican ZIKV strain from 2015 (PR15), a Brazilian ZIKV strain from 2015 (BR15), or an ancestral Asian-lineage Malaysian ZIKV strain from 1966 (MA66). With PR15, Cx. quinquefasciatus was refractory to infection (0%, N = 42) and Cx. tarsalis was infected at 4% (N = 46). No ZIKV RNA was detected in saliva from either Culex species 14 or 21 days post feeding (dpf). In contrast, Ae. aegypti developed infection rates of 85% (PR15; N = 46), 90% (BR15; N = 20), and 81% (MA66; N = 85) 14 or 15 dpf. Although MA66-infected Ae. aegypti showed higher levels of ZIKV RNA in mosquito bodies and legs, transmission rates were not significantly different across virus strains (P = 0.13, Fisher's exact test). To confirm infectivity and measure the transmitted ZIKV dose, we enumerated infectious ZIKV in Ae. aegypti saliva using Vero cell plaque assays. The expectorated plaque forming units PFU varied by viral strain: MA66-infected expectorated 13±4 PFU (mean±SE, N = 13) compared to 29±6 PFU for PR15-infected (N = 13) and 35±8 PFU for BR15-infected (N = 6; ANOVA, df = 2, F = 3.8, P = 0.035). These laboratory vector competence results support an emerging consensus that Cx. tarsalis and Cx. quinquefasciatus are not vectors of ZIKV. These results also indicate that Ae. aegypti from California are efficient laboratory vectors of ancestral and contemporary Asian lineage ZIKV

Defining the content and delivery of an intervention to Change AdhereNce to treatment in BonchiEctasis (CAN-BE): a qualitative approach incorporating the Theoretical Domains Framework, behavioural change techniques and stakeholder expert panels

BackgroundLow patient adherence to treatment is associated with poorer health outcomes in bronchiectasis. We sought to use the Theoretical Domains Framework (TDF) (a framework derived from 33 psychological theories) and behavioural change techniques (BCTs) to define the content of an intervention to change patients’ adherence in bronchiectasis (Stage 1 and 2) and stakeholder expert panels to define its delivery (Stage 3).MethodsWe conducted semi-structured interviews with patients with bronchiectasis about barriers and motivators to adherence to treatment and focus groups or interviews with bronchiectasis healthcare professionals (HCPs) about their ability to change patients’ adherence to treatment. We coded these data to the 12 domain TDF to identify relevant domains for patients and HCPs (Stage 1). Three researchers independently mapped relevant domains for patients and HCPs to a list of 35 BCTs to identify two lists (patient and HCP) of potential BCTs for inclusion (Stage 2). We presented these lists to three expert panels (two with patients and one with HCPs/academics from across the UK). We asked panels who the intervention should target, who should deliver it, at what intensity, in what format and setting, and using which outcome measures (Stage 3).ResultsEight TDF domains were perceived to influence patients’ and HCPs’ behaviours: Knowledge, Skills, Beliefs about capability, Beliefs about consequences, Motivation, Social influences, Behavioural regulation and Nature of behaviours (Stage 1). Twelve BCTs common to patients and HCPs were included in the intervention: Monitoring, Self-monitoring, Feedback, Action planning, Problem solving, Persuasive communication, Goal/target specified:behaviour/outcome, Information regarding behaviour/outcome, Role play, Social support and Cognitive restructuring (Stage 2). Participants thought that an individualised combination of these BCTs should be delivered to all patients, by a member of staff, over several one-to-one and/or group visits in secondary care. Efficacy should be measured using pulmonary exacerbations, hospital admissions and quality of life (Stage 3).ConclusionsTwelve BCTs form the intervention content. An individualised selection from these 12 BCTs will be delivered to all patients over several face-to-face visits in secondary care. Future research should focus on developing physical materials to aid delivery of the intervention prior to feasibility and pilot testing. If effective, this intervention may improve adherence and health outcomes for those with bronchiectasis in the future