Expression and Function of Heat Shock Protein 90 in the Central Nervous System of the Desert Locust, Schistocerca gregaria

In this thesis, I investigated the expression and function of the molecular chaperone heat shock protein 90 (HSP90) in the central nervous system (CNS) of the desert locust, Schistocerca gregaria. In Chapter 1, I reviewed the structure, function and CNS expression of HSP90, and argued that its role as a 'meta-regulator' of complex biological pathways and its ability to stabilise behavioural and morphological phenotypes suggests it could adaptively stabilise activity in the CNS. In Chapter 2, I exploited unique properties of the locust hind leg motor control system to gain experimental access to a monosynaptic glutamatergic synapse. The stability of synaptic transmission – measured indirectly with extracellular muscle recordings – was unaffected by pharmacological inhibition of HSP90. In seeking to verify drug penetration into the locust CNS, subsequent intracellular electrophysiological experiments using drugs with reported effects at the synapse failed to replicate previously published findings. In Chapter 3, an extensive and computationally-intensive simulation-based Bayesian power analysis concluded that further intracellular experiments would not be sufficiently powered to robustly detect likely experimental outcomes with the resources available following the COVID-19 pandemic. In Chapter 4, I demonstrated for the first time in any invertebrate that constitutive expression of HSP90 (at the protein level) was greater in the CNS than in non-neural tissue. I attempted to investigate where HSP90 was expressed in the CNS, but none of the five selected anti-HSP90 antibodies passed all validation criteria required for their use in immunofluorescence microscopy. In Chapter 5, I contextualised the major findings of my thesis and suggest promising avenues for future experiments to explore. The rigorous experiments and power analysis presented in this thesis make distinct and original contributions in the form of (a) independent replication of published work and (b) broad methodological issues that have far-reaching implications for the meaningful design and interpretation of experiments.</p

The phylogeny of the mammalian heme peroxidases and the evolution of their diverse functions-2

Cates are shown on all nodes. The TPO primate clade appears here as a polytomy as the branch lengths are extremely short, however, this is in fact resolved with a low Bootstrap of 56%. The star symbol denotes those branches that were treated as foreground in the selection analysis. The analysis of the resolved phylogeny using gene tree species tree reconciliation method implemented in GeneTree. The large filled circles represent gene duplication events, and the red branches indicate gene losses.<p><b>Copyright information:</b></p><p>Taken from "The phylogeny of the mammalian heme peroxidases and the evolution of their diverse functions"</p><p>http://www.biomedcentral.com/1471-2148/8/101</p><p>BMC Evolutionary Biology 2008;8():101-101.</p><p>Published online 27 Mar 2008</p><p>PMCID:PMC2315650.</p><p></p

Change in frequency for six words: <i>ion</i>, -_—-, <i>ctfu</i>, <i>af</i>, <i>ikr</i>, <i>ard</i>.

<p>Blue circles indicate cities where on average, at least 0.1% of users use the word during a week. A circle's area is proportional to the word's probability.</p

Induced network, showing significant coefficients among the 40 most populous MSAs (using an FDR <0.001 threshold, yielding 254 links).

<p>Blue edges represent bidirectional influence, when there are directed edges in both directions; orange links are unidirectional.</p

Statistics of metropolitan statistical areas.

<p>Mean and standard deviation for demographic attributes of the 200 Metropolitan Statistical Areas (MSAs) considered in our study.</p><p>Statistics of metropolitan statistical areas.</p

The phylogeny of the mammalian heme peroxidases and the evolution of their diverse functions-4

Uences are outgroups to the MHP clade. The following are the species abbreviations used: Dog (D); Cow (C); Macaque (Ma); Human (H); Chimp (Ch); Rat (R); Mouse (M), Chicken (G), and Opossum (Op). This phylogeny was compared to each of the resultant site stripped phylogenies. Graph showing the RMSD nodal distance () between each site-stripped phylogeny () and the ideal phylogeny. : All: refers to the complete MSA; 8: site category 8 removed from the MSA; 8, 7: categories 8 and 7 removed from the MSA and so on up to the final column that contains only the most slowly evolving category of site. Values close to/zero correspond to complete agreement between the ideal and site stripped phylogeny.<p><b>Copyright information:</b></p><p>Taken from "The phylogeny of the mammalian heme peroxidases and the evolution of their diverse functions"</p><p>http://www.biomedcentral.com/1471-2148/8/101</p><p>BMC Evolutionary Biology 2008;8():101-101.</p><p>Published online 27 Mar 2008</p><p>PMCID:PMC2315650.</p><p></p

Block diagram for our statistical modeling procedure.

<p>The dotted outline indicates repetition across samples drawn from sequential Monte Carlo.</p

Histograms of distances between pairs of connected cities,in model-inferred networks (top), versus “negative” networks from <i>Q</i> (bottom).

<p>Histograms of distances between pairs of connected cities,in model-inferred networks (top), versus “negative” networks from <i>Q</i> (bottom).</p

The phylogeny of the mammalian heme peroxidases and the evolution of their diverse functions-3

Ely selected in MPO, in blue is the heme binding site. Example of the affect on hydrogen bonding of one such mutation at positively selected position 496 in human MPO from Asparagine to Phenylalanine.<p><b>Copyright information:</b></p><p>Taken from "The phylogeny of the mammalian heme peroxidases and the evolution of their diverse functions"</p><p>http://www.biomedcentral.com/1471-2148/8/101</p><p>BMC Evolutionary Biology 2008;8():101-101.</p><p>Published online 27 Mar 2008</p><p>PMCID:PMC2315650.</p><p></p

Logistic regression coefficients for predicting links between city (MSA) pairs.

<p>95% confidence intervals are plotted; standard errors are in parentheses. Coefficient values are from standardized inputs; the mean and standard deviations are shown to the right.</p