The first record of Omosita nearctica Kirejtshuk (Coleoptera, Nitidulidae) in South Africa, with the first description of its mature larva
- Authors: Williams, Kirstin A , Clitheroe, Crystal-Leigh , Villet, Martin H , Midgley, John M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440640 , vital:73799 , https://africaninvertebrates.pensoft.net/article/58842/
- Description: Sap beetles of the genus Omosita Erichson are stored-product pests that are also associated with carrion, potentially making them biosecurity risks and forensic tools. The discovery of a specimen of the Nearctic species Omosita nearctica Kirejtshuk in South Africa prompted an investigation a decade later to determine if this species had established itself in the country, which was confirmed by the collection of further breeding specimens that also facilitated the first description of mature larvae of O. nearctica. A new key to adults of all Omosita species is presented.
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- Date Issued: 2021
The temporal occurrence of flesh flies (Diptera, Sarcophagidae) at carrion-baited traps in Grahamstown, South Africa
- Authors: Villet, Martin H , Clitheroe, Crystal-Leigh , Williams, Kirstin A
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59692 , vital:27639 , https://doi.org/10.3897/AfrInvertebr.58.9537
- Description: Eleven species of flesh fly were identified in a sample of 737 specimens captured during fortnightly trapping at three sites in Grahamstown, South Africa, over a year. Sarcophaga africa Wiedemann, 1824, S. inaequalis Austen, 1909, S. exuberans Pandelle, 1896 and S. tibialis Macquart, 1851 showed well-defined peaks between early October 2001 and late April 2002, and only S. africa was trapped at other times of year. These peaks occurred when average minimum and maximum ambient air temperatures were above 12°C and 22°C, respectively, and showed no obvious relationship to rainfall. There were indications of population cycles in all of these species. Sarcophaga hera Zumpt, 1972, S. arno Curran, 1934, S. inzi Curran, 1934, S. langi Curran, 1934, S. freyi Zumpt, 1953, S. nodosa Engel, 1925 and S. samia Curran, 1934 were too scarce to assess their patterns of occurrence rigorously. Insects attending a corpse are reputed to assist forensic entomologists in estimating the time of year when the body died. Some flesh flies provide more precise estimates than others, so several species should be used for cross-validation. Insect activity at a corpse depends on the weather, so that presence of a species indicates particular environmental conditions and not simply calendar dates (particularly if climate changes). Absence of a species is not necessarily evidence of specific conditions because species may not be present at all sites simultaneously, populations cycle even when their members are active, and low population densities may hamper detection of a species.
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- Date Issued: 2017
Plasmodium falciparum Hop: detailed analysis on complex formation with Hsp70 and Hsp90
- Authors: Hatherley, Rowan , Clitheroe, Crystal-Leigh , Faya, Ngonidzashe , Tastan Bishop, Özlem
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125708 , vital:35810 , https://doi.10.1016/j.bbrc.2014.11.103
- Description: The heat shock organizing protein (Hop) is important in modulating the activity and co-interaction of two chaperones: heat shock protein 70 and 90 (Hsp70 and Hsp90). Recent research suggested that Plasmodium falciparum Hop (PfHop), PfHsp70 and PfHsp90 form a complex in the trophozoite infective stage. However, there has been little computational research on the malarial Hop protein in complex with other malarial Hsps. Using in silico characterization of the protein, this work showed that individual domains of Hop are evolving at different rates within the protein. Differences between human Hop (HsHop) and PfHop were identified by motif analysis. Homology modeling of PfHop and HsHop in complex with their own cytosolic Hsp90 and Hsp70 C-terminal peptide partners indicated excellent conservation of the Hop concave TPR sites bound to the C-terminal motifs of partner proteins. Further, we analyzed additional binding sites between Hop and Hsp90, and showed, for the first time, that they are distinctly less conserved between human and malaria parasite. These sites are located on the convex surface of Hop TPR2, and involved in interactions with the Hsp90 middle domain. Since the convex sites are less conserved than the concave sites, it makes their potential for malarial inhibitor design extremely attractive (as opposed to the concave sites which have been the focus of previous efforts).
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- Date Issued: 2015
In-silico analysis of Plasmodium falciparum Hop protein and its interactions with Hsp70 and Hsp90
- Authors: Clitheroe, Crystal-Leigh
- Date: 2013
- Subjects: Plasmodium falciparum , Heat shock proteins , Molecular chaperones , Homology (Biology) , Protein-protein interactions , Malaria -- Chemotherapy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3896 , http://hdl.handle.net/10962/d1003819 , Plasmodium falciparum , Heat shock proteins , Molecular chaperones , Homology (Biology) , Protein-protein interactions , Malaria -- Chemotherapy
- Description: A lessor understood co-chaperone, the Hsp70/Hsp90 organising protein (Hop), has been found to play an important role in modulating the activity and co-interaction of two essential chaperones; Hsp90 and Hsp70. The best understood aspects of Hop so far indicate that residues in the concave surfaces of the three tetratricopeptide repeat (TPR) domains in the protein bind selectively to the C-terminal motifs of Hsp70 and Hsp90. Recent research suggests that P. falciparum Hop (PfHop), PfHsp90 and PfHsp70 do interact and form complex in the P. falciparum trophozooite and are overexpressed in this infective stage. However, there has been almost no computational research on malarial Hop protein in complex with other malarial Hsps.The current work has focussed on several aspects of the in-silico characterisation of PfHop, including an in-depth multiple sequence alignment and phylogenetic analysis of the protein; which showed that Hop is very well conserved across a wide range of available phyla (four Kingdoms, 60 species). Homology modelling was employed to predict several protein structures for these interactions in P. falciparum, as well as predict structures of the relevant TPR domains of Human Hop (HsHop) in complex with its own Hsp90 and Hsp70 C-terminal peptide partners for comparison. Protein complex interaction analyses indicate that concave TPR sites bound to the C-terminal motifs of partner proteins are very similar in both species, due to the excellent conservation of the TPR domain’s “double carboxylate binding clamp”. Motif analysis was combined with phylogenetic trees and structure mapping in novel ways to attain more information on the evolutionary conservation of important structural and functional sites on Hop. Alternative sites of interaction between Hop TPR2 and Hsp90’s M and C domains are distinctly less well conserved between the two species, but still important to complex formation, making this a likely interaction site for selective drug targeting. Binding and interaction energies for all modelled complexes have been calculated; indicating that all HsHop TPR domains have higher affinities for their respective C-terminal partners than do their P. falciparum counterparts. An alternate motif corresponding to the C-terminal motif of PfHsp70-x (exported to the infected erythrocyte cytosol) in complex with both human and malarial TPR1 and TPR2B domains was analysed, and these studies suggest that the human TPR domains have a higher affinity for this motif than do the respective PfHop TPR domains. This may indicate potential for a cross species protein interaction to take place, as PfHop is not transported to the human erythrocyte cytosol.
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- Date Issued: 2013
3000 miles from home: a new Gastrosericus baobabicus Pulawski, 1995 (Hymenoptera, Larridae) distribution record highlights that the Sahel has a distinct entomofaunal signature
- Authors: Clitheroe, Crystal-Leigh , Villet, Martin H
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6846 , http://hdl.handle.net/10962/d1011099
- Description: [from introduction] On October 30, 1953, an unidentified female wasp (Fig. 1) was collected from ‘Belet Uen, Somaliland’ (= Beledweyne, 4°44’N 45°12’E), situated in the valley of the Shebelle River, HiraanProvince,Somalia. It was deposited in the aculeate Hymenoptera collection of the Albany Museum, Grahamstown by D. Greathead prior to 1968. Apart from the words ‘Somaliland’ and ‘Desert Locust Survey’ the label is handwritten and the collector’snameis not recorded. Greathead’s sister, S. Gess (Albany Museum), deciphered the label and stated that he had worked for the Desert Locust Survey, investigating the natural enemies of locusts and had been in Somalia (then Somaliland) at that time (Murphy & Cock 2007). The specimen was sent in 2004 by F. Gess to W. Pulawski, who determined it as Gastrosericus baobabicus Pulawski, 1995. Gastrosericus species prey on spiders and a variety of small insects (Pulawski 1995), including Orthoptera (Krombein & Pulawski 1986), so it is likely that Greathead collected the specimen in connection with his interest in the insect enemies of Acridoidea (Orthoptera) (Greathead 1962).
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- Date Issued: 2011