Miranda M A Whitten

Miranda M A Whitten
Swansea University | SWAN · Institute of Life Science "ILS"

BSc Hons, PhD

About

72
Publications
10,606
Reads
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1,837
Citations
Introduction
My background is in insect immunology & host-parasite interactions. In recent years I've focussed on developing new RNAi delivery systems for pest / medically-important insects. I currently work with thrips (major agricultural pests), and tsetse flies (vector of African sleeping sickness). This short film summarizes the aims of my research: https://www.youtube.com/watch?v=NYiEMUT0zBU I've also worked on lobster diseases & bacterial / fungal biopesticides. I freelance as an artist/illustrator.
Additional affiliations
January 2006 - present
French National Centre for Scientific Research
Position
  • Institut de Biologie Moléculaire et Cellulaire
January 1999 - December 2007
Swansea University
Education
September 1996 - January 2000
Swansea University
Field of study
  • Innate Immunity
September 1991 - June 1994
Aston University
Field of study
  • science

Publications

Publications (72)
Article
Full-text available
Diseases of lobster shells have a significant impact on fishing industries but the risk of disease transmission between different lobster species has yet to be properly investigated. This study compared bacterial biofilm communities from American (Homarus americanus) and European lobsters (H. gammarus), to assess both healthy cuticle and diseased c...
Article
Full-text available
Lipoproteins and molecules for pattern recognition are centrally important in the innate immune response of both vertebrates and invertebrates. Mammalian apolipoproteins such as apolipoprotein E (apoE) are involved in LPS detoxification, phagocytosis, and possibly pattern recognition. The multifunctional insect protein, apolipophorin III (apoLp-III...
Article
Full-text available
When taking a blood meal on a person infected with malaria, female Anopheles gambiae mosquitoes, the major vector of human malaria, acquire nutrients that will activate egg development (oogenesis) in their ovaries. Simultaneously, they infect themselves with the malaria parasite. On traversing the mosquito midgut epithelium, invading Plasmodium ook...
Article
Full-text available
Anopheles gambiae mosquitoes are the principal vectors of malaria. A major determinant of the capacity of these mosquitoes as disease vectors is their high reproductive rate. Reproduction depends on a single insemination, which profoundly changes the behavior and physiology of females. To identify factors and mechanisms relevant to the fertility of...
Article
Full-text available
Microevolutionary adaptations and mechanisms of fungal pathogen resistance were explored in a melanic population of the Greater wax moth, Galleria mellonella. Under constant selective pressure from the insect pathogenic fungus Beauveria bassiana, 25th generation larvae exhibited significantly enhanced resistance, which was specific to this pathogen...
Book
Full-text available
Many invertebrates are serious pests of agriculture (e.g. mites and locusts), vectors of disease (e.g. mosquitoes and aquatic snails) and venomous (e.g. scorpions), whilst others are beneficial to humans as pollinators, food sources, and detritivores. Despite their obvious ecological, medical, and economic importance, this is the first comprehensiv...
Chapter
Full-text available
Textbooks on immunology rarely spend more than a few pages describing the principles of invertebrate immunology. Coming away from these often gives the reader the impression that this immune system is simple and non-specific in nature yet with over 1.3 million extant species of invertebrates, there is inevitably a great diversity of strategies to d...
Article
Full-text available
In insect reverse genetics, dietary delivery of interfering RNAs is a practical approach in nonmodel species, such as thrips, whose small size, and feeding behavior restricts the use of other delivery methods. In a laboratory context, an unsuitable diet could confound the interpretation of an RNA interference (RNAi) phenotype, however well-formulat...
Article
Full-text available
RNA interference (RNAi) is a transformative technology with great potential to control, study or even protect insects and acarines through the knockdown of target gene expression. RNAi offers unprecedented levels of control, but fundamental to its successful deployment is the need to deliver ‘trigger’ RNA in an appropriate fashion giving due consid...
Article
Full-text available
It is time to reduce the environmental footprint of insect pest control. Bacteria are the ideal tools for developing 'smart' precision bio-insecticides and preventing disease transmission by insects.
Article
Full-text available
Melanins (eumelanin and pheomelanin) are synthesised in insects for several purposes including cuticle sclerotisation and color patterning, clot formation, organogenesis and innate immunity. Traditional views of insect immunity detail the storage of pro-phenoloxidases inside specialized blood cells (hemocytes) and their release upon recognition of...
Article
Insight into animal biology and development provided by classical genetic analysis of the model organism Drosophila melanogaster was an incentive to develop advanced genetic tools for this insect. But genetic systems for the over one million other known insect species are largely undeveloped. With increasing information about insect genomes resulti...
Article
Full-text available
Microevolutionary mechanisms of resistance to a bacterial pathogen were explored in a population of the Greater wax moth, Galleria mellonella, selected for an 8.8-fold increased resistance against the entomopathogenic bacterium Bacillus thuringiensis (Bt) compared with a non-selected (suspectible) line. Defense strategies of the resistant and susce...
Article
Full-text available
This study examines how the dynamics of fungus – insect interactions can be modulated by temperature. The wax moth, Galleria mellonella, is a well-studied and important model insect whose larvae in the wild develop optimally at around 34°C in beehives. However, surprisingly little research on wax moths has been conducted at relevant temperatures. I...
Article
Full-text available
RNA interference (RNAi) methods for insects are often limited by problems with double-stranded (ds) RNA delivery, which restricts reverse genetics studies and the development of RNAi-based biocides. We therefore delegated to insect symbiotic bacteria the task of: (i) constitutive dsRNA synthesis and (ii) trauma-free delivery. RNaseIII-deficient, ds...
Article
There are few reports of bacterial diseases in crabs. A juvenile edible crab (Cancer pagurus) with a rickettsial-like infection was found in the intertidal zone at Freshwater East in South West Wales in July, 2012. Large numbers of bacteria-like particles were found in the haemolymph and within fixed phagocytes of the hepatopancreas. Molecular sequ...
Article
Full-text available
Obligate bacterial symbionts are widespread in many invertebrates, where they are often confined to specialized host cells and are transmitted directly from mother to progeny. Increasing numbers of these bacteria are being characterized but questions remain about their population structure and evolution. Here we take a comparative genomics approach...
Article
The prevalence of disease in edible crabs (Cancer pagurus) was assessed at two sites in South West Wales; one estuarine (Pembroke Ferry) and another facing open water (Freshwater East). Diseases included pink crab disease caused by Hematodinium sp., an infection of the antennal gland caused by Paramikrocytos canceri and an idiopathic inflammatory c...
Data
Data S1. Supporting experimental procedures. Figure S1. Lack of correlation between time since last molt versus the risk of lesion formation following experimental damage to claw or carapace. A, B, C = carapace; D, E, F = claw. Time zero refers to the start of the experiment. Figure S2. Lack of correlation between duration of intermolt period and r...
Article
Full-text available
In this study the cellular and humoral immune reactions of the Greater wax moth Galleria mellonella have been investigated during bacterial infection caused by oral administration of Bacillus thuringiensis. Two different dose strengths were investigated to assess the contribution of immune parameters to induced Bt resistance. Low-dose (sublethal LC...
Article
The integument of arthropods is an important first-line defence against the invasion of parasites and pathogens. Once damaged, this can be subject to colonisation by microbial agents from the surrounding environment, which in crustaceans can lead to a condition termed shell disease syndrome. This condition has been reported in several crustacean sp...
Article
Full-text available
There are varying degrees of compatibility between malaria parasite-mosquito species, and understanding this compatibility may be crucial for developing effective transmission-blocking vaccines. This study investigates the compatibility of different biological forms of a malaria vector, Anopheles stephensi, to Plasmodium berghei ANKA strain. Severa...
Article
Juvenile edible crabs, Cancer pagurus L., were surveyed from Mumbles Head and Oxwich Bay in South Wales, UK, and the number of heterotrophic bacteria and vibrios in the hemolymph was determined. The percentage of crabs with hemolymph containing bacteria was variable over the survey with higher numbers of animals affected in summer than in winter. P...
Article
Full-text available
A 'dark morph' melanic strain of the greater wax moth, Galleria mellonella, was studied for its atypical, heightened resistance to infection with the entomo-pathogenic fungus, Beauveria bassiana. We show that these insects exhibit multiple intraspecific immunity and physiological traits that distinguish them from a non-melanic, fungus-susceptible m...
Article
Full-text available
We report the 4,385,577-bp high-quality draft assembly of the bacterial symbiont Rhodococcus rhodnii strain LMG5362, isolated from the gut of Rhodnius prolixus (Hemiptera, Reduviidae, Triatominae), the principle vector of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. This sequence might provide useful information for sub...
Data
AMP gene expression in fat body of infected insects. Expression of antimicrobial peptide genes in fat body of non-selected (NS) and selected line (S) larvae after topical B. bassiana (Bb) and M.anisopliae (Ma) infection. Expression of genes was assayed in fat body tissue by Q-PCR in uninfected animals, and in animals at 24 h after topical infection...
Data
Loci used for expression analysis. (XLS)
Data
Mega-analysis of Q-PCR data. Summary showing trends in gene expression in S and NS line G. mellonella larvae in different tissues following infection with B. bassiana and M. anispoliae: effect of fungal species on gene expression. (DOC)
Data
Stress-management gene expression in fat body of insects. Expression of putative stress-management genes in fat body of non-selected (NS) and selected line (S) larvae after topical B. bassiana (Bb) and M.anisopliae (Ma) infection. Expression of genes was assayed in fat body tissue by Q-PCR in uninfected animals, and in animals at 24 h after topical...
Data
Stress-management gene expression in integuments of infected insects. Expression of putative stress-management genes in the integument of non-selected (NS) and selected line (S) larvae after topical B. bassiana (Bb) and M.anisopliae (Ma) infection. Gene expression was assayed in integument tissue by Q-PCR in uninfected animals, and in animals at 24...
Data
Susceptibility of G. mellonella selected and non-selected lines to B. bassiana. Susceptibility of Galleria mellonella larvae of selected and non-selected lines to topical fungal infection with Beauveria bassiana (7.5×107 conidia/ml). (DOC)
Data
Attributes of melanic and non-melanic G. mellonella. Attributes of selected (resistant) and non-selected (susceptible) melanic morphs of 5th instar Galleria mellonella larvae compared with a non-melanic morph. (DOC)
Data
Referenced experimental procedures. (DOC)
Data
AMP gene expression in integuments of infected insects. Expression of antimicrobial peptide genes and other immunity genes in the integument of non-selected (NS) and selected line (S) larvae after topical B. bassiana (Bb) and M. anisopliae (Ma) infection. Expression of genes was assayed in integument tissue by Q-PCR in uninfected insects, and in in...
Data
Mega-analysis of Q-PCR data. Summary showing trends in gene expression in S and NS line G. mellonella larvae in different tissues following infection with B. bassiana and M. anispoliae: effect of selection on gene expression. (DOC)
Poster
Full-text available
Health status of the European lobster (Homarus gammarus) with particular reference to epizootic shell disease
Data
Lp and Vg proteins are readily visualized by Coomassie staining. Mosquitoes were injected with dsLacZ, dsLp, or dsVg as indicated and offered a blood meal 4 d later to induce Vg expression. Hemolymph was collected 24 h after a blood meal from clipped mosquito proboscises. Hemolymph from the equivalent of 4 mosquitoes as well as 5- and 10-fold dilut...
Data
(A) Three additional repeats of the experiment shown in Figure 1A. (See Figure 1A for legend.) (B) Three additional repeats of the experiment shown in Figure 1B. (See Figure 1B for legend.) (C) Two additional repeats of the experiment shown in Figure 2A. (See Figure 2A for legend.) (0.35 MB TIF)
Data
The table summarizes the parasite scores for three independent repeats of the experiment shown in Figure 2C. Shown are parasite percentages in each of the three possible classes (live, GFP positive; dying, GFP + TEP1 positive; dead, TEP1 positive). The total number of ookinetes scored for each treatment group is given in parentheses next to the inj...
Data
Prophenoloxidase but not TEP1 or LRIM1 associates with Lp particles. (A, top panel) Coomassie-stained polyacrylamide gel resolving mosquito proteins fractionated on a potassium bromide gradient. Molecular weight standards are indicated on the left. Lp subunits (ApoI and ApoII, circled red in lane 1) are the main proteins detectable in top gradient...
Data
The supplemental text describes lipophorin particle purification from adult mosquitoes by potassium bromide gradient fractionation or immuno-precipitation and a search for immune factors that co-purify with lipophorin. (0.10 MB DOC)
Article
Full-text available
Despite the abundance of studies conducted on the role of mosquitoes in malaria transmission, the biology and interaction of Plasmodium with its insect host still holds many mysteries. This paper provides the first study to follow the sporogonic cycle of Plasmodium vivax in a wild insecticide-resistant mysorensis strain of Anopheles stephensi, a ma...
Article
Nitric oxide (NO) is a key immune effector and signaling molecule in many organisms. However, the contribution NO makes towards insect immunity has received little attention, particularly in non-dipteran species. In this study, tissue- and time-specific alterations in NO synthase (NOS) gene expression and NO production were documented in the hemipt...
Article
Members of the subfamily Triatominae, family Reduviidae, comprise a large number of insect species of which some are vectors of Trypanosoma cruzi, the causative agent of Chagas' disease. This article outlines research on the process of transformation and the dynamics of developmental stages of Trypanosoma cruzi in the triatomine insect hosts. Speci...
Article
Full-text available
The midgut epithelium of the mosquito malaria vector Anopheles is a hostile environment for Plasmodium, with most parasites succumbing to host defenses. This study addresses morphological and ultrastructural features associated with Plasmodium berghei ookinete invasion in Anopheles gambiae midguts to define the sites and possible mechanisms of para...
Article
The malaria parasite Plasmodium has an absolute requirement for both a vertebrate and a mosquito host in order to complete its life cycle, and its interactions with the latter provide the focus for this review. The mosquito midgut represents one of the most challenging environments for the survival and development of Plasmodium, and is thus also on...
Article
To investigate the molecular mechanism of the early-stage encapsulation reaction in insects, we purified a 47kDa protein from injected beads into Galleria mellonella larvae. When a cDNA clone was isolated, the 47kDa protein showed high homology with Drosophila and human calreticulin. Western blotting analysis showed that the 47kDa protein was prese...
Article
This study compares aspects of the superoxide, nitric oxide and prophenoloxidase pathways in Rhodnius prolixus hemolymph, measured in parallel, in response to Trypanosoma rangeli inoculation. Responses to two strains of T. rangeli, and two developmental forms, were studied, and the results obtained were correlated with the ability of the parasites...
Article
The respiratory burst is an NADPH oxidase-driven reduction of molecular oxygen to superoxide, which can occur in phagocytic cells as part of an antimicrobial defence, and is well documented among the vertebrates. This paper describes a process resembling the respiratory burst, which occurs in the haemolymph and haemocytes of the cockroach, Blaberus...

Questions

Questions (3)
Question
 The kit is designed for siRNA but the manufacturers claim it works equally well for dsRNA. I am hoping to use it for my dsRNAs (450-650bp), but as the kit is very expensive, it would be good to know first if anyone could share helpful tips or cautions. Many thanks.