Expression of chemosensory proteins in the tsetse fly Glossina morsitans morsitans is related to female host-seeking behaviour.

Chemosensory proteins (CSPs) are a class of soluble proteins present in high concentrations in the sensilla of insect antennae. It has been proposed that they play an important role in insect olfaction by mediating interactions between odorants and odorant receptors. Here we report, for the first time, the presence of five CSP genes in the tsetse fly Glossina morsitans morsitans, a major vector transmitting nagana in livestock.

Tsetse EP protein protects the fly midgut from trypanosome establishment.

African trypanosomes undergo a complex developmental process in their tsetse fly vector before transmission back to a vertebrate host. Typically, 90% of fly infections fail, most during initial establishment of the parasite in the fly midgut. The specific mechanism(s) underpinning this failure are unknown.

Characterisations of odorant-binding proteins in the tsetse fly Glossina morsitans morsitans.

Odorant-binding proteins (OBPs) play an important role in insect olfaction by mediating interactions between odorants and odorant receptors. We report for the first time 20 OBP genes in the tsetse fly Glossina morsitans morsitans. qRT-PCR revealed that 8 of these genes were highly transcribed in the antennae.

Prolonged gene knockdown in the tsetse fly Glossina by feeding double stranded RNA.

Reverse genetic studies based on RNA interference (RNAi) have revolutionized analysis of gene function in most insects. However the necessity of injecting double stranded RNA (dsRNA) inevitably compromises many investigations particularly those on immunity. Additionally, injection of tsetse flies often causes significant mortality.

Differential expression of fat body genes in Glossina morsitans morsitans following infection with Trypanosoma brucei brucei.

To determine which fat body genes were differentially expressed following infection of Glossina morsitans morsitans with Trypanosoma brucei brucei we generated four suppression subtractive hybridisation (SSH) libraries. We obtained 52 unique gene fragments (SSH clones) of which 30 had a known orthologue at E-05 or less. Overall the characteristics of the orthologues suggest: (i) that trypanosome infection has a considerable effect on metabolism in the tsetse fly; (ii) that self-cured flies are mounting an oxidative stress response; and (iii) that self-cured flies are displaying increased energy usage.

Antioxidant gene expression in the blood-feeding fly Glossina morsitans morsitans.

We report the characterization of 11 antioxidant genes from the tsetse fly Glossina m. morsitans. Through similarity searches which detected homology we suggest that these genes consist of two superoxide dismutases (one with a putative signal peptide), three thioredoxin peroxidases (one with a putative signal peptide), three peroxiredoxins, one further signal peptide-containing peroxidase with its closest similarity to a glutathione peroxidase, one catalase and one thioredoxin reductase.

The use of specific and generic primers to identify trypanosome infections of wild tsetse flies in Tanzania by PCR.

The accurate identification of trypanosome species and subspecies remains a challenging task in the epidemiology of human and animal trypanosomiasis in tropical Africa. Currently, there are specific PCR tests to identify about 10 different species, subspecies or subgroups of African tsetse-transmitted trypanosomes. These PCR tests have been used here to identify trypanosomes in four species of tsetse (Glossina brevipalpis, G.

Adult midgut expressed sequence tags from the tsetse fly Glossina morsitans morsitans and expression analysis of putative immune response genes.

Background: Tsetse flies transmit African trypanosomiasis leading to half a million cases annually. Trypanosomiasis in animals (nagana) remains a massive brake on African agricultural development. While trypanosome biology is widely studied, knowledge of tsetse flies is very limited, particularly at the molecular level.

Molecular cloning and sequencing of salivary gland-specific cDNAs of the blood-sucking bug Triatoma brasiliensis (Hemiptera: Reduviidae).

Haematophagous insects produce pharmacological substances in their saliva to counteract vertebrate host haemostasis events such as coagulation, vasoconstriction and platelet aggregation. To investigate the bioactive salivary molecules of the triatomine bug Triatoma brasiliensis, we produced subtraction-enriched cDNAs of salivary-gland specific genes using suppression subtractive hybridization. Six full-length differentially expressed cDNAs (Tb113, Tb125, Tb152, Tb169, Tb180 and Tb198) were selected, cloned and sequenced.

Association of midgut defensin with a novel serine protease in the blood-sucking fly Stomoxys calcitrans.

Using ELISA we provide direct evidence that the midgut defensins of the blood-sucking fly Stomoxys calcitrans are secreted into the gut lumen. We show that midgut defensin peptide levels increase up to fortyfold in response to a blood meal but not to a sugar meal. The data suggests the midgut defensin genes are post-transcriptionally regulated and that their function is protection of the stored blood meal from bacterial attack while it awaits digestion.

Regulation of midgut defensin production in the blood-sucking insect Stomoxys calcitrans.

The Stomoxys midgut defensin (Smd) family of genes are exclusively expressed in the anterior midgut of adult flies. Their putative function is protection of the stored bloodmeal from microbial attack. Smd genes are constitutively expressed, up-regulated in response to a bloodmeal and further up-regulated by immune stimulation per os but only in the presence of a bloodmeal not a sugar meal.

Grouping of trypanosome species in mixed infections in Glossina pallidipes.

Trypanosomes in the dissection-positive proboscis of Glossina pallidipes were identified by PCR using species-specific primers. Of the 3741 flies dissected 643 were proboscis positive. PCR was performed on 406 dissection-positive probosces giving positive identifications in 352 (86.

Cloning, sequencing, temporal expression and tissue-specificity of two serine proteases from the midgut of the blood-feeding fly Stomoxys calcitrans.

Using highly degenerate, serine-protease-specific PCR primers on a midgut-specific cDNA library it was estimated that a minimum of 24 independent serine proteases were expressed in the midgut of Stomoxys calcitrans. The relative abundance of these 24 independent serine proteases has been estimated by restriction analysis of PCR products, showing that 69% fall into six almost equally abundant groups. Two highly abundant serine protease cDNAs (Ssp1 and Ssp2) were isolated and sequenced.

Midgut-specific immune molecules are produced by the blood-sucking insect Stomoxys calcitrans.

We have cloned and sequenced two defensins, Smd1 and Smd2, from anterior midgut tissue of the blood-sucking fly Stomoxys calcitrans. The DNA and N-terminal protein sequences suggest both are produced as prepropeptides. Smd1 differs from the classic defensin pattern in having an unusual six-amino acid-long N-terminal sequence.