Background: Human African trypanosomiasis (HAT) develops in two stages namely early stage when tr... more Background: Human African trypanosomiasis (HAT) develops in two stages namely early stage when trypanosomes are found in the blood and late stage when trypanosomes are found in the central nervous system (CNS). The two environments are different with CNS environment reported as being hostile to the trypanosomes than the blood environment. The clinical symptoms manifested by the disease in the two environments are different. Information on whether blood stream are pathologically different from CNS trypanosomes is lacking. This study undertook to compare the inter-isolate pathological differences caused by bloodstream forms (BSF) and central nervous system (CNS) of five Trypanosoma brucei rhodesiense (Tbr) isolates in Swiss white mice. Methods: Donor mice infected with each of the five isolates were euthanized at 21 days post infection (DPI) for recovery of BSF trypanosomes in heart blood and CNS trypanosomes in brain supernatants. Groups of Swiss white mice (n = 10) were then infecte...
Savannah tsetse flies avoid flying toward tsetse fly-refractory waterbuck (Kobus defassa) mediate... more Savannah tsetse flies avoid flying toward tsetse fly-refractory waterbuck (Kobus defassa) mediated by a repellent blend of volatile compounds in their body odor comprised of δ-octalactone, geranyl acetone, phenols (guaiacol and carvacrol), and homologues of carboxylic acids (C5-C10) and 2-alkanones (C8-C13). However, although the blends of carboxylic acids and that of 2-alkanones contributed incrementally to the repellency of the waterbuck odor to savannah tsetse flies, some waterbuck constituents (particularly, nonanoic acid and 2-nonanone) showed significant attractive properties. In another study, increasing the ring size of δ-octalactone from six to seven membered ring changed the activity of the resulting molecule (ε-nonalactone) on the savannah tsetse flies from repellency to attraction. In the present study, we first compared the effect of blending ε-nonalactone, nonanoic acid and 2-nonanone in 1:1 binary and 1:1:1 ternary combination on responses ofGlossina pallidipesandGlos...
Background High-throughput sequencing generates large volumes of biological data that must be int... more Background High-throughput sequencing generates large volumes of biological data that must be interpreted to make meaningful inference on the biological function. Problems arise due to the large number of characteristics p (dimensions) that describe each record [n] in the database. Feature selection using a subset of variables extracted from the large datasets is one of the approaches towards solving this problem. Methodology In this study we analyzed the transcriptome of Glossina morsitans morsitans (Tsetsefly) antennae after exposure to either a repellant (δ-nonalactone) or an attractant (ε-nonalactone). We identified 308 genes that were upregulated or downregulated due to exposure to a repellant (δ-nonalactone) or an attractant (ε-nonalactone) respectively. Weighted gene coexpression network analysis was used to cluster the genes into 12 modules and filter unconnected genes. Discretized and association rule mining was used to find association between genes thereby predicting the ...
Odor from preferred/non-preferred tsetse fly vertebrate hosts have been exploited in R&D of attra... more Odor from preferred/non-preferred tsetse fly vertebrate hosts have been exploited in R&D of attractants/repellents of the fly for human and livestock protection. Odors from vertebrate hosts of Glossina austeni and Glossina pallidipes tsetse flies can facilitate formulation of novel attractants effective against G. austeni or improvement of existing attractant blends for G. pallidipes. We compared vertebrate blood meal sources of both fly species at Shimba Hills National Reserve, Kenya, to establish putative preferred host of either species, hence potential source of G. austeni or G. pallidipes specific odors. We trapped sympatric adult flies in 2021 and 2022 using NGU traps/sticky panels baited with 3-propylphenol, octenol, p-cresol, and acetone (POCA), collected their blood meals and characterized the meals using High Resolution Melting (HRM) vertebrate 16S rRNA- PCR (for host identification), and compared host profiles using GLM and Fisher’s exact tests. We collected 168 and 62 sy...
Tsetse flies use antennal expressed genes to navigate their environment. While most canonical gen... more Tsetse flies use antennal expressed genes to navigate their environment. While most canonical genes associated with chemoreception are annotated, potential gaps with important antennal genes are uncharacterized in Glossina morsitans morsitans. We generated antennae-specific transcriptomes from adult male G. m. morsitans flies fed/unfed on bloodmeal and/or exposed to an attractant (ε-nonalactone), a repellant (δ-nonalactone) or paraffin diluent. Using bioinformatics approach, we mapped raw reads onto G. m. morsitans gene-set from VectorBase and collected un-mapped reads (constituting the gaps in annotation). We de novo assembled these reads (un-mapped) into transcript and identified corresponding genes of the transcripts in G. m. morsitans gene-set and protein homologs in UniProt protein database to further annotate the gaps. We predicted potential protein-coding gene regions associated with these transcripts in G. m. morsitans genome, annotated/curated these genes and identified the...
<p>Both clades I and II show one to one orthology of the specific SNMP from different insec... more <p>Both clades I and II show one to one orthology of the specific SNMP from different insect species. Different symbols depict SNMPs from the different species at the terminal nodes: <i>Glossina austeni</i> (red*), <i>Glossina brevipalpis</i> (purple*), <i>Glossina fuscipes fuscipes</i> (pink*), <i>Glossina morsitans morsitans</i> (dark blue*), <i>Glossina pallidipes</i> (light orange*), <i>Drosophila melanogaster (black*)</i>, <i>Anopheles gambiae</i> (sky blue*) <i>and Musca domestica</i> (lime green*). The symbol * represents the name of the specific SNMP. Sequence alignment was performed using MuSCLE v3.8.31 and phylogeny relationship was inferred using RAxML v8 with best fitting Wheelan and Goldman (WAG) model and 1000 bootstrap iterations. Phylogenetic relationships of GRs identified in Glossina genes and their homologs in <i>An</i>. <i>gambiae</i>, <i>D</i>. <i>melanogaster</i> and <i>M</i>. <i>domestica</i> are shown in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.g006" target="_blank">Fig 6</a>. In all the tsetse species, there was expansion of Gr21a, associated with CO<sub>2</sub> detection in fruit fly and mosquitoes [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.ref064" target="_blank">64</a>,<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.ref065" target="_blank">65</a>]. Similarly, expansion of CO2 receptors was noted in <i>An</i>. <i>gambiae</i> which has expanded Gr63a, a protein co-expressed with Gr21a and involved in CO<sub>2</sub> detection [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.ref065" target="_blank">65</a>]. No homologs to sugar receptors in <i>D</i>. <i>melanogaster</i> [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.ref066" target="_blank">66</a>] were identified in any of the five <i>Glossina species (</i><a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.g006" target="_blank">Fig 6</a><i>)</i>. Similarly, <i>D</i>. <i>melanogaster</i> Gr43a, implicated in internal fructose sensing [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.ref067" target="_blank">67</a>] was absent in all tsetse species.</p
Background: Human African trypanosomiasis (HAT) develops in two stages namely early stage when tr... more Background: Human African trypanosomiasis (HAT) develops in two stages namely early stage when trypanosomes are found in the blood and late stage when trypanosomes are found in the central nervous system (CNS). The two environments are different with CNS environment reported as being hostile to the trypanosomes than the blood environment. The clinical symptoms manifested by the disease in the two environments are different. Information on whether blood stream are pathologically different from CNS trypanosomes is lacking. This study undertook to compare the inter-isolate pathological differences caused by bloodstream forms (BSF) and central nervous system (CNS) of five Trypanosoma brucei rhodesiense (Tbr) isolates in Swiss white mice. Methods: Donor mice infected with each of the five isolates were euthanized at 21 days post infection (DPI) for recovery of BSF trypanosomes in heart blood and CNS trypanosomes in brain supernatants. Groups of Swiss white mice (n = 10) were then infecte...
Savannah tsetse flies avoid flying toward tsetse fly-refractory waterbuck (Kobus defassa) mediate... more Savannah tsetse flies avoid flying toward tsetse fly-refractory waterbuck (Kobus defassa) mediated by a repellent blend of volatile compounds in their body odor comprised of δ-octalactone, geranyl acetone, phenols (guaiacol and carvacrol), and homologues of carboxylic acids (C5-C10) and 2-alkanones (C8-C13). However, although the blends of carboxylic acids and that of 2-alkanones contributed incrementally to the repellency of the waterbuck odor to savannah tsetse flies, some waterbuck constituents (particularly, nonanoic acid and 2-nonanone) showed significant attractive properties. In another study, increasing the ring size of δ-octalactone from six to seven membered ring changed the activity of the resulting molecule (ε-nonalactone) on the savannah tsetse flies from repellency to attraction. In the present study, we first compared the effect of blending ε-nonalactone, nonanoic acid and 2-nonanone in 1:1 binary and 1:1:1 ternary combination on responses ofGlossina pallidipesandGlos...
Background High-throughput sequencing generates large volumes of biological data that must be int... more Background High-throughput sequencing generates large volumes of biological data that must be interpreted to make meaningful inference on the biological function. Problems arise due to the large number of characteristics p (dimensions) that describe each record [n] in the database. Feature selection using a subset of variables extracted from the large datasets is one of the approaches towards solving this problem. Methodology In this study we analyzed the transcriptome of Glossina morsitans morsitans (Tsetsefly) antennae after exposure to either a repellant (δ-nonalactone) or an attractant (ε-nonalactone). We identified 308 genes that were upregulated or downregulated due to exposure to a repellant (δ-nonalactone) or an attractant (ε-nonalactone) respectively. Weighted gene coexpression network analysis was used to cluster the genes into 12 modules and filter unconnected genes. Discretized and association rule mining was used to find association between genes thereby predicting the ...
Odor from preferred/non-preferred tsetse fly vertebrate hosts have been exploited in R&D of attra... more Odor from preferred/non-preferred tsetse fly vertebrate hosts have been exploited in R&D of attractants/repellents of the fly for human and livestock protection. Odors from vertebrate hosts of Glossina austeni and Glossina pallidipes tsetse flies can facilitate formulation of novel attractants effective against G. austeni or improvement of existing attractant blends for G. pallidipes. We compared vertebrate blood meal sources of both fly species at Shimba Hills National Reserve, Kenya, to establish putative preferred host of either species, hence potential source of G. austeni or G. pallidipes specific odors. We trapped sympatric adult flies in 2021 and 2022 using NGU traps/sticky panels baited with 3-propylphenol, octenol, p-cresol, and acetone (POCA), collected their blood meals and characterized the meals using High Resolution Melting (HRM) vertebrate 16S rRNA- PCR (for host identification), and compared host profiles using GLM and Fisher’s exact tests. We collected 168 and 62 sy...
Tsetse flies use antennal expressed genes to navigate their environment. While most canonical gen... more Tsetse flies use antennal expressed genes to navigate their environment. While most canonical genes associated with chemoreception are annotated, potential gaps with important antennal genes are uncharacterized in Glossina morsitans morsitans. We generated antennae-specific transcriptomes from adult male G. m. morsitans flies fed/unfed on bloodmeal and/or exposed to an attractant (ε-nonalactone), a repellant (δ-nonalactone) or paraffin diluent. Using bioinformatics approach, we mapped raw reads onto G. m. morsitans gene-set from VectorBase and collected un-mapped reads (constituting the gaps in annotation). We de novo assembled these reads (un-mapped) into transcript and identified corresponding genes of the transcripts in G. m. morsitans gene-set and protein homologs in UniProt protein database to further annotate the gaps. We predicted potential protein-coding gene regions associated with these transcripts in G. m. morsitans genome, annotated/curated these genes and identified the...
<p>Both clades I and II show one to one orthology of the specific SNMP from different insec... more <p>Both clades I and II show one to one orthology of the specific SNMP from different insect species. Different symbols depict SNMPs from the different species at the terminal nodes: <i>Glossina austeni</i> (red*), <i>Glossina brevipalpis</i> (purple*), <i>Glossina fuscipes fuscipes</i> (pink*), <i>Glossina morsitans morsitans</i> (dark blue*), <i>Glossina pallidipes</i> (light orange*), <i>Drosophila melanogaster (black*)</i>, <i>Anopheles gambiae</i> (sky blue*) <i>and Musca domestica</i> (lime green*). The symbol * represents the name of the specific SNMP. Sequence alignment was performed using MuSCLE v3.8.31 and phylogeny relationship was inferred using RAxML v8 with best fitting Wheelan and Goldman (WAG) model and 1000 bootstrap iterations. Phylogenetic relationships of GRs identified in Glossina genes and their homologs in <i>An</i>. <i>gambiae</i>, <i>D</i>. <i>melanogaster</i> and <i>M</i>. <i>domestica</i> are shown in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.g006" target="_blank">Fig 6</a>. In all the tsetse species, there was expansion of Gr21a, associated with CO<sub>2</sub> detection in fruit fly and mosquitoes [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.ref064" target="_blank">64</a>,<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.ref065" target="_blank">65</a>]. Similarly, expansion of CO2 receptors was noted in <i>An</i>. <i>gambiae</i> which has expanded Gr63a, a protein co-expressed with Gr21a and involved in CO<sub>2</sub> detection [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.ref065" target="_blank">65</a>]. No homologs to sugar receptors in <i>D</i>. <i>melanogaster</i> [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.ref066" target="_blank">66</a>] were identified in any of the five <i>Glossina species (</i><a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.g006" target="_blank">Fig 6</a><i>)</i>. Similarly, <i>D</i>. <i>melanogaster</i> Gr43a, implicated in internal fructose sensing [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004421#pntd.0004421.ref067" target="_blank">67</a>] was absent in all tsetse species.</p
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