The American Journal of Tropical Medicine and Hygiene, 2020
Tsetse flies of the palpalis group, particularly Glossina fuscipes, are the main vectors of human... more Tsetse flies of the palpalis group, particularly Glossina fuscipes, are the main vectors of human African trypanosomiasis or sleeping sickness in Congo-Brazzaville. They transmit the deadly human parasite, Trypanosoma brucei gambiense and other trypanosomes that cause animal trypanosomiasis. Knowledge on diversity, population structure, population size, and gene flow is a prerequisite for designing effective tsetse control strategies. There is limited published information on these parameters including migration patterns of G. fuscipes in Congo-Brazzaville. We genotyped 288 samples of G. fuscipes from Bomassa (BMSA), Bouemba (BEMB), and Talangai (TLG) locations at 10 microsatellite loci and determined levels of genetic diversity, differentiation, structuring, and gene flow among populations. We observed high genetic diversity in all three localities. Mean expected heterozygosity was 0.77 ± 0.04, and mean allelic richness was 11.2 ± 1.35. Deficiency of heterozygosity was observed in all populations with positive and significant F IS values (0.077-0.149). Structure analysis revealed three clusters with genetic admixtures, evidence of closely related but potentially different taxa within G. fuscipes. Genetic differentiation indices were low but significant (F ST = 0.049, P < 0.05), indicating ongoing gene flow countered with a stronger force of drift. We recorded significant migration from all the three populations, suggesting exchange of genetic information between and among locations. Ne estimates revealed high and infinite population sizes in BEMB and TLG. These critical factors should be considered when planning area-wide tsetse control interventions in the country to prevent resurgence of tsetse from relict populations and/or reinvasion of cleared habitats.
Microsatellite dataset used in this study. This file includes the genotypes for 11 microsatellite... more Microsatellite dataset used in this study. This file includes the genotypes for 11 microsatellite loci for both historic and modern black rhinoceros samples. Individuals represent 12 populations and are numbered from 1-560
The black rhinoceros is again on the verge of extinction due to unsustainable poaching in its nat... more The black rhinoceros is again on the verge of extinction due to unsustainable poaching in its native range. Despite a wide historic distribution, the black rhinoceros was traditionally thought of as depauperate in genetic variation, and with very little known about its evolutionary history. This knowledge gap has hampered conservation efforts because hunting has dramatically reduced the species’ once continuous distribution, leaving five surviving gene pools of unknown genetic affinity. Here we examined the range-wide genetic structure of historic and modern populations using the largest and most geographically representative sample of black rhinoceroses ever assembled. Using both mitochondrial and nuclear datasets, we described a staggering loss of 69% of the species’ mitochondrial genetic variation, including the most ancestral lineages that are now absent from modern populations. Genetically unique populations in countries such as Nigeria, Cameroon, Chad, Eritrea, Ethiopia, Somalia, Mozambique, Malawi and Angola no longer exist. We found that the historic range of the West African subspecies (D. b. longipes), declared extinct in 2011, extends into southern Kenya, where a handful of individuals survive in the Masai Mara. We also identify conservation units that will help maintain evolutionary potential. Our results suggest a complete re-evaluation of current conservation management paradigms for the black rhinoceros
E-learning is a global move and Kenya has not been left behind. Like any other developing country... more E-learning is a global move and Kenya has not been left behind. Like any other developing country, learning resources cannot meet the ever increasing demand of university education with over 120,000 qualifiers every year. Advancements in ICT have created opportunities and allowed exploration of delivery methods that utilize these opportunities. This paper documents the strategy used to roll out successful e-Learning programmes at one of the Kenyan public universities and its constituent colleges. Although the initial investment in content development and systems establishment was enormous, return on investment at JKUAT was realised almost immediately after e-Learning for on -campus students was launched. More than USD 100,000 was saved within a period of less than one year. The paper is a form of showcase of what worked well and why we believe it worked. Every new student was required to report with a Laptop or be facilitated to acquire one through a university programme. Innovative...
Peroxisomes resolve oxidant mediated inflammatory disease conditions by releasing antioxidant enz... more Peroxisomes resolve oxidant mediated inflammatory disease conditions by releasing antioxidant enzymes that degrade reactive oxygen and nitrogen intermediates. Despite incessant exposure of the avian respiratory system to exogenous and endogenous oxidants with subsequent risk of oxidant mediated inflammatory injury, information regarding distribution of peroxisome and catalase in the chicken respiratory system is unknown. The aim of this study was to establish distribution of peroxisomes and catalase in the chicken trachea, bronchi and lung tissues. Peroxisomes formed fine electron dense granular matrix following reaction with 3,3’-diaminobenzidine and were spherical in shape with an average diameter of 1 μm. Peroxisomes were equivalently (P ≥ 0.05) distributed in the lung and bronchi tissues which had a mean volume density of 38 ± 1.5% and 37 ± 1.7% respectively. However, in the trachea, peroxisomes were significantly (P ≤ 0.05) fewer than in the bronchi and lung tissues. The mean v...
The aims of this study were to follow up on the establishment of Cotesia vestalis in the coastal ... more The aims of this study were to follow up on the establishment of Cotesia vestalis in the coastal regions of Kenya, assessing its contribution in the management of the diamondback moth (Plutella xylostella), parasitism rates, and cultural practices affecting its establishment. Post-release surveys were carried out in five counties in Kenya, Kitui, Kajiado, Kwale, Machakos and Makueni, between 2015 and 2016. The results showed that the overall parasitism rate of C. vestalis in 2015 ranged between 0% and 37.86% while that in 2016 ranged from 0% to 32.19% in the different counties. Farmers carry out routine sprays, either weekly or fortnightly, with different synthetic insecticides. Pyrethroids (60.56%) constituted most of the insecticides used, while only 3.18% of the products used were plant or microorganism- based. Farmers did most of their cabbage production during the rainy season, with production being greatly reduced during the dry seasons. The sampled diamondback moths from Kaji...
Growth and mortality variations of Leptoscarus vaigiensis was studied among six reef sites expose... more Growth and mortality variations of Leptoscarus vaigiensis was studied among six reef sites exposed to different fishing pressure in coastal Kenya in order to test the hypothesis of phenotypic plasticity. Monthly fish samples were obtained from marine parks (protected no-take areas), marine reserves (partially protected areas) and non-protected reefs from May 2011 to April 2013, and were measured for total lengths (cm) and body weights (g). Growth (K, L∞) and mortality (Z, M, F) parameters of the species were determined using the ELEFAN I program and compared between sites. Results showed higher asymptotic length (L∞) estimate (~ 31 cm) for parrotfish from a reserve site and lowest estimate (26-27 cm) from a marine park site. Fish from park sites had equal but lowest growth rates (K yr-1) of 0.46 compared to 1.73 ± 0.11 and 1.36 ± 0.84 for fish from park and reserve sites, respectively. Total mortality estimates (Z yr-1) were lower for protected areas ...
The black rhinoceros is again on the verge of extinction due to unsustainable poaching in its nat... more The black rhinoceros is again on the verge of extinction due to unsustainable poaching in its native range. Despite a wide historic distribution, the black rhinoceros was traditionally thought of as depauperate in genetic variation, and with very little known about its evolutionary history. This knowledge gap has hampered conservation efforts because hunting has dramatically reduced the species' once continuous distribution, leaving five surviving gene pools of unknown genetic affinity. Here we examined the range-wide genetic structure of historic and modern populations using the largest and most geographically representative sample of black rhinoceroses ever assembled. Using both mitochondrial and nuclear datasets, we described a staggering loss of 69% of the species' mitochondrial genetic variation, including the most ancestral lineages that are now absent from modern populations. Genetically unique populations in countries such as Nigeria, Cameroon, Chad, Eritrea, Ethiopi...
The American Journal of Tropical Medicine and Hygiene, 2020
Tsetse flies of the palpalis group, particularly Glossina fuscipes, are the main vectors of human... more Tsetse flies of the palpalis group, particularly Glossina fuscipes, are the main vectors of human African trypanosomiasis or sleeping sickness in Congo-Brazzaville. They transmit the deadly human parasite, Trypanosoma brucei gambiense and other trypanosomes that cause animal trypanosomiasis. Knowledge on diversity, population structure, population size, and gene flow is a prerequisite for designing effective tsetse control strategies. There is limited published information on these parameters including migration patterns of G. fuscipes in Congo-Brazzaville. We genotyped 288 samples of G. fuscipes from Bomassa (BMSA), Bouemba (BEMB), and Talangai (TLG) locations at 10 microsatellite loci and determined levels of genetic diversity, differentiation, structuring, and gene flow among populations. We observed high genetic diversity in all three localities. Mean expected heterozygosity was 0.77 ± 0.04, and mean allelic richness was 11.2 ± 1.35. Deficiency of heterozygosity was observed in all populations with positive and significant F IS values (0.077-0.149). Structure analysis revealed three clusters with genetic admixtures, evidence of closely related but potentially different taxa within G. fuscipes. Genetic differentiation indices were low but significant (F ST = 0.049, P < 0.05), indicating ongoing gene flow countered with a stronger force of drift. We recorded significant migration from all the three populations, suggesting exchange of genetic information between and among locations. Ne estimates revealed high and infinite population sizes in BEMB and TLG. These critical factors should be considered when planning area-wide tsetse control interventions in the country to prevent resurgence of tsetse from relict populations and/or reinvasion of cleared habitats.
Microsatellite dataset used in this study. This file includes the genotypes for 11 microsatellite... more Microsatellite dataset used in this study. This file includes the genotypes for 11 microsatellite loci for both historic and modern black rhinoceros samples. Individuals represent 12 populations and are numbered from 1-560
The black rhinoceros is again on the verge of extinction due to unsustainable poaching in its nat... more The black rhinoceros is again on the verge of extinction due to unsustainable poaching in its native range. Despite a wide historic distribution, the black rhinoceros was traditionally thought of as depauperate in genetic variation, and with very little known about its evolutionary history. This knowledge gap has hampered conservation efforts because hunting has dramatically reduced the species’ once continuous distribution, leaving five surviving gene pools of unknown genetic affinity. Here we examined the range-wide genetic structure of historic and modern populations using the largest and most geographically representative sample of black rhinoceroses ever assembled. Using both mitochondrial and nuclear datasets, we described a staggering loss of 69% of the species’ mitochondrial genetic variation, including the most ancestral lineages that are now absent from modern populations. Genetically unique populations in countries such as Nigeria, Cameroon, Chad, Eritrea, Ethiopia, Somalia, Mozambique, Malawi and Angola no longer exist. We found that the historic range of the West African subspecies (D. b. longipes), declared extinct in 2011, extends into southern Kenya, where a handful of individuals survive in the Masai Mara. We also identify conservation units that will help maintain evolutionary potential. Our results suggest a complete re-evaluation of current conservation management paradigms for the black rhinoceros
E-learning is a global move and Kenya has not been left behind. Like any other developing country... more E-learning is a global move and Kenya has not been left behind. Like any other developing country, learning resources cannot meet the ever increasing demand of university education with over 120,000 qualifiers every year. Advancements in ICT have created opportunities and allowed exploration of delivery methods that utilize these opportunities. This paper documents the strategy used to roll out successful e-Learning programmes at one of the Kenyan public universities and its constituent colleges. Although the initial investment in content development and systems establishment was enormous, return on investment at JKUAT was realised almost immediately after e-Learning for on -campus students was launched. More than USD 100,000 was saved within a period of less than one year. The paper is a form of showcase of what worked well and why we believe it worked. Every new student was required to report with a Laptop or be facilitated to acquire one through a university programme. Innovative...
Peroxisomes resolve oxidant mediated inflammatory disease conditions by releasing antioxidant enz... more Peroxisomes resolve oxidant mediated inflammatory disease conditions by releasing antioxidant enzymes that degrade reactive oxygen and nitrogen intermediates. Despite incessant exposure of the avian respiratory system to exogenous and endogenous oxidants with subsequent risk of oxidant mediated inflammatory injury, information regarding distribution of peroxisome and catalase in the chicken respiratory system is unknown. The aim of this study was to establish distribution of peroxisomes and catalase in the chicken trachea, bronchi and lung tissues. Peroxisomes formed fine electron dense granular matrix following reaction with 3,3’-diaminobenzidine and were spherical in shape with an average diameter of 1 μm. Peroxisomes were equivalently (P ≥ 0.05) distributed in the lung and bronchi tissues which had a mean volume density of 38 ± 1.5% and 37 ± 1.7% respectively. However, in the trachea, peroxisomes were significantly (P ≤ 0.05) fewer than in the bronchi and lung tissues. The mean v...
The aims of this study were to follow up on the establishment of Cotesia vestalis in the coastal ... more The aims of this study were to follow up on the establishment of Cotesia vestalis in the coastal regions of Kenya, assessing its contribution in the management of the diamondback moth (Plutella xylostella), parasitism rates, and cultural practices affecting its establishment. Post-release surveys were carried out in five counties in Kenya, Kitui, Kajiado, Kwale, Machakos and Makueni, between 2015 and 2016. The results showed that the overall parasitism rate of C. vestalis in 2015 ranged between 0% and 37.86% while that in 2016 ranged from 0% to 32.19% in the different counties. Farmers carry out routine sprays, either weekly or fortnightly, with different synthetic insecticides. Pyrethroids (60.56%) constituted most of the insecticides used, while only 3.18% of the products used were plant or microorganism- based. Farmers did most of their cabbage production during the rainy season, with production being greatly reduced during the dry seasons. The sampled diamondback moths from Kaji...
Growth and mortality variations of Leptoscarus vaigiensis was studied among six reef sites expose... more Growth and mortality variations of Leptoscarus vaigiensis was studied among six reef sites exposed to different fishing pressure in coastal Kenya in order to test the hypothesis of phenotypic plasticity. Monthly fish samples were obtained from marine parks (protected no-take areas), marine reserves (partially protected areas) and non-protected reefs from May 2011 to April 2013, and were measured for total lengths (cm) and body weights (g). Growth (K, L∞) and mortality (Z, M, F) parameters of the species were determined using the ELEFAN I program and compared between sites. Results showed higher asymptotic length (L∞) estimate (~ 31 cm) for parrotfish from a reserve site and lowest estimate (26-27 cm) from a marine park site. Fish from park sites had equal but lowest growth rates (K yr-1) of 0.46 compared to 1.73 ± 0.11 and 1.36 ± 0.84 for fish from park and reserve sites, respectively. Total mortality estimates (Z yr-1) were lower for protected areas ...
The black rhinoceros is again on the verge of extinction due to unsustainable poaching in its nat... more The black rhinoceros is again on the verge of extinction due to unsustainable poaching in its native range. Despite a wide historic distribution, the black rhinoceros was traditionally thought of as depauperate in genetic variation, and with very little known about its evolutionary history. This knowledge gap has hampered conservation efforts because hunting has dramatically reduced the species' once continuous distribution, leaving five surviving gene pools of unknown genetic affinity. Here we examined the range-wide genetic structure of historic and modern populations using the largest and most geographically representative sample of black rhinoceroses ever assembled. Using both mitochondrial and nuclear datasets, we described a staggering loss of 69% of the species' mitochondrial genetic variation, including the most ancestral lineages that are now absent from modern populations. Genetically unique populations in countries such as Nigeria, Cameroon, Chad, Eritrea, Ethiopi...
Honey bee population worldwide is dwindling due to a number of interrelated factors among them pa... more Honey bee population worldwide is dwindling due to a number of interrelated factors among them pathogens such as viruses, bacteria, fungi and metazoan parasites. These factors negatively affect agricultural production as well as the apiculture industry which is dependent on a seasonal abundance of honey bees year-round. As a result, food security and livelihood is compromised due to loss of pollinators. Majority of viruses infecting honey bees are positive-sense single-stranded RNA viruses of the order Picornavirales. The economically important viruses of bees in this order belong to family Dicistroviridae and Iflaviridae. Paenibacillus larvae and Melisococcus plutonius are bacteria known to cause bee brood diseases. This study aimed at identifying the viruses circulating in Kenyan honey bee colonies using next generation sequencing. Ribonucleic acid (RNA) was extracted from sixteen libraries and was used in cDNA synthesis using superscript II. The cDNA converted to dsDNA using Klenow reaction and used in amplification. 454 pyro sequencing was performed on genome sequencer FLX system. The resultant single reads were analyzed using CLC Genomic workbench. The reads were mapped on the full genomes of the identified viruses and then de novo assembled. The resultant contigs were interrogated using basic alignment search tool (BLAST) on national center for biotechnology information (NCBI) database. The contigs were exported to MEGA6 and used in phylogenetic analysis. The viruses identified belonged to family Iflaviridae and included deformed wing virus, Kakugo virus and Varroa destructor virus-1. Melissococcus plutonius and Enterococcus faecalis were also detected. Of the sixteen libraries sequenced, two libraries; Busia_adult and Siaya_brood reported the incidences of iflaviruses while five libraries had reads matching with M. plutonius and E. faecalis. There is need for a strategy in place for the management of bee diseases to enhance bee health and quality of hive products.
Key words: Bee viruses, Paenibacillus larvae, Melissococcus plutonius, Iflavirus, Next generation sequencing R Skilton2, S Muya3, G Michuki2, S Kabochi1, H Kutima3 and M Kasina4
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Papers by Shadrack Muya
Key words: Bee viruses, Paenibacillus larvae, Melissococcus plutonius, Iflavirus, Next generation sequencing
R Skilton2, S Muya3, G Michuki2, S Kabochi1, H Kutima3 and M Kasina4