Page 1. Behavior Genetics, Vol. 15, No. 6, 1985 Genetic Stability of Cannibalism in Tribolium con... more Page 1. Behavior Genetics, Vol. 15, No. 6, 1985 Genetic Stability of Cannibalism in Tribolium conflisllm Lori Stevens I and David B. Mertz ~ Received 5 Jan. 1985--Final 17 May 1985 This study reports the stability of genetically ...
Chagas disease caused by T. cruzi is an emerging infectious disease in the United States due to t... more Chagas disease caused by T. cruzi is an emerging infectious disease in the United States due to the immigration of infected individuals from endemic Mexico, Central and South American countries. The American Southwests growing human population has encroached upon the habitat of local triatomines, several of which are competent vectors of T. cruzi among resident small mammals. Human residents are accidental blood meal hosts of these hematophagous bugs. Many human victims suffer anaphylaxis after being bitten by the bugs. We are currently studying the rate of infection by T. cruzi of T. rubida and T. protracta, identifying their blood meal hosts and gathering data on the incidence of anaphylaxis to triatomine bites.
Triatoma dimidiata (Latreille, 1811) is the most abundant and significant insect vector of the pa... more Triatoma dimidiata (Latreille, 1811) is the most abundant and significant insect vector of the parasite Trypanosoma cruzi in Central America, and particularly in Guatemala. Tr. cruzi is the causative agent of Chagas disease, and successful disease control requires understanding the geographic distribution and degree of migration of vectors such as T. dimidiata that frequently re-infest houses within months following insecticide application. The population genetic structure of T. dimidiata collected from six villages in southern Guatemala was studied to gain insight into the migration patterns of the insects in this region where populations are largely domestic. This study provided insight into the likelihood of eliminating T. dimidiata by pesticide application as has been observed in some areas for other domestic triatomines such as Triatoma infestans. Genotypes of microsatellite loci for 178 insects from six villages were found to represent five genetic clusters using a Bayesian Markov Chain Monte Carlo method. Individual clusters were found in multiple villages, with multiple clusters in the same house. Although migration occurred, there was statistically significant genetic differentiation among villages (FR T = 0.05) and high genetic differentiation among houses within villages (FSR = 0.11). Relatedness of insects within houses varied from 0 to 0.25, i.e., from unrelated to half-sibs. The results suggest that T. dimidiata in southern Guatemala moves between houses and villages often enough that recolonization is likely, implying the use of insecticides alone is not sufficient for effective control of Chagas disease in this region and more sustainable solutions are required.
Myxobolus cerebralis, the parasite that causes whirling disease, has been a major contributor to ... more Myxobolus cerebralis, the parasite that causes whirling disease, has been a major contributor to the reduction in trout populations in the Intermountain West, U.S.A. Myxobolus cerebralis has a obligate, two host life cycle: trout produce spores that are infective to the tubificid worm host, Tubifex tubifex, and the worm produces spores that are infective to trout. Evidence collected from both field surveys in watersheds in Montana as well as laboratory experiments suggest that the structure of the worm community plays an important role in the prevalence and severity of disease in fish. Tubifex tubifex is comprised of several genetic lineages that often coexist in stream communities. Our field work has shown lineage I and III (TI and TIII) coexist in Montana streams. Several studies have shown that TIII is a highly susceptible host, more likely to be infected than TI and sometimes producing ten times the number of spores that infect fish than TI. Our field studies using caged trout f...
Tribolium flour beetles produce defensive compounds, including quinones, putatively aimed at dete... more Tribolium flour beetles produce defensive compounds, including quinones, putatively aimed at deterring predators and inhibiting microbes. Here we examine how effective the defensive secretions of Tribolium confusum and T. castaneum are at inhibiting growth of various microbes and how this varies with species, geographic strain, and sex of the beetles. We explore differences at both the kingdom and species level of common flour microbes in their susceptibility to defensive compounds. Beetle species and strains vary in their ability to inhibit microbial growth. In addition, microbes vary in their sensitivity to the beetles' defense compounds. The capability to suppress microbial growth is likely under stabilizing selection with optimum quinone production varying among populations and may be dependent on several environmental factors including temperature, humidity, and predators.
This paper reports on the effects of a cytoplasmically inherited reproductive incompatibility in ... more This paper reports on the effects of a cytoplasmically inherited reproductive incompatibility in different genetic strains of the flour beetle, Tribolium confusum. We measured the rate of spread and the effect of host population size using different initial frequencies of infection with a cytoplasmic factor that mediates reproductive incompatibility. There were two experiments, in one the infected and uninfected lines were from the same genetic strain, b-Yugoslavia. In the other, the infected line was from the "high cannibalism" bIV strain and the uninfected line from the "low cannibalism" bI strain. We estimate that the fitness ratio of infected to uninfected in b-Yugoslavia is 0.63 and the observed rate of spread for this strain corresponds to a model of cytoplasmic inheritance that takes into account the productivity differences between the infected and cured lines. In the bI-bIV experiment, because the uninfected and infected lines are from different genetic ...
In a SINE-based PCR assay, a primer set specific for guinea pig genome short interspersed element... more In a SINE-based PCR assay, a primer set specific for guinea pig genome short interspersed elements DNA was used to test the utility of genomic markers for identifying the source of vertebrate blood meals of Triatoma infestans. The investigation consisted of two assays. In Assay 1, thirty-six insects, collected from the Province of Zudáñez in Chuquisaca, Bolivia were frozen 1-40 hours after feeding, under controlled conditions, on guinea pigs. The species of the vertebrate host was confirmed from dissection of the posterior part of the abdomen of each insect followed by DNA extraction and PCR amplification. Assay 2 investigated whether the technique worked under field conditions. We analyzed the bloodmeal of 34 insects collected from households and peri-domestic structures from communities where wild and captive guinea pigs occur. After collection, the insects were maintained at room temperature for 2 months without feeding and then analyzed. In Assay 1, each of the 36 insects allowe...
Fish diseases are often caused by waterborne parasites, making them ideal systems for modeling th... more Fish diseases are often caused by waterborne parasites, making them ideal systems for modeling the non-linear relationships between biogeochemical features and disease dynamics. Myxobolus cerebralis, the causative agent of whirling disease, has been a major contributor to the loss of wild rainbow trout populations in numerous streams within the Intermountain West (Colorado, Idaho, Montana, Utah, Wyoming). The parasite alternates between
Page 1. Behavior Genetics, Vol. 15, No. 6, 1985 Genetic Stability of Cannibalism in Tribolium con... more Page 1. Behavior Genetics, Vol. 15, No. 6, 1985 Genetic Stability of Cannibalism in Tribolium conflisllm Lori Stevens I and David B. Mertz ~ Received 5 Jan. 1985--Final 17 May 1985 This study reports the stability of genetically ...
Chagas disease caused by T. cruzi is an emerging infectious disease in the United States due to t... more Chagas disease caused by T. cruzi is an emerging infectious disease in the United States due to the immigration of infected individuals from endemic Mexico, Central and South American countries. The American Southwests growing human population has encroached upon the habitat of local triatomines, several of which are competent vectors of T. cruzi among resident small mammals. Human residents are accidental blood meal hosts of these hematophagous bugs. Many human victims suffer anaphylaxis after being bitten by the bugs. We are currently studying the rate of infection by T. cruzi of T. rubida and T. protracta, identifying their blood meal hosts and gathering data on the incidence of anaphylaxis to triatomine bites.
Triatoma dimidiata (Latreille, 1811) is the most abundant and significant insect vector of the pa... more Triatoma dimidiata (Latreille, 1811) is the most abundant and significant insect vector of the parasite Trypanosoma cruzi in Central America, and particularly in Guatemala. Tr. cruzi is the causative agent of Chagas disease, and successful disease control requires understanding the geographic distribution and degree of migration of vectors such as T. dimidiata that frequently re-infest houses within months following insecticide application. The population genetic structure of T. dimidiata collected from six villages in southern Guatemala was studied to gain insight into the migration patterns of the insects in this region where populations are largely domestic. This study provided insight into the likelihood of eliminating T. dimidiata by pesticide application as has been observed in some areas for other domestic triatomines such as Triatoma infestans. Genotypes of microsatellite loci for 178 insects from six villages were found to represent five genetic clusters using a Bayesian Markov Chain Monte Carlo method. Individual clusters were found in multiple villages, with multiple clusters in the same house. Although migration occurred, there was statistically significant genetic differentiation among villages (FR T = 0.05) and high genetic differentiation among houses within villages (FSR = 0.11). Relatedness of insects within houses varied from 0 to 0.25, i.e., from unrelated to half-sibs. The results suggest that T. dimidiata in southern Guatemala moves between houses and villages often enough that recolonization is likely, implying the use of insecticides alone is not sufficient for effective control of Chagas disease in this region and more sustainable solutions are required.
Myxobolus cerebralis, the parasite that causes whirling disease, has been a major contributor to ... more Myxobolus cerebralis, the parasite that causes whirling disease, has been a major contributor to the reduction in trout populations in the Intermountain West, U.S.A. Myxobolus cerebralis has a obligate, two host life cycle: trout produce spores that are infective to the tubificid worm host, Tubifex tubifex, and the worm produces spores that are infective to trout. Evidence collected from both field surveys in watersheds in Montana as well as laboratory experiments suggest that the structure of the worm community plays an important role in the prevalence and severity of disease in fish. Tubifex tubifex is comprised of several genetic lineages that often coexist in stream communities. Our field work has shown lineage I and III (TI and TIII) coexist in Montana streams. Several studies have shown that TIII is a highly susceptible host, more likely to be infected than TI and sometimes producing ten times the number of spores that infect fish than TI. Our field studies using caged trout f...
Tribolium flour beetles produce defensive compounds, including quinones, putatively aimed at dete... more Tribolium flour beetles produce defensive compounds, including quinones, putatively aimed at deterring predators and inhibiting microbes. Here we examine how effective the defensive secretions of Tribolium confusum and T. castaneum are at inhibiting growth of various microbes and how this varies with species, geographic strain, and sex of the beetles. We explore differences at both the kingdom and species level of common flour microbes in their susceptibility to defensive compounds. Beetle species and strains vary in their ability to inhibit microbial growth. In addition, microbes vary in their sensitivity to the beetles' defense compounds. The capability to suppress microbial growth is likely under stabilizing selection with optimum quinone production varying among populations and may be dependent on several environmental factors including temperature, humidity, and predators.
This paper reports on the effects of a cytoplasmically inherited reproductive incompatibility in ... more This paper reports on the effects of a cytoplasmically inherited reproductive incompatibility in different genetic strains of the flour beetle, Tribolium confusum. We measured the rate of spread and the effect of host population size using different initial frequencies of infection with a cytoplasmic factor that mediates reproductive incompatibility. There were two experiments, in one the infected and uninfected lines were from the same genetic strain, b-Yugoslavia. In the other, the infected line was from the "high cannibalism" bIV strain and the uninfected line from the "low cannibalism" bI strain. We estimate that the fitness ratio of infected to uninfected in b-Yugoslavia is 0.63 and the observed rate of spread for this strain corresponds to a model of cytoplasmic inheritance that takes into account the productivity differences between the infected and cured lines. In the bI-bIV experiment, because the uninfected and infected lines are from different genetic ...
In a SINE-based PCR assay, a primer set specific for guinea pig genome short interspersed element... more In a SINE-based PCR assay, a primer set specific for guinea pig genome short interspersed elements DNA was used to test the utility of genomic markers for identifying the source of vertebrate blood meals of Triatoma infestans. The investigation consisted of two assays. In Assay 1, thirty-six insects, collected from the Province of Zudáñez in Chuquisaca, Bolivia were frozen 1-40 hours after feeding, under controlled conditions, on guinea pigs. The species of the vertebrate host was confirmed from dissection of the posterior part of the abdomen of each insect followed by DNA extraction and PCR amplification. Assay 2 investigated whether the technique worked under field conditions. We analyzed the bloodmeal of 34 insects collected from households and peri-domestic structures from communities where wild and captive guinea pigs occur. After collection, the insects were maintained at room temperature for 2 months without feeding and then analyzed. In Assay 1, each of the 36 insects allowe...
Fish diseases are often caused by waterborne parasites, making them ideal systems for modeling th... more Fish diseases are often caused by waterborne parasites, making them ideal systems for modeling the non-linear relationships between biogeochemical features and disease dynamics. Myxobolus cerebralis, the causative agent of whirling disease, has been a major contributor to the loss of wild rainbow trout populations in numerous streams within the Intermountain West (Colorado, Idaho, Montana, Utah, Wyoming). The parasite alternates between
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