Vertebrate Host Ecology

2020 ◽  
pp. 257-280 ◽  
Author(s):  
Thomas W. Scott
Keyword(s):  
Vertebrate Host ◽  
Host Ecology

scholarly journals Whole blood and blood components from vertebrates differentially affect egg formation in three species of anautogenous mosquitoes

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ruby E. Harrison ◽  
Mark R. Brown ◽  
Michael R. Strand
Keyword(s):  
Serum Albumin ◽  
Whole Blood ◽  
Digestive Enzyme ◽  
Vertebrate Host ◽  
Cell Protein ◽  
Blood Components ◽  
Blood Proteins ◽  
Serum Albumins ◽  
Egg Formation ◽  
Reproductive Response

Abstract Background Most female mosquitoes are anautogenous and must blood feed on a vertebrate host to produce eggs. Prior studies show that the number of eggs females lay per clutch correlates with the volume of blood ingested and that protein is the most important macronutrient for egg formation. In contrast, how whole blood, blood fractions and specific blood proteins from different vertebrates affect egg formation is less clear. Since egg formation is best understood in Aedes aegypti, we examined how blood and blood components from different vertebrates affect this species and two others: the malaria vector Anopheles gambiae and arbovirus vector Culex quinquefasciatus. Methods Adult female mosquitoes were fed blood, blood fractions and purified major blood proteins from different vertebrate hosts. Markers of reproductive response including ovary ecdysteroidogenesis, yolk deposition into oocytes and number of mature eggs produced were measured. Results Ae. aegypti, An. gambiae and C. quinquefasciatus responded differently to meals of whole blood, plasma or blood cells from human, rat, chicken and turkey hosts. We observed more similarities between the anthropophiles Ae. aegypti and An. gambiae than the ornithophile C. quinquefasciatus. Focusing on Ae. aegypti, the major plasma-derived proteins (serum albumin, fibrinogen and globulins) differentially stimulated egg formation as a function of vertebrate host source. The major blood cell protein, hemoglobin, stimulated yolk deposition when from pigs but not humans, cows or sheep. Serum albumins from different vertebrates also variably affected egg formation. Bovine serum albumin (BSA) stimulated ovary ecdysteroidogenesis, but more weakly induced digestive enzyme activities than whole blood. In contrast, BSA-derived peptides and free amino acids had no stimulatory effects on ecdysteroidogenesis or yolk deposition into oocytes. Conclusions Whole blood, blood fractions and specific blood proteins supported egg formation in three species of anautogenous mosquitoes but specific responses varied with the vertebrate source of the blood components tested.

Quantitative Trait Loci for Susceptibility to Tapeworm Infection in the Red Flour Beetle

Genetics ◽  
2003 ◽  
Vol 165 (3) ◽  
pp. 1307-1315
Author(s):  
Daibin Zhong ◽  
Aditi Pai ◽  
Guiyun Yan
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Genetic Basis ◽  
Life Cycles ◽  
Red Flour Beetle ◽  
Phenotypic Variance ◽  
Flour Beetle ◽  
Trait Loci ◽  
Host Ecology ◽  
Tapeworm Infection

Abstract Parasites have profound effects on host ecology and evolution, and the effects of parasites on host ecology are often influenced by the magnitude of host susceptibility to parasites. Many parasites have complex life cycles that require intermediate hosts for their transmission, but little is known about the genetic basis of the intermediate host's susceptibility to these parasites. This study examined the genetic basis of susceptibility to a tapeworm (Hymenolepis diminuta) in the red flour beetle (Tribolium castaneum) that serves as an intermediate host in its transmission. Quantitative trait loci (QTL) mapping experiments were conducted with two independent segregating populations using amplified fragment length polymorphism (AFLP) markers and randomly amplified polymorphic DNA (RAPD) markers. A total of five QTL that significantly affected beetle susceptibility were identified in the two reciprocal crosses. Two common QTL on linkage groups 3 and 6 were identified in both crosses with similar effects on the phenotype, and three QTL were unique to each cross. In one cross, the three main QTL accounted for 29% of the total phenotypic variance and digenic epistasis explained 39% of the variance. In the second cross, the four main QTL explained 62% of the variance and digenic epistasis accounted for only 5% of the variance. The actions of these QTL were either overdominance or underdominance. Our results suggest that the polygenic nature of beetle susceptibility to the parasites and epistasis are important genetic mechanisms for the maintenance of variation within or among beetle strains in susceptibility to tapeworm infection.

scholarly journals Wide Distribution and Diversity of Malaria-Related Haemosporidian Parasites (Polychromophilus spp.) in Bats and Their Ectoparasites in Eastern Europe

2021 ◽  
Vol 9 (2) ◽  
pp. 230
Author(s):  
Attila D. Sándor ◽  
Áron Péter ◽  
Alexandra Corduneanu ◽  
Levente Barti ◽  
István Csősz ◽  
...  
Keyword(s):  
Eastern Europe ◽  
Plasmodium Species ◽  
Wide Distribution ◽  
Parasite Diversity ◽  
Haemosporidian Parasite ◽  
High Genetic Diversity ◽  
Haemosporidian Parasites ◽  
Host Ecology ◽  
Wildlife Populations ◽  
Pcr Targeting

Malaria is responsible for major diseases of humans, while associated haemosporidians are important factors in regulating wildlife populations. Polychromophilus, a haemosporidian parasite of bats, is phylogenetically close to human-pathogenic Plasmodium species, and their study may provide further clues for understanding the evolutionary relationships between vertebrates and malarial parasites. Our aim was to investigate the distribution of Polychromophilus spp. in Eastern Europe and test the importance of host ecology and roost site on haemosporidian parasite infection of bats. We sampled bats and their ectoparasites at eight locations in Romania and Bulgaria. DNA was extracted from blood samples and ectoparasites and tested individually for the presence of DNA of Polychromophilus spp. using a nested PCR targeting a 705 bp fragment of cytB. Two species of Polychromophilus were identified: Po. melanipherus in Miniopterus schreibersii and associated ectoparasites and Po. murinus in rhinolophid and vespertilionid bats (6 species) and their ticks and nycteribiid flies. Only cave-dwelling bat species (and their ectoparasites) showed infections, and we found a strong correlation between infections with Polychromophilus parasites and Nycteribiidae prevalence. We report the high genetic diversity of Polychromophilus spp. in Eastern Europe, suggesting that the simultaneous presence of varied host and vector assemblages enhances bat haemosporidian parasite diversity.

scholarly journals Drug Resistance in Filarial Parasites Does Not Affect Mosquito Vectorial Capacity

Pathogens ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 2
Author(s):  
Erik Neff ◽  
Christopher C. Evans ◽  
Pablo D. Jimenez Castro ◽  
Ray M. Kaplan ◽  
Guha Dharmarajan
Keyword(s):  
Drug Resistance ◽  
Transmission Efficiency ◽  
Vectorial Capacity ◽  
Vertebrate Host ◽  
Mosquito Vector ◽  
Drug Resistant ◽  
Vector Borne Diseases ◽  
Asian Tiger ◽  
Significant Difference ◽  
Vector Borne

Parasite drug resistance presents a major obstacle to controlling and eliminating vector-borne diseases affecting humans and animals. While vector-borne disease dynamics are affected by factors related to parasite, vertebrate host and vector, research on drug resistance in filarial parasites has primarily focused on the parasite and vertebrate host, rather than the mosquito. However, we expect that the physiological costs associated with drug resistance would reduce the fitness of drug-resistant vs. drug-susceptible parasites in the mosquito wherein parasites are not exposed to drugs. Here we test this hypothesis using four isolates of the dog heartworm (Dirofilaria immitis)—two drug susceptible and two drug resistant—and two vectors—the yellow fever mosquito (Aedes aegypti) and the Asian tiger mosquito (Ae. albopictus)—as our model system. Our data indicated that while vector species had a significant effect on vectorial capacity, there was no significant difference in the vectorial capacity of mosquitoes infected with drug-resistant vs. drug-susceptible parasites. Consequently, contrary to expectations, our data indicate that drug resistance in D. immitis does not appear to reduce the transmission efficiency of these parasites, and thus the spread of drug-resistant parasites in the vertebrate population is unlikely to be mitigated by reduced fitness in the mosquito vector.

scholarly journals Genetic variation in Drosophila melanogaster pathogen susceptibility

Parasitology ◽  
2006 ◽  
Vol 132 (6) ◽  
pp. 767-773 ◽  
Author(s):  
M. C. TINSLEY ◽  
S. BLANFORD ◽  
F. M. JIGGINS
Keyword(s):  
Biological Control ◽  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Model Organism ◽  
Resistance Evolution ◽  
Control Programmes ◽  
Host Ecology ◽  
Insect Pathogens ◽  
Immunological Research ◽  
Pathogen Exposure

Genetic variation in susceptibility to pathogens is a central concern both to evolutionary and medical biologists, and for the implementation of biological control programmes. We have investigated the extent of such variation in Drosophila melanogaster, a major model organism for immunological research. We found that within populations, different Drosophila genotypes show wide-ranging variation in their ability to survive infection with the entomopathogenic fungus Beauveria bassiana. Furthermore, striking divergence in susceptibility has occurred between genotypes from temperate and tropical African locations. We hypothesize that this may have been driven by adaptation to local differences in pathogen exposure or host ecology. Genetic variation within populations may be maintained by temporal or spatial variation in the costs and benefits of pathogen defence. Insect pathogens are employed widely as biological control agents and entomopathogenic fungi are currently being developed for reducing malaria transmission by mosquitoes. Our data highlight the need for concern about resistance evolution to these novel biopesticides in vector populations.

scholarly journals Sexual and vertical transmission of visceral leishmaniasis

2014 ◽  
Vol 8 (04) ◽  
pp. 403-407 ◽  
Author(s):  
Andreia P Turchetti ◽  
Tayse D Souza ◽  
Tatiane A Paixão ◽  
Renato L. Santos
Keyword(s):  
Visceral Leishmaniasis ◽  
Vertical Transmission ◽  
Leishmania Infantum ◽  
Vertebrate Host ◽  
Domestic Dog ◽  
Sand Flies ◽  
Phlebotomine Sand Flies

Visceral leishmaniasis (VL) is an important zoonosis caused by Leishmania infantum, which has in the domestic dog its principal vertebrate host. VL is usually transmitted by phlebotomine sand flies, however atypical routes of transmission have been described. In this review we discuss the the role of sexual and vertical transmissions, and their role in the maintenance of VL in canine populations.

scholarly journals Contributions of Environmental Signals and Conserved Residues to the Functions of Carbon Storage Regulator A of Borrelia burgdorferi

2013 ◽  
Vol 81 (8) ◽  
pp. 2972-2985 ◽  
Author(s):  
S. L. Rajasekhar Karna ◽  
Rajesh G. Prabhu ◽  
Ying-Han Lin ◽  
Christine L. Miller ◽  
J. Seshu
Keyword(s):  
Borrelia Burgdorferi ◽  
Carbon Storage ◽  
Vertebrate Host ◽  
Acetyl Phosphate ◽  
Mobility Shift ◽  
Acetyl Coa ◽  
Site Specific ◽  
Content Type ◽  
Environmental Signals ◽  
Carbon Storage Regulator

ABSTRACTCarbon storage regulator A ofBorrelia burgdorferi(CsrABb) contributes to vertebrate host-specific adaptation by modulating activation of the Rrp2-RpoN-RpoS pathway and is critical for infectivity. We hypothesized that the functions of CsrABbare dependent on environmental signals and on select residues. We analyzed the phenotype ofcsrABbdeletion and site-specific mutants to determine the conserved and pathogen-specific attributes of CsrABb. Levels of phosphate acetyltransferase (Pta) involved in conversion of acetyl phosphate to acetyl-coenzyme A (acetyl-CoA) and posttranscriptionally regulated by CsrABbin thecsrABbmutant were reduced from or similar to those in the control strains under unfed- or fed-tick conditions, respectively. Increased levels of supplemental acetate restored vertebrate host-responsive determinants in thecsrABbmutant to parental levels, indicating that both the levels of CsrABband the acetyl phosphate and acetyl-CoA balance contribute to the activation of the Rrp2-RpoN-RpoS pathway. Site-specific replacement of 8 key residues of CsrABb(8S) with alanines resulted in increased levels of CsrABband reduced levels of Pta and acetyl-CoA, while levels of RpoS, BosR, and other members ofrpoSregulon were elevated. Truncation of 7 amino acids at the C terminus of CsrABb(7D) resulted in reducedcsrABbtranscripts and posttranscriptionally reduced levels of FliW located upstream of CsrABb. Electrophoretic mobility shift assays revealed increased binding of 8S mutant protein to the CsrA binding box upstream ofptacompared to the parental and 7D truncated protein. Two CsrABbbinding sites were also identified upstream offliWwithin theflgKcoding sequence. These observations reveal conserved and unique functions of CsrABbthat regulate adaptive gene expression inB. burgdorferi.

scholarly journals Prevalence of avian influenza and host ecology

2007 ◽  
Vol 274 (1621) ◽  
pp. 2003-2012 ◽  
Author(s):  
László Zsolt Garamszegi ◽  
Anders Pape Møller
Keyword(s):  
Avian Influenza ◽  
Host Ecology
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