Jonas King

Mississippi State University | MSU · Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology

Bed bugs (Hemiptera: Cimicidae) are a globally distributed hematophagous pest that routinely feed on humans. Unlike many blood-sucking arthropods, they have never been linked to pathogen transmission in a natural setting, and despite increasing interest in their role as disease vectors, little is known about the viruses that bed bugs naturally harb...

Gaeumannomyces graminis var. graminis (Sacc.) Arx & Oliver was originally described as the pathogen of bermudagrass decline (aka takeall root rot (TARR)); however, recent studies reported multiple ectotrophic root-infecting (ERI) fungi are associated with root rot of ultradwarf hybrid bermudagrass (UDHB): (Cynodon dactylon (L.) Pers. × C. transvaal...

Bed bugs (Cimex spp.) are urban pests of global importance. Knowledge of the immune system of bed bugs has implications for understanding their susceptibility to biological control agents, their potential to transmit human pathogens, and the basic comparative immunology of insects. Nonetheless, the immunological repertoire of the family Cimicidae r...

Bermudagrass decline (BD) is a destructive root rot disease of hybrid bermudagrass putting greens in the southeastern United States. Previous studies reported a single ectotrophic root-infecting (ERI) fungus, Gaeumannomyces graminis, associated with BD. Recently, three novel ERI fungi, Gaeumannomyces sp., Magnaporthiopsis cynodontis, and Candidacol...

In the 1930s, R. A. Cooley noted that Dermacentor occidentalis (Acarina: Ixodidae) and Dermacentor andersoni were closely related and could hybridize. Decades later, James Oliver discovered that crosses of Dermacentor variabilis, D. andersoni, and D. occidentalis could, on occasion, produce hybrids. A recent molecular analysis (both mtDNA and nDNA)...

Diseases spread by mosquitoes have killed more people than those spread by any other group of arthropod vectors and remain an important factor in determining global health and economic stability. The mosquito innate immune system can act to either modulate infection with human pathogens or fight off entomopathogens and increase the fitness and long...

Dermacentor parumapertus Neumann (Acari: Ixodidae) is a rather obscure tick found on jackrabbits in the western United States and parts of Canada and Mexico. Specimens from the northern part of their range are consistently different morphologically from ones found in southern and eastern parts of their range (particularly west Texas), leading some...

In vitro studies of liver stage (LS) development of the human malaria parasite Plasmodium falciparum are technically challenging; therefore, fundamental questions about hepatocyte receptors for invasion that can be targeted to prevent infection remain unanswered. To identify novel receptors and to further understand human hepatocyte susceptibility...

Plant pathogens are constantly emerging and spreading into new areas and there are often limited postdiagnosis treatment options for infection, making surveillance key to their control. Here we present results from a study testing the efficacy of a portable nanopore-based massively parallel sequencing (MPS) technology for use in the detection of di...

Rathayibacter toxicus is a forage grass associated Gram-positive bacterium of major concern to food safety and agriculture. This species is listed by USDA-APHIS as a plant pathogen select agent because it produces a tunicamycin-like toxin that is lethal to livestock and may be vectored by nematode species native to the U.S. The complete genomes of...

Exopolysaccharide and lantibiotic biosynthetic clusters. Gene clusters from R. toxicus FH-79 appearing to encode exopolysaccharide biosynthesis (A) and a bacteriocin or lantibiotic (B). Scale bar major ticks correspond to 5 kb, minor tics 1 kb. (PDF)

Anti-smash regions. Genomic regions putatively involved in antibiotic and secondary metabolite production for R. toxicus FH-79 and identified with the data-mining software antiSMASH v. 3.0. (PDF)

AlienHunter regions. Genomic regions of interest putatively acquired through horizontal gene transfer events for R. toxicus FH-79 and identified with the data-mining software AlienHunter. (PDF)

Nature Microbiology 2 , 17017 (2017); published online 17 February 2017; corrected 6 March 2017. In the version of this Letter originally published, the in-text citations to Supplementary Table 1 and Supplementary Data 1–7 were ambiguous.

Plasmodium parasites, the causative agents of malaria, have evolved a unique cell division cycle in the clinically relevant asexual blood stage of infection1. DNA replication commences approximately halfway through the intracellular development following invasion and parasite growth. The schizont stage is associated with multiple rounds of DNA repl...

The evolution of drug resistance is a recurrent problem that has plagued efforts to treat and control malaria. Recent emergence of artemisinin resistance in Southeast Asia underscores the need to develop novel antimalarials and identify new targetable pathways in Plasmodium parasites. Transmission-blocking approaches, which typically target gametoc...

The innate immune response is highly conserved across all eukaryotes and has been studied in great detail in several model organisms. Hemocytes, the primary immune cell population in mosquitoes, are important components of the mosquito innate immune response, yet critical aspects of their biology have remained uncharacterized. Using a novel method...

One of the critical gaps in malaria transmission biology and surveillance is our lack of knowledge about Plasmodium falciparum gametocyte biology, especially sexual dimorphic development and how sex ratios that may influence transmission from the human to the mosquito. Dissecting this process has been hampered by the lack of sex-specific protein ma...

The routine study of human malaria liver-stage biology in vitro is hampered by low infection efficiency of human hepatocellular carcinoma (HCC) lines (<0.1%), poor understanding of steady-state HCC biology, and lack of appropriate tools for trace sample analysis. HC-04 is the only HCC that supports complete development of human malaria parasites. W...

Mosquito feeding assays play an important role in quantifying malaria transmission potential in epidemiological and clinical studies. At present, membrane feeding assays are incompletely standardised. This affects our understanding of the precision of the assay and its suitability for evaluating transmission-blocking interventions. Here, we present...

Mosquito feeding assays play an important role in quantifying malaria transmission potential in epidemiological and clinical studies. At present, membrane feeding assays are incompletely standardised. This affects our understanding of the precision of the assay and its suitability for evaluating transmission-blocking interventions. Here, we present...

Background Mosquitoes respond to infection by mounting immune responses. The primary regulators of these immune responses are cells called hemocytes, which kill pathogens via phagocytosis and via the production of soluble antimicrobial factors. Mosquito hemocytes are circulated throughout the hemocoel (body cavity) by the swift flow of hemolymph (b...

http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1787&context=insectamundi We review the variegated mud-loving beetle fauna of the southeastern United States (Coleoptera: Heteroceridae), with an emphasis on Mississippi and Alabama. A key is presented to all species known to occur in the southeastern US, and includes several extra-limital...

Phagocytosis of E. coli by periostial hemocytes. (MOV)

Hemocyte migration to the periostial regions in response to E. coli infection. (MOV)

Insects counter infection with innate immune responses that rely on cells called hemocytes. Hemocytes exist in association with the insect's open circulatory system and this mode of existence has likely influenced the organization and control of anti-pathogen immune responses. Previous studies reported that pathogens in the mosquito body cavity (he...

The domestication of animals, plants, and microbes funda-mentally transformed the lifestyle and demography of the human species [1]. Although the genetic and functional underpinnings of animal and plant domestication are well understood, little is known about microbe domestication [2–6]. Here, we systematically examined genome-wide se-quence and fu...

Over the last 20 years, ecological immunology has provided much insight into how environmental factors shape host immunity and host-parasite interactions. Currently, the application of this thinking to the study of mosquito immunology has been limited. Mechanistic investigations are nearly always conducted under one set of conditions, yet vectors a...

Mosquitoes counter infection with an innate immune response that relies heavily on the action of immune cells (hemocytes). In non-mosquito insects it has been shown that hemocytes exist both in circulation and adhered to tissues (sessile). Using a novel in vivo staining technique, intravital video imaging, and microdissection we conducted an extens...

Mosquitoes transmit Plasmodium and certain arboviruses during blood feeding, when they are injected along with saliva. Mosquito saliva interferes with the host's hemostasis and inflammation response and influences the transmission success of some pathogens. One family of mosquito salivary gland proteins, named SGS, is composed of large bacterial-ty...

Although most authors have recognized five or fewer genera in the Heteroceridae, the most recent revision divided the heterocerids into 19 genera. Under this system most males can be identified to genus level based on genital morphology, but clearly females cannot be identified to genus level by this method. We conducted the first phylogenetic anal...

The insect circulatory system transports nutrients, signaling molecules, wastes and immune factors throughout the body. Here, we will present a comprehensive characterization of hemolymph propulsion in the abdomen of the mosquito Anopheles gambiae, with specific emphasis on the mechanics of hemolymph propulsion, the structure of the musculature res...

Hemolymph flow in the lateral abdomen. Lateral view of the mosquito abdomen showing the flow of intrathoracically-injected fluorescent microspheres during the three principal contraction periods. (2.67 MB MOV)

The ventral abdomen contracts in a retrograde direction during periods of anterograde heart contractions. Lateral view of the mosquito abdomen showing (1) 2 µm diameter fluorescent microspheres flowing through the heart (dorsal vessel) in anterograde and retrograde directions, and (2) periodic contractions of the ventral abdomen. (3.26 MB MOV)

Hemolymph flow in the ventral abdomen. Ventral view of the mosquito abdomen showing the flow of intrathoracically-injected fluorescent microspheres during the three principal contraction periods. (2.30 MB MOV)

Effect of mosquito manipulation on heart contraction dynamics. Serial (paired) measurements of heart contraction dynamics were obtained from mosquitoes under control (neutral) and experimental conditions. Trials tested the effect of dorsal side-up positioning vs. lateral positioning (n = 13), no fluorescence illumination vs. fluorescence illuminati...

Background: Hemolymph circulation in mosquitoes is primarily controlled by the contractile action of a dorsal vessel that runs underneath the dorsal midline and is subdivided into a thoracic aorta and an abdominal heart. Wave-like peristaltic contractions of the heart alternate in propelling hemolymph in anterograde and retrograde directions, wher...

The insect circulatory system transports nutrients, signaling molecules, wastes and immune factors to all areas of the body. The primary organ driving circulation is the dorsal vessel, which consists of an abdominal heart and a thoracic aorta. Here, we present qualitative and quantitative data characterizing the heart of the mosquito, Anopheles gam...

The Heteroceridae is a taxonomically difficult family of small (2–7 mm) beetles that live in self-constructed feeding tunnels along the shores of fresh and brackish waters worldwide. Traditional classifications of Heteroceridae accept only five genera (Heterocerus, Micilus, Augyles, Phyrites and Elythomerus) (Coleoptera: Byrrhoidea: Heteroceridae),...