Raymond St. Leger | |
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Born | |
Nationality | England |
Alma mater | Exeter University University of Bath |
Scientific career | |
Fields | Entomology Mycology Biotechnology |
Institutions | Cornell University University of Maryland |
Doctoral advisor | Professors Keith Charnley and Richard Cooper [1] |
Raymond J. St. Leger (born 1957, in London, England) is an American mycologist, entomologist, molecular biologist and biotechnologist who currently holds the rank of Distinguished University Professor in the Department of Entomology (https://entomology.umd.edu/) at the University of Maryland, College Park.
St. Leger went to the United States to begin his career at the Boyce Thompson Institute at the invitation of Donald W. Roberts. [1] According to Google Scholar, he has since then published more than 150 scientific papers and book chapters on fungal pathogens of plants, animals and insects, and on the reactions of hosts to infection. St. Leger has principally used entomopathogenic fungus (fungi that act as parasites of insects), [2] as models for understanding how pathogens in general respond to stress, [3] changing environments, [4] initiate host invasion, [5] [6] colonize tissues, [7] and counter host immune responses. [8] These investigations have also addressed the mechanisms by which new pathogens emerge with different host ranges [9] [10] [11] and genetic variation between individuals in host defenses. [12] Other interests include fungal and insect behavior and evolution, [13] molecular biology and genomics of fungi, [14] and mutualistic associations between microbes and plants that can be exploited to benefit agriculture. [15] [16]
St. Leger is also known for developing transgenic technologies, including altering insect pathogens so that they carry genes encoding spider and scorpion toxins. [17] [18] [19] [20] A field trial in Burkina Faso has shown that these engineered pathogens have the potential to control insect borne diseases such as malaria. [21] St. Leger has tested an array of "alternative engineering strategies to be consistent with the highly exploratory approach required for optimizing a pathogens biocontrol potential". [22] For example, engineering a mosquito pathogenic fungus to carry a gene for a human anti-malarial antibody so that the fungus targets the malarial parasite in the mosquito reduces the possibility of mosquitoes evolving resistance to the fungus. [23]
St. Leger has been a consultant on biotechnology to many private and public concerns, including the NIH, the USDA, the NSF, the US State Department and the Organization of American States. St. Leger has also served on many national and international policy-making committees including the Bill Gates funded National Academies Committee to study technologies to benefit Sub Saharan Africa and South Asia (2009). [24]
St. Leger is an advocate of online open education and since 2013 has co-taught with Dr. Tammatha O’Brien (https://tammatha.weebly.com/) a MOOC on the Coursera platform called Genes and the Human Condition [25] that has had more than 200,000 active learners.
St. Leger received his Bachelor of Science in biology from Exeter University, England in 1978, a Master of Science in entomology in 1980 from Birkbeck College, London University, and a Doctor of Philosophy in 1985 from the University of Bath, England.
St. Leger has received several awards for his research, he was elected a fellow of the AAAS (2012), the American Academy of Microbiology (2013), the Royal Entomological Society of London (FRES) (2011), the Entomological Society of America [26] (2019) and is a Fellow of the Royal Society of Biology (FRSB). He received the American Society for Microbiology Promega Biotechnology Research Award (2017) and was the inaugural recipient of the Tai Fung-Lan Award for International Cooperation from The Mycological Society of China (2016). St. Leger received an honorary doctorate from his alma mater of Exeter University in 2018 [27] and the Newcomb Cleveland Prize for the most impactful paper published in the journal Science in 2019. [28] St. Leger gave the Founders lecture at the 2009 Society of Invertebrate Pathology Meeting honoring his friend and frequent collaborator Donald W. Roberts. [29] [1]
An endosymbiont or endobiont is any organism that lives within the body or cells of another organism most often, though not always, in a mutualistic relationship. (The term endosymbiosis is from the Greek: ἔνδον endon "within", σύν syn "together" and βίωσις biosis "living".) Examples are nitrogen-fixing bacteria, which live in the root nodules of legumes, single-cell algae inside reef-building corals and bacterial endosymbionts that provide essential nutrients to insects.
Fungus-growing ants comprise all the known fungus-growing ant species participating in ant–fungus mutualism. They are known for cutting grasses and leaves, carrying them to their colonies' nests, and using them to grow fungus on which they later feed.
An endophyte is an endosymbiont, often a bacterium or fungus, that lives within a plant for at least part of its life cycle without causing apparent disease. Endophytes are ubiquitous and have been found in all species of plants studied to date; however, most of the endophyte/plant relationships are not well understood. Some endophytes may enhance host growth, nutrient acquisition and improve the plant's ability to tolerate abiotic stresses, such as drought and decrease biotic stresses by enhancing plant resistance to insects, pathogens and herbivores. Although endophytic bacteria and fungi are frequently studied, endophytic archaea are increasingly being considered for their role in plant growth promotion as part of the core microbiome of a plant.
Mosquito control manages the population of mosquitoes to reduce their damage to human health, economies, and enjoyment. Mosquito control is a vital public-health practice throughout the world and especially in the tropics because mosquitoes spread many diseases, such as malaria and the Zika virus.
The ant–fungus mutualism is a symbiosis seen between certain ant and fungal species, in which ants actively cultivate fungus much like humans farm crops as a food source. There is only evidence of two instances in which this form of agriculture evolved in ants resulting in a dependence on fungi for food. These instances were the attine ants and some ants that are part of the Megalomyrmex genus. In some species, the ants and fungi are dependent on each other for survival. This type of codependency is prevalent among herbivores who rely on plant material for nutrition. The microbes’ ability to convert the plant material into a food source accessible to their host makes them the ideal partner. The leafcutter ant is a well-known example of this symbiosis. Leafcutter ants species can be found in southern South America up to the United States. However, ants are not the only ground-dwelling arthropods which have developed symbioses with fungi. A mutualism with fungi is also noted in some species of termites in Africa.
An entomopathogenic fungus is a fungus that can kill or seriously disable insects.
Metarhizium robertsii – formerly known as M. anisopliae, and even earlier as Entomophthora anisopliae (basionym) – is a fungus that grows naturally in soils throughout the world and causes disease in various insects by acting as a parasitoid. Ilya I. Mechnikov named it after the insect species from which it was originally isolated – the beetle Anisoplia austriaca. It is a mitosporic fungus with asexual reproduction, which was formerly classified in the form class Hyphomycetes of the phylum Deuteromycota.
Paratransgenesis is a technique that attempts to eliminate a pathogen from vector populations through transgenesis of a symbiont of the vector. The goal of this technique is to control vector-borne diseases. The first step is to identify proteins that prevent the vector species from transmitting the pathogen. The genes coding for these proteins are then introduced into the symbiont, so that they can be expressed in the vector. The final step in the strategy is to introduce these transgenic symbionts into vector populations in the wild. One use of this technique is to prevent mortality for humans from insect-borne diseases. Preventive methods and current controls against vector-borne diseases depend on insecticides, even though some mosquito breeds may be resistant to them. There are other ways to fully eliminate them. “Paratransgenesis focuses on utilizing genetically modified insect symbionts to express molecules within the vector that are deleterious to pathogens they transmit.” The acidic bacteria Asaia symbionts are beneficial in the normal development of mosquito larvae; however, it is unknown what Asais symbionts do to adult mosquitoes.
The Clavicipitaceae are a family of fungi within the order Hypocreales. A 2008 estimate placed 43 genera in the family, but a study in 2020 has increased this number to 50.
A fungus is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from the other eukaryotic kingdoms, which by one traditional classification include Plantae, Animalia, Protozoa, and Chromista.
LUBILOSA was the name of a research programme that aimed at developing a biological alternative to the chemical control of locusts. This name is an acronym of the French title of the programme: Lutte Biologique contre les Locustes et les Sauteriaux. During its 13-year life, the programme identified an isolate of an entomopathogenic fungus belonging to the genus Metarhizium and virulent to locusts, and went through all the necessary steps to develop the commercial biopesticide product Green Muscle based on its spores.
Metarhizium acridum is the new name given to a group of fungal isolates that are known to be virulent and specific to the Acrididea (grasshoppers). Previously, this species has had variety status in Metarhizium anisopliae ; before that, reference had been made to M. flavoviride or Metarhizium sp. describing an "apparently homologous and distinctive group" of isolates that were most virulent against Schistocerca gregaria in early screening bioassays.
Marine fungi are species of fungi that live in marine or estuarine environments. They are not a taxonomic group, but share a common habitat. Obligate marine fungi grow exclusively in the marine habitat while wholly or sporadically submerged in sea water. Facultative marine fungi normally occupy terrestrial or freshwater habitats, but are capable of living or even sporulating in a marine habitat. About 444 species of marine fungi have been described, including seven genera and ten species of basidiomycetes, and 177 genera and 360 species of ascomycetes. The remainder of the marine fungi are chytrids and mitosporic or asexual fungi. Many species of marine fungi are known only from spores and it is likely a large number of species have yet to be discovered. In fact, it is thought that less than 1% of all marine fungal species have been described, due to difficulty in targeting marine fungal DNA and difficulties that arise in attempting to grow cultures of marine fungi. It is impracticable to culture many of these fungi, but their nature can be investigated by examining seawater samples and undertaking rDNA analysis of the fungal material found.
Muscardine is a disease of insects. It is caused by many species of entomopathogenic fungus. Many muscardines are known for affecting silkworms. Muscardine may also be called calcino.
The mycobiome, mycobiota, or fungal microbiome, is the fungal community in and on an organism.
Social immunity is any antiparasite defence mounted for the benefit of individuals other than the actor. For parasites, the frequent contact, high population density and low genetic variability makes social groups of organisms a promising target for infection: this has driven the evolution of collective and cooperative anti-parasite mechanisms that both prevent the establishment of and reduce the damage of diseases among group members. Social immune mechanisms range from the prophylactic, such as burying beetles smearing their carcasses with antimicrobials or termites fumigating their nests with naphthalene, to the active defenses seen in the imprisoning of parasitic beetles by honeybees or by the miniature 'hitchhiking' leafcutter ants which travel on larger worker's leaves to fight off parasitoid flies. Whilst many specific social immune mechanisms had been studied in relative isolation, it was not until Sylvia Cremer et al.'s 2007 paper "Social Immunity" that the topic was seriously considered. Empirical and theoretical work in social immunity continues to reveal not only new mechanisms of protection but also implications for understanding of the evolution of group living and polyandry.
Fungal ribotoxins are a group of extracellular ribonucleases (RNases) secreted by fungi. Their most notable characteristic is their extraordinary specificity. They inactivate ribosomes by cutting a single phosphodiester bond of the rRNA that is found in a universally conserved sequence. This cleavage leads to cell death by apoptosis. However, since they are extracellular proteins, they must first enter the cells that constitute their target to exert their cytotoxic action. This entry constitutes the rate-determining step of their action.
Metarhizium pinghaense is a species of entomopathogenic fungus in the family Clavicipitaceae. Some authorities have it as a synonym of Metarhizium anisopliae. DNA studies show that it is a good species, with strong bootstrap support.
Donald W. Roberts was an insect pathologist and one of the originators of that field. He was especially known for research into biological pest control of Lepidoptera by Metarhizium but also Beauveria bassiana. He was a Research Professor Emeritus in the Biology Department of Utah State University.
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