1
|
Araújo JPM, Evans HC, Fernandes IO, Ishler MJ, Hughes DP. Zombie-ant fungi cross continents: II. Myrmecophilous hymenostilboid species and a novel zombie lineage. Mycologia 2020; 112:1138-1170. [PMID: 33146584 DOI: 10.1080/00275514.2020.1822093] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Ophiocordyceps species infecting ants are globally distributed, with diversity concentrated in the tropics and decreasing with increasing latitude. Among these myrmecophilous species, the ones exhibiting the ability to manipulate host behavior, the so-called "zombie-ant fungi" of the O. unilateralis clade, have been studied progressively over the last decade. However, we know very little about other myrmecophilous groups, such as species within the Ophiocordyceps subgenus Neocordyceps. Species within this group exhibit Hymenostilbe asexual morphs with the ascospores readily breaking into part-spores and regularly kill their hosts on the forest floor, with few records of behavioral manipulation. Here, we describe five new species of Ophiocordyceps belonging to the subgenus Neocordyceps infecting ants in the rainforests of the Brazilian Amazon and Ghana and analyze their ability to manipulate host behavior. We also propose a new status for a species previously described as a variety, providing its phylogenetic placement for the first time. The species proposed herein can readily be separated using classic taxonomic criteria, and this is further supported by ecological and molecular multiloci data.
Collapse
Affiliation(s)
- J P M Araújo
- Department of Entomology, The Pennsylvania State University, University Park , Pennsylvania, 16802.,Tropical Biosphere Research Center, University of the Ryukyus , Nishihara, Japan.,School of Forest Resources and Conservation, University of Florida , Gainesville, Florida 32605
| | - H C Evans
- CAB International, Europe-UK , Egham, Surrey, UK
| | - I O Fernandes
- Coordenação em Biodiversidade/Entomologia, Instituto Nacional de Pesquisas da Amazônia , Manaus, Brazil
| | - M J Ishler
- Department of Entomology, The Pennsylvania State University, University Park , Pennsylvania, 16802
| | - D P Hughes
- Department of Entomology, The Pennsylvania State University, University Park , Pennsylvania, 16802.,Department of Biology, The Pennsylvania State University, University Park , Pennsylvania 16802
| |
Collapse
|
2
|
Mangold CA, Ishler MJ, Loreto RG, Hazen ML, Hughes DP. Zombie ant death grip due to hypercontracted mandibular muscles. J Exp Biol 2019; 222:jeb200683. [PMID: 31315924 PMCID: PMC6679347 DOI: 10.1242/jeb.200683] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 06/03/2019] [Indexed: 12/25/2022]
Abstract
There are numerous examples of parasites that manipulate the behavior of the hosts that they infect. One such host-pathogen relationship occurs between the 'zombie-ant fungus' Ophiocordyceps unilateralis sensu lato and its carpenter ant host. Infected ants climb to elevated locations and bite onto vegetation where they remain permanently affixed well after death. The mandibular muscles, but not the brain, of infected ants are extensively colonized by the fungus. We sought to investigate the mechanisms by which O. unilateralis s.l. may be able to influence mandibular muscle contraction despite widespread muscle damage. We found that infected muscles show evidence of hypercontraction. Despite the extensive colonization, both motor neurons and neuromuscular junctions appear to be maintained. Infection results in sarcolemmal damage, but this is not specific to the death grip. We found evidence of precise penetration of muscles by fungal structures and the presence of extracellular vesicle-like particles, both of which may contribute to mandibular hypercontraction.
Collapse
Affiliation(s)
- Colleen A Mangold
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
- Center for Infectious Disease Dynamics, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Melissa J Ishler
- Center for Infectious Disease Dynamics, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
- Department of Entomology, College of Agricultural Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Raquel G Loreto
- Center for Infectious Disease Dynamics, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
- Department of Entomology, College of Agricultural Sciences, Pennsylvania State University, University Park, PA 16802, USA
- Unit of Genetics and Genomics of Insect Vectors, Department of Parasites and Insect Vectors, Institute Pasteur, Paris 75015, France
| | - Missy L Hazen
- Huck Institutes of the Life Sciences Microscopy and Cytometry Facility, Pennsylvania State University, University Park, PA 16802, USA
| | - David P Hughes
- Center for Infectious Disease Dynamics, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
- Department of Entomology, College of Agricultural Sciences, Pennsylvania State University, University Park, PA 16802, USA
- Department of Biology, Eberly College of Science, Pennsylvania State University, University Park, PA 16802, USA
| |
Collapse
|
3
|
Khan MS, Atav AS, Ishler MJ, Rehman AU, Lozano JE, Sklar AH. Adjustment of hemodialysis dose for residual renal urea clearance: a two year study of impact on dialysis time. ASAIO J 2002; 48:374-8. [PMID: 12141466 DOI: 10.1097/00002480-200207000-00008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Urea kinetic modeling suggests that significant time reductions may be realized in hemodialysis patients with residual renal urea clearance (K(r)t/V urea). However, the actual impact of a strategy that integrates such function into the dialysis prescription is not clear, because of both uncertainty regarding the rate of decay of K(r)t/V urea, as well as potential clinical constraints upon dose reduction. To examine this issue, we retrospectively reviewed data from 51 patients with K(r)t/N urea after initiation of maintenance hemodialysis. In 31 cases, there were no clinical barriers to adjustment of the dialysis prescriptions. Regression analysis revealed that each 0.10 increment in K(r)t/V urea yielded an actual dialysis time reduction of 12 minutes per week with average cumulative reduction of 80 minutes per week per patient. At approximately 1 year after initiation of dialysis, there were still 10 patients whose dialysis prescriptions were being adjusted on the basis of K(r)t/V urea. In conclusion, our results suggest that the incorporation of K(r)t/V urea in the hemodialysis prescription allows for substantial and enduring reductions in dialysis time in a significant minority of patients. Larger prospective studies are needed to evaluate the long-term safety of this strategy in modifying the dose of hemodialysis.
Collapse
|