1
|
Berasategui A, Salem H, Moller AG, Christopher Y, Vidaurre Montoya Q, Conn C, Read TD, Rodrigues A, Ziemert N, Gerardo N. Genomic insights into the evolution of secondary metabolism of Escovopsis and its allies, specialized fungal symbionts of fungus-farming ants. mSystems 2024:e0057624. [PMID: 38904377 DOI: 10.1128/msystems.00576-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 05/14/2024] [Indexed: 06/22/2024] Open
Abstract
The metabolic intimacy of symbiosis often demands the work of specialists. Natural products and defensive secondary metabolites can drive specificity by ensuring infection and propagation across host generations. But in contrast to bacteria, little is known about the diversity and distribution of natural product biosynthetic pathways among fungi and how they evolve to facilitate symbiosis and adaptation to their host environment. In this study, we define the secondary metabolism of Escovopsis and closely related genera, symbionts in the gardens of fungus-farming ants. We ask how the gain and loss of various biosynthetic pathways correspond to divergent lifestyles. Long-read sequencing allowed us to define the chromosomal features of representative Escovopsis strains, revealing highly reduced genomes composed of seven to eight chromosomes. The genomes are highly syntenic with macrosynteny decreasing with increasing phylogenetic distance, while maintaining a high degree of mesosynteny. An ancestral state reconstruction analysis of biosynthetic pathways revealed that, while many secondary metabolites are shared with non-ant-associated Sordariomycetes, 56 pathways are unique to the symbiotic genera. Reflecting adaptation to diverging ant agricultural systems, we observe that the stepwise acquisition of these pathways mirrors the ecological radiations of attine ants and the dynamic recruitment and replacement of their fungal cultivars. As different clades encode characteristic combinations of biosynthetic gene clusters, these delineating profiles provide important insights into the possible mechanisms underlying specificity between these symbionts and their fungal hosts. Collectively, our findings shed light on the evolutionary dynamic nature of secondary metabolism in Escovopsis and its allies, reflecting adaptation of the symbionts to an ancient agricultural system.IMPORTANCEMicrobial symbionts interact with their hosts and competitors through a remarkable array of secondary metabolites and natural products. Here, we highlight the highly streamlined genomic features of attine-associated fungal symbionts. The genomes of Escovopsis species, as well as species from other symbiont genera, many of which are common with the gardens of fungus-growing ants, are defined by seven chromosomes. Despite a high degree of metabolic conservation, we observe some variation in the symbionts' potential to produce secondary metabolites. As the phylogenetic distribution of the encoding biosynthetic gene clusters coincides with attine transitions in agricultural systems, we highlight the likely role of these metabolites in mediating adaptation by a group of highly specialized symbionts.
Collapse
Affiliation(s)
- Aileen Berasategui
- Department of Biology, Emory University, Atlanta, Georgia, USA
- Cluster of Excellence-Controlling Microbes to Fight Infections, University of Tübingen, Tübingen, Germany
- Mutualisms Research Group, Max Planck Institute for Biology, Tübingen, Germany
- Amsterdam Institute for Life and Environment, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Hassan Salem
- Department of Biology, Emory University, Atlanta, Georgia, USA
- Mutualisms Research Group, Max Planck Institute for Biology, Tübingen, Germany
| | - Abraham G Moller
- Division of Infectious Diseases, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Yuliana Christopher
- Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Ciudad del Saber, Panamá City, Panama
| | - Quimi Vidaurre Montoya
- Department of General and Applied Biology, São Paulo State University (UNESP), Institute of Biosciences, Rio Claro, São Paulo, Brazil
| | - Caitlin Conn
- Department of Biology, Emory University, Atlanta, Georgia, USA
- Department of Biology, Berry College, Mount Berry, Georgia, USA
| | - Timothy D Read
- Division of Infectious Diseases, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Andre Rodrigues
- Department of General and Applied Biology, São Paulo State University (UNESP), Institute of Biosciences, Rio Claro, São Paulo, Brazil
| | - Nadine Ziemert
- Cluster of Excellence-Controlling Microbes to Fight Infections, University of Tübingen, Tübingen, Germany
- Translational Genome Mining for Natural Products, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), Interfaculty Institute for Biomedical Informatics (IBMI), University of Tübingen, Tübingen, Germany
| | - Nicole Gerardo
- Department of Biology, Emory University, Atlanta, Georgia, USA
| |
Collapse
|
2
|
Bringhurst B, Allert M, Greenwold M, Kellner K, Seal JN. Environments and Hosts Structure the Bacterial Microbiomes of Fungus-Gardening Ants and their Symbiotic Fungus Gardens. MICROBIAL ECOLOGY 2022:10.1007/s00248-022-02138-x. [PMID: 36344828 DOI: 10.1007/s00248-022-02138-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
The fungus gardening-ant system is considered a complex, multi-tiered symbiosis, as it is composed of ants, their fungus, and microorganisms associated with either ants or fungus. We examine the bacterial microbiome of Trachymyrmex septentrionalis and Mycetomoellerius turrifex ants and their symbiotic fungus gardens, using 16S rRNA Illumina sequencing, over a region spanning approximately 350 km (east and central Texas). Typically, microorganisms can be acquired from a parent colony (vertical transmission) or from the environment (horizontal transmission). Because the symbiosis is characterized by co-dispersal of the ants and fungus, elements of both ant and fungus garden microbiome could be characterized by vertical transmission. The goals of this study were to explore how both the ant and fungus garden bacterial microbiome are acquired. The main findings were that different mechanisms appear to explain the structure the microbiomes of ants and their symbiotic fungus gardens. Ant associated microbiomes had a strong host ant signature, which could be indicative of vertical inheritance of the ant associated bacterial microbiome or an unknown mechanism of active uptake or screening. On the other hand, the bacterial microbiome of the fungus garden was more complex in that some bacterial taxa appear to be structured by the ant host species, whereas others by fungal lineage or the environment (geographic region). Thus bacteria in fungus gardens appear to be acquired both horizontally and vertically.
Collapse
Affiliation(s)
- Blake Bringhurst
- Department of Biology, University of Texas at Tyler, 3900 University Blvd, Tyler, TX, 75799, USA
| | - Mattea Allert
- Department of Biology, University of Texas at Tyler, 3900 University Blvd, Tyler, TX, 75799, USA
| | - Matthew Greenwold
- Department of Biology, University of Texas at Tyler, 3900 University Blvd, Tyler, TX, 75799, USA
| | - Katrin Kellner
- Department of Biology, University of Texas at Tyler, 3900 University Blvd, Tyler, TX, 75799, USA
| | - Jon N Seal
- Department of Biology, University of Texas at Tyler, 3900 University Blvd, Tyler, TX, 75799, USA.
| |
Collapse
|
3
|
Bizarria R, de Castro Pietrobon T, Rodrigues A. Uncovering the Yeast Communities in Fungus-Growing Ant Colonies. MICROBIAL ECOLOGY 2022:10.1007/s00248-022-02099-1. [PMID: 35962280 DOI: 10.1007/s00248-022-02099-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/03/2022] [Indexed: 06/15/2023]
Abstract
Yeast-insect interactions are compelling models to study the evolution, ecology, and diversification of yeasts. Fungus-growing (attine) ants are prominent insects in the Neotropics that evolved an ancient fungiculture of basidiomycete fungi over 55-65 million years, supplying an environment for a hidden yeast diversity. Here we assessed the yeast diversity in the attine ant environment by thoroughly sampling fungus gardens across four out of five ant fungiculture systems: Acromyrmex coronatus and Mycetomoellerius tucumanus standing for leaf-cutting and higher-attine fungicultures, respectively; Apterostigma sp., Mycetophylax sp., and Mycocepurus goeldii as ants from the lower-attine fungiculture. Among the fungus gardens of all fungus-growing ants examined, we found taxonomically unique and diverse microbial yeast communities across the different fungicultures. Ascomycete yeasts were the core taxa in fungus garden samples, with Saccharomycetales as the most frequent order. The genera Aureobasidium, Candida, Papiliotrema, Starmerella, and Sugiyamaella had the highest incidence in fungus gardens. Despite the expected similarity within the same fungiculture system, colonies of the same ant species differed in community structure. Among Saccharomycotina yeasts, few were distinguishable as killer yeasts, with a classical inhibition pattern for the killer phenotype, differing from earlier observations in this environment, which should be further investigated. Yeast mycobiome in fungus gardens is distinct between colonies of the same fungiculture and each ant colony harbors a distinguished and unique yeast community. Fungus gardens of attine ants are emergent environments to study the diversity and ecology of yeasts associated with insects.
Collapse
Affiliation(s)
- Rodolfo Bizarria
- Department of General and Applied Biology, São Paulo State University (UNESP), Bela Vista, Avenida 24-A, n. 1515SP 13.506-900, Rio Claro, Brazil
- Center for the Study of Social Insects, São Paulo State University (UNESP), Rio Claro, SP, Brazil
| | - Tatiane de Castro Pietrobon
- Department of General and Applied Biology, São Paulo State University (UNESP), Bela Vista, Avenida 24-A, n. 1515SP 13.506-900, Rio Claro, Brazil
- Center for the Study of Social Insects, São Paulo State University (UNESP), Rio Claro, SP, Brazil
| | - Andre Rodrigues
- Department of General and Applied Biology, São Paulo State University (UNESP), Bela Vista, Avenida 24-A, n. 1515SP 13.506-900, Rio Claro, Brazil.
- Center for the Study of Social Insects, São Paulo State University (UNESP), Rio Claro, SP, Brazil.
| |
Collapse
|
4
|
Senula SF, Scavetta JT, Mueller UG, Seal JN, Kellner K. Cold adaptations along a range limit in an obligate symbiosis. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S. F. Senula
- Department of Biology, The University of Texas at Tyler 3900 University Blvd. Tyler Texas
| | - J. T. Scavetta
- Department of Computer Science Rowan University Glassboro NJ USA
| | - U. G. Mueller
- Department of Integrative Biology University of Texas at Austin Austin TX USA
| | - J. N. Seal
- Department of Biology, The University of Texas at Tyler 3900 University Blvd. Tyler Texas
| | - K. Kellner
- Department of Biology, The University of Texas at Tyler 3900 University Blvd. Tyler Texas
| |
Collapse
|
5
|
Bizarria R, Pagnocca FC, Rodrigues A. Yeasts in the attine ant-fungus mutualism: Diversity, functional roles, and putative biotechnological applications. Yeast 2021; 39:25-39. [PMID: 34473375 DOI: 10.1002/yea.3667] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 07/20/2021] [Accepted: 08/30/2021] [Indexed: 01/01/2023] Open
Abstract
Insects interact with a wide variety of yeasts, often providing a suitable substrate for their growth. Some yeast-insect interactions are tractable models for understanding the relationships between the symbionts. Attine ants are prominent insects in the Neotropics and have performed an ancient fungiculture of mutualistic basidiomycete fungi for more than 55-65 million years. Yeasts gain access to this sophisticated mutualism, prompting diversity, ecological, and biotechnological studies in this environment. We review half a century research in this field, surveying for recurrent yeast taxa and their putative ecological roles in this environment. We found that previous studies mainly covered the yeast diversity from a small fraction of attine ants, being Saccharomycetales, Tremellales, and Trichosporonales as the most frequent yeast or yeast-like orders found. Apiotrichum, Aureobasidium, Candida, Cutaneotrichosporon, Debaryomyces, Meyerozyma, Papiliotrema, Rhodotorula, Trichomonascus, and Trichosporon are the most frequent recovered genera. On the other hand, studies of yeasts' ecological roles on attine ant-fungus mutualism only tapped the tip of the iceberg. Previous established hypotheses in the literature cover the production of lignocellulosic enzymes, chemical detoxification, and fungus garden protection. Some of these roles have parallels in biotechnological processes. In conclusion, the attine ant environment has a hidden potential for studying yeast biodiversity, ecology, and biotechnology, which has been particularly unexplored considering the vast diversity of fungus-growing ants.
Collapse
Affiliation(s)
- Rodolfo Bizarria
- Center for the Study of Social Insects, São Paulo State University (UNESP), Rio Claro, Brazil.,Department of General and Applied Biology, São Paulo State University (UNESP), Rio Claro, Brazil
| | | | - Andre Rodrigues
- Center for the Study of Social Insects, São Paulo State University (UNESP), Rio Claro, Brazil.,Department of General and Applied Biology, São Paulo State University (UNESP), Rio Claro, Brazil
| |
Collapse
|
6
|
Beigel K, Matthews AE, Kellner K, Pawlik CV, Greenwold M, Seal JN. Cophylogenetic analyses of Trachymyrmex ant-fungal specificity: "One to one with some exceptions". Mol Ecol 2021; 30:5605-5620. [PMID: 34424571 DOI: 10.1111/mec.16140] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 08/05/2021] [Accepted: 08/11/2021] [Indexed: 01/18/2023]
Abstract
Over the past few decades, large-scale phylogenetic analyses of fungus-gardening ants and their symbiotic fungi have depicted strong concordance among major clades of ants and their symbiotic fungi, yet within clades, fungus sharing is widespread among unrelated ant lineages. Sharing has been explained using a diffuse coevolution model within major clades. Understanding horizontal exchange within clades has been limited by conventional genetic markers that lack both interspecific and geographic variation. To examine whether reports of horizontal exchange were indeed due to symbiont sharing or the result of employing relatively uninformative molecular markers, samples of Trachymyrmex arizonensis and Trachymyrmex pomonae and their fungi were collected from native populations in Arizona and genotyped using conventional marker genes and genome-wide single nucleotide polymorphisms (SNPs). Conventional markers of the fungal symbionts generally exhibited cophylogenetic patterns that were consistent with some symbiont sharing, but most fungal clades had low support. SNP analysis, in contrast, indicated that each ant species exhibited fidelity to its own fungal subclade with only one instance of a colony growing a fungus that was otherwise associated with a different ant species. This evidence supports a pattern of codivergence between Trachymyrmex species and their fungi, and thus a diffuse coevolutionary model may not accurately predict symbiont exchange. These results suggest that fungal sharing across host species in these symbioses may be less extensive than previously thought.
Collapse
Affiliation(s)
- Katherine Beigel
- Department of Biology, The University of Texas at Tyler, Tyler, Texas, USA
| | - Alix E Matthews
- Department of Biology, The University of Texas at Tyler, Tyler, Texas, USA.,College of Sciences and Mathematics and Molecular Biosciences Program, Arkansas State University, Jonesboro, Arkansas, USA
| | - Katrin Kellner
- Department of Biology, The University of Texas at Tyler, Tyler, Texas, USA
| | - Christine V Pawlik
- Department of Biology, The University of Texas at Tyler, Tyler, Texas, USA
| | - Matthew Greenwold
- Department of Biology, The University of Texas at Tyler, Tyler, Texas, USA
| | - Jon N Seal
- Department of Biology, The University of Texas at Tyler, Tyler, Texas, USA
| |
Collapse
|
7
|
Cardenas CR, Luo AR, Jones TH, Schultz TR, Adams RM. Using an integrative taxonomic approach to delimit a sibling species, Mycetomoellerius mikromelanos sp. nov. (Formicidae: Attini: Attina). PeerJ 2021; 9:e11622. [PMID: 34221725 PMCID: PMC8236233 DOI: 10.7717/peerj.11622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 05/26/2021] [Indexed: 11/24/2022] Open
Abstract
The fungus-growing ant Mycetomoellerius (previously Trachymyrmex) zeteki (Weber 1940) has been the focus of a wide range of studies examining symbiotic partners, garden pathogens, mating frequencies, and genomics. This is in part due to the ease of collecting colonies from creek embankments and its high abundance in the Panama Canal region. The original description was based on samples collected on Barro Colorado Island (BCI), Panama. However, most subsequent studies have sampled populations on the mainland 15 km southeast of BCI. Herein we show that two sibling ant species live in sympatry on the mainland: Mycetomoellerius mikromelanos Cardenas, Schultz, & Adams and M. zeteki. This distinction was originally based on behavioral differences of workers in the field and on queen morphology (M. mikromelanos workers and queens are smaller and black while those of M. zeteki are larger and red). Authors frequently refer to either species as "M. cf. zeteki," indicating uncertainty about identity. We used an integrative taxonomic approach to resolve this, examining worker behavior, chemical profiles of worker volatiles, molecular markers, and morphology of all castes. For the latter, we used conventional taxonomic indicators from nine measurements, six extrapolated indices, and morphological characters. We document a new observation of a Diapriinae (Hymenoptera: Diapriidae) parasitoid wasp parasitizing M. zeteki. Finally, we discuss the importance of vouchering in dependable, accessible museum collections and provide a table of previously published papers to clarify the usage of the name T. zeteki. We found that most reports of M. zeteki or M. cf. zeteki-including a genome-actually refer to the new species M. mikromelanos.
Collapse
Affiliation(s)
- Cody Raul Cardenas
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH, United States of America
| | - Amy Rongyan Luo
- Department of Ecology & Evolutionary Biology, University of Tennessee Knoxville, Knoxville, TN, United States of America
| | - Tappey H. Jones
- Department of Chemistry, Virginia Military Institute, Lexington, VA, United States of America
| | - Ted R. Schultz
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, District of Colombia, United States of America
| | - Rachelle M.M. Adams
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH, United States of America
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, District of Colombia, United States of America
| |
Collapse
|
8
|
Matthews AE, Kellner K, Seal JN. Male-biased dispersal in a fungus-gardening ant symbiosis. Ecol Evol 2021; 11:2307-2320. [PMID: 33717457 PMCID: PMC7920773 DOI: 10.1002/ece3.7198] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 12/08/2020] [Accepted: 12/11/2020] [Indexed: 02/06/2023] Open
Abstract
For nearly all organisms, dispersal is a fundamental life-history trait that can shape their ecology and evolution. Variation in dispersal capabilities within a species exists and can influence population genetic structure and ecological interactions. In fungus-gardening (attine) ants, co-dispersal of ants and mutualistic fungi is crucial to the success of this obligate symbiosis. Female-biased dispersal (and gene flow) may be favored in attines because virgin queens carry the responsibility of dispersing the fungi, but a paucity of research has made this conclusion difficult. Here, we investigate dispersal of the fungus-gardening ant Trachymyrmex septentrionalis using a combination of maternally (mitochondrial DNA) and biparentally inherited (microsatellites) markers. We found three distinct, spatially isolated mitochondrial DNA haplotypes; two were found in the Florida panhandle and the other in the Florida peninsula. In contrast, biparental markers illustrated significant gene flow across this region and minimal spatial structure. The differential patterns uncovered from mitochondrial DNA and microsatellite markers suggest that most long-distance ant dispersal is male-biased and that females (and concomitantly the fungus) have more limited dispersal capabilities. Consequently, the limited female dispersal is likely an important bottleneck for the fungal symbiont. This bottleneck could slow fungal genetic diversification, which has significant implications for both ant hosts and fungal symbionts regarding population genetics, species distributions, adaptive responses to environmental change, and coevolutionary patterns.
Collapse
Affiliation(s)
- Alix E. Matthews
- Department of BiologyThe University of Texas at TylerTylerTXUSA
- Present address:
College of Sciences and Mathematics and Molecular Biosciences ProgramArkansas State UniversityJonesboroARUSA
| | - Katrin Kellner
- Department of BiologyThe University of Texas at TylerTylerTXUSA
| | - Jon N. Seal
- Department of BiologyThe University of Texas at TylerTylerTXUSA
| |
Collapse
|
9
|
Shik JZ, Kooij PW, Donoso DA, Santos JC, Gomez EB, Franco M, Crumière AJJ, Arnan X, Howe J, Wcislo WT, Boomsma JJ. Nutritional niches reveal fundamental domestication trade-offs in fungus-farming ants. Nat Ecol Evol 2020; 5:122-134. [PMID: 33106603 PMCID: PMC7610523 DOI: 10.1038/s41559-020-01314-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 08/25/2020] [Indexed: 02/06/2023]
Abstract
During crop domestication, human farmers traded greater productivity for higher crop vulnerability outside specialized cultivation conditions. We found a similar domestication tradeoff across the major co-evolutionary transitions in farming systems of attine ants. First, the fundamental nutritional niches (FNNs) of cultivars narrowed during ~ 60 million years of naturally selected domestication, and laboratory experiments showed that ant farmers representing subsequent domestication stages strictly regulate protein harvest relative to cultivar FNNs. Second, ants with different farming systems differed in their abilities to harvest the resources that best matched the nutritional needs of their fungal cultivars. This was assessed by quantifying realized nutritional niches (RNNs) from analyses of items collected from the mandibles of laden ant foragers in the field. Third, extensive field collections suggest that among-colony genetic diversity of cultivars in small-scale farms may offer population-wide resilience benefits that species with large-scale farming colonies achieve by more elaborate and demanding cultivation practices of less diverse crops. Our results underscore that naturally selected farming systems have potential to shed light on nutritional tradeoffs that shaped the course of culturally evolved human farming.
Collapse
Affiliation(s)
- Jonathan Z Shik
- Section of Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark. .,Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark. .,Smithsonian Tropical Research Institute, Panama City, Republic of Panama.
| | - Pepijn W Kooij
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark.,Comparative Fungal Biology, Department of Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, London, UK.,Center for the Study of Social Insects, São Paulo State University (UNESP), Rio Claro, Brazil
| | - David A Donoso
- Departamento de Biología, Escuela Politécnica Nacional, Quito, Ecuador.,Centro de Investigación de la Biodiversidad y Cambio Climático, Universidad Tecnológica Indoamérica, Quito, Ecuador
| | - Juan C Santos
- Department of Biological Sciences, St. John's University, New York, NY, USA
| | - Ernesto B Gomez
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
| | - Mariana Franco
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
| | - Antonin J J Crumière
- Section of Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Xavier Arnan
- Centre de Recerca Ecològica i Aplicacions Forestals (CREAF), Cerdanyola del Vallès, Spain.,Department of Biological Sciences, University of Pernambuco, Garanhuns, Brazil
| | - Jack Howe
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark.,Department of Zoology, University of Oxford, Oxford, UK
| | - William T Wcislo
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
| | - Jacobus J Boomsma
- Section of Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark.,Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
10
|
High diversity and multiple invasions to North America by fungi grown by the northern-most Trachymyrmex and Mycetomoellerius ant species. FUNGAL ECOL 2020. [DOI: 10.1016/j.funeco.2019.100878] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
11
|
Matthews AE, Rowan C, Stone C, Kellner K, Seal JN. Development, characterization, and cross-amplification of polymorphic microsatellite markers for North American Trachymyrmex and Mycetomoellerius ants. BMC Res Notes 2020; 13:173. [PMID: 32204727 PMCID: PMC7092486 DOI: 10.1186/s13104-020-05015-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 03/11/2020] [Indexed: 01/19/2023] Open
Abstract
Objective The objective of this study is to develop and identify polymorphic microsatellite markers for fungus-gardening (attine) ants in the genus Trachymyrmex sensu lato. These ants are important ecosystem engineers and have been a model group for understanding complex symbiotic systems, but very little is understood about the intraspecific genetic patterns across most North American attine species. These microsatellite markers will help to better study intraspecific population genetic structure, gene flow, mating habits, and phylogeographic patterns in these species and potentially other congeners. Results Using next-generation sequencing techniques, we identified 17 and 12 polymorphic microsatellite markers from T. septentrionalis and Mycetomoellerius (formerly Trachymyrmex) turrifex, respectively, and assessed the genetic diversity of each marker. We also analyzed the cross-amplification success of the T. septentrionalis markers in two other closely related Trachymyrmex species, and identified 10 and 12 polymorphic markers for T. arizonensis and T. pomonae, respectively.
Collapse
Affiliation(s)
- Alix E Matthews
- Department of Biology, The University of Texas at Tyler, Tyler, TX, USA
| | - Chase Rowan
- Department of Biology, The University of Texas at Tyler, Tyler, TX, USA
| | - Colby Stone
- Department of Biology, The University of Texas at Tyler, Tyler, TX, USA
| | - Katrin Kellner
- Department of Biology, The University of Texas at Tyler, Tyler, TX, USA
| | - Jon N Seal
- Department of Biology, The University of Texas at Tyler, Tyler, TX, USA.
| |
Collapse
|
12
|
González CT, Saltonstall K, Fernández-Marín H. Garden microbiomes of Apterostigma dentigerum and Apterostigma pilosum fungus-growing ants (Hymenoptera: Formicidae). J Microbiol 2019; 57:842-851. [PMID: 31377982 DOI: 10.1007/s12275-019-8639-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 04/08/2019] [Accepted: 05/03/2019] [Indexed: 12/17/2022]
Abstract
Fungus-growing ants share a complex symbiosis with microbes, including fungal mutualists, antibiotic-producing bacteria, and fungal pathogens. The bacterial communities associated with this symbiosis are poorly understood but likely play important roles in maintaining the health and function of fungal gardens. We studied bacterial communities in gardens of two Apterostigma species, A. dentigerum, and A. pilosum, using next-generation sequencing to evaluate differences between the two ant species, their veiled and no-veiled fungal garden types, and across three collection locations. We also compared different parts of nests to test for homogeneity within nests. Enterobacteriaceae dominated gardens of both species and common OTUs were shared across both species and nest types. However, differences in community diversity were detected between ant species, and in the communities of A. dentigerum veiled and no-veiled nests within sites. Apterostigma pilosum had a higher proportion of Phyllobacteriaceae and differed from A. dentigerum in the proportions of members of the order Clostridiales. Within A. dentigerum, nests with veiled and no-veiled fungus gardens had similar taxonomic profiles but differed in the relative abundance of some groups, with veiled gardens having more Rhodospirillaceae and Hyphomicrobiaceae, and no-veiled having more Xanthomonadaceae and certain genera in the Enterobacteriaceae C. However, bacterial communities in Apterostigma fungal gardens are highly conserved and resemble those of the nests of other attine ants with dominant taxa likely playing a role in biomass degradation and defense. Further work is required to understand and explain how bacterial community composition of fungus-growing nests is maintained.
Collapse
Affiliation(s)
- Cely T González
- Centro de Biodiversidad y Descubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Apartado, 0843-01103, Clayton, Republic of Panama. .,Department of Biotechnology, Acharya Nagarjuna University, Guntur, India. .,Smithsonian Tropical Research Institute, P.O. Box 0843-03092, Amador, Naos, Republic of Panama.
| | - Kristin Saltonstall
- Smithsonian Tropical Research Institute, P.O. Box 0843-03092, Amador, Naos, Republic of Panama
| | - Hermógenes Fernández-Marín
- Centro de Biodiversidad y Descubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Apartado, 0843-01103, Clayton, Republic of Panama.
| |
Collapse
|
13
|
Montoya QV, Martiarena MJS, Danilo Augusto Polezel, Akazu S, Rodrigues A. More pieces to a huge puzzle: Two new Escovopsis species from fungus gardens of attine ants. MycoKeys 2019:97-118. [PMID: 30814906 PMCID: PMC6389644 DOI: 10.3897/mycokeys.46.30951] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/16/2019] [Indexed: 11/12/2022] Open
Abstract
Escovopsis (Ascomycota: Hypocreales, Hypocreaceae) is the only known parasite of the mutualistic fungi cultivated by fungus-growing ants (Formicidae: Myrmicinae: Attini: Attina, the "attines"). Despite its ecological role, the taxonomy and systematics of Escovopsis have been poorly addressed. Here, based on morphological and phylogenetic analyses with three molecular markers (internal transcribed spacer, large subunit ribosomal RNA and the translation elongation factor 1-alpha), we describe Escovopsisclavatus and E.multiformis as new species isolated from fungus gardens of Apterostigma ant species. Our analysis shows that E.clavatus and E.multiformis belong to the most derived Escovopsis clade, whose main character is the presence of conidiophores with vesicles. Nevertheless, the most outstanding feature of both new species is the presence of a swollen region in the central hypha of the conidiophore named swollen cell, which is absent in all previously described Escovopsis species. The less derived Escovopsis clades lack vesicles and their phylogenetic position within the Hypocreaceae still remains unclear. Considering the high genetic diversity in Escovopsis, the description of these new species adds barely two pieces to a huge taxonomic puzzle; however, this discovery is an important piece for building the systematics of this group of fungi.
Collapse
Affiliation(s)
- Quimi Vidaurre Montoya
- Department of Biochemistry and Microbiology, UNESP - São Paulo State University, Rio Claro, SP, Brazil São Paulo State University Rio Claro Brazil
| | - Maria Jesus Sutta Martiarena
- Department of Biochemistry and Microbiology, UNESP - São Paulo State University, Rio Claro, SP, Brazil São Paulo State University Rio Claro Brazil
| | - Danilo Augusto Polezel
- Department of Biochemistry and Microbiology, UNESP - São Paulo State University, Rio Claro, SP, Brazil São Paulo State University Rio Claro Brazil
| | - Sérgio Akazu
- Center for the Studies of Social Insects, UNESP - São Paulo State University, Rio Claro, SP, Brazil São Paulo State University Rio Claro Brazil
| | - Andre Rodrigues
- Department of Biochemistry and Microbiology, UNESP - São Paulo State University, Rio Claro, SP, Brazil São Paulo State University Rio Claro Brazil.,Center for the Studies of Social Insects, UNESP - São Paulo State University, Rio Claro, SP, Brazil São Paulo State University Rio Claro Brazil
| |
Collapse
|
14
|
Howe J, Schiøtt M, Boomsma JJ. Horizontal partner exchange does not preclude stable mutualism in fungus-growing ants. Behav Ecol 2018. [DOI: 10.1093/beheco/ary176] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Jack Howe
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Morten Schiøtt
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jacobus J Boomsma
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
15
|
Osti JF, Rodrigues A. Escovopsioides as a fungal antagonist of the fungus cultivated by leafcutter ants. BMC Microbiol 2018; 18:130. [PMID: 30305028 PMCID: PMC6180628 DOI: 10.1186/s12866-018-1265-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 09/26/2018] [Indexed: 12/04/2022] Open
Abstract
Background Fungus gardens of fungus-growing (attine) ants harbor complex microbiomes in addition to the mutualistic fungus they cultivate for food. Fungi in the genus Escovopsioides were recently described as members of this microbiome but their role in the ant-fungus symbiosis is poorly known. In this study, we assessed the phylogenetic diversity of 21 Escovopsioides isolates obtained from fungus gardens of leafcutter ants (genera Atta and Acromyrmex) and non-leafcutter ants (genera Trachymyrmex and Apterostigma) sampled from several regions in Brazil. Results Regardless of the sample locality or ant genera, phylogenetic analysis showed low genetic diversity among the 20 Escovopsisoides isolates examined, which prompted the identification as Escovopsioides nivea (the only described species in the genus). In contrast, one Escovopsioides isolate obtained from a fungus garden of Apterostigma megacephala was considered a new phylogenetic species. Dual-culture plate assays showed that Escovopsioides isolates inhibited the mycelium growth of Leucoagaricus gongylophorus, the mutualistic fungus cultivated by somes species of leafcutter ants. In addition, Escovopsioides growth experiments in fungus gardens with and without ant workers showed this fungus is detrimental to the ant-fungus symbiosis. Conclusions Here, we provide clues for the antagonism of Escovopsioides towards the mutualistic fungus of leafcutter ants. Electronic supplementary material The online version of this article (10.1186/s12866-018-1265-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Julio Flavio Osti
- Department of Biochemistry and Microbiology, São Paulo State University (UNESP), Rio Claro, Brazil
| | - Andre Rodrigues
- Department of Biochemistry and Microbiology, São Paulo State University (UNESP), Rio Claro, Brazil. .,Center for the Studies of Social Insects, São Paulo State University (UNESP), Rio Claro, Brazil.
| |
Collapse
|
16
|
Schneider SA, Okusu A, Normark BB. Molecular phylogenetics of Aspidiotini armored scale insects (Hemiptera: Diaspididae) reveals rampant paraphyly, curious species radiations, and multiple origins of association with Melissotarsus ants (Hymenoptera: Formicidae). Mol Phylogenet Evol 2018; 129:291-303. [PMID: 30195475 DOI: 10.1016/j.ympev.2018.09.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/05/2018] [Accepted: 09/05/2018] [Indexed: 11/16/2022]
Abstract
The armored scale insect tribe Aspidiotini comprises many pest species that are globally invasive and economically damaging. The taxonomy of scale insects is based almost solely upon morphological characters of adult females, and little prior work has been done to test the classification of aspidiotines against molecular evidence. To address these concerns, we reconstruct a molecular phylogeny for aspidiotine armored scales that expands greatly upon taxonomic and character representations from previous studies. Our dataset includes 127 species (356 terminal taxa) and four gene regions: 28S, EF-1α, COI-COII, and CAD. Nearly 50% of the species treated are identified as pests and several more may represent emerging pests. Phylogenetic data were analyzed in a Bayesian framework using MC3 iterations. The majority of sampled aspidiotine genera are not monophyletic as currently defined. Monophyly constraints for 'worst offenders' were imposed on the phylogeny and stepping-stone MCMC was performed to calculate marginal likelihood scores. Comparisons of marginal likelihoods from runs with constrained vs. informative priors support the interpretation that pest-rich genera are not monophyletic. We use character mapping to illustrate signal and convergence for selected traits that have been used to define or recognize genera and evaluate consistency and retention indices for these traits. The phylogeny illustrates a pervasive pattern in which extremely polyphagous pests - typically having large populations and wide geographical distributions - are frequently intertwined with range-limited specialists on the phylogeny. Finally, the phylogeny recovers three origins of ant association among the Aspidiotini. The history of ant/diaspidid symbioses involves periods of sustained partner fidelity, spanning multiple speciation events, which have been punctuated by opportunistic switches to novel partners.
Collapse
Affiliation(s)
- Scott A Schneider
- USDA, Agricultural Research Service, Henry A. Wallace Beltsville Agricultural Research Center, Systematic Entomology Laboratory, Building 005 - Room 004, 10300 Baltimore Avenue, Beltsville, MD 20705, USA(1); Graduate Program in Organismic and Evolutionary Biology, 204C French Hall, University of Massachusetts, 230 Stockbridge Road, Amherst, MA 01003, USA.
| | - Akiko Okusu
- Biology Department, 221 Morrill Science Center III, University of Massachusetts, 611 North Pleasant Street, Amherst, MA 01003, USA.
| | - Benjamin B Normark
- Graduate Program in Organismic and Evolutionary Biology, 204C French Hall, University of Massachusetts, 230 Stockbridge Road, Amherst, MA 01003, USA; Biology Department, 221 Morrill Science Center III, University of Massachusetts, 611 North Pleasant Street, Amherst, MA 01003, USA.
| |
Collapse
|
17
|
Penn HJ, Crist TO. From dispersal to predation: A global synthesis of ant-seed interactions. Ecol Evol 2018; 8:9122-9138. [PMID: 30377488 PMCID: PMC6194306 DOI: 10.1002/ece3.4377] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 05/06/2018] [Accepted: 06/27/2018] [Indexed: 11/11/2022] Open
Abstract
Ant-seed interactions take several forms, including dispersal, predation, and parasitism, whereby ants consume seed appendages without dispersal of seeds. We hypothesized that these interaction outcomes could be predicted by ant and plant traits and habitat, with outcomes falling along a gradient of cost and benefit to the plant. To test this hypothesis, we conducted a global literature review and classified over 6,000 pairs of ant-seed interactions from 753 studies across six continents. Linear models showed that seed and ant size, habitat, and dispersal syndrome were the most consistent predictors. Predation was less likely than parasitism and seed dispersal among myrmecochorous plants. A classification tree of the predicted outcomes from linear models revealed that dispersal and predation formed distinct categories based on habitat, ant size, and dispersal mode, with parasitism outcomes forming a distinct subgroup of predation based on seed size and shape. Multiple correspondence analysis indicated some combinations of ant genera and plant families were strongly associated with particular outcomes, whereas other ant-seed combinations were much more variable. Taken together, these results demonstrate that ant and plant traits are important overall predictors of potential seed fates in different habitat types.
Collapse
Affiliation(s)
- Hannah J. Penn
- Department of EntomologyLouisiana State UniversityBaton RougeLouisiana
| | | |
Collapse
|
18
|
Kellner K, Kardish MR, Seal JN, Linksvayer TA, Mueller UG. Symbiont-Mediated Host-Parasite Dynamics in a Fungus-Gardening Ant. MICROBIAL ECOLOGY 2018; 76:530-543. [PMID: 29285550 DOI: 10.1007/s00248-017-1124-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 12/01/2017] [Indexed: 06/07/2023]
Abstract
Group-living can promote the evolution of adaptive strategies to prevent and control disease. Fungus-gardening ants must cope with two sets of pathogens, those that afflict the ants themselves and those of their symbiotic fungal gardens. While much research has demonstrated the impact of specialized fungal pathogens that infect ant fungus gardens, most of these studies focused on the so-called higher attine ants, which are thought to coevolve diffusely with two clades of leucocoprinaceous fungi. Relatively few studies have addressed disease ecology of lower Attini, which are thought to occasionally recruit (domesticate) novel leucocoprinaceous fungi from free-living populations; coevolution between lower-attine ants and their fungi is therefore likely weaker (or even absent) than in the higher Attini, which generally have many derived modifications. Toward understanding the disease ecology of lower-attine ants, this study (a) describes the diversity in the microfungal genus Escovopsis that naturally infect fungus gardens of the lower-attine ant Mycocepurus smithii and (b) experimentally determines the relative contributions of Escovopsis strain (a possible garden disease), M. smithii ant genotype, and fungal cultivar lineage to disease susceptibility and colony fitness. In controlled in-vivo infection laboratory experiments, we demonstrate that the susceptibility to Escovopsis infection was an outcome of ant-cultivar-Escovopsis interaction, rather than solely due to ant genotype or fungal cultivar lineage. The role of complex ant-cultivar-Escovopsis interactions suggests that switching M. smithii farmers onto novel fungus types might be a strategy to generate novel ant-fungus combinations resistant to most, but perhaps not all, Escovopsis strains circulating in a local population of this and other lower-attine ants.
Collapse
Affiliation(s)
- Katrin Kellner
- Section of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA.
- Department of Biology, University of Texas at Tyler, Tyler, TX, 75799, USA.
| | - M R Kardish
- Section of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA
- Deptartment of Evolution and Ecology, University of California, Davis, CA, 95616, USA
| | - J N Seal
- Section of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA
- Department of Biology, University of Texas at Tyler, Tyler, TX, 75799, USA
| | - T A Linksvayer
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - U G Mueller
- Section of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA
| |
Collapse
|
19
|
Mueller UG, Kardish MR, Ishak HD, Wright AM, Solomon SE, Bruschi SM, Carlson AL, Bacci M. Phylogenetic patterns of ant-fungus associations indicate that farming strategies, not only a superior fungal cultivar, explain the ecological success of leafcutter ants. Mol Ecol 2018; 27:2414-2434. [PMID: 29740906 DOI: 10.1111/mec.14588] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 01/18/2023]
Abstract
To elucidate fungicultural specializations contributing to ecological dominance of leafcutter ants, we estimate the phylogeny of fungi cultivated by fungus-growing (attine) ants, including fungal cultivars from (i) the entire leafcutter range from southern South America to southern North America, (ii) all higher-attine ant lineages (leafcutting genera Atta, Acromyrmex; nonleafcutting genera Trachymyrmex, Sericomyrmex) and (iii) all lower-attine lineages. Higher-attine fungi form two clades, Clade-A fungi (Leucocoprinus gongylophorus, formerly Attamyces) previously thought to be cultivated only by leafcutter ants, and a sister clade, Clade-B fungi, previously thought to be cultivated only by Trachymyrmex and Sericomyrmex ants. Contradicting this traditional view, we find that (i) leafcutter ants are not specialized to cultivate only Clade-A fungi because some leafcutter species ranging across South America cultivate Clade-B fungi; (ii) Trachymyrmex ants are not specialized to cultivate only Clade-B fungi because some Trachymyrmex species cultivate Clade-A fungi and other Trachymyrmex species cultivate fungi known so far only from lower-attine ants; (iii) in some locations, single higher-attine ant species or closely related cryptic species cultivate both Clade-A and Clade-B fungi; and (iv) ant-fungus co-evolution among higher-attine mutualisms is therefore less specialized than previously thought. Sympatric leafcutter ants can be ecologically dominant when cultivating either Clade-A or Clade-B fungi, sustaining with either cultivar-type huge nests that command large foraging territories; conversely, sympatric Trachymyrmex ants cultivating either Clade-A or Clade-B fungi can be locally abundant without achieving the ecological dominance of leafcutter ants. Ecological dominance of leafcutter ants therefore does not depend primarily on specialized fungiculture of L. gongylophorus (Clade-A), but must derive from ant-fungus synergisms and unique ant adaptations.
Collapse
Affiliation(s)
- Ulrich G Mueller
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas
| | - Melissa R Kardish
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas.,Center for Population Biology, University of California, Davis, California
| | - Heather D Ishak
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas.,Department of Medicine, Stanford University, Stanford, California
| | - April M Wright
- Department of Biological Science, Southeastern Louisiana University, Hammond, Louisiana
| | - Scott E Solomon
- Department of Ecology and Evolutionary Biology, Rice University, Houston, Texas.,Department of Entomology, Smithsonian Institution, Washington, District of Columbia
| | - Sofia M Bruschi
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas.,Centro de Estudos de Insetos Sociais, Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil
| | - Alexis L Carlson
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas
| | - Maurício Bacci
- Centro de Estudos de Insetos Sociais, Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil
| |
Collapse
|
20
|
Mueller UG, Ishak HD, Bruschi SM, Smith CC, Herman JJ, Solomon SE, Mikheyev AS, Rabeling C, Scott JJ, Cooper M, Rodrigues A, Ortiz A, Brandão CRF, Lattke JE, Pagnocca FC, Rehner SA, Schultz TR, Vasconcelos HL, Adams RMM, Bollazzi M, Clark RM, Himler AG, LaPolla JS, Leal IR, Johnson RA, Roces F, Sosa-Calvo J, Wirth R, Bacci M. Biogeography of mutualistic fungi cultivated by leafcutter ants. Mol Ecol 2017; 26:6921-6937. [PMID: 29134724 DOI: 10.1111/mec.14431] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 09/19/2017] [Accepted: 10/04/2017] [Indexed: 01/03/2023]
Abstract
Leafcutter ants propagate co-evolving fungi for food. The nearly 50 species of leafcutter ants (Atta, Acromyrmex) range from Argentina to the United States, with the greatest species diversity in southern South America. We elucidate the biogeography of fungi cultivated by leafcutter ants using DNA sequence and microsatellite-marker analyses of 474 cultivars collected across the leafcutter range. Fungal cultivars belong to two clades (Clade-A and Clade-B). The dominant and widespread Clade-A cultivars form three genotype clusters, with their relative prevalence corresponding to southern South America, northern South America, Central and North America. Admixture between Clade-A populations supports genetic exchange within a single species, Leucocoprinus gongylophorus. Some leafcutter species that cut grass as fungicultural substrate are specialized to cultivate Clade-B fungi, whereas leafcutters preferring dicot plants appear specialized on Clade-A fungi. Cultivar sharing between sympatric leafcutter species occurs frequently such that cultivars of Atta are not distinct from those of Acromyrmex. Leafcutters specialized on Clade-B fungi occur only in South America. Diversity of Clade-A fungi is greatest in South America, but minimal in Central and North America. Maximum cultivar diversity in South America is predicted by the Kusnezov-Fowler hypothesis that leafcutter ants originated in subtropical South America and only dicot-specialized leafcutter ants migrated out of South America, but the cultivar diversity becomes also compatible with a recently proposed hypothesis of a Central American origin by postulating that leafcutter ants acquired novel cultivars many times from other nonleafcutter fungus-growing ants during their migrations from Central America across South America. We evaluate these biogeographic hypotheses in the light of estimated dates for the origins of leafcutter ants and their cultivars.
Collapse
Affiliation(s)
- Ulrich G Mueller
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Heather D Ishak
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Sofia M Bruschi
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA.,Centro de Estudos de Insetos Sociais, Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil
| | - Chad C Smith
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Jacob J Herman
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Scott E Solomon
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA.,Centro de Estudos de Insetos Sociais, Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil.,Department of Ecology & Evolutionary Biology, Rice University, Houston, TX, USA
| | - Alexander S Mikheyev
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA.,Okinawa Institute of Science & Technology, Kunigami, Okinawa, Japan
| | - Christian Rabeling
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA.,School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Jarrod J Scott
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Michael Cooper
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Andre Rodrigues
- Centro de Estudos de Insetos Sociais, Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil
| | - Adriana Ortiz
- Universidad Nacional de Colombia, Medellin, Colombia
| | | | - John E Lattke
- Departamento de Zoologia, Universidade Federal do Paraná, Curitiba, Brazil
| | - Fernando C Pagnocca
- Centro de Estudos de Insetos Sociais, Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil
| | - Stephen A Rehner
- Mycology and Nematology Genomic Diversity and Biology Laboratory, Beltsville, MD, USA
| | - Ted R Schultz
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | | | - Rachelle M M Adams
- Department of Evolution, Ecology & Organismal Biology, Museum of Biological Diversity, Columbus, OH, USA
| | - Martin Bollazzi
- Section of Entomology, Universidad de la República, Montevideo, Uruguay
| | - Rebecca M Clark
- Integrative Biology, University of California-Berkeley, Berkeley, CA, USA
| | - Anna G Himler
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA.,Department of Biology, College of Idaho, Caldwell, ID, USA
| | - John S LaPolla
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.,Department of Biological Sciences, Towson University, Towson, MD, USA
| | - Inara R Leal
- Departamento de Botânica, Universidade Federal de Pernambuco, Recife, PE, Brazil
| | - Robert A Johnson
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Flavio Roces
- Department of Behavioral Physiology and Sociobiology, Biozentrum, University of Würzburg, Würzburg, Germany
| | | | - Rainer Wirth
- Department of Plant Ecology and Systematics, University of Kaiserslautern, Kaiserslautern, Germany
| | - Maurício Bacci
- Centro de Estudos de Insetos Sociais, Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil
| |
Collapse
|
21
|
Branstetter MG, Ješovnik A, Sosa-Calvo J, Lloyd MW, Faircloth BC, Brady SG, Schultz TR. Dry habitats were crucibles of domestication in the evolution of agriculture in ants. Proc Biol Sci 2017; 284:rspb.2017.0095. [PMID: 28404776 PMCID: PMC5394666 DOI: 10.1098/rspb.2017.0095] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 03/14/2017] [Indexed: 11/12/2022] Open
Abstract
The evolution of ant agriculture, as practised by the fungus-farming 'attine' ants, is thought to have arisen in the wet rainforests of South America about 55-65 Ma. Most subsequent attine agricultural evolution, including the domestication event that produced the ancestor of higher attine cultivars, is likewise hypothesized to have occurred in South American rainforests. The 'out-of-the-rainforest' hypothesis, while generally accepted, has never been tested in a phylogenetic context. It also presents a problem for explaining how fungal domestication might have occurred, given that isolation from free-living populations is required. Here, we use phylogenomic data from ultra-conserved element (UCE) loci to reconstruct the evolutionary history of fungus-farming ants, reduce topological uncertainty, and identify the closest non-fungus-growing ant relative. Using the phylogeny we infer the history of attine agricultural systems, habitat preference and biogeography. Our results show that the out-of-the-rainforest hypothesis is correct with regard to the origin of attine ant agriculture; however, contrary to expectation, we find that the transition from lower to higher agriculture is very likely to have occurred in a seasonally dry habitat, inhospitable to the growth of free-living populations of attine fungal cultivars. We suggest that dry habitats favoured the isolation of attine cultivars over the evolutionary time spans necessary for domestication to occur.
Collapse
Affiliation(s)
- Michael G Branstetter
- Department of Biology, University of Utah, Salt Lake City, UT 84112, USA .,Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| | - Ana Ješovnik
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA.,Department of Entomology, University of Maryland, College Park, MD 20742, USA
| | - Jeffrey Sosa-Calvo
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA.,Center for Social Insect Research, School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Michael W Lloyd
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| | - Brant C Faircloth
- Department of Biological Sciences and Museum of Natural Science, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Seán G Brady
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| | - Ted R Schultz
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| |
Collapse
|
22
|
Farji-Brener AG, Elizalde L, Fernández-Marín H, Amador-Vargas S. Social life and sanitary risks: evolutionary and current ecological conditions determine waste management in leaf-cutting ants. Proc Biol Sci 2017; 283:rspb.2016.0625. [PMID: 27226469 DOI: 10.1098/rspb.2016.0625] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 05/04/2016] [Indexed: 11/12/2022] Open
Abstract
Adequate waste management is vital for the success of social life, because waste accumulation increases sanitary risks in dense societies. We explored why different leaf-cutting ants (LCA) species locate their waste in internal nest chambers or external piles, including ecological context and accounting for phylogenetic relations. We propose that waste location depends on whether the environmental conditions enhance or reduce the risk of infection. We obtained the geographical range, habitat and refuse location of LCA from published literature, and experimentally determined whether pathogens on ant waste survived to the high soil temperatures typical of xeric habitats. The habitat of the LCA determined waste location after phylogenetic correction: species with external waste piles mainly occur in xeric environments, whereas those with internal waste chambers mainly inhabit more humid habitats. The ancestral reconstruction suggests that dumping waste externally is less derived than digging waste nest chambers. Empirical results showed that high soil surface temperatures reduce pathogen prevalence from LCA waste. We proposed that LCA living in environments unfavourable for pathogens (i.e. xeric habitats) avoid digging costs by dumping the refuse above ground. Conversely, in environments suitable for pathogens, LCA species prevent the spread of diseases by storing waste underground, presumably, a behaviour that contributed to the colonization of humid habitats. These results highlight the adaptation of organisms to the hygienic challenges of social living, and illustrate how sanitary behaviours can result from a combination of evolutionary history and current environmental conditions.
Collapse
Affiliation(s)
| | - Luciana Elizalde
- Laboratorio Ecotono, INIBIOMA-CONICET, Pasaje Gutiérrez 1125, 8400 Bariloche, Argentina
| | - Hermógenes Fernández-Marín
- Centro de Biodiversidad y Descrubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Cuidad del Saber, Panamá, Panama
| | | |
Collapse
|
23
|
Hogan CT, Jones TH, Zhukova M, Sosa-Calvo J, Adams RM. Novel mandibular gland volatiles from Apterostigma ants. BIOCHEM SYST ECOL 2017. [DOI: 10.1016/j.bse.2017.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
24
|
Sosa-Calvo J, Ješovnik A, Vasconcelos HL, Bacci M, Schultz TR. Rediscovery of the enigmatic fungus-farming ant "Mycetosoritis" asper Mayr (Hymenoptera: Formicidae): Implications for taxonomy, phylogeny, and the evolution of agriculture in ants. PLoS One 2017; 12:e0176498. [PMID: 28489860 PMCID: PMC5425087 DOI: 10.1371/journal.pone.0176498] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/11/2017] [Indexed: 02/01/2023] Open
Abstract
We report the rediscovery of the exceedingly rarely collected and enigmatic fungus-farming ant species Mycetosoritis asper. Since the description of the type specimen in 1887, only four additional specimens are known to have been added to the world's insect collections. Its biology is entirely unknown and its phylogenetic position within the fungus-farming ants has remained puzzling due to its aberrant morphology. In 2014 we excavated and collected twenty-one colonies of M. asper in the Floresta Nacional de Chapecó in Santa Catarina, Brazil. We describe here for the first time the male and larva of the species and complement the previous descriptions of both the queen and the worker. We describe, also for the first time, M. asper biology, nest architecture, and colony demographics, and identify its fungal cultivar. Molecular phylogenetic analyses indicate that both M. asper and M. clorindae are members of the genus Cyphomyrmex, which we show to be paraphyletic as currently defined. More precisely, M. asper is a member of the Cyphomyrmex strigatus group, which we also show to be paraphyletic with respect to the genus Mycetophylax. Based on these results, and in the interest of taxonomic stability, we transfer the species M. asper, M. clorindae, and all members of the C. strigatus group to the genus Mycetophylax, the oldest available name for this clade. Based on ITS sequence data, Mycetophylax asper practices lower agriculture, cultivating a fungal species that belongs to lower-attine fungal Clade 2, subclade F.
Collapse
Affiliation(s)
- Jeffrey Sosa-Calvo
- Department of Biology, University of Rochester, Rochester NY, United States of America
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington DC, United States of America
- Department of Entomology, University of Maryland, College Park, MD, United States of America
- * E-mail: (TRS); (JSC)
| | - Ana Ješovnik
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington DC, United States of America
- Department of Entomology, University of Maryland, College Park, MD, United States of America
| | - Heraldo L. Vasconcelos
- Instituto de Biologia, Universidade Federal de Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Mauricio Bacci
- Centro de Estudos de Insetos Sociais, Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil
| | - Ted R. Schultz
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington DC, United States of America
- * E-mail: (TRS); (JSC)
| |
Collapse
|
25
|
DeMilto AM, Rouquette M, Mueller UG, Kellner K, Seal JN. Effects of substrate, ant and fungal species on plant fiber degradation in a fungus-gardening ant symbiosis. JOURNAL OF INSECT PHYSIOLOGY 2017; 98:301-308. [PMID: 28193479 DOI: 10.1016/j.jinsphys.2017.02.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 02/03/2017] [Accepted: 02/06/2017] [Indexed: 06/06/2023]
Abstract
Fungus-gardening or attine ants have outsourced most of their digestive function to a symbiotic fungus. The ants feed their fungus - essentially an external digestive organ - a variety of substrates of botanical origin, including fresh and dried flowers, leaves and insect frass (processed leaves). Although plant tissues are rich in fibers (lignocelluloses, hemicelluloses, pectins and starches) and the symbiotic fungus possesses the genetic and enzymatic machinery to metabolize these compounds, the highly derived attines, the leaf-cutters (Atta and Acromyrmex), are known to produce fiber-rich waste. While leaf-cutting ants are important consumers of primary plant tissue, there have been fewer studies on physiological activity of fungi grown by closely related ant species in the genus Trachymyrmex, which generally grow related species of fungi, have smaller colonies and consume a wider variety of fungal substrates in addition to fresh leaves and flowers. In this study, we measured the cellulase activity of the fungus-gardening ants Atta texana, Trachymyrmex arizonensis and T. septentrionalis. We then quantified fiber consumption of the fungus-gardening ants Trachymyrmex septentrionalis and Trachymyrmex arizonensis by comparing the amounts and percentages present in their food and in fungus garden refuse during a controlled feeding experiment over the span of several months. Finally, we compared waste composition of T. arizonensis colonies growing different fungal strains, because this species is known to cultivate multiple strains of Leucoagaricus in its native range. The leaf-cutting ant A. texana was found to have lower cellulytic activity than T. arizonensis or T. septentrionalis. Total lignocellulose and hemicellulose amounts were significantly lower in refuse piles than in the substrates fed to the Trachymyrmex colonies, thus these fibers were consumed by the fungal symbionts of these ant species. Although lignocellulose utilization was similar in two distinct fungal species grown by T. arizonensis colonies, hemicellulose utilization was higher in T. arizonensis colonies growing a derived leaf-cutting ant fungal symbiont than when growing a native type of symbiont. The results of this study demonstrate that fiber digestion in fungus-gardening ants is an outcome of ant-fungal interaction.
Collapse
Affiliation(s)
- Alexandria M DeMilto
- Department of Biology, University of Texas at Tyler, 3900 University Blvd, Tyler, TX 75799, USA.
| | - Monte Rouquette
- Texas Agricultural Experiment Station, Texas A&M University Agricultural Research and Extension Center at Overton, Overton, TX 75684, USA.
| | - Ulrich G Mueller
- Integrative Biology, University of Texas at Austin, 1 University Station #C0930, Austin, TX 78712, USA.
| | - Katrin Kellner
- Department of Biology, University of Texas at Tyler, 3900 University Blvd, Tyler, TX 75799, USA.
| | - Jon N Seal
- Department of Biology, University of Texas at Tyler, 3900 University Blvd, Tyler, TX 75799, USA; Integrative Biology, University of Texas at Austin, 1 University Station #C0930, Austin, TX 78712, USA.
| |
Collapse
|
26
|
Luo SX, Yao G, Wang Z, Zhang D, Hembry DH. A Novel, Enigmatic Basal Leafflower Moth Lineage Pollinating a Derived Leafflower Host Illustrates the Dynamics of Host Shifts, Partner Replacement, and Apparent Coadaptation in Intimate Mutualisms. Am Nat 2017; 189:422-435. [PMID: 28350503 DOI: 10.1086/690623] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Leafflower plant/leafflower moth brood pollination mutualisms are widespread in the Paleotropics. Leafflower moths pollinate leafflower plants, but their larvae consume a subset of the hosts' seeds. These interactions are highly phylogenetically constrained: six clades of leafflower plants are each associated with a unique clade of leafflower moths (Epicephala). Here, we report a previously unrecognized basal seventh pollinating Epicephala lineage-associated with the highly derived leafflower clade Glochidion-in Asia. Epicephala lanceolaria is a pollinator and seed predator of Glochidion lanceolarium. Phylogenetic inference indicates that the ancestor of E. lanceolaria most likely shifted onto the ancestor of G. lanceolarium and displaced the ancestral allospecific Epicephala pollinator in at least some host populations. The unusual and apparently coadapted aspects of the G. lanceolarium/E. lanceolaria reproductive cycles suggest that plant-pollinator coevolution may have played a role in this displacement and provide insights into the dynamics of host shifts and trait coevolution in this specialized mutualism.
Collapse
|
27
|
Ješovnik A, González VL, Schultz TR. Phylogenomics and Divergence Dating of Fungus-Farming Ants (Hymenoptera: Formicidae) of the Genera Sericomyrmex and Apterostigma. PLoS One 2016; 11:e0151059. [PMID: 27466804 PMCID: PMC4965065 DOI: 10.1371/journal.pone.0151059] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Accepted: 02/22/2016] [Indexed: 01/27/2023] Open
Abstract
Fungus-farming ("attine") ants are model systems for studies of symbiosis, coevolution, and advanced eusociality. A New World clade of nearly 300 species in 15 genera, all attine ants cultivate fungal symbionts for food. In order to better understand the evolution of ant agriculture, we sequenced, assembled, and analyzed transcriptomes of four different attine ant species in two genera: three species in the higher-attine genus Sericomyrmex and a single lower-attine ant species, Apterostigma megacephala, representing the first genomic data for either genus. These data were combined with published genomes of nine other ant species and the honey bee Apis mellifera for phylogenomic and divergence-dating analyses. The resulting phylogeny confirms relationships inferred in previous studies of fungus-farming ants. Divergence-dating analyses recovered slightly older dates than most prior analyses, estimating that attine ants originated 53.6-66.7 million of years ago, and recovered a very long branch subtending a very recent, rapid radiation of the genus Sericomyrmex. This result is further confirmed by a separate analysis of the three Sericomyrmex species, which reveals that 92.71% of orthologs have 99% - 100% pairwise-identical nucleotide sequences. We searched the transcriptomes for genes of interest, most importantly argininosuccinate synthase and argininosuccinate lyase, which are functional in other ants but which are known to have been lost in seven previously studied attine ant species. Loss of the ability to produce the amino acid arginine has been hypothesized to contribute to the obligate dependence of attine ants upon their cultivated fungi, but the point in fungus-farming ant evolution at which these losses occurred has remained unknown. We did not find these genes in any of the sequenced transcriptomes. Although expected for Sericomyrmex species, the absence of arginine anabolic genes in the lower-attine ant Apterostigma megacephala strongly suggests that the loss coincided with the origin of attine ants.
Collapse
Affiliation(s)
- Ana Ješovnik
- Entomology Department, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, United States of America
- Maryland Center for Systematic Entomology, Department of Entomology, University of Maryland, College Park, Maryland, United States of America
| | - Vanessa L. González
- Global Genome Initiative, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, United States of America
| | - Ted R. Schultz
- Entomology Department, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, United States of America
| |
Collapse
|
28
|
Meirelles LA, Solomon SE, Bacci M, Wright AM, Mueller UG, Rodrigues A. Shared Escovopsis parasites between leaf-cutting and non-leaf-cutting ants in the higher attine fungus-growing ant symbiosis. ROYAL SOCIETY OPEN SCIENCE 2015; 2:150257. [PMID: 26473050 PMCID: PMC4593684 DOI: 10.1098/rsos.150257] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 09/07/2015] [Indexed: 05/31/2023]
Abstract
Fungus-gardening (attine) ants grow fungus for food in protected gardens, which contain beneficial, auxiliary microbes, but also microbes harmful to gardens. Among these potentially pathogenic microorganisms, the most consistently isolated are fungi in the genus Escovopsis, which are thought to co-evolve with ants and their cultivar in a tripartite model. To test clade-to-clade correspondence between Escovopsis and ants in the higher attine symbiosis (including leaf-cutting and non-leaf-cutting ants), we amassed a geographically comprehensive collection of Escovopsis from Mexico to southern Brazil, and reconstructed the corresponding Escovopsis phylogeny. Contrary to previous analyses reporting phylogenetic divergence between Escovopsis from leafcutters and Trachymyrmex ants (non-leafcutter), we found no evidence for such specialization; rather, gardens from leafcutters and non-leafcutters genera can sometimes be infected by closely related strains of Escovopsis, suggesting switches at higher phylogenetic levels than previously reported within the higher attine symbiosis. Analyses identified rare Escovopsis strains that might represent biogeographically restricted endemic species. Phylogenetic patterns correspond to morphological variation of vesicle type (hyphal structures supporting spore-bearing cells), separating Escovopsis with phylogenetically derived cylindrical vesicles from ancestral Escovopsis with globose vesicles. The new phylogenetic insights provide an improved basis for future taxonomic and ecological studies of Escovopsis.
Collapse
Affiliation(s)
- Lucas A. Meirelles
- Department of Biochemistry and Microbiology, UNESP—São Paulo State University, Rio Claro, São Paulo, Brazil
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | | | - Mauricio Bacci
- Center for the Study of Social Insects, UNESP—São Paulo State University, Rio Claro, São Paulo, Brazil
| | - April M. Wright
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Ulrich G. Mueller
- Department of Biochemistry and Microbiology, UNESP—São Paulo State University, Rio Claro, São Paulo, Brazil
| | - Andre Rodrigues
- Department of Biochemistry and Microbiology, UNESP—São Paulo State University, Rio Claro, São Paulo, Brazil
| |
Collapse
|