scholarly journals Niche engineering demonstrates a latent capacity for fungal-algal mutualism

Science ◽  
2014 ◽  
Vol 345 (6192) ◽  
pp. 94-98 ◽  
Author(s):  
Erik F. Y. Hom ◽  
Andrew W. Murray
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Environmental Change ◽  
Life Histories ◽  
Fungal Species ◽  
Biological Complexity ◽  
Free Living ◽  
Carbon And Nitrogen ◽  
Living Species ◽  
Obligate Mutualism ◽  
Nitrogen Exchange

Mutualistic symbioses shape the evolution of species and ecosystems and catalyze the emergence of biological complexity, yet how such symbioses first form is unclear. We show that an obligate mutualism between the yeastSaccharomyces cerevisiaeand the algaChlamydomonas reinhardtii—two model eukaryotes with very different life histories—can arise spontaneously in an environment requiring reciprocal carbon and nitrogen exchange. This capacity for mutualism is phylogenetically broad, extending to otherChlamydomonasand fungal species. Furthermore, we witnessed the spontaneous association ofChlamydomonasalgal cells physically interacting with filamentous fungi. These observations demonstrate that under specific conditions, environmental change induces free-living species to become obligate mutualists and establishes a set of experimentally tractable, phylogenetically related, synthetic systems for studying the evolution of symbiosis.

scholarly journals Misinformation tactics protect rare birds from problem predators

2021 ◽  
Vol 7 (11) ◽  
pp. eabe4164
Author(s):  
Grant L. Norbury ◽  
Catherine J. Price ◽  
M. Cecilia Latham ◽  
Samantha J. Brown ◽  
A. David M. Latham ◽  
...  
Keyword(s):  
Decision Making ◽  
Threatened Species ◽  
Prey Availability ◽  
Free Living ◽  
Bird Populations ◽  
New Information ◽  
Mammalian Predators ◽  
Decision Making Processes ◽  
Living Species ◽  
Information Reliability

Efficient decision-making integrates previous experience with new information. Tactical use of misinformation can alter choice in humans. Whether misinformation affects decision-making in other free-living species, including problem species, is unknown. Here, we show that sensory misinformation tactics can reduce the impacts of predators on vulnerable bird populations as effectively as lethal control. We repeatedly exposed invasive mammalian predators to unprofitable bird odors for 5 weeks before native shorebirds arrived for nesting and for 8 weeks thereafter. Chick production increased 1.7-fold at odor-treated sites over 25 to 35 days, with doubled or tripled odds of successful hatching, resulting in a 127% increase in modeled population size in 25 years. We demonstrate that decision-making processes that respond to changes in information reliability are vulnerable to tactical manipulation by misinformation. Altering perceptions of prey availability offers an innovative, nonlethal approach to managing problem predators and improving conservation outcomes for threatened species.

scholarly journals Draft Genome Sequence of Piscirickettsia litoralis , Isolated from Seawater

2016 ◽  
Vol 4 (6) ◽  
Author(s):  
Xuehua Wan ◽  
Alex J. Lee ◽  
Shaobin Hou ◽  
Blake Ushijima ◽  
Yen P. Nguyen ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Draft Genome ◽  
Salmonid Fish ◽  
Draft Genome Sequence ◽  
Free Living ◽  
Living Species

One species of Piscirickettsia , a pathogen of salmonid fish, has been described. The genome sequence of a putative second and free-living species may provide insights into the evolution of pathogenicity in the genus.

scholarly journals Untangling the roles of parasites in food webs with generative network models

2015 ◽  
Author(s):  
Abigail Z. Jacobs ◽  
Jennifer A. Dunne ◽  
Cristopher Moore ◽  
Aaron Clauset
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Statistical Physics ◽  
Network Models ◽  
Food Web Structure ◽  
Free Living ◽  
Web Structure ◽  
Living Species ◽  
Parasitic Interactions ◽  
The Impact

Food webs represent the set of consumer-resource interactions among a set of species that co-occur in a habitat, but most food web studies have omitted parasites and their interactions. Recent studies have provided conflicting evidence on whether including parasites changes food web structure, with some suggesting that parasitic interactions are structurally distinct from those among free-living species while others claim the opposite. Here, we describe a principled method for understanding food web structure that combines an efficient optimization algorithm from statistical physics called parallel tempering with a probabilistic generalization of the empirically well-supported food web niche model. This generative model approach allows us to rigorously estimate the degree to which interactions that involve parasites are statistically distinguishable from interactions among free-living species, whether parasite niches behave similarly to free-living niches, and the degree to which existing hypotheses about food web structure are naturally recovered. We apply this method to the well-studied Flensburg Fjord food web and show that while predation on parasites, concomitant predation of parasites, and parasitic intraguild trophic interactions are largely indistinguishable from free-living predation interactions, parasite-host interactions are different. These results provide a powerful new tool for evaluating the impact of classes of species and interactions on food web structure to shed new light on the roles of parasites in food webs.

scholarly journals Trophodynamic similarities of three sympatric clupeoid species throughout their life histories in the Kii Channel as revealed by stable isotope approach

2013 ◽  
Vol 71 (1) ◽  
pp. 44-55 ◽  
Author(s):  
Naotaka Yasue ◽  
Ryu Doiuchi ◽  
Akinori Takasuka
Keyword(s):  
Stable Isotope ◽  
Isotopic Composition ◽  
Life Histories ◽  
Focal Point ◽  
Climate Impacts ◽  
Japanese Sardine ◽  
Carbon And Nitrogen ◽  
Interspecific Differences ◽  
Etrumeus Teres ◽  
Kii Channel

Abstract Yasue, N., Doiuchi R., and Takasuka, A. 2013. Trophodynamic similarities of three sympatric clupeoid species throughout their life histories in the Kii Channel as revealed by stable isotope approach. – ICES Journal of Marine Science, 71: . Trophic similarity/difference among multispecies pelagic fish is a focal point in understanding the processes of climate impacts on their population dynamics. We tested trophic overlap of Japanese anchovy Engraulis japonicus, Japanese sardine Sardinops melanostictus, and Pacific round herring Etrumeus teres in the Kii Channel, Japan, by comparing the carbon and nitrogen stable isotope ratios among these clupeoid species from the larval to adult stages throughout the year. Space and time were both significant factors of variations of the isotopic composition values for the three species, and fish size was also significant for sardine and round herring. The isotopic composition values of the three species were homogeneous when compared with those of plankton and some other non-clupeoid species. Moreover, the isotopic composition values of the three clupeoid species collected simultaneously showed closer similarities than those in different areas and dates in all life stages. Thus, spatial and temporal differences in food availability were more apparent compared with interspecific differences in prey items specific to each species. Our analysis indicated strong trophic overlaps throughout the life histories among the three clupeoid species. Hence, they are concluded to be ecologically congeneric (directly competing) species in terms of trophic positions in the pelagic ecosystem.

scholarly journals Divergence of Eukaryotic Secretory Components: the Candida albicans Homolog of the Saccharomyces cerevisiae Sec20 Protein Is N Terminally Truncated, and Its Levels Determine Antifungal Drug Resistance and Growth

2001 ◽  
Vol 183 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Yvonne Weber ◽  
Uwe J. Santore ◽  
Joachim F. Ernst ◽  
Rolf K. Swoboda
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Candida Albicans ◽  
Transcriptional Control ◽  
Secretory Pathway ◽  
Sodium Dodecyl ◽  
Fungal Species ◽  
Gene Encoding ◽  
Vesicle Traffic ◽  
Antifungal Drug Resistance ◽  
And Function

ABSTRACT Sec20p is a component of the yeast Saccharomyces cerevisiae secretory pathway that does not have a close homolog in higher eukaryotic cells. To verify the function of Sec20p in other fungal species, we characterized the gene encoding a Sec20p homolog in the human fungal pathogen Candida albicans. The deduced protein has 27% identity with, but is missing about 100 N-terminal residues compared to S. cerevisiae Sec20p, which is part of the cytoplasmic tail interacting with the cytoplasmic protein Tip20p. Because a strain lacking both C. albicans SEC20alleles could not be constructed, we placed SEC20 under transcriptional control of two regulatable promoters, MET3pand PCK1p. Repression of SEC20 expression in these strains prevented (MET3p-SEC20 allele) or retarded (PCK1p-SEC20 allele) growth and led to the appearance of extensive intracellular membranes, which frequently formed stacks. Reduced SEC20 expression in the PCK1p-SEC20strain did not affect morphogenesis but led to a series of hypersensitivity phenotypes including supersensitivity to aminoglycoside antibiotics, to nystatin, to sodium dodecyl sulfate, and to cell wall inhibitors. These results demonstrate the occurrence and function of Sec20p in a fungal species other than S. cerevisiae, but the lack of the N-terminal domain and the apparent absence of a close TIP20 homolog in the C. albicans genome also indicate a considerable diversity in mechanisms of retrograde vesicle traffic in eukaryotes.

scholarly journals What factors explain the geographical range of mammalian parasites?

2019 ◽  
Vol 286 (1903) ◽  
pp. 20190673 ◽  
Author(s):  
James E. Byers ◽  
J. P. Schmidt ◽  
Paula Pappalardo ◽  
Sarah E. Haas ◽  
Patrick R. Stephens
Keyword(s):  
Host Species ◽  
Parasite Species ◽  
Geographical Area ◽  
Complete Information ◽  
Sampling Effort ◽  
Free Living ◽  
Living Species ◽  
Habitat Breadth ◽  
Taxonomic Groups ◽  
Host Characteristics

Free-living species vary substantially in the extent of their spatial distributions. However, distributions of parasitic species have not been comprehensively compared in this context. We investigated which factors most influence the geographical extent of mammal parasites. Using the Global Mammal Parasite Database we analysed 17 818 individual geospatial records on 1806 parasite species (encompassing viruses, bacteria, protozoa, arthropods and helminths) that infect 396 carnivore, ungulate and primate host species. As a measure of the geographical extent of each parasite species we quantified the number and area of world ecoregions occupied by each. To evaluate the importance of variables influencing the summed area of ecoregions occupied by a parasite species, we used Bayesian network analysis of a subset ( n = 866) of the parasites in our database that had at least two host species and complete information on parasite traits. We found that parasites that covered more geographical area had a greater number of host species, higher average phylogenetic relatedness between host species and more sampling effort. Host and parasite taxonomic groups had weak and indirect effects on parasite ecoregion area; parasite transmission mode had virtually no effect. Mechanistically, a greater number of host species probably increases both the collective abundance and habitat breadth of hosts, providing more opportunities for a parasite to have an expansive range. Furthermore, even though mammals are one of the best-studied animal classes, the ecoregion area occupied by their parasites is strongly sensitive to sampling effort, implying mammal parasites are undersampled. Overall, our results support that parasite geographical extent is largely controlled by host characteristics, many of which are subsumed within host taxonomic identity.

Phase morphs and phoresy: New species of Antennoseius (Vitzthumia) mites (Acari: Mesostigmata: Ascidae) associated with pyrophilous carabids (Carabidae: Sericoda spp.) in Alberta, Canada

Zootaxa ◽  
2008 ◽  
Vol 1961 (1) ◽  
pp. 37-57 ◽  
Author(s):  
FRÉDÉRIC BEAULIEU ◽  
ANDREA D. DÉCHÊNE ◽  
DAVID E. WALTER
Keyword(s):  
New Species ◽  
North American ◽  
North American Species ◽  
Carabid Beetles ◽  
Free Living ◽  
Adult Females ◽  
As Species ◽  
Laboratory Cultures ◽  
Living Species ◽  
Mite Genus

The mite genus Antennoseius is composed of free-living species in soil and litter, as well as species that are phoretic on carabid beetles as adult females. Among approximately 60 described Antennoseius species, one North American species, A. janus, was found in laboratory cultures to have two female morphs: one granular, free-living morph, and one smooth, putatively phoretic morph. We here describe the adult females of A. perseus n. sp. and A. pyrophilus n. sp. collected from under the elytra of carabid beetles (Sericoda quadripunctata and S. bembidioides) associated with recently burned forests in Alberta, Canada. We also describe the female and male of a distinct, granular, non-phoretic morph of A. perseus, obtained from soil and by rearing the offspring of phoretic females. A key to the females of Antennoseius species having an ambulacrum on leg I (i.e. subgenus Vitzthumia) is provided.

First report of Gieysztoria falx Brusa, Damborenea & Noreña, 2003 (Platyhelminthes: Rhabdocoela) in southern Brazil

Zootaxa ◽  
2019 ◽  
Vol 4706 (3) ◽  
pp. 494-496
Author(s):  
JHOE REYES ◽  
DANIELA BINOW ◽  
ROGÉRIO T. VIANNA ◽  
SAMANTHA E. MARTINS
Keyword(s):  
Hot Spots ◽  
First Record ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Free Living ◽  
Similar Shape ◽  
Freshwater Habitats ◽  
Living Species ◽  
South Brazil ◽  
Shape And Size

Within Dalyelliidae Graff, 1905, Gieysztoria Ruebush & Hayes, 1939 is the most widely distributed and speciose genus, members of which live in marine, brackish, or freshwater habitats (Van Steenkiste et al., 2012). Gieysztoria is composed by ~97 free-living species (Tyler et al. 2016), and species identification is mainly made on the male copulatory system, which has an armed penis (stylet) with different configurations of spines (Noreña et al., 2016). The stylet configuration of Gieysztoria species is traditionally split into two groups: Aequales (spines of similar shape and size) and Inaequales (spines of different shape and size) (Luther, 1955). In the neotropics, specimens of Gieysztoria belong to both the Aequales and Inaequales group   and are well represented (Damborenea et al., 2005; Noreña et al., 2003). According to Braccini et al. (2016, 2017), there are 16 species of Gieysztoria in Brazil, mainly distributed in the southern region. South Brazil harbours a mosaic of wetlands that are considered hot spots of biodiversity, including the Taim Ecological Station (ESEC Taim) protected area that was designated as a Ramsar site (Ramsar, 2017). In the present study, Gieysztoria falx Brusa, Damborenea & Noreña, 2003 is registered in the ESEC Taim, located in Rio Grande do Sul. It represents the first record of G. falx in Brazil. Illustrations and comments on stylet configuration are given.

scholarly journals The Rhizobium leguminosarum bv. viciae VF39 γ-aminobutyrate (GABA) aminotransferase gene (gabT) is induced by GABA and highly expressed in bacteroids The GenBank accession number for the sequence determined in this work is AF335502.

Microbiology ◽  
2002 ◽  
Vol 148 (2) ◽  
pp. 615-623 ◽  
Author(s):  
Jürgen Prell ◽  
Bert Boesten ◽  
Philip Poole ◽  
Ursula B Priefer
Keyword(s):  
Rhizobium Leguminosarum ◽  
Free Living ◽  
Carbon And Nitrogen ◽  
Gaba Aminotransferase ◽  
Gaba Metabolism ◽  
Promoter Probe ◽  
Promoter Probe Vector ◽  
Oxoglutarate Dehydrogenase ◽  
Substrate Specifities ◽  
Free Living Conditions

A Rhizobium leguminosarum bv. viciae VF39 gene (gabT) encoding a γ-aminobutyrate (GABA) aminotransferase was identified, cloned and characterized. This gene is thought to be involved in GABA metabolism via the GABA shunt pathway, a theoretical bypass of the 2-oxoglutarate dehydrogenase complex. Mutants in gabT are still able to grow on GABA as a sole carbon and nitrogen source. 2-Oxoglutarate-dependent GABA aminotransferase activity is absent in these mutants, while pyruvate-dependent activity remains unaffected. This indicates that at least two enzymes with different substrate specifities are involved in the GABA metabolism of R. leguminosarum bv. viciae VF39. The gabT promoter was cloned into a newly constructed, stable promoter-probe vector pJP2, suitable for the study of transcriptional GUS fusions in free-living bacteria and during symbiosis. Under free-living conditions the gabT promoter is induced by GABA and repressed by succinate. Transcriptional regulation is mediated by GabR in a repressor-like manner. During symbiosis with the pea host plant gabT is induced and highly expressed in the symbiotic zone. Nodules induced by gabT mutants, however, are still effective in nitrogen fixation.

scholarly journals Evolution of Divergent Life History Strategies in Marine Alphaproteobacteria

mBio ◽  
2013 ◽  
Vol 4 (4) ◽  
Author(s):  
Haiwei Luo ◽  
Miklós Csűros ◽  
Austin L. Hughes ◽  
Mary Ann Moran
Keyword(s):  
Life History ◽  
Life Histories ◽  
Scale Up ◽  
Carbon Mineralization ◽  
Life History Strategies ◽  
Free Living ◽  
Heterotrophic Bacterioplankton ◽  
Evolutionary Origins ◽  
Eukaryotic Phytoplankton ◽  
Microbial Groups

ABSTRACT Marine bacteria in the Roseobacter and SAR11 lineages successfully exploit the ocean habitat, together accounting for ~40% of bacteria in surface waters, yet have divergent life histories that exemplify patch-adapted versus free-living ecological roles. Here, we use a phylogenetic birth-and-death model to understand how genome content supporting different life history strategies evolved in these related alphaproteobacterial taxa, showing that the streamlined genomes of free-living SAR11 were gradually downsized from a common ancestral genome only slightly larger than the extant members (~2,000 genes), while the larger and variably sized genomes of roseobacters evolved along dynamic pathways from a sizeable common ancestor (~8,000 genes). Genome changes in the SAR11 lineage occurred gradually over ~800 million years, whereas Roseobacter genomes underwent more substantial modifications, including major periods of expansion, over ~260 million years. The timing of the first Roseobacter genome expansion was coincident with the predicted radiation of modern marine eukaryotic phytoplankton of sufficient size to create nutrient-enriched microzones and is consistent with present-day ecological associations between these microbial groups. We suggest that diversification of red-lineage phytoplankton is an important driver of divergent life history strategies among the heterotrophic bacterioplankton taxa that dominate the present-day ocean. IMPORTANCE One-half of global primary production occurs in the oceans, and more than half of this is processed by heterotrophic bacterioplankton through the marine microbial food web. The diversity of life history strategies that characterize different bacterioplankton taxa is an important subject, since the locations and mechanisms whereby bacteria interact with seawater organic matter has effects on microbial growth rates, metabolic pathways, and growth efficiencies, and these in turn affect rates of carbon mineralization to the atmosphere and sequestration into the deep sea. Understanding the evolutionary origins of the ecological strategies that underlie biochemical interactions of bacteria with the ocean system, and which scale up to affect globally important biogeochemical processes, will improve understanding of how microbial diversity is maintained and enable useful predictions about microbial response in the future ocean.

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