scholarly journals Unravelling ant-symbiont network topology across Europe

2019 ◽  
Author(s):  
Thomas Parmentier ◽  
Frederik de Laender ◽  
Dries Bonte
Keyword(s):  
Species Richness ◽  
Host Range ◽  
Host Specificity ◽  
Network Topology ◽  
Colony Size ◽  
Host Factors ◽  
Social Parasites ◽  
Symbiotic Associations ◽  
Different Types ◽  
Symbiont Species

ABSTRACTLong-term associations between different species are key drivers in community composition in all ecosystems. Understanding the ecological and evolutionary drivers of these symbiotic associations is challenging because of the diversity of species and interaction types hosted in natural ecological networks. Here, we compiled the most complete database on natural ant-symbiont networks in Europe to identify the drivers of bipartite network topology. These ant-symbiont networks host an unrivalled diversity of symbiotic associations across the entire mutualism-antagonism continuum, of which the most diverse types of symbionts are (1) trophobionts: mutualistic aphids and scale insects (2) myrmecophiles: commensalistic and parasitic arthropods, and (3) social parasites: parasitic ant species. These diverse ant-symbiont networks provide a unique opportunity to tease apart ecological and evolutionary drivers. To do so, we dissected network topology and asked what determines host specificity and which host factors drive symbiont species richness and facilitate host switching for the different types of symbionts.We found an unexpectedly high number of 701 obligate symbionts associated with European ants. Symbiont type explained host specificity and the average relatedness of the targeted host species. Social parasites were associated with few, but phylogenetically highly related hosts, whereas trophobionts and myrmecophiles interacted with a higher number of hosts across a wider taxonomic distribution. Colony size, host range and habitat type predicted total symbiont richness, where ants hosts with larger colony size or larger distribution range contained more symbiont species. However, we found that different sets of host factors affected diversity in the different types of symbionts. Ecological factors, such as colony size, host range and niche width predominantly drive myrmecophile species richness, whereas evolutionary factors, such as host phylogeny and biogeography, mainly determine richness of mutualistic trophobionts and social parasites. Lastly, we found that hosts with a common biogeographic history support a more similar community of symbionts. Phylogenetic related hosts also shared more trophobionts and social parasites, but not myrmecophiles. Taken together, these results suggest that ecological and evolutionary processes drive host specificity and symbiont richness in large-scale ant-symbiont networks, but these drivers may shift in importance depending on the type of symbiosis. Our findings highlight the potential of well-characterized bipartite networks composed of different types of symbioses to identify candidate processes driving community composition.

scholarly journals A Draft Genome Sequence of Pseudomonas syringae pv. tomato T1 Reveals a Type III Effector Repertoire Significantly Divergent from That of Pseudomonas syringae pv. tomato DC3000

2009 ◽  
Vol 22 (1) ◽  
pp. 52-62 ◽  
Author(s):  
Nalvo F. Almeida ◽  
Shuangchun Yan ◽  
Magdalen Lindeberg ◽  
David J. Studholme ◽  
David J. Schneider ◽  
...  
Keyword(s):  
Host Range ◽  
Host Specificity ◽  
Pseudomonas Syringae ◽  
Genome Sequence ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Tomato Dc3000 ◽  
Type Iii ◽  
Host Range Determination ◽  
Range Determination

Diverse gene products including phytotoxins, pathogen-associated molecular patterns, and type III secreted effectors influence interactions between Pseudomonas syringae strains and plants, with additional yet uncharacterized factors likely contributing as well. Of particular interest are those interactions governing pathogen-host specificity. Comparative genomics of closely related pathogens with different host specificity represents an excellent approach for identification of genes contributing to host-range determination. A draft genome sequence of Pseudomonas syringae pv. tomato T1, which is pathogenic on tomato but nonpathogenic on Arabidopsis thaliana, was obtained for this purpose and compared with the genome of the closely related A. thaliana and tomato model pathogen P. syringae pv. tomato DC3000. Although the overall genetic content of each of the two genomes appears to be highly similar, the repertoire of effectors was found to diverge significantly. Several P. syringae pv. tomato T1 effectors absent from strain DC3000 were confirmed to be translocated into plants, with the well-studied effector AvrRpt2 representing a likely candidate for host-range determination. However, the presence of avrRpt2 was not found sufficient to explain A. thaliana resistance to P. syringae pv. tomato T1, suggesting that other effectors and possibly type III secretion system–independent factors also play a role in this interaction.

scholarly journals The longhorn beetles (Coleoptera: Cerambycidae) of National Park «Kremenetski Hory»

2020 ◽  
pp. 129-140
Author(s):  
Iryna Dovganyuk ◽  
Andrew M. Zamoroka
Keyword(s):  
Species Richness ◽  
Quantitative Study ◽  
National Park ◽  
Longhorn Beetles ◽  
Different Types ◽  
First Time

The fauna of the longhorn beetles of ecoregion of Kremenetski Hory and the eponymous National Park was studied very poorly. In the most recent catalogue of Cerambycidae of Western Podillya it was listed only 13 species for the ecoregion. Including other sources, to date, it was known 17 species of the longhorn beetles. In the current study we identified 59 species of the longhorn beetles, 42 of which are reported for the first time for National Park «Kremenetski Hory» and the ecoregion in general. Under our proposed prediction the Cerambycidae species richness should reach 100-120 species. We also presented result of quantitative study of the longhorn beetles within different types of ecosystems of National Park «Kremenetski Hory». We revealed that 10 species are the most abundant on the studied territory.

scholarly journals COMMUNITY STRUCTURE ECHINODERMS (ASTEROIDEA, OPHIUROIDEA, ECHINOIDEA AND HOLOTHUROIDEA) IN THE MARINE NATIONAL PARK EAST SULAWESI WAKATOBI

2016 ◽  
Vol 8 (1) ◽  
pp. 357-366 ◽  
Author(s):  
Eddy Yusron
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
National Parks ◽  
National Park ◽  
Diversity Index ◽  
Dead Coral ◽  
Evenness Index ◽  
Different Types ◽  
High Level ◽  
Richness Index

A study on Echinoderms community structure in marine national parks of Wakatobi, Southeast Sulawesi was conducted in six locations, i.e., Waha Beach, Coastal Sombo, Beach Houses, Beach Kapota, Banakawa beach, and Umala beach in October 2013. All of the six parks were located the Wakatobi territorial waters with coordinates of 5°06'25" S and 123°124'10 E. The results showed of 18 species of echinoderms representing six different types of Asteroidea, two types of Ophiuroidea, six types of Echinoidea, and four types of Holothuroidea. Group of starfish or Asteroidea was the most prominent on seagrass area. Based on the six transects sites, it turned out that the group of starfish (Asteridea) occupied a relatively high level of species richness. From the quantitative analysis values, we obtained diversity index (H) of 1.105 in Sombu, the highest evenness index (J) of 0.989 was found in Umala, and the highest species richness index values (D) of 0.132 was obtained in kapota. It seemed that all echinoderm groups were generally like seagrass microhabitat (12 types). While, sand and dead coral habitats were only occupied by 8 (eight) echinoderm groups. Keywords: echinoderms, diversity, Wakatobi, Southeast Sulawesi

scholarly journals The influence of forest-forming tree species on diversity and spatial distribution of algae in forest litter

2018 ◽  
Vol 45 (2) ◽  
pp. 72-81 ◽  
Author(s):  
Yevhen Maltsev ◽  
Irina Maltseva
Keyword(s):  
Species Richness ◽  
Leaf Litter ◽  
Green Algae ◽  
Tree Species ◽  
Spatial Organization ◽  
Forest Litter ◽  
Equal Distribution ◽  
Blue Green Algae ◽  
Different Types ◽  
The Relationship

Abstract The forest litter plays a significant role in forest ecosystems. The composition of the litter biota comprises micro- and mesofauna, and a great diversity of microorganisms, including unrecognized algae (eukaryotic representatives and Cyanoprokaryota). The aim of this work was to study the diversity of algae in the different types of forest litters and to clarify the relationship between the algae composition and the forest-forming tree species. Our results show that the pine forest litter is the most appropriate habitat for the development of green and yellow-green algae and that this litter type limits the variety of blue-green ones. The admixture of deciduous leaf litter to pine litter caused an increase in the species richness of blue-green algae and diatoms. The algae were unevenly distributed across the sub-horizons of pine litter. The highest species richness of algae was identified in the enzymatic sub-horizon of litter. The peculiarity of the composition of leaf litter algae was a significant variety of green, yellow-green and blue-green algae. The spatial organization of algae communities in the leaf litter was characterized by equal distribution of algae species in the litter-subhorizons.

Ecological release in lizard endoparasites from the Atlantic Forest, northeast of the Neotropical Region

Parasitology ◽  
2020 ◽  
Vol 147 (4) ◽  
pp. 491-500
Author(s):  
Adonias A. Martins Teixeira ◽  
Pablo Riul ◽  
Samuel Vieira Brito ◽  
João A. Araujo-Filho ◽  
Diêgo Alves Teles ◽  
...  
Keyword(s):  
Host Range ◽  
Host Specificity ◽  
Atlantic Forest ◽  
Positive Relationship ◽  
Niche Breadth ◽  
Neotropical Region ◽  
Parasite Abundance ◽  
Ecological Release ◽  
Parasite Richness

AbstractWe compared lizard endoparasite assemblages between the Atlantic Forest and naturally isolated forest enclaves to test the ecological release hypothesis, which predicts that host specificity should be lower (large niche breadth) and parasite abundance should be greater for parasites from isolated forest enclaves (poor assemblages) than for parasites from the coastal Atlantic Forest (rich assemblages). Parasite richness per specimen showed no difference between the isolated and non-isolated areas. Parasite abundance did not differ between the isolated and non-isolated areas but showed a positive relationship with parasite richness considering all areas (isolated and non-isolated). Furthermore, host specificity was positively related to parasite richness. Considering that host specificity is inversely proportional to the host range infected by a parasite, our results indicate that in assemblages with greater parasite richness, parasites tend to infect a smaller range of hosts than do those in simple assemblages. In summary, our study partially supports the ecological release hypothesis: in assemblages with greater parasite richness, lizard parasites from Atlantic Forest are able to increase their parasite abundance (per host), possibly through facilitated infection; however, the amplitude of infected hosts only expands in poor assemblages (lower parasite richness).

scholarly journals Mice Expressing Minimally Humanized CD81 and Occludin Genes Support Hepatitis C Virus Uptake In Vivo

2016 ◽  
Vol 91 (4) ◽  
Author(s):  
Qiang Ding ◽  
Markus von Schaewen ◽  
Gabriela Hrebikova ◽  
Brigitte Heller ◽  
Lisa Sandmann ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Host Range ◽  
Amino Acid Sequences ◽  
Host Factors ◽  
Narrow Host Range ◽  
Junction Protein ◽  
Mouse Hepatocytes

ABSTRACT Hepatitis C virus (HCV) causes chronic infections in at least 150 million individuals worldwide. HCV has a narrow host range and robustly infects only humans and chimpanzees. The underlying mechanisms for this narrow host range are incompletely understood. At the level of entry, differences in the amino acid sequences between the human and mouse orthologues of two essential host factors, the tetraspanin CD81 and the tight junction protein occludin (OCLN), explain, at least in part, HCV's limited ability to enter mouse hepatocytes. We have previously shown that adenoviral or transgenic overexpression of human CD81 and OCLN facilitates HCV uptake into mouse hepatocytes in vitro and in vivo. In efforts to refine these models, we constructed knock-in mice in which the second extracellular loops of CD81 and OCLN were replaced with the respective human sequences, which contain the determinants that are critical for HCV uptake. We demonstrate that the humanized CD81 and OCLN were expressed at physiological levels in a tissue-appropriate fashion. Mice bearing the humanized alleles formed normal tight junctions and did not exhibit any immunologic abnormalities, indicating that interactions with their physiological ligands were intact. HCV entry factor knock-in mice take up HCV with an efficiency similar to that in mice expressing HCV entry factors transgenically or adenovirally, demonstrating the utility of this model for studying HCV infection in vivo. IMPORTANCE At least 150 million individuals are chronically infected with hepatitis C virus (HCV). Chronic hepatitis C can result in progressive liver disease and liver cancer. New antiviral treatments can cure HCV in the majority of patients, but a vaccine remains elusive. To gain a better understanding of the processes culminating in liver failure and cancer and to prioritize vaccine candidates more efficiently, small-animal models are needed. Here, we describe the characterization of a new mouse model in which the parts of two host factors that are essential for HCV uptake, CD81 and occludin (OCLN), which differ between mice and humans, were humanized. We demonstrate that such minimally humanized mice develop normally, express the modified genes at physiological levels, and support HCV uptake. This model is of considerable utility for studying viral entry in the three-dimensional context of the liver and to test approaches aimed at preventing HCV entry.

scholarly journals Taxonomic structure of local floras in Sidinskiy and Pribaitakskiy steppes (Krasnoyarsk region)

2019 ◽  
Vol 16 ◽  
pp. 00002
Author(s):  
Ekaterina Antipova ◽  
Olga Enulenko
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Taxonomic Structure ◽  
Central European ◽  
Krasnoyarsk Region ◽  
Full Species ◽  
Central Asian ◽  
Different Types ◽  
Sayan Mountain ◽  
Mountain Country

Sidinskiy and Pribaitakskiy steppes are the part of the Minusinsk province of the Altai-Sayan mountain country. On the territory of steppes 12 local floras (LF) were marked and examined using the same method. Studies were carried out according to the recommendations of A.I. Tolmachev (1931): identification of different types of ecotypes of LF, the full species composition of ecotypes (flora inventory), tracking the completeness of detection in LF. In the Sidinskiy steppe the number of families in the LF varies from 25 (Syida) to 43 (v. Alha), in the Pribaitakskiy steppe there is a big difference in the number of families in the LF from 31 (Krasnoyarsk reservoir, Tuba) to 65 (Mayak, Idra). The leading families in the local steppe flora are Asteraceae, Poaceae, Fabaceae. The Fabaceae family ranks third in the top of ten families in 50 % of LF, determining the type of flora as the Mediterranean-Central Asian (Fabaceae-type). Different types of LF allow to determine the type of all steppe flora as mixed, combining features of boreal (Asteraceae-Poaceae- type) and steppes flora (Fabaceae-type) with close ties with Central European floras (Rosaceae-type). 4 distinct levels of species richness are determined: 1 − 496-544; 2 − 408-413; 3 − 319-374; 4 − 279-298 species.

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