scholarly journals Investigating diversity, evolution, development and physiology of red algal parasites from New Zealand

2021 ◽  
Author(s):  
◽  
Maren Preuss
Keyword(s):  
Host Species ◽  
High Throughput Sequencing ◽  
Phylogenetic Analyses ◽  
Host Cells ◽  
Gene Content ◽  
Infected Host ◽  
Parasite Development ◽  
Future Research ◽  
Mitochondrial Genomes ◽  
Red Algal

<p>Red algal parasites have evolved independently over a 100 times and grow only on other red algal hosts. Most parasites are closely related to their host based on the similarity of their reproductive structures. Secondary pit connections between red algal parasites and their hosts are used to transfer parasite organelles and nuclei into host cells. Morphological and physiological changes in infected host cells have been observed in some species. Parasite mitochondrial genomes are similar in size and gene content to free-living red algae whereas parasite plastids are highly reduced. Overall, red algal parasites are poorly studied and thus the aim of this study was to increase the general knowledge of parasitic taxa with respect to their diversity, evolutionary origin, development, physiology, and organelle evolution. Investigation of the primary literature showed that most species descriptions of red algal parasites were poor and did not meet the criteria for defining a parasitic relationship. This literature study also revealed a lack of knowledge of many key parasitic processes including early parasite development, host cell “control”, and parasite origin. Many of these poorly studied research areas were addressed in this thesis. Phylogenetic analyses, using a range of markers from all three genomes (cpDNA: rbcL, nDNA: actin, LSU rRNA; mtDNA: cox1), showed different patterns of phylogenetic relationships for the four new red algal parasites and their hosts. The parasites Phycodrys novae-zelandiophila sp. nov. and Vertebrata aterrimophila sp. nov. closest relative is its host species. Cladhymenia oblongifoliophila sp. nov. closest relative is its host species based on nuclear and mitochondrial markers whereas the plastid markers group the parasite with Cladhymenia lyallii, suggesting that the parasite plastid was acquired when previously parasitizing C. lyallii. Judithia parasitica sp. nov. grows on two Blastophyllis species but the parasites’ closest relative is the non-host species Judithia delicatissima. Developmental studies of the parasite Vertebrata aterrimophila, showed a unique developmental structure (“trunk-like” cell) not known in other parasites, plus localised infection vi and few changes in infected host cells. High-throughput-sequencing revealed mitochondrial genomes of similar size, gene content and order in the parasite Pterocladiophila hemisphaerica to its host Pterocladia lucida, and a reduced non-photosynthetic plastid in the parasite. Mitochondrial (mt) and plastid (cp) genome phylogenies placed Pterocladiophila hemisphaerica on long branches, either as sister to Ceramiales (mt) or Gracilariales (cp). Further analyses, filtering non-elevated plastid genes grouped the parasite neither with the Gracilariales (mt) or Gelidiales (cp) on shorter branches but without support. Nuclear phylogeny grouped P. hemisphaerica as sister to the Gelidiales and other red algal orders and was the only phylogenetic relationship with support. Investigations of photosystem II capacity using PAM fluorometry, and quantifying chlorophyll a content in three pigmented parasites, showed different host nutrient dependencies. Rhodophyllis parasitica and Vertebrata aterrimophila are not able to photosynthesize and are fully dependent on host nutrients. Pterocladiophila hemisphaerica is able to photosynthesize independently, even though it has a reduced non-photosynthetic plastid genome, and therefore is only partially dependent on its host. This study advances our current understanding of red algal parasites and highlights many possibilities for future research including genome evolution and understanding parasite diversity.</p>

scholarly journals Investigating diversity, evolution, development and physiology of red algal parasites from New Zealand

2021 ◽  
Author(s):  
◽  
Maren Preuss
Keyword(s):  
Host Species ◽  
High Throughput Sequencing ◽  
Phylogenetic Analyses ◽  
Host Cells ◽  
Gene Content ◽  
Infected Host ◽  
Parasite Development ◽  
Future Research ◽  
Mitochondrial Genomes ◽  
Red Algal

<p>Red algal parasites have evolved independently over a 100 times and grow only on other red algal hosts. Most parasites are closely related to their host based on the similarity of their reproductive structures. Secondary pit connections between red algal parasites and their hosts are used to transfer parasite organelles and nuclei into host cells. Morphological and physiological changes in infected host cells have been observed in some species. Parasite mitochondrial genomes are similar in size and gene content to free-living red algae whereas parasite plastids are highly reduced. Overall, red algal parasites are poorly studied and thus the aim of this study was to increase the general knowledge of parasitic taxa with respect to their diversity, evolutionary origin, development, physiology, and organelle evolution. Investigation of the primary literature showed that most species descriptions of red algal parasites were poor and did not meet the criteria for defining a parasitic relationship. This literature study also revealed a lack of knowledge of many key parasitic processes including early parasite development, host cell “control”, and parasite origin. Many of these poorly studied research areas were addressed in this thesis. Phylogenetic analyses, using a range of markers from all three genomes (cpDNA: rbcL, nDNA: actin, LSU rRNA; mtDNA: cox1), showed different patterns of phylogenetic relationships for the four new red algal parasites and their hosts. The parasites Phycodrys novae-zelandiophila sp. nov. and Vertebrata aterrimophila sp. nov. closest relative is its host species. Cladhymenia oblongifoliophila sp. nov. closest relative is its host species based on nuclear and mitochondrial markers whereas the plastid markers group the parasite with Cladhymenia lyallii, suggesting that the parasite plastid was acquired when previously parasitizing C. lyallii. Judithia parasitica sp. nov. grows on two Blastophyllis species but the parasites’ closest relative is the non-host species Judithia delicatissima. Developmental studies of the parasite Vertebrata aterrimophila, showed a unique developmental structure (“trunk-like” cell) not known in other parasites, plus localised infection vi and few changes in infected host cells. High-throughput-sequencing revealed mitochondrial genomes of similar size, gene content and order in the parasite Pterocladiophila hemisphaerica to its host Pterocladia lucida, and a reduced non-photosynthetic plastid in the parasite. Mitochondrial (mt) and plastid (cp) genome phylogenies placed Pterocladiophila hemisphaerica on long branches, either as sister to Ceramiales (mt) or Gracilariales (cp). Further analyses, filtering non-elevated plastid genes grouped the parasite neither with the Gracilariales (mt) or Gelidiales (cp) on shorter branches but without support. Nuclear phylogeny grouped P. hemisphaerica as sister to the Gelidiales and other red algal orders and was the only phylogenetic relationship with support. Investigations of photosystem II capacity using PAM fluorometry, and quantifying chlorophyll a content in three pigmented parasites, showed different host nutrient dependencies. Rhodophyllis parasitica and Vertebrata aterrimophila are not able to photosynthesize and are fully dependent on host nutrients. Pterocladiophila hemisphaerica is able to photosynthesize independently, even though it has a reduced non-photosynthetic plastid genome, and therefore is only partially dependent on its host. This study advances our current understanding of red algal parasites and highlights many possibilities for future research including genome evolution and understanding parasite diversity.</p>

scholarly journals Recent advances in understanding mitochondrial genome diversity

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 270 ◽  
Author(s):  
Rafael Zardoya
Keyword(s):  
Mitochondrial Genome ◽  
High Throughput Sequencing ◽  
Gene Content ◽  
Mitochondrial Genomes ◽  
Genetic Codes ◽  
Evolutionary Trajectories ◽  
Gene Structures ◽  
Mitochondrial Genome Diversity ◽  
Conserved Gene ◽  
Self Splicing

Ever since its discovery, the double-stranded DNA contained in the mitochondria of eukaryotes has fascinated researchers because of its bacterial endosymbiotic origin, crucial role in encoding subunits of the respiratory complexes, compact nature, and specific inheritance mechanisms. In the last few years, high-throughput sequencing techniques have accelerated the sequencing of mitochondrial genomes (mitogenomes) and uncovered the great diversity of organizations, gene contents, and modes of replication and transcription found in living eukaryotes. Some early divergent lineages of unicellular eukaryotes retain certain synteny and gene content resembling those observed in the genomes of alphaproteobacteria (the inferred closest living group of mitochondria), whereas others adapted to anaerobic environments have drastically reduced or even lost the mitogenome. In the three main multicellular lineages of eukaryotes, mitogenomes have pursued diverse evolutionary trajectories in which different types of molecules (circular versus linear and single versus multipartite), gene structures (with or without self-splicing introns), gene contents, gene orders, genetic codes, and transfer RNA editing mechanisms have been selected. Whereas animals have evolved a rather compact mitochondrial genome between 11 and 50 Kb in length with a highly conserved gene content in bilaterians, plants exhibit large mitochondrial genomes of 66 Kb to 11.3 Mb with large intergenic repetitions prone to recombination, and fungal mitogenomes have intermediate sizes of 12 to 236 Kb.

scholarly journals First mitochondrial genomes of five hoverfly species of the genus Eristalinus (Diptera: Syrphidae)

Genome ◽  
2019 ◽  
Vol 62 (10) ◽  
pp. 677-687 ◽  
Author(s):  
Gontran Sonet ◽  
Yannick De Smet ◽  
Min Tang ◽  
Massimiliano Virgilio ◽  
Andrew Donovan Young ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Phylogenetic Analyses ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Mitochondrial Genomes ◽  
Base Pairs ◽  
Protein Coding ◽  
Phylogenetic Informativeness ◽  
Molecular Phylogenetic ◽  
Phylogenetic Hypotheses

The hoverfly genus Eristalinus (Diptera, Syrphidae) contains many widespread pollinators. The majority of the species of Eristalinus occur in the Afrotropics and their molecular systematics still needs to be investigated. This study presents the first complete and annotated mitochondrial genomes for five species of Eristalinus. They were obtained by high-throughput sequencing of total genomic DNA. The total length of the mitogenomes varied between 15 757 and 16 245 base pairs. Gene composition, positions, and orientation were shared across species, and were identical to those observed for other Diptera. Phylogenetic analyses (maximum likelihood and Bayesian inference) based on the 13 protein coding and both rRNA genes suggested that the subgenus Eristalinus was paraphyletic with respect to the subgenus Eristalodes. An analysis of the phylogenetic informativeness of all protein coding and rRNA genes suggested that NADH dehydrogenase subunit 5 (nad5), cytochrome c oxidase subunit 1, nad4, nad2, cytochrome b, and 16S rRNA genes are the most promising mitochondrial molecular markers to result in supported phylogenetic hypotheses of the genus. In addition to the five complete mitogenomes currently available for hoverflies, the five mitogenomes published here will be useful for broader molecular phylogenetic analyses among hoverflies.

scholarly journals Red algal parasites: A synopsis of described species, their hosts, distinguishing characters and areas for continued research

2020 ◽  
Author(s):  
Maren Preuss ◽  
WA Nelson ◽  
Giuseppe Zuccarello
Keyword(s):  
Host Cell ◽  
Red Algae ◽  
Host Cells ◽  
Parasite Development ◽  
Cellular Interactions ◽  
Cell Control ◽  
Full Extent ◽  
Red Algal ◽  
Algal Groups ◽  
Parasite Biodiversity

© 2017 Walter de Gruyter GmbH, Berlin/Boston. Red algal parasites are diverse organisms that are unusual due to the fact that many are closely related to their hosts. Parasitism has developed many times within different red algal groups, but the full extent of parasite biodiversity is unknown, as parasites are easily overlooked due to their small size and often low abundance. Additionally, the literature on red algal parasites is dispersed and has not been compiled in over 30 years. Although criteria have been proposed to define what constitutes a red algal parasite, many parasites are poorly described, and the cellular interactions with their host are poorly known. A few studies have demonstrated that parasites transfer organelles to host cells, which can alter the physiology of the host to the benefit of the parasite. Here, we apply a set of defining criteria for parasites to a compiled list of all described red algal parasites. Our results highlight the lack of knowledge of many key parasitic processes including early parasite development, host cell "control", and parasite origin. Until the biology of more parasites is studied, generalisations on the processes of parasitism in red algae may be premature. We hope this synopsis will stimulate research into this fascinating group.

scholarly journals One Hundred Mitochondrial Genomes of Cicadas

2018 ◽  
Vol 110 (2) ◽  
pp. 247-256 ◽  
Author(s):  
Piotr Łukasik ◽  
Rebecca A Chong ◽  
Katherine Nazario ◽  
Yu Matsuura ◽  
De Anna C Bublitz ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Purifying Selection ◽  
Evolutionary Rates ◽  
Future Research ◽  
Mitochondrial Genomes ◽  
Protein Coding ◽  
Coding Regions ◽  
Mitochondrial Genome Evolution ◽  
Taxonomic Framework

Abstract Mitochondrial genomes can provide valuable information on the biology and evolutionary histories of their host organisms. Here, we present and characterize the complete coding regions of 107 mitochondrial genomes (mitogenomes) of cicadas (Insecta: Hemiptera: Auchenorrhyncha: Cicadoidea), representing 31 genera, 61 species, and 83 populations. We show that all cicada mitogenomes retain the organization and gene contents thought to be ancestral in insects, with some variability among cicada clades in the length of a region between the genes nad2 and cox1, which encodes 3 tRNAs. Phylogenetic analyses using these mitogenomes recapitulate a recent 5-gene classification of cicadas into families and subfamilies, but also identify a species that falls outside of the established taxonomic framework. While protein-coding genes are under strong purifying selection, tests of relative evolutionary rates reveal significant variation in evolutionary rates across taxa, highlighting the dynamic nature of mitochondrial genome evolution in cicadas. These data will serve as a useful reference for future research into the systematics, ecology, and evolution of the superfamily Cicadoidea.

scholarly journals Histone H2A and Bovine Neutrophil Extracellular Traps Induce Damage of Besnoitia besnoiti-Infected Host Endothelial Cells but Fail to Affect Total Parasite Proliferation

Biology ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 78 ◽  
Author(s):  
Conejeros ◽  
Velásquez ◽  
Grob ◽  
Zhou ◽  
Salecker ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Host Cell ◽  
Cell Damage ◽  
Neutrophil Extracellular Traps ◽  
Host Cells ◽  
Infected Host ◽  
Parasite Development ◽  
Besnoitia Besnoiti ◽  
Extracellular Traps ◽  
Bovine Endothelial Cells

Besnoitia besnoiti tachyzoites infect and develop in bovine endothelial cells in vivo and trigger the release of neutrophil extracellular traps (NETs) from bovine polymorphonuclear neutrophils (PMN). The purpose of this study was to analyze if pure B. besnoiti tachyzoite-triggered NETs would damage endothelial host cells and subsequently influence intracellular development and proliferation of B. besnoiti tachyzoites in primary bovine endothelial cells. For comparison purposes, isolated A23187-induced NETs were also used. Thus, we here evaluated endothelial host cell damage triggered by histone 2A (H2A) and B. besnoiti tachyzoite-induced NET preparations and furthermore estimated the effects of PMN floating over B. besnoiti-infected endothelium under physiological flow conditions on endothelial host cell viability. Overall, all treatments (H2A, B. besnoiti-triggered NETs and floating PMN) induced endothelial cell death of B. besnoiti-infected host cells. However, though host cell damage led to significantly altered intracellular parasite development with respect to parasitophorous vacuole diameter and numbers, the total proliferation of the parasite over time was not significantly affected by these treatments thereby denying any direct effect of NETs on intracellular B. besnoiti replication.

scholarly journals Red algal parasites: A synopsis of described species, their hosts, distinguishing characters and areas for continued research

2020 ◽  
Author(s):  
Maren Preuss ◽  
WA Nelson ◽  
Giuseppe Zuccarello
Keyword(s):  
Host Cell ◽  
Red Algae ◽  
Host Cells ◽  
Parasite Development ◽  
Cellular Interactions ◽  
Cell Control ◽  
Full Extent ◽  
Red Algal ◽  
Algal Groups ◽  
Parasite Biodiversity

© 2017 Walter de Gruyter GmbH, Berlin/Boston. Red algal parasites are diverse organisms that are unusual due to the fact that many are closely related to their hosts. Parasitism has developed many times within different red algal groups, but the full extent of parasite biodiversity is unknown, as parasites are easily overlooked due to their small size and often low abundance. Additionally, the literature on red algal parasites is dispersed and has not been compiled in over 30 years. Although criteria have been proposed to define what constitutes a red algal parasite, many parasites are poorly described, and the cellular interactions with their host are poorly known. A few studies have demonstrated that parasites transfer organelles to host cells, which can alter the physiology of the host to the benefit of the parasite. Here, we apply a set of defining criteria for parasites to a compiled list of all described red algal parasites. Our results highlight the lack of knowledge of many key parasitic processes including early parasite development, host cell "control", and parasite origin. Until the biology of more parasites is studied, generalisations on the processes of parasitism in red algae may be premature. We hope this synopsis will stimulate research into this fascinating group.

scholarly journals Mitogenomic analyses provide further evidence for multiple miniaturization events during the evolution of Seychelles caecilian amphibians

2021 ◽  
Author(s):  
Annie J. Gwilt ◽  
Jeffrey W. Streicher ◽  
Simon T. Maddock
Keyword(s):  
Mitochondrial Genome ◽  
Phylogenetic Relationships ◽  
High Throughput Sequencing ◽  
Phylogenetic Analyses ◽  
Strong Support ◽  
Mitochondrial Genomes ◽  
Genome Sequences ◽  
Sequence Capture ◽  
Target Sequences ◽  
Targeted Sequence Capture

AbstractWhole mitochondrial genomes have been helpful in estimating phylogenetic relationships in many organismal groups, including caecilian amphibians. Despite the increasing ease of obtaining mitochondrial genome sequences from high-throughput sequencing, several species of caecilian lack this important molecular resource. As part of a targeted-sequence capture project of nuclear ultraconserved elements for a small but substantially diverse radiation of caecilian amphibians found on the granitic Seychelles, we examined off-target sequences to determine if we captured enough mitochondrial fragments to reconstruct mitogenomes. We reconstructed (near-)complete mitogenomes for six of the eight species of Seychelles caecilians and completed 14 independent phylogenetic analyses (Bayesian inference and maximum likelihood) on different mitochondrial datasets assembled using different alignment techniques. As with other studies, we were unable to fully resolve internal phylogenetic relationships of the group. However, we found strong support in most analyses that a recently described miniaturized species, Hypogeophis pti, and another similarly-sized miniaturized species, H. brevis are not sister taxa. Our study suggests that miniature species of caecilians likely evolved at least twice on the Seychelles and highlights the need to revise genus-level taxonomy of Seychelles caecilians while providing further evidence that off-target sequences often contain enough mitochondrial fragments to reconstruct mitogenomes.

scholarly journals The (non) accuracy of mitochondrial genomes for family level phylogenetics: the case of erebid moths (Lepidoptera; Erebidae)

2021 ◽  
Author(s):  
Hamid Reza Ghanavi ◽  
Victoria Twort ◽  
Tobias Joannes Hartman ◽  
Reza Zahiri ◽  
Niklas Wahlberg
Keyword(s):  
Mitochondrial Dna ◽  
Phylogenetic Relationships ◽  
High Throughput Sequencing ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Mitochondrial Genomes ◽  
The Family ◽  
History Of ◽  
Genomic Scale

The use of molecular data to study evolutionary history of different organisms, revolutionized the field of systematics. Now with the appearance of high throughput sequencing (HTS) technologies more and more genetic sequence data is available. One of the important sources of genetic data for phylogenetic analyses has been mitochondrial DNA. The limitations of mitochondrial DNA for the study of phylogenetic relationships have been thoroughly explored in the age of single locus phylogenies. Now with the appearance of genomic scale data, more and more mitochondrial genomes are available. Here we assemble 47 mitochondrial genomes using whole genome Illumina short reads of representatives of the family Erebidae (Lepidoptera), in order to evaluate the accuracy of mitochondrial genome application in resolving deep phylogenetic relationships. We find that mitogenomes are inadequate for resolving subfamily level relationships in Erebidae, but given good taxon sampling, we see its potential in resolving lower level phylogenetic relationships.

scholarly journals Red algal parasites: a synopsis of described species, their hosts, distinguishing characters and areas for continued research

2017 ◽  
Vol 60 (1) ◽  
Author(s):  
Maren Preuss ◽  
Wendy A. Nelson ◽  
Giuseppe C. Zuccarello
Keyword(s):  
Host Cell ◽  
Red Algae ◽  
Host Cells ◽  
Parasite Development ◽  
Cellular Interactions ◽  
Cell Control ◽  
Full Extent ◽  
Red Algal ◽  
Algal Groups ◽  
Parasite Biodiversity

AbstractRed algal parasites are diverse organisms that are unusual due to the fact that many are closely related to their hosts. Parasitism has developed many times within different red algal groups, but the full extent of parasite biodiversity is unknown, as parasites are easily overlooked due to their small size and often low abundance. Additionally, the literature on red algal parasites is dispersed and has not been compiled in over 30 years. Although criteria have been proposed to define what constitutes a red algal parasite, many parasites are poorly described, and the cellular interactions with their host are poorly known. A few studies have demonstrated that parasites transfer organelles to host cells, which can alter the physiology of the host to the benefit of the parasite. Here, we apply a set of defining criteria for parasites to a compiled list of all described red algal parasites. Our results highlight the lack of knowledge of many key parasitic processes including early parasite development, host cell “control”, and parasite origin. Until the biology of more parasites is studied, generalisations on the processes of parasitism in red algae may be premature. We hope this synopsis will stimulate research into this fascinating group.

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