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

© 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.

2020 ◽  
Author(s):  
Maren Preuss ◽  
WA Nelson ◽  
Giuseppe Zuccarello

© 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.


2017 ◽  
Vol 60 (1) ◽  
Author(s):  
Maren Preuss ◽  
Wendy A. Nelson ◽  
Giuseppe C. Zuccarello

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.


2021 ◽  
Author(s):  
◽  
Maren Preuss

<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>


2014 ◽  
Vol 83 (4) ◽  
pp. 369-375 ◽  
Author(s):  
Eric D. Salomaki ◽  
Christopher E. Lane

Parasitism is a common life strategy throughout the eukaryotic tree of life. Many devastating human pathogens, including the causative agents of malaria and toxoplasmosis, have evolved from a photosynthetic ancestor. However, how an organism transitions from a photosynthetic to a parasitic life history strategy remains mostly unknown. This is largely because few systems present the opportunity to make meaningful comparisons between a parasite and a close free-living relative. Parasites have independently evolved dozens of times throughout the Florideophyceae (Rhodophyta), and often infect close relatives. The accepted evolutionary paradigm proposes that red algal parasites arise by first infecting a close relative and over time diversify and infect more distantly related species. This provides a natural evolutionary gradient of relationships between hosts and parasites that share a photosynthetic common ancestor. Elegant microscopic work in the late 20th century provided detailed insight into the infection cycle of red algal parasites and the cellular interactions between parasites and their hosts. Those studies led to the use of molecular work to further investigate the origins of the parasite organelles and reveal the evolutionary relationships between hosts and their parasites. Here we synthesize the research detailing the infection methods and cellular interactions between red algal parasites and their hosts. We offer an alternative hypothesis to the current dogma of red algal parasite evolution and propose that red algae can adopt a parasitic life strategy through multiple evolutionary pathways, including direct infection of distant relatives. Furthermore, we highlight potential directions for future research to further evaluate parasite evolution in red algae.


2020 ◽  
Author(s):  
Maren Preuss ◽  
Giuseppe Zuccarello

© 2019, © 2019 British Phycological Society. Parasitic red algae grow only on other red algae and have over 120 described species. Developmental studies in red algal parasites are few, although they have shown that secondary pit connections formed between parasite and host and proposed that this was an important process in successful parasitism. Furthermore, it was recorded that the transfer of parasite nuclei by these secondary pit connections led to different host cell effects. We used developmental studies to reconstruct early stages and any host cell effects of a parasite on Vertebrata aterrima. A mitochondrial marker (cox1) and morphological observations (light and fluorescence microscopy) were used to describe this new red algal parasite as Vertebrata aterrimophila sp. nov. Early developmental stages show that a parasite spore connects via secondary pit connections with a pericentral host cell after cuticle penetration. Developmental observations revealed a unique connection cell that grows into a ‘trunk-like’ structure. Host cell transformation after infection by the parasite included apparent increases in both carbohydrate concentrations and nuclear size, as well as structural changes. Analyses of molecular phylogenies and reproductive structures indicated that the closest relative of V. aterrimophila is its host, V. aterrima. Our study shows a novel developmental parasite stage (‘trunk-like’ cell) and highlights the need for further developmental studies to investigate the range of developmental patterns and host effects in parasitic red algae.


Biology ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 78 ◽  
Author(s):  
Conejeros ◽  
Velásquez ◽  
Grob ◽  
Zhou ◽  
Salecker ◽  
...  

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.


2017 ◽  
Vol 114 (31) ◽  
pp. E6361-E6370 ◽  
Author(s):  
Susan H. Brawley ◽  
Nicolas A. Blouin ◽  
Elizabeth Ficko-Blean ◽  
Glen L. Wheeler ◽  
Martin Lohr ◽  
...  

Porphyra umbilicalis(laver) belongs to an ancient group of red algae (Bangiophyceae), is harvested for human food, and thrives in the harsh conditions of the upper intertidal zone. Here we present the 87.7-Mbp haploidPorphyragenome (65.8% G + C content, 13,125 gene loci) and elucidate traits that inform our understanding of the biology of red algae as one of the few multicellular eukaryotic lineages. Novel features of thePorphyragenome shared by other red algae relate to the cytoskeleton, calcium signaling, the cell cycle, and stress-tolerance mechanisms including photoprotection. Cytoskeletal motor proteins inPorphyraare restricted to a small set of kinesins that appear to be the only universal cytoskeletal motors within the red algae. Dynein motors are absent, and most red algae, includingPorphyra, lack myosin. This surprisingly minimal cytoskeleton offers a potential explanation for why red algal cells and multicellular structures are more limited in size than in most multicellular lineages. Additional discoveries further relating to the stress tolerance of bangiophytes include ancestral enzymes for sulfation of the hydrophilic galactan-rich cell wall, evidence for mannan synthesis that originated before the divergence of green and red algae, and a high capacity for nutrient uptake. Our analyses provide a comprehensive understanding of the red algae, which are both commercially important and have played a major role in the evolution of other algal groups through secondary endosymbioses.


2020 ◽  
Author(s):  
Maren Preuss ◽  
Giuseppe Zuccarello

© 2019, © 2019 British Phycological Society. Parasitic red algae grow only on other red algae and have over 120 described species. Developmental studies in red algal parasites are few, although they have shown that secondary pit connections formed between parasite and host and proposed that this was an important process in successful parasitism. Furthermore, it was recorded that the transfer of parasite nuclei by these secondary pit connections led to different host cell effects. We used developmental studies to reconstruct early stages and any host cell effects of a parasite on Vertebrata aterrima. A mitochondrial marker (cox1) and morphological observations (light and fluorescence microscopy) were used to describe this new red algal parasite as Vertebrata aterrimophila sp. nov. Early developmental stages show that a parasite spore connects via secondary pit connections with a pericentral host cell after cuticle penetration. Developmental observations revealed a unique connection cell that grows into a ‘trunk-like’ structure. Host cell transformation after infection by the parasite included apparent increases in both carbohydrate concentrations and nuclear size, as well as structural changes. Analyses of molecular phylogenies and reproductive structures indicated that the closest relative of V. aterrimophila is its host, V. aterrima. Our study shows a novel developmental parasite stage (‘trunk-like’ cell) and highlights the need for further developmental studies to investigate the range of developmental patterns and host effects in parasitic red algae.


Phytotaxa ◽  
2018 ◽  
Vol 364 (1) ◽  
pp. 1 ◽  
Author(s):  
E. K. GANESAN ◽  
JOHN A. WEST ◽  
ORLANDO NECCHI JR.

An annotated bibliographic catalogue of Indian red algae (Rhodophyta) occurring in freshwater and estuarine habitats (moist terrestrial soils, ponds, streams, rivers, lakes, large inland brackish water lagoons and coastal estuaries), based on more than a century (1846 to 2017) of publications is presented in a single coherent work for the first time. There have been 81 taxonomic entities (species, varieties and doubtful records), distributed among 21 genera recorded for the vast Indian sub-continent. Species distribution among the 21 genera are as follows: Audouinella—12; Balliopsis—1; Batrachospermum—11; Bostrychia—7; Caloglossa—8; Catenella—3; Chroodactylon (including Asterocytis)—2; Chroothece—1; Compsopogon—8, Compsopogonopsis—1; Hildenbrandia—1; Kumanoa—7; Kyliniella—1; Lemanea—6; Nothocladus—1; Polysiphonia—1; Porphyridium—1; Sheathia—1; Sirodotia—4; Thorea—2; and Tuomeya—2. Of the seven currently recognized classes of Rhodophyta, no members of Bangiophyceae, Cyaniodiophyceae, or Rhodellophyceae are recorded from India. For each taxon, the following information is provided: (i) valid and currently accepted binomial (ii) synonyms as applicable to Indian records (iii) references with distribution in India and (iv) brief notes. Descriptions of new species based on Indian collections (holotypes) are indicated and some new combinations were made, when necessary. Several generic records (e.g., Balliopsis, Hildenbrandia, Kyliniella, Nothocladus and Tuomeya) and some species records (e.g. Batrachospermum longiarticulatum, Lemanea australis, L. catenata, L. fluviatilis, L. mamillosa, L. torulosa and Thorea hispida) warrant detailed confirmatory data based on reinvestigation of fresh collections for morphology, reproduction and particularly molecular data to confirm the presence in the country. Future collections, especially in the Indian Biodiversity Hotspots (Indo-Burma, Western and Eastern Ghats and Andaman & Nicobar Islands), may uncover the occurrence of genera such as Bangia, Cyanidium and Nemalionopsis known to be present in neighbouring countries of Pakistan, Nepal and Thailand. Geothermal (acidic) hot water springs in India may reveal the presence of extremophilic unicellular red algal genera like Cyanidium, Cyanidioschyzon and Galdieria of the Cyanidiophyceae. Two maps showing the political and biogeographic zones of India are included. The need to preserve holotype and duplicate/voucher specimens with GPS data of future collections of red algal groups in a centralized national facility is also highlighted.


2019 ◽  
Author(s):  
Renugah Naidu ◽  
Trang TT Chu ◽  
Jaishree Tripathi ◽  
Yang Hu ◽  
Gowtham Subramanian ◽  
...  

AbstractPlasmodia are host-specific, both at the organism and cellular levels. During asexual development, Plasmodium spp. infect cells of erythroid lineage, with an overall propensity towards reticulocytes. This applies to even Plasmodium (P.) falciparum, the most common causative agent of human malaria, implications of which remain unexplored. Herein, for the first time, we characterize the developmental stages and features of P. falciparum cultured in vitro in young reticulocytes (CD71+) in comparison to standard normocyte (CD71-) cultures. We demonstrate that there are notable differences in the patterns of invasion, development and sensitivity to potent antimalarials (such as artemisinin and dihydroartemisinin) for parasites residing in CD71+ reticulocytes. Through a transcriptomic approach, we report that P. falciparum parasites are able to sense the host cell environment, and calibrate their metabolic and host cell remodelling pathways through differential gene expression. These results form an exciting avenue on which hitherto unexplored interactions between Plasmodium spp and different stages of host red blood cells could be investigated in the broader contexts of drug resistance, host tropism and zoonosis.Author SummaryParasites causing malaria infect red blood cells for development and proliferation during asexual development. This asexual erythrocytic stage determines higher parasite densities and eventual disease manifestation. Although the most virulent species of Plasmodium infecting humans known as Plasmodium falciparum is able to infect red blood cells of all ages, these parasites show a preference for younger blood cells. Of note, the biochemical and biophysical properties of young and adult red blood cells vary significantly. Herein, we undertook a comparative profiling of invasion process, parasite development and drug response of Plasmoddium falciparum in two host cells: young red blood cells (reticulocytes) and mature red blood cells (normocytes). We demonstrate that P. falciparum infects human reticulocytes with higher affinity and demonstrate differential sensitivity to drugs such as artemisinin while they reside within reticulocytes. Furthermore, we show that P. falciparum is able to detect differences in host environment and adapt to it by changing the expression of genes required for host cell remodelling.


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