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2. Systematic comparison of unilamellar vesicles reveals that archaeal core lipid membranes are more permeable than bacterial membranes.

Author

Łapińska, Urszula, Glover, Georgina, Kahveci, Zehra, Irwin, Nicholas, Milner, David, Tourte, Maxime, Albers, Sonja-Verena, Santoro, Alyson, Richards, Thomas, and Pagliara, Stefano

Subjects
Archaea, Unilamellar Liposomes, Glycerol, Cell Membrane, Bacteria, Membrane Lipids, Phospholipids, Phosphates, Lipid Bilayers
Abstract

One of the deepest branches in the tree of life separates the Archaea from the Bacteria. These prokaryotic groups have distinct cellular systems including fundamentally different phospholipid membrane bilayers. This dichotomy has been termed the lipid divide and possibly bestows different biophysical and biochemical characteristics on each cell type. Classic experiments suggest that bacterial membranes (formed from lipids extracted from Escherichia coli, for example) show permeability to key metabolites comparable to archaeal membranes (formed from lipids extracted from Halobacterium salinarum), yet systematic analyses based on direct measurements of membrane permeability are absent. Here, we develop a new approach for assessing the membrane permeability of approximately 10 μm unilamellar vesicles, consisting of an aqueous medium enclosed by a single lipid bilayer. Comparing the permeability of 18 metabolites demonstrates that diether glycerol-1-phosphate lipids with methyl branches, often the most abundant membrane lipids of sampled archaea, are permeable to a wide range of compounds useful for core metabolic networks, including amino acids, sugars, and nucleobases. Permeability is significantly lower in diester glycerol-3-phosphate lipids without methyl branches, the common building block of bacterial membranes. To identify the membrane characteristics that determine permeability, we use this experimental platform to test a variety of lipid forms bearing a diversity of intermediate characteristics. We found that increased membrane permeability is dependent on both the methyl branches on the lipid tails and the ether bond between the tails and the head group, both of which are present on the archaeal phospholipids. These permeability differences must have had profound effects on the cell physiology and proteome evolution of early prokaryotic forms. To explore this further, we compare the abundance and distribution of transmembrane transporter-encoding protein families present on genomes sampled from across the prokaryotic tree of life. These data demonstrate that archaea tend to have a reduced repertoire of transporter gene families, consistent with increased membrane permeation. These results demonstrate that the lipid divide demarcates a clear difference in permeability function with implications for understanding some of the earliest transitions in cell origins and evolution.

Published
2023

4. Genetic tool development in marine protists: emerging model organisms for experimental cell biology

Author

Faktorová, Drahomíra, Nisbet, R Ellen R, Fernández Robledo, José A, Casacuberta, Elena, Sudek, Lisa, Allen, Andrew E, Ares, Manuel, Aresté, Cristina, Balestreri, Cecilia, Barbrook, Adrian C, Beardslee, Patrick, Bender, Sara, Booth, David S, Bouget, François-Yves, Bowler, Chris, Breglia, Susana A, Brownlee, Colin, Burger, Gertraud, Cerutti, Heriberto, Cesaroni, Rachele, Chiurillo, Miguel A, Clemente, Thomas, Coles, Duncan B, Collier, Jackie L, Cooney, Elizabeth C, Coyne, Kathryn, Docampo, Roberto, Dupont, Christopher L, Edgcomb, Virginia, Einarsson, Elin, Elustondo, Pía A, Federici, Fernan, Freire-Beneitez, Veronica, Freyria, Nastasia J, Fukuda, Kodai, García, Paulo A, Girguis, Peter R, Gomaa, Fatma, Gornik, Sebastian G, Guo, Jian, Hampl, Vladimír, Hanawa, Yutaka, Haro-Contreras, Esteban R, Hehenberger, Elisabeth, Highfield, Andrea, Hirakawa, Yoshihisa, Hopes, Amanda, Howe, Christopher J, Hu, Ian, Ibañez, Jorge, Irwin, Nicholas AT, Ishii, Yuu, Janowicz, Natalia Ewa, Jones, Adam C, Kachale, Ambar, Fujimura-Kamada, Konomi, Kaur, Binnypreet, Kaye, Jonathan Z, Kazana, Eleanna, Keeling, Patrick J, King, Nicole, Klobutcher, Lawrence A, Lander, Noelia, Lassadi, Imen, Li, Zhuhong, Lin, Senjie, Lozano, Jean-Claude, Luan, Fulei, Maruyama, Shinichiro, Matute, Tamara, Miceli, Cristina, Minagawa, Jun, Moosburner, Mark, Najle, Sebastián R, Nanjappa, Deepak, Nimmo, Isabel C, Noble, Luke, Novák Vanclová, Anna MG, Nowacki, Mariusz, Nuñez, Isaac, Pain, Arnab, Piersanti, Angela, Pucciarelli, Sandra, Pyrih, Jan, Rest, Joshua S, Rius, Mariana, Robertson, Deborah, Ruaud, Albane, Ruiz-Trillo, Iñaki, Sigg, Monika A, Silver, Pamela A, Slamovits, Claudio H, Jason Smith, G, Sprecher, Brittany N, Stern, Rowena, Swart, Estienne C, Tsaousis, Anastasios D, Tsypin, Lev, Turkewitz, Aaron, and Turnšek, Jernej

Subjects
Genetics, Biotechnology, Life Below Water, Biodiversity, DNA, Ecosystem, Environment, Eukaryota, Green Fluorescent Proteins, Marine Biology, Models, Biological, Species Specificity, Transformation, Genetic, Biological Sciences, Technology, Medical and Health Sciences, Developmental Biology
Abstract

Diverse microbial ecosystems underpin life in the sea. Among these microbes are many unicellular eukaryotes that span the diversity of the eukaryotic tree of life. However, genetic tractability has been limited to a few species, which do not represent eukaryotic diversity or environmentally relevant taxa. Here, we report on the development of genetic tools in a range of protists primarily from marine environments. We present evidence for foreign DNA delivery and expression in 13 species never before transformed and for advancement of tools for eight other species, as well as potential reasons for why transformation of yet another 17 species tested was not achieved. Our resource in genetic manipulation will provide insights into the ancestral eukaryotic lifeforms, general eukaryote cell biology, protein diversification and the evolution of cellular pathways.

Published
2020

5. Publisher Correction: Genetic tool development in marine protists: emerging model organisms for experimental cell biology

Author

Faktorová, Drahomíra, Nisbet, R Ellen R, Fernández Robledo, José A, Casacuberta, Elena, Sudek, Lisa, Allen, Andrew E, Ares, Manuel, Aresté, Cristina, Balestreri, Cecilia, Barbrook, Adrian C, Beardslee, Patrick, Bender, Sara, Booth, David S, Bouget, François-Yves, Bowler, Chris, Breglia, Susana A, Brownlee, Colin, Burger, Gertraud, Cerutti, Heriberto, Cesaroni, Rachele, Chiurillo, Miguel A, Clemente, Thomas, Coles, Duncan B, Collier, Jackie L, Cooney, Elizabeth C, Coyne, Kathryn, Docampo, Roberto, Dupont, Christopher L, Edgcomb, Virginia, Einarsson, Elin, Elustondo, Pía A, Federici, Fernan, Freire-Beneitez, Veronica, Freyria, Nastasia J, Fukuda, Kodai, García, Paulo A, Girguis, Peter R, Gomaa, Fatma, Gornik, Sebastian G, Guo, Jian, Hampl, Vladimír, Hanawa, Yutaka, Haro-Contreras, Esteban R, Hehenberger, Elisabeth, Highfield, Andrea, Hirakawa, Yoshihisa, Hopes, Amanda, Howe, Christopher J, Hu, Ian, Ibañez, Jorge, Irwin, Nicholas AT, Ishii, Yuu, Janowicz, Natalia Ewa, Jones, Adam C, Kachale, Ambar, Fujimura-Kamada, Konomi, Kaur, Binnypreet, Kaye, Jonathan Z, Kazana, Eleanna, Keeling, Patrick J, King, Nicole, Klobutcher, Lawrence A, Lander, Noelia, Lassadi, Imen, Li, Zhuhong, Lin, Senjie, Lozano, Jean-Claude, Luan, Fulei, Maruyama, Shinichiro, Matute, Tamara, Miceli, Cristina, Minagawa, Jun, Moosburner, Mark, Najle, Sebastián R, Nanjappa, Deepak, Nimmo, Isabel C, Noble, Luke, Novák Vanclová, Anna MG, Nowacki, Mariusz, Nuñez, Isaac, Pain, Arnab, Piersanti, Angela, Pucciarelli, Sandra, Pyrih, Jan, Rest, Joshua S, Rius, Mariana, Robertson, Deborah, Ruaud, Albane, Ruiz-Trillo, Iñaki, Sigg, Monika A, Silver, Pamela A, Slamovits, Claudio H, Jason Smith, G, Sprecher, Brittany N, Stern, Rowena, Swart, Estienne C, Tsaousis, Anastasios D, Tsypin, Lev, Turkewitz, Aaron, and Turnšek, Jernej

Subjects
Biological Sciences, Technology, Medical and Health Sciences, Developmental Biology
Abstract

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Published
2020

7. A distinct lineage of giant viruses brings a rhodopsin photosystem to unicellular marine predators

Author

Needham, David M, Yoshizawa, Susumu, Hosaka, Toshiaki, Poirier, Camille, Choi, Chang Jae, Hehenberger, Elisabeth, Irwin, Nicholas AT, Wilken, Susanne, Yung, Cheuk-Man, Bachy, Charles, Kurihara, Rika, Nakajima, Yu, Kojima, Keiichi, Kimura-Someya, Tomomi, Leonard, Guy, Malmstrom, Rex R, Mende, Daniel R, Olson, Daniel K, Sudo, Yuki, Sudek, Sebastian, Richards, Thomas A, DeLong, Edward F, Keeling, Patrick J, Santoro, Alyson E, Shirouzu, Mikako, Iwasaki, Wataru, and Worden, Alexandra Z

Subjects
Microbiology, Biological Sciences, Ecology, Genetics, Infectious Diseases, Neurosciences, Infection, Life Below Water, Biological Evolution, Ecosystem, Eukaryota, Genome, Viral, Giant Viruses, Metagenomics, Oceans and Seas, Phycodnaviridae, Phylogeny, Protons, Rhodopsin, Seawater, Viral Proteins, giant viruses, viral evolution, marine carbon cycle, single-cell genomics, host-virus interactions, host–virus interactions
Abstract

Giant viruses are remarkable for their large genomes, often rivaling those of small bacteria, and for having genes thought exclusive to cellular life. Most isolated to date infect nonmarine protists, leaving their strategies and prevalence in marine environments largely unknown. Using eukaryotic single-cell metagenomics in the Pacific, we discovered a Mimiviridae lineage of giant viruses, which infects choanoflagellates, widespread protistan predators related to metazoans. The ChoanoVirus genomes are the largest yet from pelagic ecosystems, with 442 of 862 predicted proteins lacking known homologs. They are enriched in enzymes for modifying organic compounds, including degradation of chitin, an abundant polysaccharide in oceans, and they encode 3 divergent type-1 rhodopsins (VirR) with distinct evolutionary histories from those that capture sunlight in cellular organisms. One (VirRDTS) is similar to the only other putative rhodopsin from a virus (PgV) with a known host (a marine alga). Unlike the algal virus, ChoanoViruses encode the entire pigment biosynthesis pathway and cleavage enzyme for producing the required chromophore, retinal. We demonstrate that the rhodopsin shared by ChoanoViruses and PgV binds retinal and pumps protons. Moreover, our 1.65-Å resolved VirRDTS crystal structure and mutational analyses exposed differences from previously characterized type-1 rhodopsins, all of which come from cellular organisms. Multiple VirR types are present in metagenomes from across surface oceans, where they are correlated with and nearly as abundant as a canonical marker gene from Mimiviridae Our findings indicate that light-dependent energy transfer systems are likely common components of giant viruses of photosynthetic and phagotrophic unicellular marine eukaryotes.

Published
2019

11. Peace Leadership Education

Author

Atwi, Rabab, primary, McIntyre Miller, Whitney, additional, Abdou, Annmary S., additional, Alomair, Miznah O., additional, Irwin, Nicholas J., additional, Hilt, Lisa, additional, Lotfi, Negeen, additional, murray, sylvia, additional, and Richmond, Gabrielle, additional

Published
2022
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23. New Parabasalia symbionts Snyderella spp. and Daimonympha gen. nov. from South American Rugitermes termites and the parallel evolution of a cell with a rotating “head”

Author

Hehenberger, Elisabeth, primary, Boscaro, Vittorio, additional, James, Erick R., additional, Hirakawa, Yoshihisa, additional, Trznadel, Morelia, additional, Mtawali, Mahara, additional, Fiorito, Rebecca, additional, del Campo, Javier, additional, Karnkowska, Anna, additional, Kolisko, Martin, additional, Irwin, Nicholas A. T., additional, Mathur, Varsha, additional, Scheffrahn, Rudolf H., additional, and Keeling, Patrick J., additional

Published
2023
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24. Multiple parallel origins of parasitic Marine Alveolates

Author

Holt, Corey C., primary, Hehenberger, Elisabeth, additional, Tikhonenkov, Denis V., additional, Jacko-Reynolds, Victoria K. L., additional, Okamoto, Noriko, additional, Cooney, Elizabeth C., additional, Irwin, Nicholas A. T., additional, and Keeling, Patrick J., additional

Published
2023
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26. Is it really bridging the gap? Fiber internet's impact on housing values and homebuyer demographics.

Author

Wolf, David and Irwin, Nicholas

Subjects
*RURAL housing, *INTERNET, *HOUSING, *FIBERS, *HOME prices
Abstract

Fiber internet expansion represents a path to improved economic vitality for Americans, but it is unclear who benefits from it and by how much. We examine the effects of subsidized fiber internet expansion on home prices and homebuyer demographics using data from Wisconsin and an IV approach to correct for fiber network endogeneity. We find fiber internet increases urban and rural housing values by 1.83% ($3,462) and decreases the likelihood a homebuyer is white by 2.88%, but in urban areas only. Fiber internet therefore does not appear to drive minority homebuyers away but may contribute to the urban‐rural racial divide. [ABSTRACT FROM AUTHOR]

Published
2024
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31. Shuffled ATG8 interacting motifs form an ancestral bridge between UFMylation and autophagy

Author

Picchianti, Lorenzo, primary, Sánchez de Medina Hernández, Víctor, additional, Zhan, Ni, additional, Irwin, Nicholas AT, additional, Groh, Roan, additional, Stephani, Madlen, additional, Hornegger, Harald, additional, Beveridge, Rebecca, additional, Sawa‐Makarska, Justyna, additional, Lendl, Thomas, additional, Grujic, Nenad, additional, Naumann, Christin, additional, Martens, Sascha, additional, Richards, Thomas A, additional, Clausen, Tim, additional, Ramundo, Silvia, additional, Karagöz, G Elif, additional, and Dagdas, Yasin, additional

Published
2023
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32. New Parabasalia symbionts Snyderella spp. and Daimonympha gen. nov. from South American Rugitermes termites and the parallel evolution of a cell with a rotating “head”

Author

Natural Sciences and Engineering Research Council of Canada, Campo, Javier del [0000-0002-5292-1421], Hehenberger, Elisabeth, Boscaro, Vittorio, James, Erick R., Hirakawa, Yoshihisa, Trznadel, Morelia, Mtawali, Mahara, Fiorito, Rebecca, Campo, Javier del, Karnkowska, Anna, Kolisko, Martin, Irwin, Nicholas A. T., Mathur, Varsha, Scheffrahn, Rudolf H., Keeling, Patrick J., Natural Sciences and Engineering Research Council of Canada, Campo, Javier del [0000-0002-5292-1421], Hehenberger, Elisabeth, Boscaro, Vittorio, James, Erick R., Hirakawa, Yoshihisa, Trznadel, Morelia, Mtawali, Mahara, Fiorito, Rebecca, Campo, Javier del, Karnkowska, Anna, Kolisko, Martin, Irwin, Nicholas A. T., Mathur, Varsha, Scheffrahn, Rudolf H., and Keeling, Patrick J.

Abstract

Most Parabasalia are symbionts in the hindgut of “lower” (non-Termitidae) termites, where they widely vary in morphology and degree of morphological complexity. Large and complex cells in the class Cristamonadea evolved by replicating a fundamental unit, the karyomastigont, in various ways. We describe here four new species of Calonymphidae (Cristamonadea) from Rugitermes hosts, assigned to the genus Snyderella based on diagnostic features (including the karyomastigont pattern) and molecular phylogeny. We also report a new genus of Calonymphidae, Daimonympha, from Rugitermes laticollis. Daimonympha's morphology does not match that of any known Parabasalia, and its SSU rRNA gene sequence corroborates this distinction. Daimonympha does however share a puzzling feature with a few previously described, but distantly related, Cristamonadea: a rapid, smooth, and continuous rotation of the anterior end of the cell, including the many karyomastigont nuclei. The function of this rotatory movement, the cellular mechanisms enabling it, and the way the cell deals with the consequent cell membrane shear, are all unknown. “Rotating wheel” structures are famously rare in biology, with prokaryotic flagella being the main exception; these mysterious spinning cells found only among Parabasalia are another, far less understood, example.

Published
2023

33. Shuffled ATG8 interacting motifs form an ancestral bridge between UFMylation and C53-mediated autophagy

Author

Picchianti, Lorenzo, Sanchez de Medina Hernandez, Victor, Zhan, Ni, Irwin, Nicholas, Groh, Roan, Stephani, Madlen, Hornegger, Harald, Beveridge, Rebecca, Sawa-Makarska, Justyna, Lendl, Thomas, Grujic, Nenad, Naumann, Christin, Martens, Sascha, Richards, Thomas, Clausen, Tim, Ramundo, Silvia, Karagoz, Elif, and Dagdas, Yasin

Abstract

Raw data and supplementary data organized as referenced in the main text, figure legends, methods and appendix.

Published
2022
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37. Author Reply to Peer Reviews of Shuffled ATG8 interacting motifs form an ancestral bridge between UFMylation and C53-mediated autophagy

Author

Dagdas, Yasin, primary, Karagöz, G. Elif, additional, Ramundo, Silvia, additional, Clausen, Tim, additional, Richards, Thomas A., additional, Martens, Sascha, additional, Grujic, Nenad, additional, Lendl, Thomas, additional, Sawa-Makarska, Justyna, additional, Beveridge, Rebecca, additional, Hornegger, Harald, additional, Stephani, Madlen, additional, Irwin, Nicholas A. T., additional, Zhan, Ni, additional, de Medina Hernández, Víctor Sánchez, additional, and Picchianti, Lorenzo, additional

Published
2022
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38. Shuffled ATG8 interacting motifs form an ancestral bridge between UFMylation and C53-mediated autophagy

Author

Picchianti, Lorenzo, primary, de Medina Hernández, Víctor Sánchez, additional, Zhan, Ni, additional, Irwin, Nicholas A. T., additional, Stephani, Madlen, additional, Hornegger, Harald, additional, Beveridge, Rebecca, additional, Sawa-Makarska, Justyna, additional, Lendl, Thomas, additional, Grujic, Nenad, additional, Martens, Sascha, additional, Richards, Thomas A., additional, Clausen, Tim, additional, Ramundo, Silvia, additional, Karagöz, G. Elif, additional, and Dagdas, Yasin, additional

Published
2022
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40. Additional file 5 of Microscopic marine invertebrates are reservoirs for cryptic and diverse protists and fungi

Author

Holt, Corey C., Boscaro, Vittorio, Van Steenkiste, Niels W. L., Herranz, Maria, Mathur, Varsha, Irwin, Nicholas A. T., Buckholtz, Gracy, Leander, Brian S., and Keeling, Patrick J.

Abstract

Additional file 5: Supplementary Figure 4. Marine alveolate (top) and Stramenopiles (bottom) phylogenies with sequence labels and UltraFast bootstrap support values. Maximum-likelihood phylogeny of all MALV and host-associated Stramenopiles ASVs, reference sequences, and BLAST hits using the GTR+F+R7 substitution model. Individual ASVs indicated by bold tip labels and white rectangles in grey ring. Accompanying dots reflect presence in each host phylum (coloured accordingly).

Published
2022
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41. Additional file 3 of Microscopic marine invertebrates are reservoirs for cryptic and diverse protists and fungi

Author

Holt, Corey C., Boscaro, Vittorio, Van Steenkiste, Niels W. L., Herranz, Maria, Mathur, Varsha, Irwin, Nicholas A. T., Buckholtz, Gracy, Leander, Brian S., and Keeling, Patrick J.

Abstract

Additional file 3: Supplementary Figure 2. Ciliophora phylogeny with sequence labels and UltraFast bootstrap support values. Maximum-likelihood phylogeny of all Ciliophora ASVs, reference sequences, and BLAST hits using the GTR+F+R7 substitution model. Individual ASVs indicated by bold tip labels and white rectangles in grey ring. Accompanying dots reflect presence in each host phylum (coloured accordingly).

Published
2022
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42. Additional file 4 of Microscopic marine invertebrates are reservoirs for cryptic and diverse protists and fungi

Author

Holt, Corey C., Boscaro, Vittorio, Van Steenkiste, Niels W. L., Herranz, Maria, Mathur, Varsha, Irwin, Nicholas A. T., Buckholtz, Gracy, Leander, Brian S., and Keeling, Patrick J.

Abstract

Additional file 4: Supplementary Figure 3. Fungi phylogeny with sequence labels and UltraFast bootstrap support values. Maximum-likelihood phylogeny of all Fungi ASVs, reference sequences, and BLAST hits using the GTR+F+R7 substitution model. Individual ASVs indicated by bold tip labels and white rectangles in grey ring. Accompanying dots reflect presence in each host phylum (coloured accordingly).

Published
2022
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43. Supplement Figures from A diversified and segregated mRNA spliced-leader system in the parasitic Perkinsozoa

Author

Alacid, Elisabet, Irwin, Nicholas A. T., Smilansky, Vanessa, Milner, David S., Kilias, Estelle S., Leonard, Guy, and Richards, Thomas A.

Abstract

Spliced-leader trans-splicing (SLTS) has been described in distantly related eukaryotes and acts to mark mRNAs with a short 5′ exon, giving different mRNAs identical 5′ sequence-signatures. The function of these systems is obscure. The Perkinsozoa encompasses a diversity of parasitic protists that infect bivalves, toxic-tide dinoflagellates, fish and frog tadpoles. Here, we report considerable sequence variation in the SLTS-system across the Perkinsozoa and find that multiple variant SLTS-systems are encoded in parallel in the important Perkinsozoa parasite Parvilucifera sinerae. These results demonstrate that the transcriptome of P. sinerae is segregated based on the addition of different spliced-leader (SL) exons. This segregation marks different gene categories, suggesting that SL-segregation relates to functional differentiation of the transcriptome. By contrast, both sets of gene categories are present in the single SL-transcript type sampled from Maranthos, implying that the SL-segregation of the Parvilucifera transcriptome is a recent evolutionary innovation. Furthermore, we show that the SLTS-system marks a subsection of the transcriptome with increased mRNA abundance and includes genes that encode the spliceosome system necessary for SLTS-function. Collectively, these data provide a picture of how the SLTS-systems can vary within a major evolutionary group and identify how transcriptional-complexity can be achieved through SL-segregation.

Published
2022
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45. Membrane permeability differentiation at the lipid divide

Author

Łapińska, Urszula, primary, Glover, Georgina, additional, Kahveci, Zehra, additional, Irwin, Nicholas A. T., additional, Milner, David S., additional, Tourte, Maxime, additional, Albers, Sonja-Verena, additional, Santoro, Alyson E., additional, Richards, Thomas A., additional, and Pagliara, Stefano, additional

Published
2021
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47. Phylogenomics Identifies a New Major Subgroup of Apicomplexans, Marosporida class nov., with Extreme Apicoplast Genome Reduction

Author

Mathur, Varsha, Kwong, Waldan K., Husnik, Filip, Irwin, Nicholas A., Kristmundsson, Árni, Gestal, C., Freeman, Mark, Keeling, Patrick J., Mathur, Varsha, Kwong, Waldan K., Husnik, Filip, Irwin, Nicholas A., Kristmundsson, Árni, Gestal, C., Freeman, Mark, and Keeling, Patrick J.

Abstract

The phylum Apicomplexa consists largely of obligate animal parasites that include the causative agents of human diseases such as malaria. Apicomplexans have also emerged as models to study the evolution of nonphotosynthetic plastids, as they contain a relict chloroplast known as the apicoplast. The apicoplast offers important clues into how apicomplexan parasites evolved from free-living ancestors and can provide insights into reductive organelle evolution. Here, we sequenced the transcriptomes and apicoplast genomes of three deep-branching apicomplexans, Margolisiella islandica, Aggregata octopiana, and Merocystis kathae. Phylogenomic analyses show that these taxa, together with Rhytidocystis, form a new lineage of apicomplexans that is sister to the Coccidia and Hematozoa (the lineages including most medically significant taxa). Members of this clade retain plastid genomes and the canonical apicomplexan plastid metabolism. However, the apicoplast genomes of Margolisiella and Rhytidocystis are the most reduced of any apicoplast, are extremely GC-poor, and have even lost genes for the canonical plastidial RNA polymerase. This new lineage of apicomplexans, for which we propose the class Marosporida class nov., occupies a key intermediate position in the apicomplexan phylogeny, and adds a new complexity to the models of stepwise reductive evolution of genome structure and organelle function in these parasites

Published
2021

48. Characterization of new cristamonad species from kalotermitid termites including a novel genus, Runanympha

Author

Natural Sciences and Engineering Research Council of Canada, Tula Foundation, European Commission, Singh, Racquel A., Boscaro, Vittorio, James, Erick R., Karnkowska, Anna, Kolisko, Martin, Gavelis, Gregory S., Okamoto, Noriko, Campo, Javier del, Fiorito, Rebecca, Hehenberger, Elisabeth, Irwin, Nicholas A. T., Mathur, Varsha, Scheffrahn, Rudolf H., Keeling, Patrick J., Natural Sciences and Engineering Research Council of Canada, Tula Foundation, European Commission, Singh, Racquel A., Boscaro, Vittorio, James, Erick R., Karnkowska, Anna, Kolisko, Martin, Gavelis, Gregory S., Okamoto, Noriko, Campo, Javier del, Fiorito, Rebecca, Hehenberger, Elisabeth, Irwin, Nicholas A. T., Mathur, Varsha, Scheffrahn, Rudolf H., and Keeling, Patrick J.

Abstract

Cristamonadea is a large class of parabasalian protists that reside in the hindguts of wood-feeding insects, where they play an essential role in the digestion of lignocellulose. This group of symbionts boasts an impressive array of complex morphological characteristics, many of which have evolved multiple times independently. However, their diversity is understudied and molecular data remain scarce. Here we describe seven new species of cristamonad symbionts from Comatermes, Calcaritermes, and Rugitermes termites from Peru and Ecuador. To classify these new species, we examined cells by light and scanning electron microscopy, sequenced the symbiont small subunit ribosomal RNA (rRNA) genes, and carried out barcoding of the mitochondrial large subunit rRNA gene of the hosts to confirm host identification. Based on these data, five of the symbionts characterized here represent new species within described genera: Devescovina sapara n. sp., Devescovina aymara n. sp., Macrotrichomonas ashaninka n. sp., Macrotrichomonas secoya n. sp., and Macrotrichomonas yanesha n. sp. Additionally, two symbionts with overall morphological characteristics similar to the poorly-studied and probably polyphyletic ‘joeniid’ Parabasalia are classified in a new genus Runanympha n. gen.: Runanympha illapa n. sp., and Runanympha pacha n. sp.

Published
2021

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