1
|
Zheng P, Kumadaki K, Quek C, Lim ZH, Ashenafi Y, Yip ZT, Newby J, Alverson AJ, Jie Y, Jedd G. Cooperative motility, force generation and mechanosensing in a foraging non-photosynthetic diatom. Open Biol 2023; 13:230148. [PMID: 37788707 PMCID: PMC10547550 DOI: 10.1098/rsob.230148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 09/01/2023] [Indexed: 10/05/2023] Open
Abstract
Diatoms are ancestrally photosynthetic microalgae. However, some underwent a major evolutionary transition, losing photosynthesis to become obligate heterotrophs. The molecular and physiological basis for this transition is unclear. Here, we isolate and characterize new strains of non-photosynthetic diatoms from the coastal waters of Singapore. These diatoms occupy diverse ecological niches and display glucose-mediated catabolite repression, a classical feature of bacterial and fungal heterotrophs. Live-cell imaging reveals deposition of secreted extracellular polymeric substance (EPS). Diatoms moving on pre-existing EPS trails (runners) move faster than those laying new trails (blazers). This leads to cell-to-cell coupling where runners can push blazers to make them move faster. Calibrated micropipettes measure substantial single-cell pushing forces, which are consistent with high-order myosin motor cooperativity. Collisions that impede forward motion induce reversal, revealing navigation-related force sensing. Together, these data identify aspects of metabolism and motility that are likely to promote and underpin diatom heterotrophy.
Collapse
Affiliation(s)
- Peng Zheng
- Temasek Life Sciences Laboratory, 117604 Singapore
| | - Kayo Kumadaki
- Department of Physics, National University of Singapore, 117542 Singapore
- Mechanobiology Institute, National University of Singapore, 117411 Singapore
| | | | - Zeng Hao Lim
- Temasek Life Sciences Laboratory, 117604 Singapore
- Department of Biological Sciences, National University of Singapore, 117543 Singapore, Singapore
| | - Yonatan Ashenafi
- Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2G1
| | - Zhi Ting Yip
- Department of Biological Sciences, National University of Singapore, 117543 Singapore, Singapore
| | - Jay Newby
- Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2G1
| | - Andrew J. Alverson
- Department of Biological Sciences, University of Arkansas, SCEN 601, Fayetteville, AR 72701, USA
| | - Yan Jie
- Department of Physics, National University of Singapore, 117542 Singapore
- Mechanobiology Institute, National University of Singapore, 117411 Singapore
| | - Gregory Jedd
- Temasek Life Sciences Laboratory, 117604 Singapore
- Department of Biological Sciences, National University of Singapore, 117543 Singapore, Singapore
| |
Collapse
|
2
|
Genetic Diversity and Geographical Distribution of the Red Tide Species Coscinodiscus granii Revealed Using a High-Resolution Molecular Marker. Microorganisms 2022; 10:microorganisms10102028. [PMID: 36296304 PMCID: PMC9612147 DOI: 10.3390/microorganisms10102028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 09/28/2022] [Accepted: 10/05/2022] [Indexed: 11/07/2022] Open
Abstract
Diatoms are responsible for approximately 40% of the global primary photosynthetic production and account for up to 20% of global carbon fixation. Coscinodiscus granii is a red tide forming species of the phylum Bacillariophyta that has been detected in a wide range of coastal regions, suggesting the possibility of the existence of high genetic diversity with differential adaptation. Common molecular markers including 18S rDNA, 16S rDNA, ITS, cox1, and rbcL do not provide sufficient resolution for distinguishing intra-species genetic diversity, hindering in-depth research on intra-species genetic diversity and their spatial and temporal dynamics. In this project, we aimed to develop molecular markers with high resolution and specificity for C. granii, attempting to identify different taxa of this species, which will set up a stage for subsequent functional assays. Comparative genomics analysis of the mtDNAs of C. granii strains identified a genomic region with high genomic variations, which was used to guide the development of a molecular marker with high resolution and high specificity. This new molecular marker, which was named cgmt1 (C. granii mitochondrial 1), was 376 bp in size and differentiated C. granii samples collected in coastal regions of China into three different clades. Preliminary analysis of field samples collected in various coastal regions in China revealed that C. granii clades were almost exclusively found in the Bohai Sea and the north Yellow Sea. This newly developed molecular marker cgmt1 could be used for tracking intra-species genetic diversity and biogeographic distribution of C. granii in different ecosystems.
Collapse
|
3
|
Gene loss, pseudogenization, and independent genome reduction in non-photosynthetic species of Cryptomonas (Cryptophyceae) revealed by comparative nucleomorph genomics. BMC Biol 2022; 20:227. [PMID: 36209116 PMCID: PMC9548191 DOI: 10.1186/s12915-022-01429-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 09/30/2022] [Indexed: 11/30/2022] Open
Abstract
Background Cryptophytes are ecologically important algae of interest to evolutionary cell biologists because of the convoluted history of their plastids and nucleomorphs, which are derived from red algal secondary endosymbionts. To better understand the evolution of the cryptophyte nucleomorph, we sequenced nucleomorph genomes from two photosynthetic and two non-photosynthetic species in the genus Cryptomonas. We performed a comparative analysis of these four genomes and the previously published genome of the non-photosynthetic species Cryptomonas paramecium CCAP977/2a. Results All five nucleomorph genomes are similar in terms of their general architecture, gene content, and gene order and, in the non-photosynthetic strains, loss of photosynthesis-related genes. Interestingly, in terms of size and coding capacity, the nucleomorph genome of the non-photosynthetic species Cryptomonas sp. CCAC1634B is much more similar to that of the photosynthetic C. curvata species than to the non-photosynthetic species C. paramecium. Conclusions Our results reveal fine-scale nucleomorph genome variation between distantly related congeneric taxa containing photosynthetic and non-photosynthetic species, including recent pseudogene formation, and provide a first glimpse into the possible impacts of the loss of photosynthesis on nucleomorph genome coding capacity and structure in independently evolved colorless strains. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01429-6.
Collapse
|
4
|
Çiftçi O, Alverson AJ, van Bodegom P, Roberts WR, Mertens A, Van de Vijver B, Trobajo R, Mann DG, Pirovano W, van Eijk I, Gravendeel B. Phylotranscriptomics reveals the reticulate evolutionary history of a widespread diatom species complex. JOURNAL OF PHYCOLOGY 2022; 58:643-656. [PMID: 35861132 PMCID: PMC9804273 DOI: 10.1111/jpy.13281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 06/29/2022] [Indexed: 06/15/2023]
Abstract
In contrast to surveys based on a few genes that often provide limited taxonomic resolution, transcriptomes provide a wealth of genomic loci that can resolve relationships among taxonomically challenging lineages. Diatoms are a diverse group of aquatic microalgae that includes important bioindicator species and many such lineages. One example is Nitzschia palea, a widespread species complex with several morphologically defined taxonomic varieties, some of which are critical pollution indicators. Morphological differences among the varieties are subtle and phylogenetic studies based on a few genes fail to resolve their evolutionary relationships. We conducted morphometric and transcriptome analyses of 10 Nitzschia palea strains to resolve the relationships among strains and taxonomic varieties. Nitzschia palea was resolved into three clades, one of which corresponds to a group of strains with narrow linear-lanceolate valves. The other morphological group recovered in the shape outline analysis was not monophyletic and consisted of two clades. Gene-tree concordance analyses and phylogenetic network estimations revealed patterns of incomplete lineage sorting and gene flow between intraspecific lineages. We detected reticulated evolutionary patterns among lineages with different morphologies, resulting in a putative recent hybrid. Our study shows that phylogenomic analyses of unlinked nuclear loci, complemented with morphometrics, can resolve complex evolutionary histories of recently diverged species complexes.
Collapse
Affiliation(s)
- Ozan Çiftçi
- Institute of Environmental Sciences (CML)Leiden UniversityBox 95182300 RALeidenThe Netherlands
- Naturalis Biodiversity CenterDarwinweg 22333 CRLeidenThe Netherlands
- BaseClear B.VSylviusweg 742333 BELeidenthe Netherlands
| | - Andrew J. Alverson
- Department of Biological SciencesUniversity of Arkansas, 1 University of ArkansasFayettevilleArkansas72701USA
| | - Peter van Bodegom
- Institute of Environmental Sciences (CML)Leiden UniversityBox 95182300 RALeidenThe Netherlands
| | - Wade R. Roberts
- Department of Biological SciencesUniversity of Arkansas, 1 University of ArkansasFayettevilleArkansas72701USA
| | | | - Bart Van de Vijver
- Meise Botanic Garden Meise, Research DepartmentNieuwelaan 381860MeiseBelgium
- University of Antwerp, Department of Biology – ECOBEUniversiteitsplein 1B‐2610WilrijkBelgium
| | - Rosa Trobajo
- IRTA‐Institute for Food and Agricultural Research and Technology, Marine and Continental Waters ProgrammeCtra de Poble Nou Km 5.5, E43540, La RàpitaCataloniaSpain
| | - David G. Mann
- IRTA‐Institute for Food and Agricultural Research and Technology, Marine and Continental Waters ProgrammeCtra de Poble Nou Km 5.5, E43540, La RàpitaCataloniaSpain
- Royal Botanic Garden EdinburghEdinburghEH3 5LRScotlandUK
| | | | - Iris van Eijk
- Bayer Crop ScienceLeeuwenhoekweg 522661 CZBergschenhoekThe Netherlands
| | - Barbara Gravendeel
- Naturalis Biodiversity CenterDarwinweg 22333 CRLeidenThe Netherlands
- Radboud Institute for Biological and Environmental SciencesHeyendaalseweg 1356500 GLNijmegenThe Netherlands
| |
Collapse
|
5
|
Cahoon AB, VanGundy RD. Alveolates (dinoflagellates, ciliates and apicomplexans) and Rhizarians are the most common microbial eukaryotes in temperate Appalachian karst caves. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:538-548. [PMID: 35388620 PMCID: PMC9542216 DOI: 10.1111/1758-2229.13060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 03/02/2022] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
The purpose of this study was to survey the eukaryotic microbiome of two karst caves in the Valley and Ridge physiographic region of the Appalachian Mountains. Caves are known to harbour eukaryotic microbes but their very low densities and small cell size make them difficult to collect and identify. Microeukaryotes were surveyed using two methodologies, filtering water and submerging glass microscope slides mounted in periphytometers in cave pools. The periphyton sampling yielded 13.5 times more unique amplicon sequence variants (ASVs) than filtered water. The most abundant protist supergroup was Alveolata with large proportions of the ASVs belonging to dinoflagellate, ciliate and apicomplexan clades. The next most abundant were Rhizarians followed by Stramenopiles (diatoms and chrysophytes) and Ameobozoans. Very few of the ASVs, 1.5%, matched curated protist sequences with greater than 99% identity and only 2.5% could be identified from surface plankton samples collected in the same region. The overall composition of the eukaryotic microbiome appears to be a combination of bacterial grazers and parasitic species that could possibly survive underground as well as cells, cysts and spores probably transported from the surface.
Collapse
Affiliation(s)
- A. Bruce Cahoon
- Department of Natural SciencesThe University of Virginia's College at WiseWiseVA24293USA
| | - Robert D. VanGundy
- Department of Natural SciencesThe University of Virginia's College at WiseWiseVA24293USA
| |
Collapse
|
6
|
Liu S, Wang Y, Xu Q, Zhang M, Chen N. Comparative analysis of full-length mitochondrial genomes of five Skeletonema species reveals conserved genome organization and recent speciation. BMC Genomics 2021; 22:746. [PMID: 34654361 PMCID: PMC8520197 DOI: 10.1186/s12864-021-07999-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 09/03/2021] [Indexed: 12/05/2022] Open
Abstract
Background Skeletonema species are prominent primary producers, some of which can also cause massive harmful algal blooms (HABs) in coastal waters under specific environmental conditions. Nevertheless, genomic information of Skeletonema species is currently limited, hindering advanced research on their role as primary producers and as HAB species. Mitochondrial genome (mtDNA) has been extensively used as “super barcode” in the phylogenetic analyses and comparative genomic analyses. However, of the 21 accepted Skeletonema species, full-length mtDNAs are currently available only for a single species, S. marinoi. Results In this study, we constructed full-length mtDNAs for six strains of five Skeletonema species, including S. marinoi, S. tropicum, S. grevillei, S. pseudocostatum and S. costatum (with two strains), which were isolated from coastal waters in China. The mtDNAs of all of these Skeletonema species were compact with short intergenic regions, no introns, and no repeat regions. Comparative analyses of these Skeletonema mtDNAs revealed high conservation, with a few discrete regions of high variations, some of which could be used as molecular markers for distinguishing Skeletonema species and for tracking the biogeographic distribution of these species with high resolution and specificity. We estimated divergence times among these Skeletonema species using 34 mtDNAs genes with fossil data as calibration point in PAML, which revealed that the Skeletonema species formed the independent clade diverging from Thalassiosira species approximately 48.30 Mya. Conclusions The availability of mtDNAs of five Skeletonema species provided valuable reference sequences for further evolutionary studies including speciation time estimation and comparative genomic analysis among diatom species. Divergent regions could be used as molecular markers for tracking different Skeletonema species in the fields of coastal regions. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07999-z.
Collapse
Affiliation(s)
- Shuya Liu
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 266071, Qingdao, China.,Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Yichao Wang
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 266071, Qingdao, China.,Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China.,University of Chinese Academy of Sciences, Beijing, 10039, China
| | - Qing Xu
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 266071, Qingdao, China.,Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China.,College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Mengjia Zhang
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 266071, Qingdao, China.,Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China.,University of Chinese Academy of Sciences, Beijing, 10039, China
| | - Nansheng Chen
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 266071, Qingdao, China. .,Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China. .,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China. .,Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, V5A 1S6, Canada.
| |
Collapse
|
7
|
Zhang M, Cui Z, Liu F, Chen N. Definition of a High-Resolution Molecular Marker for Tracking the Genetic Diversity of the Harmful Algal Species Eucampia zodiacus Through Comparative Analysis of Mitochondrial Genomes. Front Microbiol 2021; 12:631144. [PMID: 33841358 PMCID: PMC8024477 DOI: 10.3389/fmicb.2021.631144] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 02/23/2021] [Indexed: 11/13/2022] Open
Abstract
The cosmopolitan phytoplankton species Eucampia zodiacus is a common harmful algal bloom (HAB) species that have been found to cause HABs in essentially all coastal regions except the Polar regions. However, molecular information for this HAB species is limited with only a few molecular markers. In this project, we constructed the mitochondrial genome (mtDNA) of E. zodiacus, which was also the first mtDNA constructed for any species in the order Hemiaulales that includes 145 reported species (including two additional HAB species Cerataulina bicornis and Cerataulina pelagica). Comparative analysis of eight E. zodiacus strains revealed that they could not be distinguished using common molecular markers, suggesting that common molecular markers do not have adequate resolution for distinguishing E. zodiacus strains. However, these E. zodiacus strains could be distinguished using whole mtDNAs, suggesting the presence of different genotypes due to evolutionary divergence. Through comparative analysis of the mtDNAs of multiple E. zodiacus strains, we identified a new molecular marker ezmt1 that could adequately distinguish different E. zodiacus strains isolated in various coastal regions in China. This molecular marker ezmt1, which was ∼400 bp in size, could be applied to identify causative genotypes during E. zodiacus HABs through tracking the dynamic changes of genetic diversity of E. zodiacus in HABs.
Collapse
Affiliation(s)
- Mengjia Zhang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Institute of Oceanology, University of Chinese Academy of Sciences, Beijing, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Zongmei Cui
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Institute of Oceanology, University of Chinese Academy of Sciences, Beijing, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Feng Liu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Nansheng Chen
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.,Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| |
Collapse
|
8
|
Tanifuji G, Kamikawa R, Moore CE, Mills T, Onodera NT, Kashiyama Y, Archibald JM, Inagaki Y, Hashimoto T. Comparative Plastid Genomics of Cryptomonas Species Reveals Fine-Scale Genomic Responses to Loss of Photosynthesis. Genome Biol Evol 2020; 12:3926-3937. [PMID: 31922581 PMCID: PMC7058160 DOI: 10.1093/gbe/evaa001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2020] [Indexed: 01/20/2023] Open
Abstract
Loss of photosynthesis is a recurring theme in eukaryotic evolution. In organisms that have lost the ability to photosynthesize, nonphotosynthetic plastids are retained because they play essential roles in processes other than photosynthesis. The unicellular algal genus Cryptomonas contains both photosynthetic and nonphotosynthetic members, the latter having lost the ability to photosynthesize on at least three separate occasions. To elucidate the evolutionary processes underlying the loss of photosynthesis, we sequenced the plastid genomes of two nonphotosynthetic strains, Cryptomonas sp. CCAC1634B and SAG977-2f, as well as the genome of the phototroph Cryptomonas curvata CCAP979/52. These three genome sequences were compared with the previously sequenced plastid genome of the nonphotosynthetic species Cryptomonas paramecium CCAP977/2a as well as photosynthetic members of the Cryptomonadales, including C. curvata FBCC300012D. Intraspecies comparison between the two C. curvata strains showed that although their genome structures are stable, the substitution rates of their genes are relatively high. Although most photosynthesis-related genes, such as the psa and psb gene families, were found to have disappeared from the nonphotosynthetic strains, at least ten pseudogenes are retained in SAG977-2f. Although gene order is roughly shared among the plastid genomes of photosynthetic Cryptomonadales, genome rearrangements are seen more frequently in the smaller genomes of the nonphotosynthetic strains. Intriguingly, the light-independent protochlorophyllide reductase comprising chlB, L, and N is retained in nonphotosynthetic SAG977-2f and CCAC1634B. On the other hand, whereas CCAP977/2a retains ribulose-1,5-bisphosphate carboxylase/oxygenase-related genes, including rbcL, rbcS, and cbbX, the plastid genomes of the other two nonphotosynthetic strains have lost the ribulose-1,5-bisphosphate carboxylase/oxygenase protein-coding genes.
Collapse
Affiliation(s)
- Goro Tanifuji
- Department of Zoology, National Museum of Nature and Science, Ibaraki, Japan
| | - Ryoma Kamikawa
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Christa E Moore
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Tyler Mills
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Naoko T Onodera
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Yuichiro Kashiyama
- Department of Applied Chemistry and Food Science, Fukui University of Technology, Fukui, Japan
| | - John M Archibald
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Yuji Inagaki
- Center for Computational Sciences, University of Tsukuba, Ibaraki, Japan.,Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan
| | - Tetsuo Hashimoto
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan
| |
Collapse
|
9
|
Substrate specificity of plastid phosphate transporters in a non-photosynthetic diatom and its implication in evolution of red alga-derived complex plastids. Sci Rep 2020; 10:1167. [PMID: 31980711 PMCID: PMC6981301 DOI: 10.1038/s41598-020-58082-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/07/2020] [Indexed: 02/07/2023] Open
Abstract
The triose phosphate transporter (TPT) is one of the prerequisites to exchange metabolites between the cytosol and plastids. In this study, we demonstrated that the four plastid TPT homologues in the non-photosynthetic diatom Nitzschia sp. NIES-3581 were highly likely integrated into plastid envelope membranes similar to counterparts in the model photosynthetic diatom Phaeodactylum tricornutum, in terms of target membranes and C-terminal orientations. Three of the four Nitzschia TPT homologues are capable of transporting various metabolites into proteo-liposomes including triose phosphates (TPs) and phosphoenolpyruvate (PEP), the transport substrates sufficient to support the metabolic pathways retained in the non-photosynthetic diatom plastid. Phylogenetic analysis of TPTs and closely related transporter proteins indicated that diatoms and other algae with red alga-derived complex plastids possess only TPT homologues but lack homologues of the glucose 6-phosphate transporter (GPT), xylulose 5-phosphate transporter (XPT), and phosphoenolpyruvate transporter (PPT). Comparative sequence analysis suggests that many TPT homologues of red alga-derived complex plastids potentially have the ability to transport mainly TPs and PEP. TPTs transporting both TPs and PEP highly likely mediate a metabolic crosstalk between a red alga-derived complex plastid and the cytosol in photosynthetic and non-photosynthetic species, which explains the lack of PPTs in all the lineages with red alga-derived complex plastids. The PEP-transporting TPTs might have emerged in an early phase of endosymbiosis between a red alga and a eukaryote host, given the broad distribution of that type of transporters in all branches of red alga-derived complex plastid-bearing lineages, and have probably played a key role in the establishment and retention of a controllable, intracellular metabolic connection in those organisms.
Collapse
|
10
|
Kayama M, Maciszewski K, Yabuki A, Miyashita H, Karnkowska A, Kamikawa R. Highly Reduced Plastid Genomes of the Non-photosynthetic Dictyochophyceans Pteridomonas spp. (Ochrophyta, SAR) Are Retained for tRNA-Glu-Based Organellar Heme Biosynthesis. FRONTIERS IN PLANT SCIENCE 2020; 11:602455. [PMID: 33329672 PMCID: PMC7728698 DOI: 10.3389/fpls.2020.602455] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 11/03/2020] [Indexed: 05/05/2023]
Abstract
Organisms that have lost their photosynthetic capabilities are present in a variety of eukaryotic lineages, such as plants and disparate algal groups. Most of such non-photosynthetic eukaryotes still carry plastids, as these organelles retain essential biological functions. Most non-photosynthetic plastids possess genomes with varied protein-coding contents. Such remnant plastids are known to be present in the non-photosynthetic, bacteriovorous alga Pteridomonas danica (Dictyochophyceae, Ochrophyta), which, regardless of its obligatory heterotrophic lifestyle, has been reported to retain the typically plastid-encoded gene for ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) large subunit (rbcL). The presence of rbcL without photosynthetic activity suggests that investigating the function of plastids in Pteridomonas spp. would likely bring unique insights into understanding the reductive evolution of plastids, their genomes, and plastid functions retained after the loss of photosynthesis. In this study, we demonstrate that two newly established strains of the non-photosynthetic genus Pteridomonas possess highly reduced plastid genomes lacking rbcL gene, in contrast to the previous report. Interestingly, we discovered that all plastid-encoded proteins in Pteridomonas spp. are involved only in housekeeping processes (e.g., transcription, translation and protein degradation), indicating that all metabolite synthesis pathways in their plastids are supported fully by nuclear genome-encoded proteins. Moreover, through an in-depth survey of the available transcriptomic data of another strain of the genus, we detected no candidate sequences for nuclear-encoded, plastid-directed Fe-S cluster assembly pathway proteins, suggesting complete loss of this pathway in the organelle, despite its widespread conservation in non-photosynthetic plastids. Instead, the transcriptome contains plastid-targeted components of heme biosynthesis, glycolysis, and pentose phosphate pathways. The retention of the plastid genomes in Pteridomonas spp. is not explained by the Suf-mediated constraint against loss of plastid genomes, previously proposed for Alveolates, as they lack Suf genes. Bearing all these findings in mind, we propose the hypothesis that plastid DNA is retained in Pteridomonas spp. for the purpose of providing glutamyl-tRNA, encoded by trnE gene, as a substrate for the heme biosynthesis pathway.
Collapse
Affiliation(s)
- Motoki Kayama
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Kacper Maciszewski
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Akinori Yabuki
- Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan
| | - Hideaki Miyashita
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Anna Karnkowska
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
- *Correspondence: Anna Karnkowska,
| | - Ryoma Kamikawa
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- Ryoma Kamikawa,
| |
Collapse
|
11
|
Kim JI, Jeong M, Archibald JM, Shin W. Comparative Plastid Genomics of Non-Photosynthetic Chrysophytes: Genome Reduction and Compaction. FRONTIERS IN PLANT SCIENCE 2020; 11:572703. [PMID: 33013997 PMCID: PMC7511666 DOI: 10.3389/fpls.2020.572703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/24/2020] [Indexed: 05/11/2023]
Abstract
Spumella-like heterotrophic chrysophytes are important eukaryotic microorganisms that feed on bacteria in aquatic and soil environments. They are characterized by their lack of pigmentation, naked cell surface, and extremely small size. Although Spumella-like chrysophytes have lost their photosynthetic ability, they still possess a leucoplast and retain a plastid genome. We have sequenced the plastid genomes of three non-photosynthetic chrysophytes, Spumella sp. Baeckdong012018B8, Pedospumella sp. Jangsampo120217C5 and Poteriospumella lacustris Yongseonkyo072317C3, and compared them to the previously sequenced plastid genome of "Spumella" sp. NIES-1846 and photosynthetic chrysophytes. We found the plastid genomes of Spumella-like flagellates to be generally conserved with respect to genome structure and housekeeping gene content. We nevertheless also observed lineage-specific gene rearrangements and duplication of partial gene fragments at the boundary of the inverted repeat and single copy regions. Most gene losses correspond to genes for proteins involved in photosynthesis and carbon fixation, except in the case of petF. The newly sequenced plastid genomes range from ~55.7 kbp to ~62.9 kbp in size and share a core set of 45 protein-coding genes, 3 rRNAs, and 32 to 34 tRNAs. Our results provide insight into the evolutionary history of organelle genomes via genome reduction and gene loss related to loss of photosynthesis in chrysophyte evolution.
Collapse
Affiliation(s)
- Jong Im Kim
- Department of Biology, Chungnam National University, Daejeon, South Korea
| | - Minseok Jeong
- Department of Biology, Chungnam National University, Daejeon, South Korea
| | - John M. Archibald
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Woongghi Shin
- Department of Biology, Chungnam National University, Daejeon, South Korea
- *Correspondence: Woongghi Shin,
| |
Collapse
|
12
|
Jirsová D, Füssy Z, Richtová J, Gruber A, Oborník M. Morphology, Ultrastructure, and Mitochondrial Genome of the Marine Non-Photosynthetic Bicosoecid Cafileria marina Gen. et sp. nov. Microorganisms 2019; 7:microorganisms7080240. [PMID: 31387253 PMCID: PMC6723347 DOI: 10.3390/microorganisms7080240] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 07/25/2019] [Accepted: 08/01/2019] [Indexed: 12/16/2022] Open
Abstract
In this paper, we describe a novel bacteriophagous biflagellate, Cafileria marina with two smooth flagellae, isolated from material collected from a rock surface in the Kvernesfjorden (Norway). This flagellate was characterized by scanning and transmission electron microscopy, fluorescence, and light microscopy. The sequence of the small subunit ribosomal RNA gene (18S) was used as a molecular marker for determining the phylogenetic position of this organism. Apart from the nuclear ribosomal gene, the whole mitochondrial genome was sequenced, assembled, and annotated. Morphological observations show that the newly described flagellate shares key ultrastructural characters with representatives of the family Bicosoecida (Heterokonta). Intriguingly, mitochondria of C. marina frequently associate with its nucleus through an electron-dense disc at the boundary of the two compartments. The function of this association remains unclear. Phylogenetic analyses corroborate the morphological data and place C. marina with other sequence data of representatives from the family Bicosoecida. We describe C. marina as a new species from a new genus in this family.
Collapse
Affiliation(s)
- Dagmar Jirsová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Zoltán Füssy
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Jitka Richtová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Ansgar Gruber
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Miroslav Oborník
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic.
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic.
| |
Collapse
|
13
|
Crowell RM, Nienow JA, Cahoon AB. The complete chloroplast and mitochondrial genomes of the diatom Nitzschia palea (Bacillariophyceae) demonstrate high sequence similarity to the endosymbiont organelles of the dinotom Durinskia baltica. JOURNAL OF PHYCOLOGY 2019; 55:352-364. [PMID: 30536677 DOI: 10.1111/jpy.12824] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 11/07/2018] [Indexed: 06/09/2023]
Abstract
Nitzschia palea is a common freshwater diatom used as a bioindicator because of its tolerance of polluted waterways. There is also evidence it may be the tertiary endosymbiont within the "dinotom" dinoflagellate Durinskia baltica. A putative strain of N. palea was collected from a pond on the University of Virginia's College at Wise campus and cultured. For initial identification, three markers were sequenced-nuclear 18S rDNA, the chloroplast 23S rDNA, and rbcL. Morphological characteristics were determined using light and scanning electron microscopy; based on these observations the cells were identified as N. palea and named strain "Wise." DNA from N. palea was deep sequenced and the chloroplast and mitochondrial genomes assembled. Single gene phylogenies grouped N. palea-Wise within a clearly defined N. palea clade and showed it was most closely related to the strain "SpainA3." The chloroplast genome of N. palea is 119,447 bp with a quadripartite structure, 135 protein-coding, 28 tRNA, and 3 rRNA genes. The mitochondrial genome is 37,754 bp with a single repeat region as found in other diatom chondriomes, 37 protein-coding, 23 tRNA, and 2 rRNA genes. The chloroplast genomes of N. palea and D. baltica have identical gene content, synteny, and a 92.7% pair-wise sequence similarity with most differences occurring in intergenic regions. The N. palea mitochondrial genome and D. baltica's endosymbiont mitochondrial genome also have identical gene content and order with a sequence similarity of 90.7%. Genome-based phylogenies demonstrated that D. baltica is more similar to N. palea than any other diatom sequence currently available. These data provide the genome sequences of two organelles for a widespread diatom and show they are very similar to those of Durinskia baltica's endosymbiont.
Collapse
Affiliation(s)
- Roseanna M Crowell
- Department of Natural Sciences, University of Virginia's College at Wise, Wise, Virginia, 24293, USA
| | - James A Nienow
- Department of Biology, Valdosta State University, Valdosta, Georgia, 31698, USA
| | - Aubrey Bruce Cahoon
- Department of Natural Sciences, University of Virginia's College at Wise, Wise, Virginia, 24293, USA
| |
Collapse
|