Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Endosymbiotic Evolution of Algae, Secondary Heterotrophy and Parasitism.

ABSTRACT: Photosynthesis is a biochemical process essential for life, serving as the ultimate source of chemical energy for phototrophic and heterotrophic life forms. Since the machinery of the photosynthetic electron transport chain is quite complex and is unlikely to have evolved multiple independent times, it is believed that this machinery has been transferred to diverse eukaryotic organisms by endosymbiotic events involving a eukaryotic host and a phototrophic endosymbiont. Thus, photoautotrophy, as a benefit, is transmitted through the evolution of plastids. However, many eukaryotes became secondarily heterotrophic, reverting to hetero-osmotrophy, phagotrophy, or parasitism. Here, I briefly review the constructive evolution of plastid endosymbioses and the consequential switch to reductive evolution involving losses of photosynthesis and plastids and the evolution of parasitism from a photosynthetic ancestor.

SUBMITTER: Obornik M

PROVIDER: S-EPMC6681372 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Endosymbiotic Evolution of Algae, Secondary Heterotrophy and Parasitism.

Oborník Miroslav M

Biomolecules 20190708 7

Photosynthesis is a biochemical process essential for life, serving as the ultimate source of chemical energy for phototrophic and heterotrophic life forms. Since the machinery of the photosynthetic electron transport chain is quite complex and is unlikely to have evolved multiple independent times, it is believed that this machinery has been transferred to diverse eukaryotic organisms by endosymbiotic events involving a eukaryotic host and a phototrophic endosymbiont. Thus, photoautotrophy, as ...[more]

PMID: 31288476

Similar Datasets

The complete mitochondrial genome of a transitional form in secondary endosymbiotic Cryptophyte algae <i>Guillardia theta</i> strain CCMP2712.

Project description:The complete mitochondrial genome of Guillardia theta strain CCMP2712 was sequenced, assembled, and annotated in this study. The circular genome is 35,013 bp in size and it contains 36 protein-coding genes (PCGs), 28 transfer RNA genes (tRNA), and 2 ribosomal RNA genes (rRNA). The overall GC contents of the mitochondrial genome are 28.9%. The phylogenetic tree was constructed to validate the taxonomic relationship based on the complete mitogenomes of G. theta strain CCMP2712 through combining with seven Cryptophyta and four Heterokontophyta algae. The complete mitochondrial genome of the Guillardia theta strain CCMP2712 will provide more information for the evolution of secondary endosymbiotic species.

| S-EPMC7871985 | biostudies-literature

Signatures of Transcription Factor Evolution and the Secondary Gain of Red Algae Complexity.

Project description:Red algae (Rhodophyta) belong to the superphylum Archaeplastida, and are a species-rich group exhibiting diverse morphologies. Theory has it that the unicellular red algal ancestor went through a phase of genome contraction caused by adaptation to extreme environments. More recently, the classes Porphyridiophyceae, Bangiophyceae, and Florideophyceae experienced genome expansions, coinciding with an increase in morphological complexity. Transcription-associated proteins (TAPs) regulate transcription, show lineage-specific patterns, and are related to organismal complexity. To better understand red algal TAP complexity and evolution, we investigated the TAP family complement of uni- and multi-cellular red algae. We found that the TAP family complement correlates with gain of morphological complexity in the multicellular Bangiophyceae and Florideophyceae, and that abundance of the C2H2 zinc finger transcription factor family may be associated with the acquisition of morphological complexity. An expansion of heat shock transcription factors (HSF) occurred within the unicellular Cyanidiales, potentially as an adaption to extreme environmental conditions.

| S-EPMC8304369 | biostudies-literature

Evolution of the Tetrapyrrole Biosynthetic Pathway in Secondary Algae: Conservation, Redundancy and Replacement.

Project description:Tetrapyrroles such as chlorophyll and heme are indispensable for life because they are involved in energy fixation and consumption, i.e. photosynthesis and oxidative phosphorylation. In eukaryotes, the tetrapyrrole biosynthetic pathway is shaped by past endosymbioses. We investigated the origins and predicted locations of the enzymes of the heme pathway in the chlorarachniophyte Bigelowiella natans, the cryptophyte Guillardia theta, the "green" dinoflagellate Lepidodinium chlorophorum, and three dinoflagellates with diatom endosymbionts ("dinotoms"): Durinskia baltica, Glenodinium foliaceum and Kryptoperidinium foliaceum. Bigelowiella natans appears to contain two separate heme pathways analogous to those found in Euglena gracilis; one is predicted to be mitochondrial-cytosolic, while the second is predicted to be plastid-located. In the remaining algae, only plastid-type tetrapyrrole synthesis is present, with a single remnant of the mitochondrial-cytosolic pathway, a ferrochelatase of G. theta putatively located in the mitochondrion. The green dinoflagellate contains a single pathway composed of mostly rhodophyte-origin enzymes, and the dinotoms hold two heme pathways of apparently plastidal origin. We suggest that heme pathway enzymes in B. natans and L. chlorophorum share a predominantly rhodophytic origin. This implies the ancient presence of a rhodophyte-derived plastid in the chlorarachniophyte alga, analogous to the green dinoflagellate, or an exceptionally massive horizontal gene transfer.

| S-EPMC5115734 | biostudies-literature

Evolution of heterotrophy in chrysophytes as reflected by comparative transcriptomics.

Project description:Shifts in the nutritional mode between phototrophy, mixotrophy and heterotrophy are a widespread phenomenon in the evolution of eukaryotic diversity. The transition between nutritional modes is particularly pronounced in chrysophytes and occurred independently several times through parallel evolution. Thus, chrysophytes provide a unique opportunity for studying the molecular basis of nutritional diversification and of the accompanying pathway reduction and degradation of plastid structures. In order to analyze the succession in switching the nutritional mode from mixotrophy to heterotrophy, we compared the transcriptome of the mixotrophic Poterioochromonas malhamensis with the transcriptomes of three obligate heterotrophic species of Ochromonadales. We used the transcriptome of P. malhamensis as a reference for plastid reduction in the heterotrophic taxa. The analyzed heterotrophic taxa were in different stages of plastid reduction. We investigated the reduction of several photosynthesis related pathways e.g. the xanthophyll cycle, the mevalonate pathway, the shikimate pathway and the tryptophan biosynthesis as well as the reduction of plastid structures and postulate a presumable succession of pathway reduction and degradation of accompanying structures.

| S-EPMC6019013 | biostudies-literature

Gene gain facilitated endosymbiotic evolution of Chlamydiae.

Project description:Chlamydiae is a bacterial phylum composed of obligate animal and protist endosymbionts. However, other members of the Planctomycetes-Verrucomicrobia-Chlamydiae superphylum are primarily free living. How Chlamydiae transitioned to an endosymbiotic lifestyle is still largely unresolved. Here we reconstructed Planctomycetes-Verrucomicrobia-Chlamydiae species relationships and modelled superphylum genome evolution. Gene content reconstruction from 11,996 gene families suggests a motile and facultatively anaerobic last common Chlamydiae ancestor that had already gained characteristic endosymbiont genes. Counter to expectations for genome streamlining in strict endosymbionts, we detected substantial gene gain within Chlamydiae. We found that divergence in energy metabolism and aerobiosis observed in extant lineages emerged later during chlamydial evolution. In particular, metabolic and aerobic genes characteristic of the more metabolically versatile protist-infecting chlamydiae were gained, such as respiratory chain complexes. Our results show that metabolic complexity can increase during endosymbiont evolution, adding an additional perspective for understanding symbiont evolutionary trajectories across the tree of life.

| S-EPMC9816063 | biostudies-literature

Accelerated evolution and Muller's rachet in endosymbiotic bacteria.

Project description:Many bacteria live only within animal cells and infect hosts through cytoplasmic inheritance. These endosymbiotic lineages show distinctive population structure, with small population size and effectively no recombination. As a result, endosymbionts are expected to accumulate mildly deleterious mutations. If these constitute a substantial proportion of new mutations, endosymbionts will show (i) faster sequence evolution and (ii) a possible shift in base composition reflecting mutational bias. Analyses of 16S rDNA of five independently derived endosymbiont clades show, in every case, faster evolution in endosymbionts than in free-living relatives. For aphid endosymbionts (genus Buchnera), coding genes exhibit accelerated evolution and unusually low ratios of synonymous to nonsynonymous substitutions compared to ratios for the same genes for enterics. This concentration of the rate increase in nonsynonymous substitutions is expected under the hypothesis of increased fixation of deleterious mutations. Polypeptides for all Buchnera genes analyzed have accumulated amino acids with codon families rich in A+T, supporting the hypothesis that substitutions are deleterious in terms of polypeptide function. These observations are best explained as the result of Muller's ratchet within small asexual populations, combined with mutational bias. In light of this explanation, two observations reported earlier for Buchnera, the apparent loss of a repair gene and the overproduction of a chaperonin, may reflect compensatory evolution. An alternative hypothesis, involving selection on genomic base composition, is contradicted by the observation that the speedup is concentrated at nonsynonymous sites.

| S-EPMC39726 | biostudies-other

Comparative genomics of mitochondria in chlorarachniophyte algae: endosymbiotic gene transfer and organellar genome dynamics.

Project description:Chlorarachniophyte algae possess four DNA-containing compartments per cell, the nucleus, mitochondrion, plastid and nucleomorph, the latter being a relic nucleus derived from a secondary endosymbiont. While the evolutionary dynamics of plastid and nucleomorph genomes have been investigated, a comparative investigation of mitochondrial genomes (mtDNAs) has not been carried out. We have sequenced the complete mtDNA of Lotharella oceanica and compared it to that of another chlorarachniophyte, Bigelowiella natans. The linear mtDNA of L. oceanica is 36.7 kbp in size and contains 35 protein genes, three rRNAs and 24 tRNAs. The codons GUG and UUG appear to be capable of acting as initiation codons in the chlorarachniophyte mtDNAs, in addition to AUG. Rpl16, rps4 and atp8 genes are missing in L.oceanica mtDNA, despite being present in B. natans mtDNA. We searched for, and found, mitochondrial rpl16 and rps4 genes with spliceosomal introns in the L. oceanica nuclear genome, indicating that mitochondrion-to-host-nucleus gene transfer occurred after the divergence of these two genera. Despite being of similar size and coding capacity, the level of synteny between L. oceanica and B. natans mtDNA is low, suggesting frequent rearrangements. Overall, our results suggest that chlorarachniophyte mtDNAs are more evolutionarily dynamic than their plastid counterparts.

| S-EPMC4757882 | biostudies-literature

Cytoklepty in the plankton: a host strategy to optimize the bioenergetic machinery of endosymbiotic algae

Project description: Not available

| EMPIAR-10672 | biostudies-other

Comparative rates of evolution in endosymbiotic nuclear genomes.

Project description:BackgroundThe nucleomorphs associated with secondary plastids of cryptomonads and chlorarachniophytes are the sole examples of organelles with eukaryotic nuclear genomes. Although not as widespread as their prokaryotic equivalents in mitochondria and plastids, nucleomorph genomes share similarities in terms of reduction and compaction. They also differ in several aspects, not least in that they encode proteins that target to the plastid, and so function in a different compartment from that in which they are encoded.ResultsHere, we test whether the phylogenetically distinct nucleomorph genomes of the cryptomonad, Guillardia theta, and the chlorarachniophyte, Bigelowiella natans, have experienced similar evolutionary pressures during their transformation to reduced organelles. We compared the evolutionary rates of genes from nuclear, nucleomorph, and plastid genomes, all of which encode proteins that function in the same cellular compartment, the plastid, and are thus subject to similar selection pressures. Furthermore, we investigated the divergence of nucleomorphs within cryptomonads by comparing G. theta and Rhodomonas salina.ConclusionChlorarachniophyte nucleomorph genes have accumulated errors at a faster rate than other genomes within the same cell, regardless of the compartment where the gene product functions. In contrast, most nucleomorph genes in cryptomonads have evolved faster than genes in other genomes on average, but genes for plastid-targeted proteins are not overly divergent, and it appears that cryptomonad nucleomorphs are not presently evolving rapidly and have therefore stabilized. Overall, these analyses suggest that the forces at work in the two lineages are different, despite the similarities between the structures of their genomes.

| S-EPMC1523203 | biostudies-literature

Evolution of spliceosomal introns following endosymbiotic gene transfer.

Project description:BackgroundSpliceosomal introns are an ancient, widespread hallmark of eukaryotic genomes. Despite much research, many questions regarding the origin and evolution of spliceosomal introns remain unsolved, partly due to the difficulty of inferring ancestral gene structures. We circumvent this problem by using genes originated by endosymbiotic gene transfer, in which an intron-less structure at the time of the transfer can be assumed.ResultsBy comparing the exon-intron structures of 64 mitochondrial-derived genes that were transferred to the nucleus at different evolutionary periods, we can trace the history of intron gains in different eukaryotic lineages. Our results show that the intron density of genes transferred relatively recently to the nuclear genome is similar to that of genes originated by more ancient transfers, indicating that gene structure can be rapidly shaped by intron gain after the integration of the gene into the genome and that this process is mainly determined by forces acting specifically on each lineage. We analyze 12 cases of mitochondrial-derived genes that have been transferred to the nucleus independently in more than one lineage.ConclusionsRemarkably, the proportion of shared intron positions that were gained independently in homologous genes is similar to that proportion observed in genes that were transferred prior to the speciation event and whose shared intron positions might be due to vertical inheritance. A particular case of parallel intron gain in the nad7 gene is discussed in more detail.

| S-EPMC2834692 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data