Mitochondrial Genome of a Tertiary Endosymbiont Retains Genes for Electron Transport Proteins

@article{Imanian2007MitochondrialGO,
  title={Mitochondrial Genome of a Tertiary Endosymbiont Retains Genes for Electron Transport Proteins},
  author={Behzad Imanian and Kevin J. Carpenter and Patrick J. Keeling},
  journal={Journal of Eukaryotic Microbiology},
  year={2007},
  volume={54}
}
ABSTRACT. Mitochondria and plastids originated through endosymbiosis, and subsequently became reduced and integrated with the host in similar ways. Plastids spread between lineages through further secondary or even tertiary endosymbioses, but mitochondria appear to have originated once and have not spread between lineages. Mitochondria are also generally lost in secondary and tertiary endosymbionts, with the single exception of the diatom tertiary endosymbiont of dinoflagellates like… 

The dinoflagellates Durinskia baltica and Kryptoperidinium foliaceum retain functionally overlapping mitochondria from two evolutionarily distinct lineages

It is shown that both host and endosymbiont mitochondrial genomes encode genes for electron transport proteins, and that all genes are transcribed and that those ascribed to the host mitochondrial genome are extensively edited at the RNA level, as expected for a dinoflagellate mitochondrion-encoded gene.

Tertiary Endosymbiosis in Two Dinotoms Has Generated Little Change in the Mitochondrial Genomes of Their Dinoflagellate Hosts and Diatom Endosymbionts

Overall, the endosymbiont and host mitochondrial genomes in the two dinotoms have changed surprisingly little from those of free-living diatoms and dinoflagellates, irrespective of their long coexistence side by side in dinotom.

Endosymbiotic Gene Transfer in Tertiary Plastid-Containing Dinoflagellates

Low level of detectable EGT in both dinoflagellate lineages is found, with only 9 genes and 90 genes of possible tertiary endosymbiotic origin in dinotoms and kareniaceans, respectively, suggesting that tertiary endsymbioses did not heavily impact the host din oflageLLate genomes.

Horizontal Gene Transfer and Redundancy of Tryptophan Biosynthetic Enzymes in Dinotoms

Investigation of transcription of genes involved in biosynthesis of the amino acid tryptophan in three species finds that cells with a unique nuclear and mitochondrial redundancy derived from two evolutionarily distinct eukaryotic lineages retain redundant sets of transcripts and likely metabolic pathways for theynthesis of small molecules and extend their redundancy to their two distinct nuclear genomes.

Functional Relationship between a Dinoflagellate Host and Its Diatom Endosymbiont.

Deep sequencing of both the host and endosymbiont transcriptomes from two dinotoms showed little or no functional reduction in either the endosYmbionT or host, and no evidence for genetic integration.

2 . 1 Modern-Day Plastids and Their Genomes

This chapter provides an overview of the origin and diversification of plastids across the eukaryotic tree of life, an area of basic research that has benefited tremendously from advances in genomics and molecular biology.

Chapter 2 Plastid Origins

This chapter provides an overview of the origin and diversification of plastids across the eukaryotic tree of life, an area of basic research that has benefited tremendously from advances in genomics and molecular biology.

Plastid Origins

This chapter provides an overview of the origin and diversification of plastids across the eukaryotic tree of life, an area of basic research that has benefited tremendously from advances in genomics and molecular biology.

References

SHOWING 1-10 OF 60 REFERENCES

HSP90, Tubulin and Actin are Retained in the Tertiary Endosymbiont Genome of Kryptoperidinium foliaceum

The first protein-coding gene sequences from the K. foliaceum endosymbiont and host nuclear genomes are reported, raising the interesting question of whether any genes have transferred between the two nuclear genomes.

Complete nucleotide sequence of the chlorarachniophyte nucleomorph: nature's smallest nucleus.

Although originating by two independent endosymbioses, chlorarachniophyte and cryptomonad nucleomorph genomes have converged upon remarkably similar architectures but differ in many molecular details that reflect two distinct trajectories to hypercompaction and reduction.

Ribosomal RNA Analysis Indicates a Benthic Pennate Diatom Ancestry for the Endosymbionts of the Dinoflagellates Peridinium foliaceum and Peridinium balticum (Pyrrhophyta)

This study has examined the phylogenetic origin of the P. foliaceum and P. Balticum heterokont endosymbionts through analaysis of their nuclear small subunit ribosomal RNA genes, and clearly demonstrates both endosYmbiont are pennate diatoms belonging to the family Bacillariaceae.

IDENTITY OF THE ENDOSYMBIONT OF PERIDINIUM FOLIACEUM (PYRROPHYTA): ANALYSIS OF THE rbcLS OPERON 1

The data strongly suggest that the P. foliaceum symbiont originated from a photosynthetic diatom, which would provide a free‐living model system with which the photosynthetics of other algal species could be compared.

Nuclear-encoded, plastid-targeted genes suggest a single common origin for apicomplexan and dinoflagellate plastids.

Results address several outstanding issues and indicate that apicomplexan and dinoflagellate plastids appear to be the result of a single endosymbiotic event which occurred relatively early in eukaryotic evolution, also giving rise to the plastid-targeted GAPDH genes of heterokonts and cryptomonads.

PRIMARY AND SECONDARY ENDOSYMBIOSIS AND THE ORIGIN OF PLASTIDS

The theory of endosymbiosis describes the origin of plastids from cyanobacterial‐like prokaryotes living within eukaryotic host cells, and morphological, biochemical, and molecular studies provide clear evidence of a proKaryotic ancestry for plastid ancestry.

A mitochondrial remnant in the microsporidian Trachipleistophora hominis

It is shown that a highly specific antibody raised against a Trachipleistophora hominis Hsp70 protein detects the presence of numerous tiny organelles with double membranes in this human microsporidial parasite, providing further evidence of the reluctance of eukaryotes to lose the mitochondrial organelle, even when its canonical function of aerobic respiration has been apparently lost.

Photosynthetic eukaryotes unite: endosymbiosis connects the dots.

Algal diversity is examined and endosymbiosis is shown to be a major force in algal evolution, with long-standing issues such as the chromalveolate hypothesis and the extent of endOSymbiotic gene transfer clarified.

THE SYMBIOTIC BIRTH AND SPREAD OF PLASTIDS: HOW MANY TIMES AND WHODUNIT?

The evidence for a single origin of primary plastids is discussed in the context of a paper in this issue challenging this view, and recent evidence concerning the number of secondary plastid endosymbioses is reviewed.

Cryptic organelles in parasitic protists and fungi.

...