How do bacterial endosymbionts work with so few genes?

McCutcheon, John P.; Garber, Arkadiy I.; Spencer, Noah; Warren, Jessica M.

doi:10.1371/journal.pbio.3002577

Cited by 4 publications

(1 citation statement)

References 91 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In some cases, these bacteria have undergone radical changes that challenge our current understanding of how cells operate. McCutcheon and colleagues [7] delve into this subject, exploring the question, "how can such systems be viable with so few genes. "…”

mentioning

confidence: 99%

Symbiosis: In search of a deeper understanding

Richards,

Moran

2024

PLoS Biol

View full text Add to dashboard Cite

How do distinct species cofunction in symbiosis, despite conflicting interests? A new collection of articles explores emerging themes as researchers exploit modern research tools and new models to unravel how symbiotic interactions function and evolve.Symbiosis is a puzzle: seemingly in defiance of the view that biological organisms are selfish entities, nature has provided numerous examples of distantly related species "working together." These ecological interactions have been fundamental to the emergence of Earth's biological systems, for example, driving how eukaryotic cells evolved [1], how plants colonized the terrestrial biome [2], and how coral reef ecosystems are built [3]. Yet scratch below the surface, and collaborations between species are never fully cooperative. Many interactions remain transient maximizations of ecological, metabolic, or protective benefit. Even in long-established endosymbioses, in which a microbial symbiont lives within cells of the host, selection drives each species to evolve in directions that are often to their partner's detriment [4]. Consequences for symbionts can include entrapment, genetic appropriation, genome reduction, loss of autonomy, expulsion, and being digested. And, from the host side, symbiosis can lead to obligate dependence on partners that are erratically present or that are mutation ridden and ecologically fragile. Such dynamics might appear to make these interactions inherently unstable, yet they arise frequently and often persist across considerable periods of time and many generations.This fundamental dichotomy has fired interest in the study of symbiosis. Furthermore, we now know that, despite these destabilizing forces, symbiosis has generated radical evolutionary outcomes that have shaped the tree of life. Biologists are interested in the forces that drive the origins of symbioses and their subsequent evolution, and in symbioses that generate different kinds of outcomes, ranging from diversification and ecological success to extinction. For example, symbiosis has driven how eukaryotic cells relocate respiratory pathways [5] and how photosynthesis is co-opted, time and time again [1].The field of symbiosis research crosses many disciplines and has a long history. For many decades, symbiosis research (such as the work of WallinAU : PleasenotethatthecitationtheworkofWallino , one of the early proponents of the symbiotic ancestry of mitochondria) operated largely from the natural history perspective [1,6]. These early experiments were few in number and often turned out to be wrong, although sometimes the underlying hypothesis was later proven to be correct [6]. As part of this collection, John Archibald discusses the history of endosymbiosis research and its legacy across modern experimental and genomic endeavors [6].

show abstract

mentioning

confidence: 99%

Symbiosis: In search of a deeper understanding

Richards,

Moran

2024

PLoS Biol

View full text Add to dashboard Cite

show abstract

De novogenome sequence assembly of the RNAi-tractable endosymbiosis model systemParamecium bursaria186b reveals factors shaping intron repertoire

Leonard,

Jenkins,

Savory

et al. 2024

Preprint

View full text Add to dashboard Cite

How two species engage in stable endosymbiosis is a biological quandary. The study of facultative endosymbiotic interactions has emerged as a useful approach to understand how endosymbiotic functions can arise. The ciliate protistParamecium bursariahosts green algae of the order Chlorellales in a facultative photo-endosymbiosis. We have recently reported RNAi as a tool for understanding gene function inParamecium bursaria186b, CCAP strain 1660/18 [1]. To complement this work, here we report a highly complete host genome andtranscriptome sequence dataset, using both Illumina and PacBio sequencing methods to aid genome analysis and to enable the design of RNAi experiments. Our analyses demonstrateParamecium bursaria, like other ciliates such as diverse species ofParamecia, possess numerous tiny introns. These data, combined with the alternative genetic code common to ciliates, makes gene identification and annotation challenging. To explore intron evolutionary dynamics further we show that alternative splicing leading to intron retention occurs at a higher frequency among the smaller number of longer introns, identifying a source of selection against longer introns. These data will aid the investigation of genome evolution in theParameciaand provide additional source data for the exploration of endosymbiotic functions.

show abstract

Protein import into bacterial endosymbionts and evolving organelles

Sørensen,

Stiller,

Kröninger

et al. 2024

The FEBS Journal

View full text Add to dashboard Cite

Bacterial endosymbionts are common throughout the eukaryotic tree of life and provide a range of essential functions. The intricate integration of bacterial endosymbionts into a host led to the formation of the energy‐converting organelles, mitochondria and plastids, that have shaped eukaryotic evolution. Protein import from the host has been regarded as one of the distinguishing features of organelles as compared to endosymbionts. In recent years, research has delved deeper into a diverse range of endosymbioses and discovered evidence for ‘exceptional’ instances of protein import outside of the canonical organelles. Here we review the current evidence for protein import into bacterial endosymbionts. We cover both ‘recently evolved’ organelles, where there is evidence for hundreds of imported proteins, and endosymbiotic systems where currently only single protein import candidates are described. We discuss the challenges of establishing protein import machineries and the diversity of mechanisms that have independently evolved to solve them. Understanding these systems and the different independent mechanisms, they have evolved is critical to elucidate how cellular integration arises and deepens at the endosymbiont to organelle interface. We finish by suggesting approaches that could be used in the future to address the open questions. Overall, we believe that the evidence now suggests that protein import into bacterial endosymbionts is more common than generally realized, and thus that there is an increasing number of partnerships that blur the distinction between endosymbiont and organelle.

show abstract

How do bacterial endosymbionts work with so few genes?

Cited by 4 publications

References 91 publications

Symbiosis: In search of a deeper understanding

Symbiosis: In search of a deeper understanding

De novogenome sequence assembly of the RNAi-tractable endosymbiosis model systemParamecium bursaria186b reveals factors shaping intron repertoire

Protein import into bacterial endosymbionts and evolving organelles

Contact Info

Product

Resources

About