Publication Date:
2022-05-26
Description:
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Photosynthesis Research 107 (2011): 117-132, doi:10.1007/s11120-010-9546-8.
Description:
Many non-photosynthetic species of protists and metazoans are capable of hosting viable algal
endosymbionts or their organelles through adaptations of phagocytic pathways. A form of mixotrophy,
acquired phototrophy (AcPh) encompasses a sweet of endosymbiotic and organelle retention interactions,
that range from facultative to obligate. AcPh is a common phenomenon in aquatic ecosystems, with
endosymbiotic associations generally more prevalent in nutrient poor environments, and organelle retention
typically associated with more productive ones. All AcPhs benefit from enhanced growth due to access to
photosynthetic products, however the degree of metabolic integration and dependency in the host varies
widely. AcPhs are mixotrophic, using both heterotrophic and phototrophic carbon sources. AcPh is found
in at least four of the major eukaryotic supergroups, and is the driving force in the evolution of secondary
and tertiary plastid acquisitions. Mutualistic resource partitioning characterizes most algal endosymbiotic
interactions, while organelle retention is a form of predation, characterized by nutrient flow (i.e. growth) in
one direction. AcPh involves adaptations to recognize specific prey or endosymbionts and to house
organelles or endosymbionts within the endomembrane system but free from digestion. In many cases,
hosts depend upon AcPh for the production of essential nutrients, many of which remain obscure. The
practice of AcPh has led to multiple independent secondary and tertiary plastid acquisition events among
several eukaryote lineages, giving rise to the diverse array of algae found in modern aquatic ecosystems.
This review highlights those AcPhs that are model research organisms for both metazoans and protists.
Much of the basic biology of AcPhs remains enigmatic, particularly 1) which essential nutrients or factors
make certain forms of AcPh obligatory, 2) how hosts regulate and manipulate endosymbionts or
sequestered organelles, and 3) what genomic imprint, if any, AcPh leaves on non-photosynthetic host
species.
Description:
Supported by NSF grant OCE-0851269
Keywords:
Acquired phototrophy
;
Mixotrophy
;
Kleptoplastidy
;
Karyoklepty
;
Endosymbiosis
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
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