Single cell genome analysis supports a link between phagotrophy and primary plastid endosymbiosis
نویسندگان
چکیده
Two cases of primary plastid endosymbiosis are known. The first occurred ca. 1.6 billion years ago and putatively gave rise to the canonical plastid in algae and plants. The second is restricted to a genus of rhizarian amoebae that includes Paulinella chromatophora. Photosynthetic Paulinella species gained their plastid from an α-cyanobacterial source and are sister to plastid-lacking phagotrophs such as Paulinella ovalis that ingest cyanobacteria. To study the role of feeding behavior in plastid origin, we analyzed single-cell genome assemblies from six P. ovalis-like cells isolated from Chesapeake Bay, USA. Dozens of contigs in these cell assemblies were derived from prey DNA of α-cyanobacterial origin and associated cyanophages. We found two examples of horizontal gene transfer (HGT) in P. ovalis-like nuclear DNA from cyanobacterial sources. This work suggests the first evidence of a link between feeding behavior in wild-caught cells, HGT, and plastid primary endosymbiosis in the monophyletic Paulinella lineage.
منابع مشابه
Migration of the Plastid Genome to the Nucleus in a Peridinin Dinoflagellate
Dinoflagellate algae are important primary producers and of significant ecological and economic impact because of their ability to form "red tides". They are also models for evolutionary research because of an unparalleled ability to capture photosynthetic organelles (plastids) through endosymbiosis. The nature and extent of the plastid genome in the dominant perdinin-containing dinoflagellates...
متن کاملComment on "The evolution of modern eukaryotic phytoplankton".
Falkowski et al. (1) reviewed the evidence that three disparate groups of algae— dinoflagellates, diatoms, and coccolitho-phores, each with plastids derived from red algae by secondary endosymbiosis—have come to dominate the oceans_ flora over the past 250 million years and speculated about the forces responsible for this domination. Central to this speculation is the Bportable plastid hypothes...
متن کاملPhylogenomic Analysis of “Red” Genes from Two Divergent Species of the “Green” Secondary Phototrophs, the Chlorarachniophytes, Suggests Multiple Horizontal Gene Transfers from the Red Lineage before the Divergence of Extant Chlorarachniophytes
The plastids of chlorarachniophytes were derived from an ancestral green alga via secondary endosymbiosis. Thus, genes from the "green" lineage via secondary endosymbiotic gene transfer (EGT) are expected in the nuclear genomes of the Chlorarachniophyta. However, several recent studies have revealed the presence of "red" genes in their nuclear genomes. To elucidate the origin of such "red" gene...
متن کاملGene replacement of fructose-1,6-bisphosphate aldolase supports the hypothesis of a single photosynthetic ancestor of chromalveolates.
Plastids (photosynthetic organelles of plants and algae) are known to have spread between eukaryotic lineages by secondary endosymbiosis, that is, by the uptake of a eukaryotic alga by another eukaryote. But the number of times this has taken place is controversial. This is particularly so in the case of eukaryotes with plastids derived from red algae, which are numerous and diverse. Despite th...
متن کاملDid trypanosomatid parasites contain a eukaryotic alga-derived plastid in their evolutionary past?
The Trypanosomatidae is closely related to euglenids that harbor plastids acquired from a green alga via secondary endosymbiosis. This discovery led to the idea that trypanosomatid parasites contained a green alga-derived plastid in their evolutionary past, an evolutionary scenario that was criticized based on the rarity of plant/plastid/cyanobacterium-like genes in the completely sequenced gen...
متن کامل