How to Lose the Plasmalemma? Lessons From Ciliates, Dinoflagellates and Euglenids

Horizontal and endosymbiotic gene transfer in early plastid evolution

“…While the phylogeny of plastid genes supports that a single red alga was at the origin of all complex red plastids (Yoon et al, 2002;Muñoz-G omez et al, 2017), most phylogenetic analyses of nuclear genes have suggested that CASH lineages are not monophyletic. This has been interpreted as an indication that complex red plastids were acquired through an undetermined number of events that may have included serial tertiary endosymbioses and kleptoplastidy in different hosts (Bodył et al, 2009;Baurain et al, 2010;Petersen et al, 2014;Bodył, 2017). Conversely, the origin of complex green plastids is much clearer: euglenids and chlorarachniophytes acquired their plastids from two independent secondary endosymbioses involving two distantly related green algal endosymbionts (Jackson et al, 2018).…”

Explaining the Origin of Three‐Membrane‐Bound Plastids in Dinoflagellates and Euglenophytes: Kleptoplastidy via Myzocytosis?

“…This is a reply to a comment published in BioEssays in the category “Thoughts and Opinions” by Andrzej Bodył on our paper “Cellular compartmentation follows rules: The Schnepf theorem, its consequences and exceptions.” In this article we introduced the “compartmentation rule” or Schnepf theorem, originally formulated by Eberhard Schnepf, to the international scientific community. We critically review the theorem and clearly state that as for every good rule there are exceptions to the Schnepf theorem as well, especially in case of endosymbiotically derived cellular structures, such as the three membrane‐bound complex plastids of dinoflagellates and euglenophytes, respectively, as well as in case of parasitism .…”

“…Daniel Moog and Uwe G. Maier* This is a reply to a comment published in BioEssays in the category "Thoughts and Opinions" by Andrzej Bodył [1] on our paper "Cellular compartmentation follows rules: The Schnepf theorem, its consequences and exceptions." [2] In this article we introduced the "compartmentation rule" or Schnepf theorem, originally formulated by Eberhard Schnepf, to the international scientific community.…”

“…This situation would in fact be rather unlikely unless the host would already be in possession of a plastid of the same or similar type (replacement; see later). However, admittedly, when we were discussing myzocytosis in the light of dinoflagellate and euglenophyte plastid evolution, we did not consider karyoklepty that might occur in parallel to kleptoplasty as a potential consequence of myzocytosis …”

“…However, admittedly, when we were discussing myzocytosis in the light of dinoflagellate and euglenophyte plastid evolution, we did not consider karyoklepty that might occur in parallel to kleptoplasty as a potential consequence of myzocytosis. [1,3] Assuming that the stolen nucleus (kleptokaryon) is still capable of providing gene products necessary for plastid maintenance, it might be possible to keep the plastid in an active state at least as long as the kleptokaryon is functional. The "part-time photosynthetic" predator might be able to continuously capture new kleptokaryons and Àplastids from its prey which might indeed enable maintaining the stolen organelles on evolutionary time scales.…”