Plastids sequestered by sacoglossan sea slugs have long been a puzzle. Some sacoglossans feed on siphonaceous algae and can retain the plastids in the cytosol of their digestive gland cells. There, the stolen plastids (kleptoplasts) can remain photosynthetically active in some cases for months. Our current data shows that kleptoplasty evolved multiple times independently in sacoglossan sea slugs. On what basis? We are performing comparative analysis on sister species such as Elysia timida and Elysia cornigera to understand how some slugs have evolved to better tolerate starvation (that is ROS stress) and profit from kleptoplasty. Furthermore are we analyzing the photobiology of algae, whose plastids survive long-term in the slugs. For this we've also switched to model systems such as Chlamydomonas (a collaborative project with Prof. Jörg Nickelsen from the LMU Munich) and Arabidopsis (a collaborative project with Prof. Peter Jahnshere at the HHU) to test a few of our theories.

These integrative approaches enable us to investigate two phenomena associated with sacoglossan slugs in parallel: (i) the nature of kleptoplasts as long-term maintainable reserves in an animal cell and (ii) the mechanism allowing those isolated plastids to remain active for months.

For some nice slug images I recommend: http://ngm.nationalgeographic.com/2008/06/nudibranchs/doubilet-photography

or
 http://opistobranquis.info/en

 

Relevant Publications:

de Vries J, Woehle C, Christa G, Wägele H, Tielens AGM, Jahns P, Gould SB: Comparison of sister species identifies factors underpinning plastid compatibility in green slugs. Proc R Soc Lond B 282:20142519 (2015)

de Vries J, Rauch C, Christa G, Gould SB: Green see slugs: an animal's guide to plastid symbiosis. Acta Soc Bot Poln 83:415-21 (2014).

de Vries J, Christa G, Gould SB: Plastid survival in the cytosol of animal cells. Trends Plant Sci 19:347–350 (2014)pdf

Christa G, de Vries, Jahns P, Gould SB: Switching off photosynthesis: The dark side of sacoglossan slugs. Commun Integr Biol 7:e28029 (2014). pdf

Schmitt V, Händeler K, Gunkel S, Escande ML, Menzel D, Gould SB, Martin WF, Wägele H: Chloroplast incorporation and long-term photosynthetic performance through the life cycle in laboratory cultures of Elysia timida (Sacoglossa, Heterobranchia). Front Zool 11:5 (2014)pdf

Christa G, Zimorski V, Woehle C, Tielens AGM, Wägele H, Martin WF, Gould SB: Plastid-bearing sea slugs fix CO2 in the light but do not require photosynthesis to survive. Proc R Soc Lond B 281:20132493 (2014). pdf 

de Vries J, Habicht J, Woehle C, Huang C, Christa G, Wägele H, Nickelsen J, Martin WF, Gould SB: Is ftsH the key to plastid longevity in sacoglossan slugs? Genome Biol Evol 5:2540–2548 (2013). pdf

Martin WF, Hazkani-Covo E, Shavit-Grievink L, Schmitt V, Händeler K, Gould SB, Landan G, Graur D, Dagan T: Gene transfers from organelles to the nucleus. How much, what happens, and why none in Elysia. Endocytobiosis Cell Res 23:16–20 (2012). pdf

Wagele H, Deusch O, Handeler K, Martin R, Schmitt V, Christa G, Pinzger B, Gould SB, Dagan T, Klussmann-Kolb A, Martin W: Transcriptomic evidence that longevity of acquired plastids in the photosynthetic slugs Elysia timida and Plakobranchus ocellatus does not entail lateral transfer of algal nuclear genes. Mol Biol Evol 28:699–706 (2011). pdf

Responsible for the content: E-MailProf. Dr. William F. Martin