Abstract
Photosynthetic assimilation of 14CO2 by the symbiotic green alga Platymonas convolutae Parke et Manton in the marine flatworm Convoluta roscoffensis Graff has been investigated and compared with that in free-living P. subcordiformis and P. tetrathele. All Platymonas species investigated rapidly incorporate 14CO2 into a complex variety of soluble and insoluble assimilates. The rate of dark fixation is considerably lower in P. convolutae. Typical 14C-assimilate patterns are rather uniform in all Platymonas species, but the time courses of 14C-labelling of several compounds are very different. The percentage of 14C-aspartate and 14C-malate is significantly higher in P. convolutae after short-term-photosynthesis, whereas 14C-labelled phosphate esters predominate in the free-living Platymonas species. A comparison of the kinetics of 14C-labelling and of the distribution of 14C-activity between soluble and insoluble fractions suggests that glucose and fructose, not mannitol, as well as several amino acids (especially alanine) move from the algal partner to the tissue of the animal host. The significance of these findings is discussed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Literature Cited
Craigie, J.S., J. McLachlan, W. Majak, R.G. Ackman and C.S. Tocher: Photosynthesis in algae. II. Green algae with special reference to Dunaliella spp. and Tetraselmis spp. Can. J. Bot. 44, 1247–1254 (1966)
—, R. G. Ackman and C. S. Tocher: Photosynthesis in algae. III. Distribution of soluble carbohydrates and dimethyl-β-propiothetin in marine unicellular Chlorophyceae and Prasinophyceae. Can. J. Bot. 45, 1327–1343 (1967)
Droop, M. R.: Algae and invertebrates in symbiosis. Symp. Soc. gen. Microbiol. 13, 171–179 (1963)
Feige, B., H. Gimmler, W. D. Jeschke und W. Simonis: Eine Methode zur dünnschichtchromatographischen Auftrennung von 14C- und 32p-markierten Stoffwechselprodukten. J. Chromat. 41, 80–90 (1969)
Fraenkel, G.: Quelques observations sur le comportement de Convoluta roscoffensis. Cah. Biol. mar. 2, 155–160 (1961)
Gooday, G. W.: A physiological comparison of the symbiotic alga Platymonas convolutae and its free-living relatives. J. mar. biol. Ass. U. K. 50, 199–208 (1970)
Guéven, M.: Observations écologiques sur Convoluta roscoffensis Graff. Cah. Biol. mar. 1, 203–220 (1960)
Keeble, F. and F. W. Gamble: The origin and nature of the green cells of Convoluta roscoffensis. Q. Jl miscrosc. Sci. 51, 167–219 (1907)
Kremer, B. P.: Mannitmetabolismus in der marinen Braunalge Fucus serratus. Z. Pflanzenphysiol. 74, 255–263 (1975a)
—: Photosynthetische 14CO2-Assimilations durch den Endosymbionten Platymonas convolutae. Naturwissenschaften 62, 97–98 (1975b)
McLaughlin, J. J. A. and P. A. Zahl: Endozoic algae. In: Symbiosis, Vol. 1. pp 257–297. Ed. by S. M. Henry, New York: Academic Press 1966
Muscatine, L.: Symbiosis of Hydra and algae. III. Extracellular products of the algae. Comp. Biochem. Physiol. 16, 77–92 (1965)
—: Glycerol excretion by symbiotic algae from corals and Tridacna and its control by the host. Science, N. Y. 156, p. 519 (1967)
—, J. E. Boyle and D. C. Smith: Symbiosis of the acoel flatworm Convoluta roscoffensis with the alga Platymonas convolutae. Proc. R. Soc. (Ser. B) 187, 221–234 (1974)
— and C. Hand: Direct evidence for the transfer of materials from symbiotic algae to the tissues of a coelenterate. Proc. natn. Acad. Sci. U. S. A. 44, 1259–1263 (1958)
—, S. J. Karakashian and M. W. Karakashian: Soluble extracellular products of algae symbiotic with a cilliate, a sponge, and a mutant Hydra. Comp. Biochem. Physiol. 20, 1–12 (1967)
Nozawa, K., D. J. Taylor and L. Provasoli: Respiration and photosynthesis in Convoluta roscoffensis Graff, infected with various symbionts. Biol. Bull. mar. biol. Lab., Woods Hole 143, 420–430 (1972)
Oschman, J. L.: Development of the symbiosis of Convoluta roscoffensis and Platymonas spec. J. Phycol. 2, 105–111 (1966)
— and P. Gray: A study of the fine structure of Convoluta roscoffensis and its endosymbiotic algae. Trans. Am. microsc. Soc. 84, 368–375 (1965)
Parke, M. and I. Manton: The specific identity of the algal symbiont in Convoluta roscoffensis. J. mar. biol. Ass. U. K. 47, 445–464 (1967)
Provasoli, L., T. Yamasu and I. Manton: Experiments on the resynthesis of symbiosis in Convoluta roscoffensis with different flagellate cultures. J. mar. biol. Ass. U. K. 48, 465–479 (1968)
Rees, W. R. and T. Reynolds: A solvent for the paper chromatographic separation of glucose and sorbitol. Nature, Lond. 181, p. 763 (1958)
Smith, D. C., L. Muscatine and D. H. Lewis: Carbohydrate movement from autotrophs to heterotrophs in parasitic and mutualistic symbiosis. Biol. Rev. 44, 17–90 (1969)
Suzuki, H.: Starch-type polysaccharide and mannitol in Platymonas. Phytochem. 13, 1159–1160 (1974)
Taylor, D. L.: Algal symbionts of invertebrates. A. Rev. Microbiol. 27, 171–187 (1973a)
— The cellular interactions of algal-invertebrate symbiosis. Adv. mar. Biol. 11, 1–56 (1973b)
— Nutrition of algal-invertebrate symbiosis. I. Utilization of soluble organic nutrients by symbiont-free hosts. Proc. R. Soc. (Ser. B) 186, 357–368 (1974)
Touster, R. K. and D. R. D. Shaw: Biochemistry of the acyclic polyols. Physiol. Rev. 42, 181–220 (1962)
Trench, R. K.: Chloroplasts as functional endosymbionts in the mollusc Tridachia crispata (Bergh.), (Opisthobranchia, Sacoglossa). Nature, Lond. 222 1071–1072 (1969)
Author information
Authors and Affiliations
Additional information
Communicated by O. Kinne, Hamburg
Rights and permissions
About this article
Cite this article
Kremer, B.P. 14CO2-Fixation by the endosymbiotic alga Platymonas convolutae within the turbellrian Convoluta roscoffensis . Mar. Biol. 31, 219–226 (1975). https://doi.org/10.1007/BF00387150
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00387150