Skip to main content
SpringerLink
Log in

Structure, function, and formation of extrusive organelles — microtoxicysts in the rhizopodPenardia cometa

  • Original Papers
  • Published:
Protoplasma Aims and scope Submit manuscript

Summary

A study of the structure, function, and development of extrusive organelles (microtoxicysts) in the unusual bacteriovorous rhizopodPenardia cometa is performed. Microtoxicysts are located in the cortical cytoplasm of the cell body and in special thickenings on reticulopodia. Similar types of extrusomes have been observed in some cercomonads. The microtoxicysts are organized as membrane-bound vesicles of a complex form. An oviform-conical axial element lies inside each vesicle and is directed with its narrower end towards the plasma membrane. An internal cylindrical tube occupies the central part of the axial element; it is turned out as the organelle is shot out. The extrusomes ofP. cometa originate from and develop in derivates of the endoplasmic reticulum, the initial diameter of proextrusome vesicles is twice the diameter of the mature organelles. At late stages of maturation the microtoxicysts adopt their characteristic form and orientation. The mode of construction, ejection and development is compared with that in some other carnivorous and bacterivorous protists.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Bardele CF (1969) Ultrastruktur der “Kornchen” auf den Axopodien vonRaphidiophrys (Centrohelida, Heliozoa). Z Naturforsch 24 b: 362–363

    Google Scholar 

  • — (1972) Cell cycle, morphogenesis and ultrastructure in pseudoheliozoanClathrulina elegans. Z Zellforsch 130: 219–242

    PubMed  Google Scholar 

  • Benwitz G (1982) Entwicklung der Haptocysten vonEphelota (Suctoria, Ciliata). Protistologica 28: 459–472

    Google Scholar 

  • Brugerolle G (1985) Ultrastructure d'Hedriocystis pellucida (Heliozoa Desmothoracida) et de sa forme migratrice flagellee. Protistologica 21: 259–265

    Google Scholar 

  • —, Mignot JP (1983) Caracteristiques ultrastructurales de l'HelioflagelleTetradimorpha (Hsiung) et leur interet pour l'etude phyletique des Heliozoaires. J Protozool 30: 473–480

    Google Scholar 

  • — — (1984) Les caracteristiques ultrastructurales de l'helioflagelleDimorpha mutans Gruber (Sarcodina-Actinopoda) et leur interet phyletique. Protistologica 20: 97–112

    Google Scholar 

  • Febvre-Chevalier C (1980) Behaviour and cytology ofActinocoryne contractilis nov.gen. nov.sp., a new stalked Heliozoa (Centrohelidia). J Mar Biol Assoc UK 60: 909–928

    Google Scholar 

  • Hausmann K (1972) Die “Extrusome” der Protisten. Mikrokosmos 61: 114–117

    Google Scholar 

  • — (1978) Extrusive organelles in protists. Int Rev Cytol 52: 197–276

    PubMed  Google Scholar 

  • Hibberd DJ, Norris RE (1984) Cytology and ultrastructure ofChlorarachnion reptans (Chlorarachniophyta divisio nova, Chlorarachniophyceae classis nova). J Phycol 20: 310–330

    Google Scholar 

  • Hovasse R, Mignot JP (1975) Trichocystes et organites analogues chez les protistes. Ann Biol 14: 397–422

    Google Scholar 

  • Karpov SA, Zhukov BF (1987) Cytological peculiarities of the colourless flagellateThaumatomonas lauterborni. Tsitologia 29: 1168–1171 (in Russian)

    Google Scholar 

  • Mignot JP, Brugerolle G (1975) Etude ultrastructurale phagotropheColponema loxodes Stein. Protistologica 11: 429–444

    Google Scholar 

  • Mikrjukov KA (1995) Formation of extrusive organelles — kinetocysts in the heliozoonChlamydaster sterni. Tsitologia 37 (in press) (in Russian)

  • —, Mylnikov AP (1995) Fine structure of an unusual amoebaPenardia cometa containing extrusomes and kinetosomes. Eur J Protistol 31: 90–96

    Google Scholar 

  • Mylnikov AP (1986 a) Biology and ultrastructure of amoeboid flagellates from the Cercomonadida ord. nov. Zool Zhurn 65: 783–792 (in Russian)

    Google Scholar 

  • — (1986 b) Ultrastructure of a colourless amoeboid flagellate.Cercomonas sp. Arch Protistenk 131: 239–248

    Google Scholar 

  • — (1988) The ultrastructure of flagellate extrusomes. Tsitologia 30: 1402–1408 (in Russian)

    Google Scholar 

  • — (1990) Characteristic features of the ultrastructure of colourless flagellateHeteromita sp. Tsitologia 32: 567–571 (in Russian)

    Google Scholar 

  • Patterson DJ, Fenchel T (1990)Massisteria marina Larsen & Patterson, 1990, a widespread and abundant bacterivorous protist associated with marine detritus. Mar Ecol Prog Ser 62: 11–19

    Google Scholar 

  • Saedeleer H De (1934) Beitrag zur Kenntnis der Rhizopoden: morphologische und systematische Untersuchungen und ein Klassifikationsversuch. Mem Mus R Hist Nat Belg 60: 3–112

    Google Scholar 

  • Swale EMF, Belcher JH (1974)Gyromitus clisomatus Skuja — a free living colourless flagellate. Arch Protistenk 116: 211–220

    Google Scholar 

  • — — (1975)Gyromitus limax nov. sp. — free-living colourless amoebo-flagellate. Arch Protistenk 117: 20–26

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Invertebrate Zoology, Faculty of Biology, Moscow University, 119899, Moscow, Russia

    K. A. Mikrjukov

Authors
  1. K. A. Mikrjukov
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Mikrjukov, K.A. Structure, function, and formation of extrusive organelles — microtoxicysts in the rhizopodPenardia cometa . Protoplasma 188, 186–191 (1995). https://doi.org/10.1007/BF01280370

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01280370

Keywords

Search

Navigation