Roux's archives of developmental biology

, Volume 196, Issue 3, pp 158–164

Development of in vitro fertilized embryos of the polyclad flatworm, Hoploplana inquilina, following blastomere separation and deletion

  • Barbara Conta Boyer


After in vitro fertilization of naked eggs of the polyclad turbellarian, Hoploplana inquilina, both cell separation experiments and deletions of specific blastomeres are possible. With these techniques one can analyze the developmental potential of isolated blastomeres and determine if the embryonic axes have been established at the four-cell stage in this primitive, equally-cleaving spiralian embryo. Two-cell separation experiments with development of both halves resulted in pairs of larvae 1) neither of which had an eye (29%), 2) both of which had one eye (19%), and 3) one of which was eyeless and the other was one-eyed (43%). Deletion of one blastomere at the four-cell stage resulted in 68% one-eyed, 28% two-eyed and 3% eyeless larvae. The one-eyed larvae were asymmetric with respect to eye position with more having right than left eyes. Abnormal or missing ventrolateral lobes occurred with deletion of any of the macromeres at four cells but were significantly more common when A or C rather than B or D was deleted. The experiments support the hypothesis that eye development is a consequence of cytoplasmic localization of both a specific eye precursor and an inducer which segregate independently of cleavage planes, and indicate that the embryonic axes have been determined at the four-cell stage.

Key words

Polyclad Mosaic development Spiral cleavage Determination Symmetry 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Arnolds WJA, Biggelaar JAM van den, Verdonk NH (1983) Spatial aspects of cell interactions involved in the determination of dorsoventral polarity in equally cleaving gastropods and regulative abilities in their embryos, as studied by micromere deletions in Lymnaea and Patella. Wilhelm Roux's Arch 192:75–85Google Scholar
  2. Biggelaar JAM van den (1976) Development of dorsoventral polarity preceding the formation of the mesentoblast in Lymnaea stagnalis. Proc K Ned Akad Wet C 79:112–126Google Scholar
  3. Biggelaar JAM van den (1977) Development of dorsoventral polarity and mesentoblast determination in Patella vulgata. J Morphol 154:157–186Google Scholar
  4. Biggelaar JAM van den, Dorresteijn AWC, Laat SW de, Bluemink JG (1981) The role of topographical factors in cell interaction and determination of cell lines in molluscan development. In: Schweiger HG (ed) International cell biology 1980–1981. Springer, Berlin Heidelberg New York, pp 526–538Google Scholar
  5. Biggelaar JAM van den, Guerrier P (1979) Dorsoventral polarity and mesentoblast determination as concomitant results of cellular interactions in the mollusk Patella vulgata. Dev Biol 68:462–471Google Scholar
  6. Biggelaar JAM van den, Guerrier P (1983) Origin of spatial organization. In: Verdonk NH, Biggelaar JAM van den, Tompa AS (eds) The mollusca, vol 3. Academic Press, New York, pp 179–213Google Scholar
  7. Boyer BC (1986) Determinative development in the polyclad turbellarian, Hoploplana inquilina. Int J Invert Repro Dev 9:243–251Google Scholar
  8. Cather JN (1971) Cellular interactions in the regulation of development in annelids and molluscs. Adv Morphogen 9:67–125Google Scholar
  9. Clement AC (1952) Experimental studies on germinal localization in Ilyanassa I. The role of the polar lobe in determination of the cleavage pattern and its influence in later development. J Exp Zool 121:593–626Google Scholar
  10. Clement AC (1956) Experimental studies on germinal localization in Ilyanassa II. The development of isolated blastomeres. J Exp Zool 132:427–446Google Scholar
  11. Clement AC (1976) Cell determination and organogenesis in molluscan development: A reappraisal based on deletion experiments in Ilyanassa. Am Zool 16:447–453Google Scholar
  12. Dohmen MR, Verdonk NH (1979) Cytoplasmic localization in mosaic eggs. In: Newth DR, Balls M (eds) Maternal effects in development. Cambridge University Press, pp 127–145Google Scholar
  13. Dongen CAM van, Geilenkirchen WLM (1975) The development of Dentalium with special reference to the significance of the polar lobe IX. Division chronology and development of the cell pattern in Dentalium dentale after removal of the polar lobe at first cleavage. Proc K Ned Akad Wet C 78:358–375Google Scholar
  14. Guerrier P, Biggelaar JAM van den, Dongen CAM van, Verdonk NH (1978) Significance of the polar lobe for the determination of dorsoventral polarity in Dentalium vulgare (da Costa). Dev Biol 63:233–242Google Scholar
  15. Martindale MQ, Doe CQ, Morrill JB (1985) The role of animalvegetal interaction with respect to the determination of dorsoventral polarity in the equal-cleaving spiralian, Lymnaea palustris. Wilhelm Roux's Arch 194:281–295Google Scholar
  16. Palaszewski PP, Boyer BC (1983) Reproduction in Hoploplana and Stylochus: developmental and cytoskeletal research possibilities. Biol Bull 165:502Google Scholar
  17. Rooney LM, Boyer BC (1984) New aspects of development of the polyclad, Hoploplana inquilina. Biol Bull 167:519–520Google Scholar
  18. Surface FM (1907) The early development of a polyclad, Planocera inquilina. Proc Acad Natl Sci 59:514–559Google Scholar
  19. Verdonk NH (1979) Symmetry and asymmetry in the embryonic development of molluscs. In: Spoel S van der, Bruggen AC van, Lever J (eds) Pathways in malacology. Bohm, Scheltema& Holkema, Utrecht, pp 25–45Google Scholar
  20. Verdonk NH, Cather JN (1983) Morphogenetic determination and differentiation. In: Verdonk NH, Biggelaar JAM van den, Tompa AS (eds) The mollusca, vol 3. Academic Press, New York, pp 91–122Google Scholar
  21. Wilson EB (1904) Experimental studies on germinal localization II. Experiments on the cleavage-mosaic in Patella and Dentalium. J Exp Zool 1:197–268Google Scholar

Copyright information

© Springer-Verlag 1987

Authors and Affiliations

  • Barbara Conta Boyer
    • 1
  1. 1.Union College and The Marine Biological LaboratoryUSA
  2. 2.Department of BiologyUnion CollegeSchenectadyUSA

Personalised recommendations