Summary
Patterning processes during embryonic development of Hydractinia echinata were analysed for alterations in morphology and physiology as well as for changes at the cellular level by means of treatment with proportioning altering factor (PAF). PAF is an endogenous factor known to change body proportions and to stimulate nerve cell differentiation in hydroids (Plickert 1987, 1989). Applied during early embryogenesis, this factor interferes with the proper establishment of polarity in the embryo. Instead of normal shaped planulae with one single anterior and one single posterior end, larvae with multiple termini develop. Preferentially, supernumerary posterior ends, which give rise to polyp head structures during metamorphosis, form while anterior ends are reduced. The formation of such polycaudal larvae coincide with an increase in the number of interstitial cells and their derivatives at the expense of epithelial cells. Treatment of further advanced embryonic stages causes an increase in length, presumably due to the general stimulation of cell proliferation observed in such embryos. Also, the spatial arrangement of cells (i.e. cells in proliferation and RFamide (Arg-Phe-amide immunopositive nerve cells) is altered by PAF. Larvae that develop from treated embryos display altered physiological properties and are remarkably different from normal planulae with respect to their morphogenetic potential: (1) Larvae lose their capacity to regenerate missing anterior parts; isolated posterior larva fragments form regenerates of a bicaudal phenotype. (2) In accordance with the frequently observed reduction of anterior structures, the capacity to respond to metamorphosis-inducing stimuli decreases. (3) The morphogenetic potential to form basal polyp parts is found to be reduced. In contrast, the potential to form head structures during metamorphosis increases, since primary polyps with supernumerary hypostomes and tentacles metamorphose from treated animals.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Berking S (1979) Analysis of head and foot formation in Hydra by means of an endogenous inhibitor. Roux's Arch Dev Biol 186:189–210
Berking S (1984) Metamorphosis in Hydractinia echinata. Insights into pattern formation in hydroids. Roux's Arch Dev Biol 193:370–378
Berking S (1986) Is homarine a morphogen in the marine hydroid Hydractinia? Roux's Arch Dev Biol 195:33–38
Berking S (1987) Homarine (N-methylpicolinic acid) and trigonelline (N-methylnicotinic acid) appear to be involved in pattern control in a marine hydroid. Development 99:211–220
Berking S (1988) Ammonia, tetraethylammonium, barium and amiloride induce metamorphosis in the marine hydroid Hydractinia. Roux's Arch Dev Biol 197:1–9
Berking S (1991) Control of metamorphosis and pattern formation in Hydractinia (Hydrozoa, Cnidaria). BioEssays 13:323–329
Bode PM, Bode HR (1984) Patterning in Hydra. In: Malacinski GM, Bryant SV (eds) Pattern formation Macmillan Press, New York, pp 213–536
Freeman G (1980) The role of cleavage in the establishment of the anterior-posterior axis of the hydrozoan embryo. In: Tardent P, Tardent R (eds) Developmental and cellular biology of coelenterates. Elsevier/North-Holland Biomedical Press, Amsterdam New York Oxford, pp 97–108
Freeman G (1981) The role of polarity in the development of the hydrozoan planula larva. Roux's Arch Dev Biol 190:168–184
Gierer A, Meinhard H (1972) A theory of biological pattern formation. Kybernetik 12:30–39
Grimmelikhuijzen CJP (1985) Antisera to the sequence Arg-Pheamide visualise neuronal centralisations in hydroid polyps. Cell Tissue Res 241:171–181
Kroiher M, Plickert G, Müller WA (1990) Pattern of cell proliferation in embryogenesis and planula development of Hydractinia echinata predicts the postmetamorphic body pattern. Roux's Arch Dev Biol 199:156–163
Leitz T, Wirth A (1991) Vanadate, known to interfere with signal transduction, induces metamorphosis in Hydractinia (Coelenterate; Hydrozoa) and causes profound alterations of the larval and postmetamorphic body pattern. Differentiation 47:119–127
Martin VJ, Thomas MB (1983) Establishment and maintenance of morphological polarity in epithelial planulae. Trans Am Microsc Soc 102:18–24
Müller WA (1984) Retinoids and pattern formation in a hydroid. J Embryol Exp Morphol 81:253–271
Müller WA, Buchal G (1973) Metamorphose-Induktion bei Planulalarven: II. Induktion durch monovalente Kationen: Die Bedeutung des Gibbs-Donan Verhdltnisses and der Na+/K+-ATPase. Roux's Arch Dev Biol 173:122–135
Müller WA, Plickert G (1982) Quantitative analysis of an inhibitory gradient field in the hydrozoan stolo. Roux's Arch Dev Biol 191:56–63
Müller WA, Mitze A, Wickhorst JP, Meier-Menge HM (1977) Polar morphogenesis in early hydroid development. Action of cesium, of neurotransmitters and of an intrinsic head activator on pattern formation. Roux's Arch Dev Biol 182:311–328
Müller WA, Hauch A, Plickert G (1987) Morphogenetic factors in hydroids: I. Stolon tip activation and inhibition. J Exp Zool 243:111–124
Plickert G (1987) Low-molecular-weight factors from colonial hydroids affect pattern formation. Roux's Arch Dev Biol 196:248–256
Plickert G (1989) Proportion altering factor (PAF) stimulates nerve cell formation in Hydractinia echinata. Cell Differ Dev 26:19–28
Plickert G (1990) Experimental analysis of developmental processes in marine hydroids. In: Marthy HJ (ed) Experimental embryology in aquatic plants and animals. Plenum Press, New York, pp 59–81
Plickert G, Kroiher M (1988) Proliferation kinetics and cell lineages can be studied in whole mounts and macerated tissues by means of BrdU/anti-BrdU technique. Development 103:791–794
Plickert G, Kroiher M, Munck A (1988) Cell proliferation and early differentiation during embryonic development and metamorphosis of Hydractinia echinata. Development 103:795–803
Schaller HC (1973) Isolation and characterisation of a low-molecular-weight substance activating head and bud formation in Hydra. J Embryol Exp Morphol 20:27–38
Schmid V, Plickert G (1990) The proportioning altering factor (PAF) and the in vitro transdifferentiation of isolated striated muscle of jellyfish into nerve cells. Differentiation 44:95–102
Schwoerer-Böhning B, Kroiher M, Müller WA (1990) Signal transmission and covert prepattern in the metamorphosis of Hydractinia echinata (Hydrozoa). Roux's Arch Dev Biol 198:245–251
Spindler KD, Müller WA (1972) Induction of metamorphosis by bacteria and by a lithium pulse in the larvae of Hydractinia echinata (Hydrozoa). Roux's Arch Dev Biol 169:271–280
Wolpert L (1970) Towards a theoretical biology. In: Waddington HC (ed) 3. Drafts. Aldine, Chicago
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kroiher, M., Plickert, G. Analysis of pattern formation during embryonic development of Hydractinia echinata . Roux's Arch Dev Biol 201, 95–104 (1992). https://doi.org/10.1007/BF00420420
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00420420