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A model for ascidian development and developmental modifications during evolution

  • William R. Jeffery (a1)

Extract

Ascidian development is reviewed and a model is presented for specification of the larval body plan and cell fate during embryogenesis. The model involves the combined activity of determinants inherited from the egg and inductive cell interactions in the embryo. It is suggested that there are four determinant systems in the egg which are segregated to different blastomeres during cleavage. The ectodermal, endodermal, and muscle determinants specify cell fate autonomously, while the axial determinants initiate cell-shape changes at gastrulation and generate a cascade of inductive activities establishing the larval body plan. In the proposed signalling cascade, the endoderm induces notochord by generating a planar inductive signal late during the cleavage phase, and the notochord cells in turn induce the nervous system by generating a vertical inductive signal in the overlying ectoderm during gastrulation. Ultraviolet (UV) irradiation experiments are described which suggest that axial and muscle determinants exhibit UV-sensitive components resembling nucleic acids and proteins, respectively. The model is evaluated in terms of developmental changes during the evolutionary transition from indirect to direct development. This transition can be explained according to the model by loss or inactivation of the muscle determinants and modification of the inductive activities generated by the axial determinants. These changes are supported by recent studies of embryogenesis in direct-developing ascidians.

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Bates, W.R. & Jeffery, W.R., 1987. Localization of axial determinants in the vegetal pole region of ascidian eggs. Developmental Biology, 124, 6576.
Berrill, N.J., 1931. Studies in tunicate development. II. Abbreviation of development in the Molgulidae. Philosophical Transactions of the Royal Society of London (B), 219, 281346.
Conklin, E.G., 1905. The organization and cell lineage of the ascidian egg. Journal of the Academy of Natural Sciences of Philadelphia, 13, 1119.
Deno, T., Nishida, H. & Satoh, N., 1984. Autonomous muscle cell differentiation in partial embryos according to the newly-verified cell lineages. Developmental Biology, 104, 322328.
Jeffery, W.R., 1984. Pattern formation by ooplasmic segregation in ascidian eggs. Biological Bulletin. Marine Biological Laboratory, Woods Hole, 166, 277298.
Jeffery, W.R., 1990a. Ultraviolet irradiation during ooplasmic segregation prevents gastrulation, sensory cell induction, and axis formation in the ascidian embryo. Developmental Biology, 140, 388400.
Jeffery, W.R., 1990b. An ultraviolet-sensitive maternal mRNA encoding a cytoskeletal protein may be involved in axis determination in the ascidian embryo. Developmental Biology, 141, 141148.
Jeffery, W.R., 1992. A gastrulation center in the ascidian egg. Development, supplement 1992, 5363.
Jeffery, W.R., 1993. Role of cell interactions in ascidian muscle and pigment cell specification. Wilhelm Roux's Archives of Developmental Biology, 202, 103111.
Jeffery, W.R. & Capco, D.G., 1978. Differential accumulation and localization of maternal poly (A)-containing RNA during early development of the ascidian, Styela. Developmental Biology, 67, 152166.
Jeffery, W.R. & Swalla, B.J., 1990. Anural development in ascidians: evolutionary modification and elimination of the tadpole larva. Seminars in Developmental Biology, 1, 253261.
Jeffery, W.R. & Swalla, B.J., 1992. Factors necessary for restoring an evolutionary change in an anural ascidian embryo. Developmental Biology, 153, 194205.
Jeffery, W.R. & Swalla, B.J., 1993. An ankryin-like protein in ascidian eggs and its role in the evolution of direct development. Zygote, 1, in press.
Kovilur, S., Jacobson, J.W., Beach, R.L., Jeffery, W.R. & Tomlinson, C.R., 1993. Evolution of the chordate muscle actin gene. Journal of Molecular Evolution, 36, 361368.
Nishida, H., 1987. Cell lineage analysis in ascidian embryos by intracellular injection of a tracer enzyme. III. Up to the tissue restricted stage. Developmental Biology, 121, 526541.
Nishida, H., 1990. Determinative mechanisms in secondary muscle lineages of ascidian embryos: development of muscle specific features in isolated muscle progenitor cells. Development, 108, 559568.
Nishida, H., 1991. Induction of brain and sensory pigment cells in the ascidian embryo analysed by experiments with isolated blastomeres. Development, 112, 389395.
Nishida, H., 1992a. Determination of developmental fates of blastomeres in ascidian embryos. Development, Growth and Differentiation, 34, 253262.
Nishida, H., 1992b. Developmental potential for tissue differentiation of fully dissociated cells of the ascidian embryo. Wilhelm Roux's Archives of Developmental Biology, 201, 8187.
Nishida, H., 1992c. Regionality of egg cytoplasm that promotes muscle differentiation in embryos of the ascidian Halocynthia roretzi. Development, 116, 521529.
Nishida, H. & Satoh, N., 1983. Cell lineage analysis in ascidian embryos by intracellular injection of a tracer enzyme. I. Up to the eight-cell stage. Developmental Biology, 99, 382394.
Nishida, H. & Satoh, N., 1985. Cell lineage analysis in ascidian embryos by intracellular injection of a tracer enzyme. II. The 16- and 32-cell stages. Developmental Biology, 110, 440454.
Nishida, H. & Satoh, N., 1989. Determination and regulation in the pigment cell lineage of the ascidian embryo. Developmental Biology, 132, 355367.
Nishikata, T., Mita-Miyazawa, I., Deno, T., Takamura, K. & Satoh, N., 1987. Expression of epidermis-specific antigens during embryogenesis of the ascidian, Halocynthia roretzi. Developmental Biology, 121, 408416.
Reverberi, G., Ortolani, G. & Farinella-Ferruzza, N., 1960. The causal formation of the brain in the ascidian larva. Ada Embryologiae et Morphologiae Experimentalis, 3, 296336.
Rose, S.M., 1939. Embryonic induction in the Ascidia. Biological Bulletin. Marine Biological Laboratory, Woods Hole, 77, 216232.
Sardet, C., Speksnijder, J.E., Inoué, S. & Jaffe, L.F., 1989. Fertilization and ooplasmic movements in the ascidian egg. Development, 105, 237249.
Swalla, B.J. 1992. The role of maternal factors in ascidian muscle development. Seminars in Developmental Biology, 3, 287295.
Swalla, B.J., Badgett, M.R. & Jeffery, W.R., 1991. Identification of a cytoskeletal protein localized in the myoplasm of ascidian eggs: localization is modified during anural development. Development, 111, 425436.
Swalla, B.J. & Jeffery, W.R., 1990. Interspecific hybridization between an anural and urodele ascidian: differential expression of urodele features suggests multiple mechanisms control anural development. Developmental Biology, 142, 319334.
Swalla, B.J., Makabe, K.W., Satoh, N. & Jeffery, W.R. 1993. Novel genes expressed differentially in ascidians with alternate modes of development. Development, 119, 307318.
Whittaker, J.R., 1973. Segregation during ascidian embryogenesis of egg cytoplasmic information for tissue specific enzyme development. Proceedings of the National Academy of Sciences of the United States of America, 70, 20962100.
Whittaker, J.R., 1980. Acetylcholinesterase development in extra cells caused by changing the distribution of myoplasm in ascidian embryos. Journal of Embryology and Experimental Morphology, 55, 343354.
Whittaker, J.R., 1990. Determination of alkaline phosphatase expression in endodermal cell lineages of an ascidian embryo. Biological Bulletin. Marine Biological Laboratory, Woods Hole, 178, 222230.

A model for ascidian development and developmental modifications during evolution

  • William R. Jeffery (a1)

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