Ascidian Larvae and the Events of Metamorphosis

  title={Ascidian Larvae and the Events of Metamorphosis},
  author={Richard A. Cloney},
  journal={Integrative and Comparative Biology},
  • R. A. Cloney
  • Published 1 November 1982
  • Geology
  • Integrative and Comparative Biology
SYNOPSIS. Ascidian larvae settle and metamorphose after only a brief free—swimming period; they are all lecilhotrophic. Extrinsic factors (chemical and physical) may trigger metamorphosis but none are known to be essential. The major larval structures may be classified as transitory larval organs (TLO), prospective juvenile organs (PJO) or larvaljuvenile organs (LJO). TLO are phagocytized or otherwise destroyed at metamorphosis; the PJO and LJO become the functional parts of the juvenile or… 
The effect of larval age on morphology and gene expression during ascidian metamorphosis.
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Metamorphosis in solitary ascidians
A thorough view of the molecular regulation of ascidians' metamorphosis is presented by combining recent molecular data to the already established cellular events.
A morphological and genetic characterization of metamorphosis in the ascidian Boltenia villosa
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Ecological Consequences of Altering the Timing Mechanism for Metamorphosis in Anural Ascidians
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Formation of adult organs through metamorphosis in ascidians
How the cells and tissues in the ascidians larval body are converted into those of adults are discussed, suggesting that the ascidian larvae of solitary species are a transient stage of development.
Settlement and Metamorphosis of the Tropical Ascidian Herdmania curvata
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A complement response may activate metamorphosis in the ascidian Boltenia villosa
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Lumichrome. A larval metamorphosis-inducing substance in the ascidian Hhalocynthia roretzi.
It was demonstrated that lumichrome is localized predominantly in the basal region of the adhesive organ and the posterior part of the larval trunk, and proposed that Lumichrome functions as a natural inducer for larval metamorphosis in H. roretzi.
Further characterization of genes expressed during Ciona intestinalis metamorphosis.
Differential screening between mRNAs of swimming larvae and those of juveniles in Ciona intestinalis allowed the isolation of cDNA clones for genes whose expression is upregulated during metamorphosis, and the characterization of four genes (Ci-meta3, Ci-meta4, CI-meta5 and Ci- meta6) is reported here.


It is a rather strange coincidence that so many different factors have similar effects in either inhibiting or accelerating the onset of metamorphosis in widely divergent groups. Of these factors the
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The effective range of concentration of cytochalasin B which prevents tail resorption exhibited a striking phylogenetic correlation.
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A comparative study of the fine structure of these cells in larvae from different families has revealed wide variations in the pattern of organization of the sarcotubular system.