Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-28T00:22:33.504Z Has data issue: false hasContentIssue false
  • English
  • Français

The accumulation of radioactive iodine by Amphioxus

Published online by Cambridge University Press:  11 May 2009

I. M. Thomas
I. M. Thomas
Affiliation:
Department of Zoology, University of Adelaide
Get access Rights & Permissions [Opens in a new window]

Extract

The endostyle of Amphioxus has for a long time been regarded as homologous with the subpharyngeal gland of the cyclostome ammocoete larva. This view was promulgated by Müller (1873) and by Dohrn (1886), and has been supported by many workers, for example Leach (1944). The metamorphosis of portions of the subpharyngeal gland to the thyroid gland of the adult lamprey was followed by Marine (1913), and uptake of radioactive iodine by certain cell elements of the subpharyngeal gland was demonstrated by Gorbman & Creaser (1942). At the same time the latter workers failed to establish the presence of iodine in the endostyle of Amphioxus by autoradio-graphic techniques. Gorbman (1941), however, showed that the ascidian Perophora annectans could accumulate radioactive iodine in its pharyngeal stolon but not in its endostyle. The part of the pharyngeal stolon involved is derived from the endostylar region of the pharynx. Recently, Sembrat (1953) has shown that endostyles of Amphioxus implanted into larval axolotls accelerated their metamorphosis, and concludes from this that the organs contain an ‘active substance (or substances) which may evoke amphibian metamorphosis similarly to the active hormone of the thyroid gland. It is probable that the substance is not identical with thyroxin which may be inferred from the fact that the endostyle’ of Branchiostoma does not accumulate radioactive iodine (Gorbman & Creaser, 1942) as well as from its different and tolerably little efficacious influence on the amphibian metamorphosis as compared with typical metamorphic symptoms induced by the thyroid gland.’ The work about to be described has demonstrated the presence of iodine in the endostyle, and suggests, further, that it is present in the form of a ‘thyroid hormone-like’ substance, thereby supporting Sembrat's general conclusion.

Type
Research Article
Information
Journal of the Marine Biological Association of the United Kingdom , Volume 35 , Issue 1 , February 1956 , pp. 203 - 210
Copyright
Copyright © Marine Biological Association of the United Kingdom 1956

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Barrington, E. J. W., 1937. The digestive system of Amphioxus (Branchiostoma) lanceolatus. Phil. Trans., B, Vol. 228, pp. 269–312.Google Scholar
Dohrn, A., 1886. Die Thyreoidea bei Petromyzon, Amphioxus und den Tunicaten. Mitt. zool. Sta. Neapel., Bd. 6, pp. 49–92.Google Scholar
Doniach, I. & Pelc, S. R., 1950. Autoradiographic technique. Brit. J. Radiol, Vol. 235 pp. 184–92.CrossRefGoogle Scholar
Gorbman, A., 1941. Identity of an iodine-storing tissue in an ascidian. Science, Vol. 94, p. 192.CrossRefGoogle Scholar
Gorbman, A. & Creaser, C. W., 1942. Accumulation of radioactive iodine by the endostyle of larval lampreys, and the problem of homology of the thyroid. J. exp. Zool., Vol. 89, pp. 391–402.CrossRefGoogle Scholar
Leach, W. J., 1944. The archetypal position of Amphioxus and Ammocoetes and the role of endocrines in chordate evolution. Amer. Nat., Vol. 78, pp. 341–57.CrossRefGoogle Scholar
Marine, D., 1913. The metamorphosis of the endostyle (thyroid gland) of Ammocoetes branchiate (larval land-locked Petromyzon marinus) or Petromyzon dorsatus (Wilder). J. exp. Med., Vol. 17, pp. 379–95.CrossRefGoogle ScholarPubMed
Müller, W., 1873. Über die Hypobranchialrinne der Tunicaten und deren Vorhandsein bei Amphioxus und den Cyclostomen. Jena. Z. Naturw., Bd. 7, pp. 327–32.Google Scholar
Sembrat, K., 1953. Effect of the endostyle of the lancelet (Branchiostoma lanceolatum Pall.) on the metamorphosis of axolotl. Zool. Polon., Vol. 6, Fasc. 1, pp. 3–19.Google Scholar
Weel, P. B. Van, 1937. Die Ernahrungsbiologie von Amphioxus lanceolatus. Pubbl. Staz. zool. Napoli, Vol. 16, pp. 221–72.Google Scholar